shell ox exploration plan

UNITED STATES GOVERNMENT MEMORANDUM

To: Public Information (MS 5030)Plans Section, Office of Field Operations (MS 5231)

Public Information copy of Exploration Plan

Control # - S-07444

Type - Supplemental Exploration Plan

Lease(s) - OCS-G19939 Block - 348 Mississippi Canyon AreaOCS-G26252 Block - 391 Mississippi Canyon AreaOCS-G26253 Block - 392 Mississippi Canyon Area

Operator - Shell Gulf of Mexico Inc.

Subsea Wells CST, C, H, I, & J AND previously approved Subsea Wells B, C, E, and FSEMISUBMERSIBLE

Attached is a copy of the subject plan for public comments on issues that should be addressed in an Environmental Assessment.

It has been deemed submitted as of this date and is under review for approval.

Karen DunlapPlan Coordinator

Description -

Rig Type -

Subject:

From:

April 13, 2011

Shell Gulf of Mexico IncAn Affilliate of Shell Oil Company

P. O. Box 61933New Orleans, LA 70161-1933

United States of AmericaTel +1 504 728 7215Fax +1 504 728 6747

Email [email protected]

December 21, 2010

Regional Supervisor Office of Field Operations Bureau of Ocean Energy Management, Regulation & Enforcement 1201 Elmwood Park Boulevard New Orleans, LA 70123-2394 Attn: Plans Group MS 5321 SUBJECT: Supplemental Exploration Plan OCS-G 19939, Mississippi Canyon Block 348 OCS-G 26252, Mississippi Canyon Block 391 OCS-G 26253, Mississippi Canyon Block 392 Offshore Alabama S7444 Shell Gulf of Mexico Inc (SGOMI) submitted subject Exploration Plan September 20, 2010 and additional information on October 26, 2010. Enclosed is updated information to add MC 348 to our previously approved plan (N-9387). This Plan consists of a series of attachments describing our intended operations. The attachments we desire to be exempted from disclosure under the Freedom of Information Act are marked “Confidential” and excluded from the Public Information Copies of this submittal. Enclosed is a copy of a letter from the surface operator of OCS-G 19939, ATP Oil and Gas Corporation, acknowledging that they have no objections to our three proposed locations on that lease. Should you require additional information, please contact me as indicated above. Kind regards

Sylvia A. Bellone

RECORD of Plan Information Requests/Amendments Supplemental Exploration Plan S07444 Mississippi Canyon Blocks 348, 391 & 392

12/21/2010 Shell submitted a Supplemental Exploration Plan for Wells BJ. 1/7/2011 Received an information request from BOEM. 1/12/2011 Shell provided the following changes in response to the 1/7/2011 information request:

Changed OCS Number in cover letter Provided copy of pay.gov confirmation Plan Information Form Corrected BHL for Location C (Page 5) Updated ESR/chemosynthetic maps to show 2000’ clearance circles (Pages 7780)

ORSP added specific wells associated with WCD numbers and statement relating to certification submittal (Page 115)

Removed Texas CZM Certification (Page 153156) Sent Additional PI CD’s for Alabama CZM

2/7/2011 Received an information request from BOEM 2/7/2011 Shell provided the following changes in response to the 2/7/2011 information request:

Updated Projected Generated Waste Table (Page 108) Updated Projected Ocean Discharges Table (Page 109) Updated Solid & Liquid Waste Transportation Table (Pages 148149)


corrected the generated wastes (page 108), projected ocean discharges (page 109), solid and liquid waste (page 148149) and waste disposal (page 151) changing all amounts to “per well”

correcting the number for synthetic drilling mud in the waste disposal table (Page 151) added synthetic based cuttings to the waste disposal table (page 151)

4/7/11 Received information request from BOEM 4/8/11 Shell provided the following changes to the Plan:

Corrected 30 CFR citation regarding H2S (Page 98 in Proprietary, 3 in PI)

U. S. Department of the Interior OMB Control Number: 1010-0049 Minerals Management Service OMB Approval Expires: August 31, 2006

OCS PLAN INFORMATION FORM General Information

Type of OCS Plan: X Exploration Plan (EP) Development Operations Coordination Document (DOCD) Company Name: Shell Gulf of Mexico Inc MMS Operator Number: 2117

Address: P. O. Box 61933 Contact Person: Sylvia Bellone

New Orleans, LA 70161-1933 Phone Number: (504) 728-7215

E-Mail Address: [email protected]

Lease(s): OCS-G 19939, 26252, 26253 Area: MC Block(s):348,391,392 Project Name (If Applicable): NA

Objective(s): X Oil Gas Sulphur Salt Onshore Base: Boothville & Fourchon

Distance to Closest Land (Miles): 72

Description of Proposed Activities (Mark all that apply)

X Exploration drilling Development drilling

Well completion Installation of production platform

Well test flaring (for more than 48 hours) Installation of production facilities

Installation of caisson or platform as well protection structure Installation of satellite structure

Installation of subsea wellheads and/or manifolds Commence production

Installation of lease term pipelines Other (Specify and describe)

Have you submitted or do you plan to submit a Conservation Information Document to accompany this plan?

Yes X No

Do you propose to use new or unusual technology to conduct your activities? Yes X No

Do you propose any facility that will serve as a host facility for deepwater subsea development? Yes X No

Do you propose any activities that may disturb an MMS-designated high-probability archaeological area?

X Yes No

Have all of the surface locations of your proposed activities been previously reviewed and approved by MMS? *B-F approved 6/26/09 N-09387,** G-J requested in this plan

X*

Yes X**

No

Tentative Schedule of Proposed Activities Proposed Activity Start Date End Date No. of Days

Drill well H 03/01/2011 06/15/2011 107

Drill well C 06/16/2011 09/26/2011 102

Drill well C Sidetrack 09/27/2011 12/01/2011 65

Drill well B 03/01/2012 06/8/2012 100

Drill well D 03/01/2013 06/8/2013 100

Drill well E 03/01/2014 06/8/2014 100

Drill well F 03/01/2015 06/8/2015 100

Drill well G 03/01/2016 06/8/2016 100

Drill well I 03/01/2017 06/8/2017 100

Drill well J 03/01/2018 06/8/2018 100

Description of Drilling Rig Description of Production Platform Jackup Drillship Caisson Tension leg platform Gorilla Jackup Platform rig Well protector Compliant tower

X Semisubmersible Submersible Fixed platform Guyed tower

DP Semisubmersible Other (Attach Description) Subsea manifold Floating production system

Drilling Rig Name (If Known): Transocean Deepwater Nautilus

Spar Other (Attach Description)

Description of Lease Term Pipelines From (Facility/Area/Block) To (Facility/Area/Block) Diameter (Inches) Length (Feet)

NA

MMS Form MMS-137 (August 2003) Page 1 of 11 PUBLIC INFORMATION

OCS PLAN INFORMATION FORM (CONTINUED) Include one copy of this page for each proposed well/structure

Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): B Subsea Completion

Anchor Radius (if applicable) in feet: 15,500’ X Yes No

Surface Location Bottom-Hole Location (For Wells)

Lease No. OCS-G 26253

Area Name Mississippi Canyon

Block No. 392

Blockline Departures (in feet)

N/S Departure: 3757 FNL

E/W Departure: 3768 FWL

Lambert X-Y coordinates

X: 1318488

Y: 10387283

Latitude/ Longitude

Latitude 28.61933891

Longitude -88.00373155

TVD (Feet): MD (Feet): Water Depth (Feet): 7,210

Anchor Locations for Drilling Rig or Construction Barge (If anchor radius supplied above, not necessary) Anchor Name or No

Area Block X Coordinate Y Coordinate Length of Anchor Chain on Seafloor X = Y =

X = Y =

X = Y =

X = Y =

X = Y =

X = Y =

X = Y =

X = Y =

Paperwork Reduction Act of 1995 Statement: The Paperwork Reduction Act of 1995 (44 U.S.C. Chapter 35) requires us to inform you that MMS collects this information as part of an applicant’s Exploration Plan or Development Operations Coordination Document submitted for MMS approval. We use the information to facilitate our review and data entry for OCS plans. We will protect proprietary data according to the Freedom of Information Act and 30 CFR 250.196. An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid Office of Management and Budget Control Number. The use of this form is voluntary. The public reporting burden for this form is included in the burden for preparing Exploration Plans and Development Operations Coordination Documents. We estimate that burden to average 580 hours per response, including the time for reviewing instructions, gathering and maintaining data, and completing and reviewing the form. Direct comments regarding the burden estimate or any other aspect of this form to the Information Collection Clearance Officer, Mail Stop 4230, Minerals Management Service, 1849 C Street, N.W., Washington, DC 20240.



Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): C Subsea Completion





Block No. 391



E/W Departure: 1287 FEL


X: 1313433

Y: 10387068

Latitude/ Longitude






X = Y =

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Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): C ST Subsea Completion





Block No. 391





X: 1313433

Y: 10387068

Latitude/ Longitude


Longitude –88.01948463




X = Y =

X = Y =

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Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): D Subsea Completion





Block No. 392





X: 1321210

Y: 10388951

Latitude/ Longitude






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Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): E Subsea Completion

Anchor Radius (if applicable) in feet: 15,500 X Yes No




Block No. 392





X: 1319934

Y: 10389880

Latitude/ Longitude






X = Y =

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Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): F Subsea Completion





Block No. 392





X: 1316078

Y: 10389735

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Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): G Subsea Completion





Block No. 391





X: 1311375’

Y: 10387150’

Latitude/ Longitude






X = Y =

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MMS Form MMS-137 (August 2003) Page 8 of 11 PBULIC INFORMATION


Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): H Subsea Completion





Block No. 348


N/S Departure: 1670 FSL



X: 1325455’

Y: 10392710’

Latitude/ Longitude




Anchor Locations for Drilling Rig or Construction Barge (If anchor radius supplied above, not necessary) Anchor Name or No.

Area Block X Coordinate Y Coordinate Length of Anchor Chain on Seafloor

X = Y =

X = Y =

X = Y =

X = Y =

X = Y =

X = Y =

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Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): I Subsea Completion





Block No. 348





X: 1324995’

Y: 10392900’

Latitude/ Longitude






X = Y =

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Proposed Well/Structure Location Well or Structure Name/Number (If renaming well or structure, reference previous name): J Subsea Completion





Block No. 348





X: 1325905’

Y: 10392450’

Latitude/ Longitude






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Supplemental Exploration Plan OCS-G 19939, Mississippi Canyon Block 348 OCS-G 26252, Mississippi Canyon Block 391 OCS-G 26253, Mississippi Canyon Block 392

Offshore Alabama

1. PLAN CONTENTS

(1a) DESCRIPTION, OBJECTIVES & SCHEDULE The Initial Exploration Plan for MC 391 and 392 was for the drilling of 6 wells, A through F (N-09387 approved June 26, 2009). The Appomattox discovery well, (MC392-#1; 608174117200), was drilled under the approved EP, “A” surface location, on September 1, 2009 and reached objective TD on December 22, 2009. Following wireline evaluation, drilling operations resumed on a down-dip sidetrack (MC392-#1ST1; 608174117201) on December 30. 2009. This initial sidetrack well reached objective TD on January 30, 2010. Following wireline evaluation, the second down-dip sidetrack, (MC392-#1St2; 608174117202) began drilling on February 18, 2010, and drilled to a depth of 27, 545’ MD on February 21, 2010 when stuck drill pipe forced a bypass. The bypass well, (MC392-#1ST2BP1; 608174117202) reached TD on March 12, 2010, when drill pipe became stuck and the well was finalized and temporarily abandoned. Following the temporary abandonment, the rig was released on April 1, 2010. This Supplemental Exploration Plan adds MC Block 348 and four additional locations including G on MC391, and H, I, and J on MC348. Appraisal drilling was planned to start mid-2010 but has been delayed due to SGOMI’s inability to acquire permits due to the moratorium and new requirements. The current schedule is to resume drilling operations as soon as possible. This program will consist of three back-to-back appraisal operations including drilling a well on MC348, followed by an appraisal well and sidetrack on MC391.

(1b) LOCATION See attached Maps. (1c) RIG SAFETY AND POLLUTION FEATURES: The Rig we plan to use will comply with all of the regulations of the American Bureau of Shipping (ABS), International Maritime Organization (IMO) and the United States Coast Guard (USCG). All drilling operations will be conducted under the provisions of 30 CFR, Part 250, Subpart D, and other applicable regulations and notices, including those regarding the avoidance of potential drilling hazards and safety and pollution prevention control. Such measures as inflow detection and well control, monitoring for loss of circulation and seepage loss, and casing design will be our primary safety measures. Primary pollution prevention measures are contaminated and non-contaminated drain system, mud drain system, and oily water processing.

(1d) Storage Tanks

Type of Storage Tank

Type of Facility

Tank Capacity (bbls)

Number of Tanks

Total Capacity (bbls)

Fluid Gravity (API)

Diesel Tank in Pontoon Drilling Rig 2202 4 8808 Marine Diesel (0.87 SG)

Diesel Tank in Pontoon Drilling Rig 4554 4 18,216 Marine Diesel (0.87 SG)

Diesel Day Tank 3rd Deck

Drilling Rig 196 2 392 Marine Diesel (0.87 SG)

Diesel Settling Tank 3rd Deck


Diesel Settling Tank 3rd Deck


Lube Oil Tank 3rd Deck Drilling Rig 55 1 55 Lube Oil (0.93 SG) Lube Oil Tank 3rd Deck Drilling Rig 37 2 74 Lube Oil (0.93 SG) Hyd. Oil Tank 3rd Deck Drilling Rig 55 1 55 Hydraulic Oil (0.93

SG) Synthetic Drilling Fluid Base Oil Column Tank

Drilling Rig 1484 2 2968 Synthetic Base Oil (0.93 SG)

(1e) Pollution Prevention Measures I. DRAIN SYSTEM Drains are provided on the rig in all spaces and on all decks where water or oil can accumulate. The drains are divided into two categories, non-contaminated and contaminated. All deck drains are fitted with a removable strainer plate to prevent debris entering the system. Deck Drainage from rainfall, rig washing, deck washing, and runoff from curbs and gutters, including drip pans and work areas, are discharged depending on if it comes in contact with the contaminated or non-contaminated areas of the rig. 1.) Non-contaminated Drains Non-contaminated drains are designated as drains that do not contain hydrocarbons and can be discharged directly overboard. The salt water from the discharge of the fresh water makers and engine coolers is routed to the cuttings chute to provide a flush to keep the chute clear. All other non-contaminated drains are, where feasible, routed to the starboard caisson. 2.) Contaminated Drains Contaminated drains are designated as drains that contain hydrocarbons and cannot be discharged overboard. When oil-based mud is used for drilling it will have to be collected in portable tanks and sent to shore for processing. Two headers are routed for the contaminated drains, one for oily water, which is routed to the separator tanks, and one for waste oil, which is routed to the waste oil tanks. In the areas where a spillage of oily water or hydrocarbon is possible, two foot valves are supplied, one for each header. The operator will make the decision on where to route the spillage. Separation and waste oil tanks are supplied in each of the aft columns. The headers in each of the decks are sealed from one another by using seal pots to prevent gas migration throughout the rig.

3.) Mud Drain System A separate drain system is furnished for the mud handling areas. Sumps are provided in the following areas to collect mud spills: ! Mud Pump Rooms ! Auxiliary Machinery Room ! Sack Storage Room ! Shale Shaker Room The drains are pumped by two pneumatic mud drain pumps, which can route the drains either to overboard in the case of water-based muds, or to the main deck for collection into drums in the case of oil-based muds. 4.) Oily Water Processing The oily water is initially routed to the Separator Tanks. One tank is located in the 28.5 m flat in each of the aft columns. The tank has sufficient residence time to allow for natural separation of oil and water. The oil is manually drained to the Waste Oil Holding Tank located in the 28.5 m flat in each of the aft columns from where it is pumped to the International Shore Connection for collection into drums. The residual water in the separator is routed to the Oily Water Separator for further processing. The Oily Water Separator is a compact, single stage, gravity-type vessel using a coalescer plate pack principle of separation. The oily water is drawn into the separator where the majority of the oil separates in the gravity stage below the oil chamber into which it rises and collects. The water pump draws the liquid through a multi-stage plate pack, which encourages the remaining oil droplets to coalesce and rise through the pack to the oil chamber. Clean water is drawn from the rear end of the unit by the water pump to an overboard discharge connection. Capacitance probes are fitted to detect the oil level in the oil chamber, controlling the pump to give fully automatic operation. A 15-ppm oil content meter is installed on the water outlet to prevent oil discharges to the sea if any of the separation or monitoring systems should fail. When oil/air covers the lower probe, the water pump stops, the oily water inlet valve closes, and the water inlet and oil/air discharge valves open to discharge the oil to the Waste Oil Holding Tank. When the top probe again senses water, the inlet oily water valve opens, the oil/air and water inlet valves close, and the pump again starts.

All discharges will be in accordance with applicable NPDES permits. See Attachment 18, EIA, Section C.1.2, Water Quality

(1f) Additional Measures HSE (health safety and environment) are the primary topics in pre-tour and pre-job safety meetings. The discussion around no harm to people or environment is a key mindset. All personnel are reminded daily to inspect work areas for safety issues as well as potential pollution issues. All tools that come to and from the Rig have their pollution pans inspected, cleaned and confirmation of plugs installed prior to leaving dock and prior to loading on the boat. Preventive Maintenance of Rig equipment includes visual inspection of hydraulic lines and reservoirs on routine scheduled basis. All pollution pans on Rig are inspected daily. Containment dikes are installed around all oil containment, drum storage areas, fuel vents, and fuel storage tanks. All used oil and fuel is collected and sent in for recycling. Every drain on the Rig is assigned a number on a checklist. The checklist is used daily to verify drain plugs are installed. All trash containers are checked and emptied daily. The trash containers are kept covered. Trash is disposed of in a compactor and shipped in via boat. The Rig is involved in a recycling program for cardboard, plastic, paper, glass, and aluminum. Fuel hoses and SBM are changed on annual basis. TODO spill prevention fittings are installed on all liquid take on hoses. Waste paint thinner is recycled on board with a solvent still to reduce hazard of shipping and storage. All equipment on board utilizes Envirorite hydraulic fluid as opposed to hydraulic oil. Shell has obtained ISO14001 certification. Shell uses low sulfur diesel fuel on the rig.


Offshore Alabama

2 GENERAL INFORMATION (2a) Application and Permits

Applications/Permits Issuing Agency Status Rig Move BOEMRE Pending

(2b) Drilling Fluids

Type of Drilling Fluid Estimated Volume of Drilling Fluid Used per Well

Synthetic-Based (internal olefin, ester) 8,000 bbls/well Water-based (seawater, freshwater, barite) 20,000 bbls/well

Oil-based (diesel, mineral oil) 0 bbls (2c) Production Production rates are not applicable to exploration plans. (2d) Oil Characteristics (if known)

Provide the estimated chemical and physical characteristics of the oils that will be

handled, stored, or transported on/by the facility.

Characteristic Analytical Methodologies Should Be Compatible With:

1. Gravity (API) 37.5 2. Flash Point (ºC N/A* 3. Pour Point (ºC) -23° C 4. Viscosity (Centipoise at 25 ºC) 8 cP 5. Wax Content (wt %) 4.8% 6. Asphaltene Content (wt %) 1.2% 7. Resin Content (wt %) 5.2% 8. Boiling point distribution including,

for each fraction, the percent volume or weight and the boiling point range in ºC

N/A*

9. Sulphur (wt %) 0.76 0.3% *We did not run flash point or boiling point analyses on this MDT sample.

Note: If the distillation information in Item No. 8 in the above table is not available, the GOMR may accept the following information in lieu of Items Nos. 5, 6, 7, and 8: weight percent total of saturates, aromatics, waxes, asphaltenes, and resins; and total BTEX (ppm) using analytical methods compatible with the Hydrocarbon Groups methodology found in Jokuty et al., 1996). All in wt% Topped Basis

SARA (Topped Basis) All in wt % Well # Saturates Aromatics Resin Asphaltenes MC392-#1; 608174117200 59.9% 33.7% 5.2% 1.2%

Identify the oil you analyze. Refer to the following sample chart.

Oil from one well Oil from more than one

well sampled on a facility

Oil from a pipeline system

·Area/Block MC 392 ·MMS platform NA ·API Well No. 608174117200 ·Completion perforation interval 24,938’ MD ·MMS’s reservoir name Jurassic Norphlet Sandstone ·Sample date 12/16/2009 ·Sample No.(if more than one is taken) SSB 22670-VA

N/A N/A

(2e) New Or Unusual Technology No new or unusual technology is proposed to be used during operations proposed in this Plan. (2f) Bonding The bond requirement for the activities proposed in this EP are satisfied by an area-wide bond furnished and maintained according o 30 CFR Part 256, subpart I; NTL No. 2000-G16, Guideline for General Lease Surety Bonds;” and National NTL No. 2003-N06, “Supplemental Bond Procures.” (2g) Oil Spill Financial Responsibility (OSFR) Shell Gulf of Mexico Inc (SGOMI), MMS Operator Number 2117, has demonstrated oil spill financial responsibility for the facilities proposed in the EP according to 30 CFR part 253, and NTL No. 99-N01, “Guidelines for Oil Spill Financial Responsibility for Covered Facilities.” (2h) Deepwater well control statement Shell Gulf of Mexico Inc (SGOMI), MMS Operator Number 2117, has the financial capability to drill a relief well and conduct other emergency well control operations.

(2i) Suspension of Production Information regarding Suspension of Production is not included as it is only applies to wells that have been produced which does not apply to the wells proposed in this EP. (2j) Blowout scenario Summary This Section 2j was prepared by Shell Gulf of Mexico Inc. (Shell) pursuant to the guidance provided in the Bureau of Ocean Energy Management, Regulation and Enforcement’s (BOEMRE) Notice to Lessees (NTL) No. 2010-N06 with respect to blowout and worst case discharge scenario descriptions. Shell focuses on an integrated, three-pronged approach to a blowout, including prevention, intervention /containment, and recovery. Shell believes that the best way to manage blowouts is to prevent them from happening. Significant effort goes into the design and execution of wells and into building and maintaining staff competence with the goal of safe and environmentally sound well construction. Shell continues to invest independently in Research and Development (R&D) to improve safety and reliability of our well systems. Shell intends to comply with all applicable laws, regulations, rules and Notice to Lessees. Shell is a founding member of the Marine Well Containment Company (MWCC) and will have access to an integrated subsea well control and containment system that can be rapidly deployed through the MWCC. MWCC is a non-profit organization that owns, manages, and provides fully trained crews and operates the subsea containment system during a response. The near term containment response capability will include lessons learned and equipment used in the Macondo response. Shell is investing in R&D to improve containment systems. Also, Shell is a member of Clean Caribbean America (CCA), Marine Spill Response Corporation (MSRC), Clean Gulf Associates (CGA), and OSRL/EARL to provide the resources necessary to respond to a spill as outlined in our Regional Oil Spill Response Plan (OSRP, October 2010). The Worst Case Discharge (WCD) blowout scenario for Appomattox is calculated for the MC-391 C location Southwest penetration of the Norphlet Sand and based on the guidelines outlined in NTL No. 2010-N06 along with subsequent Frequently Asked Questions (FAQ). Shell is submitting MC-391 C (this well) as the new worst-case scenario to the BOEMRE for inclusion in our Regional OSRP. In the unlikely event of a spill, Shell’s Regional OSRP (October 2010) is designed to contain and respond to a spill that meets or exceeds this WCD. The WCD does not take into account potential flow mitigating factors such as well bridging, obstructions in wellbore, reservoir barriers, or early intervention.

Uncontrolled blowout (volume first day) 405,000 bbl Uncontrolled blowout rate (first 30-days average daily rate) 371,000 bopd Duration of flow (days) based on relief well 128 days Total volume of spill (bbls) for 128 days 45 MMBO

Table 1 Worst Case Discharge Summary The Appomattox discovery is located approximately 72 miles east-southeast of the nearest shoreline in the Gulf of Mexico (GOM), in water depths of approximately 7,200 feet (ft) across the discovery. The structural component of the target is defined by a faulted anticline approximately 5 miles long by 4 miles wide, with the top of the objective near -25,000 ft subsea (SS). The south fault block contains one previously drilled well with two sidetracks (MC-392 #1, #1ST1, #1ST2BP1) drilled in 2009-2010. The only objective horizon with predicted flow potential is the Norphlet reservoir of Jurassic age.

1) Purpose Pursuant to 30 CFR 250.213(g), 250.219, 250.250, and NTL No. 2010-N06, this document provides a blowout scenario description, further information regarding any potential oil spill, the assumptions and calculations used to determine the WCD and the measures taken to firstly enhance the ability to prevent a blowout and secondly to respond and manage a blowout scenario if it were to occur. These calculations are based on best technical estimates of subsurface parameters that are derived from the offset Appomattox well and seismic. These parameters are better than or consistent with the estimates used by Shell to justify the investment. Therefore, these assumed parameters were used to calculate the WCD. They do not reflect probabilistic estimates. 2) Background This attachment has been developed to document the additional information requirements for Exploration Plans as requested by NTL No. 2010-N06 in response to the explosion and sinking of the Mobile Offshore Drilling Unit (MODU) Deepwater Horizon and the resulting subsea well blowout and recovery operations of the exploration well at the MC-252 Macondo location. 3) Information Requirements

a) Blowout scenario

All well locations addressed in this EP were assessed for WCD. The MC-391 well from the approved C location to the South Fault Block represented the highest flow potential. The C well will be drilled to the Norphlet reservoir as outlined in the Geological and Geophysical Information Section of the Supplemental EP, and described above, using a subsea wellhead system, conductor, surface and intermediate casing program, and using a MODU rig with a marine riser and subsea blowout preventer (BOP). A hydrocarbon influx and a well control event are modeled to occur from the Norphlet reservoir. The simulated blowout modeled results in unrestricted flow from the well at the seafloor, which represents the WCD (no restrictions in wellbore, failure/loss of the subsea BOP, and a blowout to the seabed). b) Estimated flow rate of the potential blowout

Category EP Type of Activity Drilling Facility Location (area/block) MC-391 Facility Designation MODU Distance to Nearest Shoreline (miles) 72 Statute miles Uncontrolled blowout (volume first day) 405,000 bbl Uncontrolled blowout rate (first 30-days average daily rate) 371,000 bopd

Table 2 Estimated Flow Rates of a Potential Blowout

c) Total volume and maximum duration of the potential blowout

Duration of flow (days) 128 days total duration to drill relief well

(14 rig mob, 3 transit, 80 spud to top Norphlet, 31 ranging). Total volume of spill (bbls) 45 MMBO based on 128 days flowing.

Note: From CMG dynamic reservoir models

Table 3 Estimated Duration and Volume of a Potential Blowout

There is usually a decline in the discharge rate as time proceeds, which is illustrated by the differences between the first 24-hour volume and 30-day average rate. At very short times, e.g. during the first 24 hours, the pressure profile in the reservoir changes from the moment when a well first starts flowing to a pseudo-steady state pressure profile with time, and as a result the rate declines. At somewhat longer time scales, effects such as reservoir voidage and the impact of boundaries can cause the rate to drop continuously with production. Simulation and material balance models can include these effects and form the basis of the NTL No. 2010-N06 calculations for 24-hour and 30-day rates as well as maximum duration volumes. d) Assumptions and calculations used in determining the worst case discharge

Omitted from Public Information Copies.

e) Potential for the well to bridge over

Mechanical failure/collapse of the borehole in a blowout scenario is influenced by several factors including in-situ stress, rock strength, and fluid velocities at the sand face. Given the substantial fluid velocities inherent in the WCD, and the scenario as defined where the formation is not supported by a cased and cemented wellbore, it is possible that the borehole may fail/collapse/bridge over within the span of a few days, significantly reducing the outflow rates. However, this WCD scenario does not include any bridging. f) Likelihood for intervention to stop the blowout.

Safety of operations is our top priority. Maintaining well control at all times to prevent a blowout is the key focus of our operations. This is derived from robust standards, well design, prudent operations, competency of personnel, and strong HSE focus. Collectively, these constitute a robust system making blowouts extremely rare events. Intervention Devices: Notwithstanding these facts, the main scenario for recovery from a blowout event is via intervention with the BOP attached to the well. There are built in redundancies in the BOP system to allow activation of selected components with the intent to seal off the well bore. As a minimum, the Shell contracted rig fleet in the GOM will have redundancies meeting NTL No. 2010-N05 (to the extent applicable) and the Drilling Safety Rule with respect to Remotely Operated Vehicle (ROV) hot stab capabilities, a deadman system, and an autoshear system. Additionally the Deepwater Nautilus (moored semi-submersible) has a gas handler system at the top of the riser consisting of 2 annular preventers that can be closed in to allow hydrocarbons in the riser to be contained or circulated thru the rig’s well control system. The rig also has 2 shearing rams in the BOP for added redundancy. Also, the Nautilus is equipped with a deadman system and an autoshear system. Containment: The experience of gaining control over the Macondo well has resulted in a better understanding of the necessary equipment and systems for well containment. As a result, industry and government are better equipped and prepared today to contain an oil well blowout in deepwater (See page 17 of the Decision Memorandum dated October 1, 2010). Shell is further analyzing these advances and incorporating them into its comprehensive approach to help prevent and, if needed, control another deepwater control incident.

Should the interventions at the well not be possible, specialized equipment can be used to connect to a riser stub, damaged connector, casing stub or to the sea floor and allow the well to be shut-in to contain the blowout. The subsea containment assembly and other specialized connection devices will be available from the Marine Well Containment Company (MWCC). If full shut-in, following capping is not possible because of well integrity issues, the well can be flowed with back-pressure maintained via the MWCC specialized well flow equipment. Shell is a founding member in the Marine Well Containment Company which is currently constructing the containment equipment and developing contracts for access to near term response capability. The near term response capability will incorporate lessons learned and technology advances as they apply to containment. Shell is currently in the process of concluding contracts that will secure the availability of some of the equipment and vessels used by BP during the Macondo response. The MWCC website can be accessed for a full description of the systems and components. It is expected that key components of containment equipment will be available in January 2011. The MWCC will own, maintain, and deploy both existing equipment and equipment being constructed for well intervention and containment. The newly constructed system will be designed to be flexible and adaptable, and be responsive to a wide range of potential scenarios, deepwater depths up to 10,000 feet, weather conditions, and flow rates. Once constructed, the system components will be fully tested to ensure functionality and will be maintained in a state of continuous operational readiness. In the event of a future incident, mobilization to the field will start within days and the system will be fully operational within weeks. Once built, the new containment system will further enhance Shell’s Regional OSRP Shell is investing in Research and Development activities on its own to identify additional containment components and equipment that will potentially increase the range of applications and effectiveness for equipment similar to that of MWCC, and systems that can be deployed more effectively in the water column that resemble “tents or capture domes”, and enhance well shut-in capability. g) Availability of a rig to drill a relief well and rig package constraints

Blowout intervention can be conducted from an ROV equipped vessel, the existing drilling rig or from another drilling rig. Shell has an active portfolio of well operations in the GOM which will be supported by a total of four to six MODU rigs in 2010 – 2015 timeframe. The dynamically positioned rigs under contract, the Noble Danny Adkins and the Bully 1, will be the preferred rigs for blowout intervention work. However, moored rigs can also be used in some scenarios. Additionally, in the event of a blowout, there is the distinct possibility that other non-contracted rigs in the GOM could be utilized whether for increased expediency or better suitability. All efforts will be made at the time to secure the appropriate rig. Shell’s current contracted rigs capable of operating at Appomattox water depths and reservoir depths are in the following table:

Table 4 Shell Contracted Rigs Capable at Appomattox.

Above are current as of December 2010. Future modifications may change the rig’s capability.

Rig capabilities need to be assessed on a work scope specific basis.

*Bully 1 estimated arrival July 2011.

Rig!Name Rig!TypeNoble!Danny!Adkins dynamically!positioned!drill!shipBully!1* dynamically!positioned!drill!shipDeepwater!Nautilus moored!semiNoble!Jim!Thompson moored!semi

h) Time taken to contract a rig, move it onsite, and drill a relief well Relief well operations will immediately take priority and displace any activity from Shell’s contracted rig fleet. The list of rigs capable of operating at Appomattox is tabled above. It is expected to take an average of 14 days to safely secure the well that the rig is working on up to the point the rig departs location, and an additional three days transit to mobilize to the relief well site depending on distance to the site. The relief well will take approximately 80 days to drill down to the last casing string above the blowout zone, plus approximately 31 days for precision ranging activity to intersect the blowout well bore. Total time to drill a relief well would be ~128 days for the Appomattox wells. If a moored rig is chosen to conduct the relief well operations, anchor handlers would be prioritized to prepare mooring on the relief well site while the rig is being mobilized. This mooring activity is not expected to delay initiation of relief well drilling operations. Shell has three deepwater anchor handlers, the Laney, Dino, and Ross Chouest, on long term contract to support its moored rigs. It is not possible to drill relief wells from any existing platforms due to distances of over fifteen miles to the discovery. i) Measures proposed to enhance ability to prevent blowout and to reduce likelihood

of a blowout.

Shell believes that the best way to manage blowouts is to prevent them from happening. Detailed below are the measures employed by Shell with the goal of no harm to people or the environment. The Macondo incident has highlighted the importance of these practices. The lessons learned from the investigation are, and will continue to be, incorporated into our operations. Standards: Shell’s well design and operations adhere to internal corporate standards, the Code of Federal Regulations, and industry standards. A robust management of change process is in place to handle un-defined or exception situations. Ingrained in the Shell standards for well control is the philosophy of multiple barriers in the well design and operations on the well. Risk Management: Shell believes that prevention of major incidents is best managed through the systematic identification and mitigation process (Safety Case). The safety case requirement is ingrained into Shell’s Health, Security, Safety, Environment, and Social Performance Control Framework. All Shell contracted rigs in the GOM have been operating with a Safety Case and will continue to do so. A Safety Case requires both the owner and contractors to systematically identify the risks in drilling operations and align plans to mitigate those risks; an alignment which is critical before drilling begins. Well Design Workflow: The Well Delivery Process (WDP) is a rigorous internal assurance process with defined decision gates. The WDP leverages functional experts (internal and external) to examine the well design at the conceptual and detailed design stages for robustness before making a recommendation to the management review board. Shell’s involvement in global deepwater drilling, starting in the GOM in the mid-1980’s, provides a significant depth and breadth of internal drilling and operational expertise. Third party vendors and rig contractors are involved in all stages of the planning, providing their specific expertise. A Drill the Well On Paper (DWOP) exercise is conducted with rig personnel and vendors involved in execution of the well. This forum communicates the well plan, and solicits input as to the safety of the plan and procedures proposed.

Well and rig equipment qualification, certification, and quality assurance: All rigs will meet all applicable rules, regulations, and Notice to Lessees. Shell works closely with rig contractors to ensure proper upkeep of all rig equipment, which meets or exceeds the strictest of Shell, industry, or regulatory requirements. Well tangibles are governed by our internal quality assurance/control standards and industry standards.

MWD/LWD/PWD Tools: Shell intends to use these tools at Appomattox. The MWD/LWD/PWD tools are run on the drill string so that data on subsurface zones can be collected as the well advances in real time instead of waiting until the drill string is pulled to run wireline logs. Data from the tools are monitored and interpreted real time against prognosis to provide early warning of abnormal pressures to allow measures to be taken to progress the well safely. Mud Logger: Mud logging personnel continually monitor returning drilling fluids for indications of hydrocarbons, utilizing both a hot wire and a gas chromatograph. An abrupt increase in gas or oil carried in the returning fluid can be an indication of an impending kick. The mud logger also monitors drill cuttings returned to the surface in the drilling fluid for changes in lithology that can be an indicator that the well has penetrated or is about to penetrate a hydrocarbon-bearing interval. Mud logging instruments also monitor penetration rate to provide an early indication of drilling breaks that show the bit penetrating a zone that could contain hydrocarbons. The mud logging personnel are in close communication with both the drilling foreman and Shell representative to report any observed anomalies so appropriate action can be taken. Remote Monitoring: The Real Time Operating Center has been used by Shell to complement and support traditional rig-site monitoring since 2003. Well site operations are lived virtually by onshore teams consisting of geoscientists, petrophysicists, well engineers, and 24/7 monitoring specialists. The same real time well control indicators monitored by the rig personnel are watched by the monitoring specialist for an added layer of redundancy. Competency and Behavior: A structured training program for Well Engineers and Foreman is practiced, which includes internal professional examinations to verify competency. Other industry training in well control, such as by International Association of Drilling Contractors (IADC) and International Well Control Forum (IWCF) are also mandated. Progressions have elements of competency and Shell continues to have comprehensive internal training programs. The best systems and processes can be defeated by lack of knowledge and/or improper values. We believe that a combination of HSE tools (e.g. stop work, pre-job analysis, behavior based safety, DWOPs, audits), management HSE involvement and enforcement (e.g. compliance to life saving rules) have created a strong safety culture in our operations. j) Measures to conduct effective and early intervention in the event of a blowout. The response to a blowout is contained in our Well Control Contingency Plan (WCCP) which is a specific requirement of our internal well control standards. The WCCP in turn is part of the wider emergency response framework within Shell that addresses the overall organization response to an emergency situation. Resources are dedicated to these systems and drills are run frequently to test preparedness (security, medical, oil spill, and hurricane). This same framework is activated and tested during hurricane evacuations, thereby maintaining a fresh and responsive team.

The WCCP specifically addresses implementing actions at the emergency site that will ensure personnel safety, organizing personnel and their roles in the response, defining information requirements, establishing protocols to mobilize specialists and pre-selecting sources, and developing mobilization plans for personnel, material and services for well control procedures. The plan references individual activity checklists, a roster of equipment and services, initial information gathering forms, a generic description of relief well drilling, strategy and guidelines, intervention techniques and equipment, site safety management, exclusion zones, and re-boarding. As set forth in 3f of this document, Shell is currently analyzing recent advances in containment technology and equipment and will incorporate them as they become available and is a founding member of MWCC.

k) Arrangements for drilling a relief well

The size of the Shell contracted rig fleet in the GOM from 2010-2015 ensures that there is adequate well equipment (e.g. casing and wellhead) available for relief wells. Rigs and personnel will also be readily available within Shell, diverted from their active roles elsewhere. Resources from other operators can also be leveraged should the need arise. Generally, relief well plans will mirror the blowout well, incorporating any learning on well design based on root cause analysis of the blowout. A generic relief well description is outlined in the WCCP. l) Assumptions and calculations used in approved or proposed OSRP

Shell is submitting MC-391 C (this well) as the new exploratory worst-case scenario to the BOEMRE for inclusion in our Regional OSRP. Shell has designed a response program (Regional OSRP October 2010) based upon a regional capability of responding to a range of spill volumes, from small operational spills up to and including the WCD from an exploration well blowout. Shell’s program is developed to fully satisfy federal oil spill planning regulations. The Regional OSRP presents specific information on the response program that includes a description of personnel and equipment mobilization, the incident management team organization, and the strategies and tactics used to implement effective and sustained spill containment and recovery operations.


Offshore Alabama

3 GEOLOGICAL AND GEOPHYSICAL INFORMATION (3a) Geological description Omitted from PI Copies. (3b) Structure Contour Map(s) Omitted from PI Copies. (3c) Interpreted 2D and/or 3D Seismic line(s) Omitted from PI Copies. (3d) Geological Structure Cross-section(s) Omitted from PI Copies. (3e) Shallow Hazards Report See 3f below. (3f) Shallow Hazards Assessment Well Locations B-F were previously cleared in our initial Exploration Plan N-09387, approved as of June 26, 2009. Shell submitted a shallow hazard report prepared by Fugro Geo-consulting, Inc, for Mississippi Canyon 347, 348, 391, and 392 and Initial Exploration Plan (EP) for Mississippi Canyon 391, Proposed Location C, Mississippi Canyon 392, Proposed Locations A, B, D, E, F, and the associated generic anchor pattern on May 19, 2009. This Initial EP and generic anchor patterns were approved on June 30, 2009 (Plan Control No. N-09387). Shell is now supplementing with a shallow hazard report prepared for Marathon, by Fugro-McClelland Marine Geosciences, for approval of Mississippi Canyon 348, Proposed Locations H, I and J and MC 391 G and their associated generic 13,000’ anchor patterns. Based on a high-resolution geophysical survey, consisting of frequency enhanced 3-D seismic, Enhanced Surface Renderings (ESR’s), ESR’s with amplitudes applied and AUV high-resolution data, Mississippi Canyon 348, Proposed Locations G, H, I & J appear suitable for the planned activity. Patricia Yu Arlette C. Nunez Geologist Shallow Hazards Coordinator

(3g) High-Resolution Seismic Lines See attached ESR (Water Bottom & Amplitude)

(3h) & (3i) Stratigraphic Column with Time vs depth table

Omitted from PI Copies.

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Offshore Alabama

4 Hydrogen Sulfide

(4a) Concentration

10-40 ppm H2S

(4b) Classification

Based on CFR 250.490 (c), Shell requests that the Regional Supervisor, Field Operations, classify the area in the proposed drilling operations as an area where H2S is known. (4c) H2S Contingency Plan When we submit the application to drill, Shell Gulf of Mexico Inc will also submit to the appropriate BOEMRE GOMR district office, and request approval of the H2S Contingency Plan prepared according to 30 CFR 250.490(f) before conducting the proposed exploration activities. (4d) Modeling Report Not applicable


Offshore Alabama

5 Mineral Resource Conservation Information Information regarding Mineral Resource Conservation is not included in the Supplemental Exploration Plan as it only applies to a DOCD proposing production.


Offshore Alabama

6 Biological, Physical, and Socioeconomic Information (6a) Chemosynthetic Communities Report

Well Locations B-F were previously cleared in our initial Exploration Plan N-09387, approved as of June 26, 2009.

Biological Information

NTL 2009-G40, dated January 27, 2010, for water depths greater than 984 feet – MMS statement

Mississippi Canyon 348, Proposed Locations H, I, and J and Mississippi Canyon 391, Proposed Location G and the associated generic 13,000’ radial anchor patterns:

! Features or areas that could support high-density chemosynthetic communities are not within 2000 feet of each proposed mud and cuttings discharge location.

! Features or areas that could support high-density chemosynthetic communities are not located within 250 feet of any seafloor disturbance resulting from the use of anchors (including those caused by anchors, anchor chains, wire ropes, seafloor template installation, and pipelines constructions). Seafloor disturbances include all “temporary” disturbances caused during mooring operations (e.g., anchor deployment, setting and retrieval) as well as those caused by anchoring activities conducted prior to a MODU arriving on location (e.g., pre-installation of suction piles and cables; where seafloor impacts are much greater while the cables are located on the seafloor prior to being pulled taut and attached to the MODU). The generic anchor radius is 13,000’, with an additional buffer of 1,000’, for a total clearance of 14,000’.

History

Shell submitted a shallow hazard report prepared by Fugro Geo-Consulting, Inc, for Mississippi Canyon 347, 348, 391, and 392 and Initial Exploration Plan (EP) for Mississippi Canyon 391, Proposed Location C, Mississippi Canyon 392, Proposed Locations A, B, D, E, F, and the associated generic anchor pattern on May 19, 2009. This Initial EP and generic anchor patterns were approved on June 30, 2009, Plan Control No. N9387. Shell is now supplementing with a shallow hazard report prepared for Marathon, by Fugro-McClelland Marine Geosciences, for approval of Mississippi Canyon 348, Proposed Locations H, I and J and MC 391 G their associated generic 13,000’ anchor patterns.

Proposed Locations Proposed Location G, Mississippi Canyon 391: X = 1,311,375 3890’ FNL Y = 10,387,150 3345’ FEL

MC 391, Proposed Location G is located in a water depth of approximately 7168 feet. There is no evidence of seafloor or near-surface faulting, slumping, amplitudes or fluid expulsion features within 2000 feet of Proposed Location G. Mississippi Canyon 391, Proposed Location G will not disturb any high-density areas of chemosynthetic communities. MC 391, Proposed Location G will be positioned 8400 feet west of Shell’s previously drilled MC 392-1ST2BP1 wellsite, 12471 feet southwest of Marathon’s MC348 SS-1 wellsite, 14057 feet southwest of Marathon’s MC348 SS-2 wellsite, and 18713 feet northwest of Anadarko’s MC 392 #1 wellsite. MC 391, Proposed Location G will not disturb these previously drilled wellsites. The closest seafloor sonar target (#4) is identified 8745 feet north of Proposed Location G. There are no seafloor sonar targets identified within 2000 feet of Proposed Location G. Currently, there are flowlines and umbilicals associated with MC 348 SS-1 and SS-2 wellsites. These flowlines and umbilicals are located over 12,000 feet northeast of Proposed Location G. There are no other flowlines or umbilicals in the vicinity of Proposed Location G. Proposed Location H, Mississippi Canyon 348: X = 1,325,455 1670’ FSL Y = 10,392,710 5105’ FEL MC 348, Proposed Location H is located in a water depth of approximately 7261 feet. There is no evidence of seafloor or near-surface faulting, slumping, amplitudes or fluid expulsion features within 2000 feet of Proposed Location H. Mississippi Canyon 348, Proposed Location H will not disturb any high-density areas of chemosynthetic communities. MC 348, Proposed Location H will be positioned 4985 feet southeast of Marathon’s MC 348 SS-1 wellsite, 8033 feet southeast of Marathon’s MC 348 SS-2 wellsite, 8007 feet northeast of Shell’s MC 392-1ST2BP1 wellsite and 13836 feet north of Anadarko’s MC 392-1 wellsite. MC 348, Proposed Location H will not disturb these previously drilled wellsites. The nearest seafloor sonar target (#8) is identified 7011 feet southeast of Proposed Location H. There are no seafloor sonar targets identified within 2000 feet of Proposed Location H. Currently, there are flowlines and umbilicals associated with MC 348 SS-1 and SS-2 wellsites. These flowlines and umbilicals are located over 5,000 feet northeast of Proposed Location H. There are no other flowlines or umbilicals in the vicinity of Proposed Location H. Proposed Location I, Mississippi Canyon 348: X = 1,324,995 1860’ FSL Y = 10,392,900 5565’ FEL MC 348, Proposed Location I is located in a water depth of approximately 7259 feet. There is no evidence of seafloor or near-surface faulting, slumping, amplitudes or fluid expulsion features within

2000 feet of Proposed Location I. Mississippi Canyon 348, Proposed Location I will not disturb any high-density areas of chemosynthetic communities. MC 348, Proposed Location I will be positioned 4489 feet southeast of Marathon’s MC 348 SS-1 wellsite, 7908 feet south of Marathon’s MC 348 SS-2 wellsite, 7828 feet northeast of Shell’s MC 392-1ST2BP1 wellsite and 14123 feet north of Anadarko’s MC 392-1 wellsite. MC 348, Proposed Location I will not disturb these previously drilled wellsites. The nearest seafloor sonar target (#8) is identified 7,503 feet southeast of Proposed Location I. There are no seafloor sonar targets identified within 2000 feet of Proposed Location I. Currently, there are flowlines and umbilicals associated with MC 348 SS-1 and SS-2 wellsites. These flowlines and umbilicals are located approximately 4,500 feet northeast of Proposed Location I. There are no other flowlines or umbilicals in the vicinity of Proposed Location I. Proposed Location J, Mississippi Canyon 348: X = 1,325,905 1410’ FSL Y = 10,392,450 4655’ FEL MC 348, Proposed Location J is located in a water depth of approximately 7264 feet. There is no evidence of seafloor or near-surface faulting, slumping, amplitudes or fluid expulsion features within 2000 feet of Proposed Location J. Mississippi Canyon 348, Proposed Location J will not disturb any high-density areas of chemosynthetic communities. MC 348, Proposed Location J will be positioned 5504 feet southeast of Marathon’s MC 348 SS-1 wellsite, 8158 feet northeast of Shell’s MC 392-1ST2BP1 wellsite, 8256 feet south of Marathon’s MC 348 SS-2 wellsite and 13495 feet north of Anadarko’s MC 392-1 wellsite. MC 348, Proposed Location J will not disturb these previously drilled wellsites. The nearest seafloor sonar target (#8) is identified approximately 6491 feet southeast of Proposed Location J. There are no seafloor sonar targets identified within 2000 feet of Proposed Location J. Currently, there are flowlines and umbilicals associated with MC 348 SS-1 and SS-2 wellsites. These flowlines and umbilicals are located approximately 5,500 feet northeast of Proposed Location J. There are no other flowlines or umbilicals in the vicinity of Proposed Location J.

Anchor Patterns The descriptions below are of the seafloor within 13,000 feet of each wellsite, with the additional required 1,000 foot buffer zone for a total of 14,000 foot radial review.

MC 391, Proposed Location G, Generic 13,000’ Radius Anchor Pattern

There is no evidence of seafloor or near-surface faulting, slumping, amplitudes or fluid expulsion features within 14,000 feet of Proposed Location G. Mississippi Canyon 391, Proposed Location G and 13,000’ radial anchor pattern will not disturb any high-density areas of chemosynthetic communities.

Twelve side-scan sonar targets have been identified within the survey area. Three of these targets have been identified within the 13,000’ radius of MC 391, Proposed Location G. Sonar target #1 (33’ X 39’) is located 11804 feet west of Proposed Location G. Sonar target #3 (16’ X 14’) is located 10498 feet southwest of Proposed Location G. Sonar target #4 (20’ X 6’) is located 8745’ north of Proposed Location G. Sonar target #6 (14’ X 17’) is located 10991 feet southeast of Proposed Location G. Sonar target #2 (34’ X 15’) is located within the additional 1,000’ buffer zone for the 13,000’ radius for Proposed Location G. All seafloor sonar targets have 100’ avoidance areas. MC 391, Proposed Location G and anchor pattern will not interfere with these seafloor sonar targets. MC 391, Proposed Location G will be positioned 8400 feet south of Shell’s previously drilled MC 392-1ST2BP1 wellsite, 12471 feet southwest of Marathon’s MC348 SS-1 wellsite, 14057 feet southwest of Marathon’s MC348 SS-2 wellsite, and 18713 feet northwest of Anadarko’s MC 392 #1 wellsite. All existing wells have a 500’ avoidance zone. MC 391, Proposed Location G will not disturb these previously drilled wellsites. Flowlines and umbilicals for ATP are located in MC 348, Proposed Location G in MC391 has a l3,000-foot radial generic anchor pattern. Shell has placed a 500’ avoidance zone around these flowlines and umbilicals. None of the anchors or cables for Proposed Location G will be positioned within 500 feet of these flowlines and umbilicals. Based on a high-resolution geophysical survey, consisting of frequency enhanced 3-D seismic, Enhanced Surface Renderings (ESR’s), ESR’s with amplitudes applied, and AUV high-resolution data, Mississippi Canyon 391, Proposed Location G appears suitable for the planned activity.

MC 348, Proposed Location H, Generic 13,000’ Radius Anchor Pattern There is no evidence of seafloor or near-surface faulting, slumping, amplitudes or fluid expulsion features within 14,000 feet of Proposed Location H. Mississippi Canyon 348, Proposed Location H and 13,000’ radial anchor pattern will not disturb any high-density areas of chemosynthetic communities. Twelve side-scan sonar targets have been identified within the survey area. Five of these targets have been identified within the 13,000’ radius of MC 348, Proposed Location H. Sonar target #4 (20’ X 4) is identified 11152 feet west of Proposed Location H. Sonar target #5(15’ X 9’) is identified 8642 feet north of Proposed Location H. Sonar target #6 (14’ X 17’) is located 11177 feet south of Proposed Location H. Sonar target #8 (20’ X 5’) is located 7011 feet southeast of Proposed Location H. Sonar target #9 (15’ X 8’) is located 10435 feet east of Proposed Location H. All seafloor sonar targets have 100’ avoidance areas. MC 348, Proposed Location H and anchor pattern will not interfere with these seafloor sonar targets. MC 348, Proposed Location H will be positioned 4985 feet southeast of Marathon’s MC 348 SS-1 wellsite, 8033 feet southeast of Marathon’s MC 348 SS-2 wellsite, 8007 feet northeast of Shell’s MC 392-1ST2BP1 wellsite and 13836 feet north of Anadarko’s MC 392-1 wellsite. All existing wells have a 500’ avoidance zone. MC 348, Proposed Location H and 13,000’ radial anchor pattern will not disturb these previously drilled wellsites. Flowlines and umbilicals for ATP are located in MC 348, Proposed Location H in MC348 has a l3,000-foot radial generic anchor pattern. Shell has placed a 500’ avoidance zone around these flowlines and umbilicals. None of the anchors or cables for Proposed Location H will be positioned within 500 feet of these flowlines and umbilicals.

Based on a high-resolution geophysical survey, consisting of frequency enhanced 3-D seismic, Enhanced Surface Renderings (ESR’s), ESR’s with amplitudes applied, and AUV high-resolution data, Mississippi Canyon 348, Proposed Location H appears suitable for the planned activity.

MC 348, Proposed Location I, Generic 13,000’ Radius Anchor Pattern There is no evidence of seafloor or near-surface faulting, slumping, amplitudes or fluid expulsion features within 14,000 feet of Proposed Location I. Mississippi Canyon 348, Proposed Location I and 13,000’ radial anchor pattern will not disturb any high-density areas of chemosynthetic communities. Twelve side-scan sonar targets have been identified within the survey area. Five of these targets have been identified within the 13,000’ radius of MC 348, Proposed Location I. Sonar target #4 (20’ X 4) is identified 10661 feet west of Proposed Location I. Sonar target #5(15’ X 9’) is identified 8234 feet northwest of Proposed Location I. Sonar target #6 (14’ X 17’) is located 11191 feet south of Proposed Location I. Sonar target #8 (20’ X 5’) is located 7503 feet southeast of Proposed Location I. Sonar target #9 (15’ X 8’) is located 10844 feet east of Proposed Location I. All seafloor sonar targets have 100’ avoidance areas. MC 348, Proposed Location I and anchor pattern will not interfere with these seafloor sonar targets MC 348, Proposed Location I will be positioned 4489 feet southeast of Marathon’s MC 348 SS-1 wellsite, 7908 feet south of Marathon’s MC 348 SS-2 wellsite, 7828 feet northeast of Shell’s MC 392-1ST2BP1 wellsite and 14123 feet north of Anadarko’s MC 392-1 wellsite. All existing wells have a 500’ avoidance zone. MC 348, Proposed Location I and 13,000’ radial anchor pattern will not disturb these previously drilled wellsites. Flowlines and umbilicals for ATP are located in MC 348, Proposed Location I in MC348 has a l3,000-foot radial generic anchor pattern. Shell has placed a 500’ avoidance zone around these flowlines and umbilicals. None of the anchors or cables for Proposed Location I will be positioned within 500 feet of these flowlines and umbilicals. Based on a high-resolution geophysical survey, consisting of frequency enhanced 3-D seismic, Enhanced Surface Renderings (ESR’s), ESR’s with amplitudes applied, and AUV high-resolution data, Mississippi Canyon 348, Proposed Location I appears suitable for the planned activity.

MC 348, Proposed Location J, Generic 13,000’ Radius Anchor Pattern There is no evidence of seafloor or near-surface faulting, slumping, amplitudes or fluid expulsion features within 14,000 feet of Proposed Location J. Mississippi Canyon 348, Proposed Location J and 13,000’ radial anchor pattern will not disturb any high-density areas of chemosynthetic communities. Twelve side-scan sonar targets have been identified within the survey area. Five of these targets have been identified within the 13,000’ radius of MC 348, Proposed Location J. Sonar target #4 (20’ X 4) is identified 9616 feet west of Proposed Location J. Sonar target #5(15’ X 9’) is identified 9111 feet northwest of Proposed Location J. Sonar target #6 (14’ X 17’) is located 1117 feet south of Proposed Location J. Sonar target #8 (20’ X 5’) is located 6491 feet southeast of Proposed Location J. Sonar target #9 (15’ X 8’) is located 10238 feet east of Proposed Location J. All targets are given a 100’ avoidance area. MC 348, Proposed Location I and anchor pattern will not interfere with these unidentified side scan sonar targets.

MC 348, Proposed Location J will be positioned 5504 feet southeast of Marathon’s MC 348 SS-1 wellsite, 8158 feet northeast of Shell’s MC 392-1ST2BP1 wellsite, 8256 feet south of Marathon’s MC 348 SS-2 wellsite and 13495 feet north of Anadarko’s MC 392-1 wellsite. MC 348, Proposed Location J will not disturb these previously drilled wellsites. All existing wells have a 500’ avoidance zone. MC 348, Proposed Location J and 13,000’ radial anchor pattern will not disturb these previously drilled wellsites. Flowlines and umbilicals for ATP are located in MC 348, Proposed Location J in MC348 has a l3,000-foot radial generic anchor pattern. Shell has placed a 500’ avoidance zone around these flowlines and umbilicals. None of the anchors or cables for Proposed Location J will be positioned within 500 feet of these flowlines and umbilicals. Based on a high-resolution geophysical survey, consisting of frequency enhanced 3-D seismic, Enhanced Surface Renderings (ESR’s), ESR’s with amplitudes applied, and AUV high-resolution data, Mississippi Canyon 348, Proposed Location J appears suitable for the planned activity. John W. Harris Patrick Jackson Arlette C. Nunez Sr. Staff Geologist Sr. Staff Geophysicist Shallow Hazards Coordinator

(6b) Topographic features map The proposed locations are not near any topographic features. (6c) Topographic Features Statement (Shunting) Not applicable (6d) Live Bottoms (Pinnacle Trend Map) The proposed locations are not near live bottoms. (6e) Live Bottoms (Low Relief) Map Not applicable (6f) Potentially Sensitive Biological Features The proposed locations are not near any potentially sensitive biological features. (6g) Remotely Operated Vehicle (ROV) Monitoring Plan In accordance with the provisions of NTL No. 2008-G06, Remotely Operated Vehicle Surveys in Deepwater, Mississippi Canyon Blocks 348, 391 & 392 are located in Grid 17, which is an area that does not have adequate ROV survey coverage. Therefore we are proposing to run the pre and post ROV survey in accordance with the NTL. An ROV survey was submitted on April 27, 2010 following the drilling of the OCS-G 26253 No. 1 well, Location A approved in our Initial Exploration Plan N-09387.

(6h) Threatened and Endanger Species Information There are 5 species of sea turtles that may be found in the Gulf of Mexico (see table). No critical habitat for these species has been designated in the Gulf of Mexico. Common Name Scientific Name T/E StatusHawksbill Turtle Eretmochelys imbricata E Green Turtle Chelonia mydas T Kemp's Ridley Turtle Lepidochelys kempii E Leatherback Turtle Dermochelys coriacea E Loggerhead Turtle Caretta caretta T There are 28 species of marine mammals that may be found in the Gulf of Mexico (see table). Of the species listed as Endangered, only the Sperm whale is found in the project area. No critical habitat for these species has been designated in the Gulf of Mexico.

Common Name Scientific Name T/E StatusAtlantic Spotted Dolphin Stenella frontalis

Blainville's Beaked Whale Mesoplodon densirostris Blue Whale Balaenoptera musculus E

Bottlenose Dolphin Tursiops truncatus Bryde's Whale Balaenoptera edeni

Clymene Dolphin Stenella clymene Cuvier's Beaked Whale Ziphius cavirostris

Dwarf Sperm Whale Kogia simus False Killer Whale Pseudorca crassidens

Fin Whale Balaenoptera physalus E Fraser's Dolphin Lagenodelphis hosei

Gervais' Beaked Whale Mesoplodon europaeus Humpback Whale Megaptera novaeangliae E

Killer Whale Orcinus orca Melon-headed Whale Peponocephala electra

Minke Whale Balaenoptera acutorostrata Northern Right Whale Eubalaena glacialis

Pantropical Spotted Dolphin Stenella attenuata Pygmy Killer Whale Feresa attenuata

Pygmy Sperm Whale Kogia breviceps Risso's Dolphin Grampus griseus

Rough-toothed Dolphin Steno bredanensis Sei Whale Balaenoptera borealis E

Short-finned Pilot Whale Globicephala macrorhynchus Sowerby's Beaked Whale Mesoplodon bidens

Sperm Whale Physeter macrocephalus E Spinner Dolphin (Long-snouted) Stenella longirostris

Striped Dolphin Stenella coeruleoalba The EIA, EP Attachment 18, discusses potential impacts and mitigation measures related to threatened and endangered species.

(6i) Archaeological Report FUGRO's March 2009 Archeological Survey, which is part of the Shallow Hazards Report, concludes that the evaluation of the high-resolution geophysical survey data collected within the survey area indicates that twelve sonar contacts are located with the survey area. Sonar contact Nos. 1, 2, & 10 are all small isolated features that are likely geologic in origin. Sonar contact Nos. 7, 8, & 11 are all isolated linear features that are interpreted as probable modern debris. The remaining six contacts are all unidentified amorphous objects. None of the twelve sonar contacts identified are interpreted as archeologically significant. (6j) Air and Water Quality Information Pursuant to NTL No. 2008-G04, the proposed operations proposed in this EP do not required Shell to provide additional information relating to air and water quality information. For specific information relating to air and water quality refers to EIA, Attachment 18. (6k) Socioeconomic Information Pursuant to NTL No. 2008-G04, the proposed operations proposed in this EP do not required Shell to provide additional information relating to socioeconomic information. For specific information relating to socioeconomic refer to EIA, Attachment 18.


Offshore Alabama

(7a) Projected Generated Wastes

Type of Waste Composition Projected Amount Describe how it will it be treated,

stored, or downhole disposed of at your facility

Spent Drilling Fluids Synthetic-based drilling muds

12,000 bbls/well

Re-used. 55 bbls SBM retained on cuttings as reported under “washed drill

cuttings from SBM” below. Spent Drilling Fluids Water based drilling fluid 20,000 bbls/well Discharge at mudline prior to riser

installation. Washed Cuttings from water based

hole interval

Cuttings coated with water based drilling muds

3,500 bbls/well Discharge at mudline prior to riser installation.

Washed Drill cuttings from

synthetic based hole interval

Drill cuttings 3,500 bbls/well Cuttings dryer treatment to average ROC of 2.4%. Treated cuttings will be

discharged overboard during drilling of SBM interval.

Sanitary Waste Treated human body waste from toilets

6,325 bbls/well 59 bbls/day max

capacity

USCG-approved MSD with chlorination. Starboard Caisson

Domestic Waste Gray water (laundry, galley, lavatory)

19,250 bbls/well Food grinder. Starboard Caisson

Produced water Formation water NA NA Excess cement Cement slurry 420 bbls/well Discharged at mudline Desalination unit brine water

Rejected water from water maker unit

1020 bbls/well

Cuttings chute

Deck drainage Uncontaminated fresh or seawater

10,800 bbls/well Depending on rainfall

Oily water is treated in Oily Water Separator

Port & Starboard Caisson Drill Cuttings Synthetic based cuttings w/

ROC greater than 6.9% 75 bbls/ well

Cuttings boxes transported via Offshore

Support Vessels Newpark Environmental Services

Chemical products and general hazardous waste

Used cooking oil Used motor oil

Oily rags Antifreeze

Aerosol Cans Fluorescent Bulbs

330 bbls/well

Labeled Drums transported via Offshore Support Vessels to Safety Kleen or Lamp

Environmental Industries

Trash and debris Refuge generated during installation and production

650 bbls/well

Recyclables to ARC, New Iberia, LA. Non- recycleables to landfill at Avondale, LA

Transported in big bags. Cooling water Seawater with no addition

of chemicals 28,000,000 bbls/well

Port & Starboard Caisson

Fire water Seawater with no addition of chemicals

28,000,000 bbls/well

Port & Starboard Caisson

Ballast water Uncontaminated seawater used to maintain proper

draft

128,000 bbls/well Discharged Port & Starboard low sea chests, 75.5’ below waterline

Blowout Preventer Fluid

Stackmagic 200/0/5% glycol based on 2% mixture

with potable water

80 bbls/well Discharged at mudline

(7b) Projected Ocean Discharges

Type of Waste

Total Amount to be Discharged

Discharge Rate Discharge Method

Water based mud 20,000 bbls/well 1,500 bbls/hr

Seafloor discharge prior to marine riser installation

Washed Drill cuttings from synthetic based

hole interval

3,500 bbls/well 100 bbls/day Shunt through a downpipe to 15’ below the water’s surface

Synthetic based drilling fluid adhering to washed

drill cuttings

55 bbls/well 2.5 bbls/day Shunt through a downpipe to 15’ below the water’s surface

Drill Cuttings from water

base drilling interval 3,500 bbls/well 65 bbls/hr Seafloor discharge prior to

marine riser installation Chemical product waste NA NA NA

Excess cement 420 bbls/well 420 bbls/day Discharged at the seafloor during riserless drilling/ cementing of 22” casing

Cooling water 28,000,000 bbls/well 260,982/bbls/day Port & Starboard caisson 23’ below waterline

Sanitary waste 6,325 bbls/well 16.5 gal/person/day at max. 150 person POB

Treated in the MSD** prior to discharge to meet NPDES limits

Domestic waste 19,250 bbls/well 180 bbls/day Grinded to less than 25 mm mesh size and discharge

overboard @ 2’ below waterline Desalination unit brine

water 1020 bbls/well 9.5 bbls/day Port & Stbd caisson 23’ below

waterline Deck drainage 10,800 bbls/well 10 bbls/hr (dependent

on rainfall) Shunt through downpipe to 23 ft

below the water’s surface Ballast water 128,000 bbls/well 94,357 bbls to

deballast rig on location (one time

process) Daily ballast = 314 bbls/day-

approximate

Discharged thru low sea chests 75.5’ below waterline

Firewater Bypass 28,000,000 bbls/well 260,982 bbls/day Port & Stbd caissons 23’ below waterline

Blowout Preventer Fluid Stackmagic 200/0/5% glycol based on 2% mixture with potable

water

80 bbls/well 1 bbl/day Discharged at mudline

(7c) Modeling Report Shell did not model the trajectory for discharges since it is not required in the GOM.

8 AIR EMISSIONS INFORMATION

(8a) Emissions Worksheet and Screening Questions

Screening Questions for EP’s Yes No Is any calculated Complex Total (CT) Emission amount (in tons) associated with your proposed exploration activities more than 90% of the amounts calculated using the following formulas: CT = 3400D2/3 for CO, and CT 33.3D for the other air pollutants (where D distance to shore in miles)?

x

Do your emission calculations include any emission reduction measures or modified emission factors?

x Are your proposed exploration activities located east of 87.5° W longitude? x Do you expect to encounter H2S at concentrations greater than 20 parts per million (ppm)?

x Do you propose to flare or vent natural gas for more than 48 continuous hours From any proposed well?

x Do you propose to burn produced hydrocarbon liquids? x

(8b) If you answer no to all of the above screening questions from the appropriate table, provide:

(1) Summary information regarding the peak year emissions for both Plan Emissions and Complex Total Emissions, if applicable. This information is compiled on the summary form of the two sets of worksheets. You can submit either these summary forms or use the format below. You do not need to include the entire set of worksheets.

Air Pollutant Plan

Emission1

Amounts (tons)

Calculated Exemption2

Amounts (tons)

Calculated Complex Total

Emission Amounts3

(tons) Carbon monoxide CO Particulate matter (PM) NA Sulphur dioxide (SO2) Nitrogen oxides (NOx) Volatile organic compounds (VOC)

1 For activities proposed in your EP or DOCD, list the projected emissions calculated from the worksheets. 2 List the exemption amounts for your proposed activities calculated by using the formulas in 30 CFR 250.303(d). 3 List the complex total emissions associated with your proposed activities calculated from the worksheets

(2) Contact: Sylvia Bellone, (504) 728-7215, Sylvia.Bellone@ shell.com

(1) Worksheets COMPANY Shell Gulf of Mexico Inc AREA Mississippi Canyon BLOCK 348, 391, 392 LEASE OCS-G 19939, 26252, 26253 PLATFORM MODU WELL B, C, D, E, F, G, H, I, & J COMPANY CONTACT SYLVIA BELLONE TELEPHONE NO. 504 728 7215 REMARKS EP # OF WELLS 9 DAYS TO DRILL EACH # DRILLING DAYS IN 2011 274 # DRILLING DAYS IN 2012 100 # DRILLING DAYS IN 2013-2018 100 START DATE 3/1/2011 MOB/DEMOB 3 DAYS TOWING TO & FROM, 5 DAYS EACH PULL/SET ANCHORS DIST TO LAND 72 SHOREBASE BAYOU FOURCHON-WATER, BOOTHVILLE -AIR DIST TO SHOREBASE 138 NAUT (WATER), 97 STAT (AIR) TESTING/FLARING NO Estimated 4 work boats and 7 helicopters each week Assume work boats at MODU 20 hour every day, underway 4 hours. Assume cement units run 5% of the total drilling time.

"Yes" "No" Air Quality Screening Questions NO 1. Are the proposed activities east of 87.5o W latitude? YES 2. Are H2S concentrations greater than 20 ppm expected? NO 3. Is gas flaring proposed for greater than 48 continuous hours per well? NO 4. Is produced liquid burning proposed? NO 5. Is the exploratory activity within 25 miles of shore?

NO 6. Are semi-submersible activities involved and is the facility within 50 miles of shore?

NO 7. Are drillship operations involved and is the facility within 120 miles of shore?

NO 8. Will the exploratory activity be collocated (same surface location) on a production facility?

If ALL questions are answered "No": Submit only this coversheet with your plan; a full set of spreadsheets is not needed.

If ANY of questions 1 through 7 is answered "Yes": Prepare and submit a full set of EP spreadsheets with your plan.

If question number 8 is answered "Yes": Prepare and submit a full set of DOCD spreadsheets showing the cumulative emissions from both the proposed activities and the existing production platform.

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKSShell Gulf of Mexico Inc Mississippi Canyon 348, 391, 392 OCS-G 19939, MODU B, C, D, E, F, G, H, I, & J SYLVIA BELLONE 504 728 7210

OPERATIONS EQUIPMENT RATING MAX. FUEL ACT. FUEL RUN TIME MAXIMUM POUNDS PER HOUR ESTIMATED TONSDiesel Engines HP GAL/HR GAL/D

Nat. Gas Engines HP SCF/HR SCF/DBurners MMBTU/HR SCF/HR SCF/D HR/D DAYS PM SOx NOx VOC CO PM SOx NOx VOC CO

DRILLING PRIME MOVER #1>600hp diesel 7340 354.522 8508.53 24 274 5.17 23.73 177.84 5.34 38.80 17.01 78.04 584.74 17.54 127.58PRIME MOVER #2>600hp diesel 7340 354.522 8508.53 24 274 5.17 23.73 177.84 5.34 38.80 17.01 78.04 584.74 17.54 127.58PRIME MOVER #3>600hp diesel 7340 354.522 8508.53 1 274 5.17 23.73 177.84 5.34 38.80 0.71 3.25 24.36 0.73 5.32PRIME MOVER #4>600hp diesel 7340 354.522 8508.53 1 274 5.17 23.73 177.84 5.34 38.80 0.71 3.25 24.36 0.73 5.32CRANE<600hp diesel 564 27.2412 653.79 12 274 1.24 1.82 17.39 1.39 3.76 2.04 3.00 28.59 2.29 6.19CRANE<600hp diesel 564 27.2412 653.79 12 274 1.24 1.82 17.39 1.39 3.76 2.04 3.00 28.59 2.29 6.19CEMENT UNIT>600hp diesel 1800 86.94 2086.56 1 14 1.27 5.82 43.61 1.31 9.52 0.01 0.04 0.31 0.01 0.07WORK BOAT >600hp diesel 3420 165.186 3964.46 4 80 2.41 11.06 82.86 2.49 18.08 0.39 1.77 13.26 0.40 2.89WORK BOAT AT IDLE>600hp dies 1140 55.062 1321.49 20 80 0.80 3.69 27.62 0.83 6.03 0.64 2.95 22.10 0.66 4.82CREW BOAT>600hp diesel 3420 165.186 3964.46 4 80 2.41 11.06 82.86 2.49 18.08 0.39 1.77 13.26 0.40 2.89TOWING VESSEL >600hp diesel 16,500 796.95 19126.80 24 3 11.63 53.35 399.78 11.99 87.22 0.42 1.92 14.39 0.43 3.14ANCHOR HANDLINGVESSEL>60 15,200 734.16 17619.84 24 20 10.71 49.15 368.28 11.05 80.35 2.57 11.80 88.39 2.65 19.28ANCHOR HANDLINGVESSEL>60 29,000 1400.7 33616.80 24 20 20.44 93.77 702.64 21.08 153.30 4.91 22.51 168.63 5.06 36.79

MISC. BPD SCF/HR COUNTTANK- 0 0 0 0.00 0.00

DRILLING OIL BURN 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00WELL TEST GAS FLARE 0 0 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

2011 YEAR TOTAL 72.86 326.48 2453.81 75.35 535.32 48.84 211.32 1595.73 50.73 348.06

EXEMPTION DISTANCE FROM LAND IN 2397.60 2397.60 2397.60 2397.60 58843.78

72.0

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKSShell Gulf of Mexico Inc Mississippi Canyon 348, 391, 392 OCS-G 19939, MODU B, C, D, E, F, G, H, I, & J SYLVIA BELLONE 504 728 7215 0



DRILLING PRIME MOVER #1>600hp diesel 7340 354.522 8508.53 24 100 5.17 23.73 177.84 5.34 38.80 6.21 28.48 213.41 6.40 46.56PRIME MOVER #2>600hp diesel 7340 354.522 8508.53 24 100 5.17 23.73 177.84 5.34 38.80 6.21 28.48 213.41 6.40 46.56PRIME MOVER #3>600hp diesel 7340 354.522 8508.53 1 100 5.17 23.73 177.84 5.34 38.80 0.26 1.19 8.89 0.27 1.94PRIME MOVER #4>600hp diesel 7340 354.522 8508.53 1 100 5.17 23.73 177.84 5.34 38.80 0.26 1.19 8.89 0.27 1.94CRANE<600hp diesel 564 27.2412 653.79 12 100 1.24 1.82 17.39 1.39 3.76 0.75 1.09 10.44 0.83 2.26CRANE<600hp diesel 564 27.2412 653.79 12 100 1.24 1.82 17.39 1.39 3.76 0.75 1.09 10.44 0.83 2.26CEMENT UNIT>600hp diesel 1800 86.94 2086.56 1 100 1.27 5.82 43.61 1.31 9.52 0.06 0.29 2.18 0.07 0.48WORK BOAT >600hp diesel 3420 165.186 3964.46 4 31 2.41 11.06 82.86 2.49 18.08 0.15 0.69 5.14 0.15 1.12WORK BOAT AT IDLE>600hp dies 1140 55.062 1321.49 20 31 0.80 3.69 27.62 0.83 6.03 0.25 1.14 8.56 0.26 1.87CREW BOAT>600hp diesel 3420 165.186 3964.46 4 31 2.41 11.06 82.86 2.49 18.08 0.15 0.69 5.14 0.15 1.12

FACILITY TOWING VESSEL >600hp diesel 16,500 796.95 19126.80 24 3 11.63 53.35 399.78 11.99 87.22 0.42 1.92 14.39 0.43 3.14INSTALLATION ANCHOR HANDLINGVESSEL>60 15,200 734.16 17619.84 24 10 10.71 49.15 368.28 11.05 80.35 1.29 5.90 44.19 1.33 9.64

ANCHOR HANDLINGVESSEL>60 29,000 1400.7 33616.80 24 10 20.44 93.77 702.64 21.08 153.30 2.45 11.25 84.32 2.53 18.40



2012 YEAR TOTAL 72.86 326.48 2453.81 75.35 535.32 19.19 83.40 629.40 19.93 137.29

EXEMPTION CALCULATION

DISTANCE FROM LAND IN MILES 2397.60 2397.60 2397.60 2397.60 58843.78

72.0

COMPANY AREA BLOCK LEASE PLATFORM WELL CONTACT PHONE REMARKSShell Gulf of Mexico Inc Mississippi Canyon 348, 391, 392 OCS-G 19939, MODU B, C, D, E, F, G, H, I, & J SYLVIA BELLONE 504 728 7215 0



DRILLING PRIME MOVER #1>600hp diesel 7340 354.522 8508.53 24 100 5.17 23.73 177.84 5.34 38.80 6.21 28.48 213.41 6.40 46.56PRIME MOVER #2>600hp diesel 7340 354.522 8508.53 24 100 5.17 23.73 177.84 5.34 38.80 6.21 28.48 213.41 6.40 46.56PRIME MOVER #3>600hp diesel 7340 354.522 8508.53 1 100 5.17 23.73 177.84 5.34 38.80 0.26 1.19 8.89 0.27 1.94PRIME MOVER #4>600hp diesel 7340 354.522 8508.53 1 100 5.17 23.73 177.84 5.34 38.80 0.26 1.19 8.89 0.27 1.94CRANE<600hp diesel 564 27.2412 653.79 12 100 1.24 1.82 17.39 1.39 3.76 0.75 1.09 10.44 0.83 2.26CRANE<600hp diesel 564 27.2412 653.79 12 100 1.24 1.82 17.39 1.39 3.76 0.75 1.09 10.44 0.83 2.26CEMENT UNIT>600hp diesel 1800 86.94 2086.56 1 100 1.27 5.82 43.61 1.31 9.52 0.06 0.29 2.18 0.07 0.48WORK BOAT >600hp diesel 3420 165.186 3964.46 4 31 2.41 11.06 82.86 2.49 18.08 0.15 0.69 5.14 0.15 1.12WORK BOAT AT IDLE>600hp dies 1140 55.062 1321.49 20 31 0.80 3.69 27.62 0.83 6.03 0.25 1.14 8.56 0.26 1.87CREW BOAT>600hp diesel 3420 165.186 3964.46 4 31 2.41 11.06 82.86 2.49 18.08 0.15 0.69 5.14 0.15 1.12

FACILITY TOWING VESSEL >600hp diesel 16,500 796.95 19126.80 24 3 11.63 53.35 399.78 11.99 87.22 0.42 1.92 14.39 0.43 3.14INSTALLATION ANCHOR HANDLINGVESSEL>60 15,200 734.16 17619.84 24 10 10.71 49.15 368.28 11.05 80.35 1.29 5.90 44.19 1.33 9.64

ANCHOR HANDLINGVESSEL>60 29,000 1400.7 33616.80 24 10 20.44 93.77 702.64 21.08 153.30 2.45 11.25 84.32 2.53 18.40



2013-18 YEAR TOTAL 72.86 326.48 2453.81 75.35 535.32 19.19 83.40 629.40 19.93 137.29

EXEMPTION CALCULATION

DISTANCE FROM LAND IN MILES 2397.60 2397.60 2397.60 2397.60 58843.78

72.0

COMPANY AREA BLOCK LEASE PLATFORM WELL Shell Gulf of Mexico Inc

Mississippi Canyon 348, 391, 392 OCS-G 19939, 26252,

26253 MODU B, C, D, E, F, G, H, I, & J

Emitted Substance Year

PM SOx NOx VOC CO

2011 48.84 211.32 1595.73 50.73 348.06 2012 19.19 83.40 629.40 19.93 137.29

2013-18 19.19 83.40 629.40 19.93 137.29 Allowable 2397.60 2397.60 2397.60 2397.60 58843.78

(9a) Oil Spill Response Planning

(i) All the proposed activities and facilities in this EP will be covered by the Regional OSRP filed by Shell Offshore Inc (0689) in accordance with 30 CFR 250. An update to the Regional OSRP was filed with the BOEMRE October 2010 and is pending approval. This plan covers Shell Gulf of Mexico Inc (SGOMI) (2117) operations in the Gulf of Mexico. AN OSRP Certification in accordance with 30 CFR 254.2 was submitted and accepted by the BOEMRE on December 3, 2010.

(ii) Spill Response Sites: Primary Response Equipment Locations Preplanned Staging Location(s) Venice, LA; Houma, LA; Pascagoula, MS;

Fort Jackson, LA Fourchon, LA; Pascagoula, MS; Fort Jackson, LA;

Venice, LA

(iii) The names of the oil spill removal organizations (OSRO’s) under contract include Clean Gulf Associates (CGA), Marine Spill Response Company (MSRC), Clean Caribbean America (CCA), and OSRL/EARL.

(iv) Worst Case Scenario Determination

Category Regional OSRP EP Type of Activity1 Drilling Rig & Subsea

Installation Drilling Rig & Subsea

Installation Facility Location (area/block) MC 391 MC 391 Facility Designation2 C C Distance to Nearest Shoreline (miles) 72 72 Volume3 Storage tanks (total) Flowlines (on facility) Pipelines Uncontrolled blowout (volume per day) Total Volume

N/A N/A N/A

405,000* BOPD 405,000 Bbls

N/A N/A N/A

405,000* BOPD 405,000 Bbls

Type of Oil(s) - (crude oil, condensate, diesel) Crude oil Crude oil API Gravity(s)4 37.5º 37.5º

*24 hour rate (371,000 BOPD 30 day rate) Footnotes: 1. Types of activities include pipeline, platform, caisson, subsea completion or manifold, and mobile drilling rig. 2. E.g., Well No. 2, Platform JA, Pipeline Segment No. 6373. 3. Your regional OSRP worst-case scenario volume must be taken from the appropriate section of your regional OSRP.

For EP’s, the worst-case scenario volume must be determined by using the daily worst-case discharge volume determined using the guidance at 30 CFR 254.47(b). For DOCD’s, the daily worst-case discharge volume must be determined by using the guidance at 30 CFR 254.47 (a) and/or (b), as appropriate.

4. Provide API gravity of all oils given under “Type of Oil(s)” above. Estimate for EP’s. SGOMI submitted the new worst-case scenario to the BOEMRE GOMR on October 26, 2010 for inclusion in our Regional OSRP.

(9b) Oil Spill Response Discussion

A. Volume of the Worst Case Discharge Please refer to Section 2j of this EP.

B. Trajectory Analysis

Trajectories of a spill and the probability of it impacting a land segment have been projected utilizing information in the BOEMRE Oil Spill Risk Analysis Model (OSRAM) for the Central and Western Gulf of Mexico available on the BOEMRE website using 30 day impact. Offshore areas along the trajectory between the source and land segment contact could be impacted. The land segment contact probabilities are shown in Table 9.C.1.

Area/Block OCS-G Launch Area Land Segment Contact %

Exploratory MC 391 26252 57

CAMERON, LA VERMILION, LA

TERREBONNE, LA LA FOURCHE, LA

PLAQUEMINES, LA ST. BERNARD, LA

HANCOCK & HARRISON, MS JACKSON, MS MOBILE, AL

BALDWIN, AL ESCAMBIA, FL OKALOOSA, FL

WALTON, FL BAY, FL

1 1 2 2

21 3 1 1 1 1 1 1 1 1

Table 9.C.1 Probability of Land Segment Impact

C. Resource Identification

The locations identified in Table 9.C.1 are the highest probable land segments to be impacted using the BOEMRE Oil Spill Risk Analysis Model (OSRAM). The environmental sensitivities are identified using the appropriate National Oceanic and Atmospheric Administration (NOAA) Environmental Sensitivity Index (ESI) maps for the given land segment. ESI maps provide a concise summary of coastal resources that are at risk if an oil spill occurs nearby. Examples of at-risk resources include biological resources (such as birds and shellfish beds), sensitive shorelines (such as marshes and tidal flats), and human-use resources (such as public beaches and parks). In the event an oil spill occurs, ESI maps can help responders meet one of the main response objectives: reducing the environmental consequences of the spill and the cleanup efforts. Additionally, ESI maps can be used by planners to identify vulnerable locations, establish protection priorities, and identify cleanup strategies. The following is a list of resources of special economic or environmental importance that potentially could be impacted by the Mississippi Canyon 391 WCD scenario.

Onshore/Nearshore: Plaquemines Parish is identified as the most probable impacted Parish within the Gulf of Mexico for the Exploratory Worst Case Discharge. The Plaquemines Parish has a total area of 2,429 square miles of which, 845 square miles of it is land and 1,584 square miles is water. Plaquemines Parish includes two National Wildlife Refuges and one Wildlife Management Area including the Breton National Wildlife Refuge, the Delta National Wildlife Refuge, and the Pass a Loutre Wildlife Management Area. Key ESI maps for Plaquemines Parish and the legend are shown in Figures 9.C.1 through 9.C.5. Offshore: An offshore spill may require an Essential Fishing Habitat (EFH) Assessment. This assessment would include a description of the spill, analysis of the potential adverse effects on EFH and the managed species; conclusions regarding the effects on the EFH; and proposed mitigation, if applicable.

Significant pre-planning of joint response efforts was undertaken in response to provisions of the National Contingency Plan (NCP). Area Contingency Plans (ACPs) were developed to provide a well coordinated response to oil discharges and other hazardous releases. The One Gulf Plan is specific to the Gulf of Mexico to advance the unity of policy and effort in each of the Gulf Coast ACPs. Strategies used for the response to an oil spill regarding protection of identified resources are detailed in the One Gulf Plan and relevant Gulf Coast ACP.

D. Worst Case Discharge Response

Shell will make every effort to respond to the Mississippi Canyon 391 Worst Case Discharge as effectively as possible. Applied Science Associates (ASA) conducted a deepwater blowout simulation for The Response Group to better determine subsurface and surface evaporation and dispersion rates. Below is a table outlining the applicable evaporation and dispersion quantities:

Mississippi Canyon Block 391 Calculations

(BBLS)

i. 30 Day Average WCD = 371,000 bbls

ii. Subsurface dispersion – 25% (Water Depth = ~7,200’) -93,000 bbls

iii. REMAINING WCD AFTER SUBSURFACE DISPERSION 278,000 bbls

iv. Surface dispersion and evaporation – 25% -69,500 bbls

TOTAL REMAINING ~209,000 bbls

Table 9.D.1 Oil Remaining After Subsurface and Surface Dispersion Shell has contracted OSROs to provide equipment, personnel, materials and support vessels as well as temporary storage equipment to be considered in order to cope with a WCD spill. Under adverse weather conditions, major response vessels and Transrec skimmers are still effective and safe in sea states of 6-8 ft. If sea conditions prohibit safe mechanical recovery efforts, then natural dispersion and airborne chemical dispersant application (visibility & wind conditions permitting) may be the only safe and viable recovery option.

MSRC OSRV 8 foot seas VOSS System 4 foot seas Expandi Boom 6 foot seas, 20 knot winds Dispersants Winds more than 25 knots,

Visibility less than 3 nautical miles, or Ceiling less than 1,000 feet.

Table 9.D.2 Operational Limitations of Response Equipment Upon notification of the spill, Shell would request a partial or full mobilization of contracted resources, including, but not limited to, skimming vessels, oil storage vessels, dispersant aircraft, subsea dispersant, shoreline protection, wildlife protection, and containment equipment. Following is a list of the contracted resources including de-rated recovery capacity, personnel, and estimated response times (procurement, load out, travel time to the site, and deployment). The Incident Commander or designee may contact other service companies if the Unified Command deems such services necessary to the response efforts. Subsea Control and Containment: Shell, as a founding member of the Marine Well Containment Company (MWCC), will have access to a fully integrated subsea well control and containment system that can be rapidly deployed through the MWCC. The Marine Well Containment System (MWCS) is designed to contain oil flow in the unlikely event of an underwater well blowout, address a variety of spill scenarios in the Gulf of Mexico, operate in deepwater depths up to 10,000 feet, and is capable of containing/collecting 100,000 barrels per day (4.2 million gallons per day). Furthermore, the equipment is designed, constructed, tested, and available for rapid response.

By using lessons learned from the recent Gulf of Mexico subsea well blowout incident, the MWCS has been designed to have components that will be fully tested and maintained in a state of continuous readiness, including a knowledgeable deployment staff. Additionally, the system is designed to be flexible and adaptable for a variety of potential future spill scenarios. Equipment will have the capability to be connected to the well or sea floor to provide full containment of the hydrocarbons for a multitude of spill scenarios in the Gulf of Mexico. It is designed to operate in a wide range of weather conditions and oil flow rates, and is scalable to allow for future expansion. This system, when operational, will connect by risers to vessels that are designed to safely capture, store and offload the oil. This improves safety and environmental protection by fully securing the well via capping and shut-in or by containing the oil flow until the well is under control. It also enhances safe operations by reducing congestion (e.g. fewer vessels, risers / flowlines). MWCC equipment will include well containment assemblies, flowlines and risers, subsea utility modules (hydraulic power, hydrate control, dispersant injection) and marine capture vessels. The MWCC LLC is expected to be fully formed by the end of January 2011. Mutual aid agreements, formal contracts for the BP containment equipment, and other call-off contracts for necessary response vessels are expected to be in place by the end of December 2010. All these contracts and the functional specifications of the MWCS will be available for review by the BOEM at that point. Containment capability of the MWCC will include the near term capability from the BP equipment, other former BP responders, and mutual aid equipment from MWCC members as well as the MWCS as it is delivered in phases. These subsea well containment resources, systems, and equipment will include:

Marine Vessels

! Helix Producer 1 floating production unit ! Helix Q-4000 DP3 mobile offshore drilling unit

Subsea Containment Equipment: ! GE Latching Cap ! Flex joint overshot ! 2 manifolds ! 3” flexible pipe ! 6” flexible pipe ! Single valve manifold tree ! Subsea shut-off device ! Flex joint transition spool ! Three ram capping stack ! Subsea chokes

Riser Systems: ! 2 free standing riser systems ! Drill string riser/ polished bore receptacle system ! Light duty Intervention system (under mutual aid assistance)

Subsea Utility Systems: ! Hydrate injection system ! Subsea autonomous dispersant injection (SADI) system ! Subsea sourced dispersant injection system ! Hydrate remediation system (under mutual aid assistance) ! Subsea hydraulic accumulator and distribution system (under mutual aid assistance)

In the interim until the full MWCS is in place and available, containment equipment from BP and other responders to the BP event will be available as it is retrieved and refurbished. The experience of gaining control over the Macondo well has resulted in a better understanding of the necessary equipment and systems for well containment. As a result, industry and government are better equipped and prepared today to contain an oil well blowout in deepwater (see page 17 of the Decision Memorandum dated October 1, 2010). Shell is further analyzing these advances and incorporating them into its comprehensive approach to help prevent and, if needed, control another deepwater well control incident. Any needed additional drill rigs or ships, remotely operated vessels and heavy lift installation vessels will be immediately contracted and available at the beginning of an incident.

Appendix D of the OSRP contains a list of companies that Shell has under contract or through mutual aid agreements to provide all resources needed to provide subsea containment capabilities.

Mechanical Recovery (skimming): Response strategies include skimming utilizing available OSROs Oil Spill Response Vessels (OSRVs), Oil Spill Response Barges (OSRBs), ID Boats, and Quick Strike OSRVs. There is a combined de-rated recovery rate capability of approximately 865,993 barrels/day. Temporary storage associated with the identified skimming and temporary storage equipment equals approximately 836,574 barrels.

De-rated Recovery Rate

(bopd) Storage (bbls)

Offshore Recovery 749,000 607,750 Offshore Storage 211,500 Nearshore Recovery 116,993 17,324

Total 865,993 836,574 Table 9.D.3 Mechanical Recovery Combined De-Rated Capability

Table 9.D.4 Offshore On-Water Recovery Activation List

Table 9.D.5 Offshore On-Water Storage Activation List Table 9.D.6 Nearshore On-Water Recovery Activation List Oil Storage: The strategy for transferring, storing and disposing of oil collected in these recovery zones is to utilize two 150,000-160,000 ton (dead weight) tankers mobilized by Shell (or any other tanker immediately available). The recovered oil would be transferred to Motiva’s Norco, LA storage and refining facility, or would be stored at Delta Commodities, Inc. Harvey, LA facility. Aerial Surveillance: Aircraft can be mobilized to detect, monitor, and target response to oil spills. Aircraft and spotters can be mobilized within hours of an event. Table 9.D.7 Aerial Surveillance Activation List Aerial Dispersant: Depending on proximity to shore and water depth, dispersants may be a viable response option. If appropriate and approved, 4 to 5 sorties from three DC-3’s can be made within the first 12 hour operating day of the response. These aerial systems could disperse approximately 7,704 to 9,630 barrels of oil per day. Additionally, 3 to 4 sorties from the BE90 King Air and 3 to 4 sorties from the Hercules C-130A within the first 12 hour operating day of the response could disperse 4,600 to 6,100 barrels of oil per day. For continuing dispersant operations, the CCA’s Aerial Dispersant Delivery System (ADDS) would be mobilized. The ADDS has a dispersant spray capability of 5,000 gallons per sortie. Table 9.D.8 Offshore Aerial Dispersant Activation List Vessel Dispersant: Vessel dispersant application is another available response option. If appropriate, vessel spray systems can be installed on offshore vessels of opportunity using inductor nozzles (installed on fire-water monitors), skid mounted systems, or purpose-built boom arm spray systems. Vessels can apply dispersant within the first 12-24 hours of the response and continually as directed. Table 9.D.9 Offshore Boat Spray Dispersant Activation List Subsea Dispersant: Shell has contracted with Wild Well Control for a subsea dispersant package. Subsea dispersant application has been found to be highly effective at reducing the amount of oil reaching the surface. Additional data collection, laboratory tests and field tests will help in facilitating the optimal application rate and effectiveness numbers. For planning purposes, The system has the potential to disperse approximately 24,500 to 34,000 barrels of oil per day. Table 9.D.10 Subsea Dispersant Package Activation List In-Situ Burning: Open-water in-situ burning (ISB) also may be used as a response strategy, depending on the circumstances of the release. ISB services may be provided by the primary OSRO contractors. If appropriate conditions exist and approvals are granted, one or multiple ISB task forces could be deployed offshore. Task forces typically consist of two to four fire teams, each with two vessels capable of towing fire boom, guide boom or tow line with either a handheld or aerially-deployed oil ignition system. At least one support/safety boat would be present during active burning operations to provide logistics, safety and monitoring support.

Depending upon a number of factors, up to 4 burns per 12-hour day could be completed per ISB fire team. Most fire boom systems can be used for approximately 8-12 burns before being replaced. Fire intensity and weather will be the main determining factors for actual burns per system. Although the actual amount of oil that will be removed per burn is dependent on many factors, recent data suggests that a typical burn might eliminate approximately 750 barrels. For planning purposes and based on the above assumptions, a single task force of four fire teams with the appropriate weather and safety conditions could complete four burns per day and remove up to ~12,000 bbls/day. In-situ burning nearshore and along shorelines may be a possible option based on several conditions and with appropriate approvals, as outlined in Section 19, In-situ Burn Plan (OSRP). In-situ burning along certain types of shorelines may be used to minimize physical damage where access is limited or if it is determined that mechanical/manual removal may cause a substantial negative impact on the environment. All safety considerations will be evaluated. In addition, Shell will assess the situation and can make notification within 48 hours of the initial spill to begin ramping up fire boom production through contracted OSRO(s). There are potential limitations that need to be assessed prior to ISB operations. Some limitations include atmospheric and sea conditions; oil weathering; air quality impacts; safety of response workers; and risk of secondary fires. Table 9.D.11 In-Situ Burn Equipment Activation List Shoreline Protection: If the spill went unabated, shoreline impact in St. Bernard or Plaquemines Parish, LA would depend upon existing environmental conditions. Nearshore response may include the deployment of shoreline boom on beach areas, or protection and sorbent boom on vegetated areas. Strategies would be based upon surveillance and real time trajectories provided by The Response Group that depict areas of potential impact given actual sea and weather conditions. Strategies from the New Orleans, Louisiana Area Contingency Plan, The Response Group and Unified Command would be consulted to ensure that environmental and special economic resources would be correctly identified and prioritized to ensure optimal protection. The Response Group shoreline response guides depict the protection response modes applicable for oil spill clean-up operations. Each response mode is schematically represented to show optimum deployment and operation of the equipment in areas of environmental concern. Supervisory personnel have the option to modify the deployment and operation of equipment allowing a more effective response to site-specific circumstances. Table 9.D.12 Shoreline Protection and Wildlife Support List Wildlife Protection: If wildlife is threatened due to a spill, the contracted OSRO’s have resources available to Shell, which can be utilized to protect and/or rehabilitate wildlife. The resources under contract for the protection and rehabilitation of affected wildlife are in Table 9.D.12.

(9c) Modeling Report Not applicable

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Table!9D6!Nearshore!On"Water!Recovery!Activation!List!(continuedO!

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Table 9.D.7 Aerial Surveillance Activation List

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Table 9.D.9 Offshore Boat Spray Dispersant Activation List

Table 9.D.10 Subsea Dispersant Package Activation List

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Offshore Alabama

10 Environmental Monitoring Information

(10a) Monitoring Systems A rig based Acoustic Doppler Current Profiler (ADCP) is used to continuously monitor the current beneath the rig. Metocean conditions such as sea states, wind speed, ocean currents, etc. will also be continuously monitored (10b) Incidental Takes No incidental takes are anticipated. Shell implements the mitigation measures and monitors for incidental takes of protected species according to the following notices to lessees and operators from the Minerals Management Service: NTL No.2007-G02 “Implementation of Seismic Survey Mitigation Measures and Protected

Species Observer Program” – during seismic operations NTL No.2007-G03 “Marine Trash and Debris Awareness and Elimination” NTL No.2007-G04 “Vessel Strike Avoidance and Injured/Dead Protected Species

Reporting” (10c) Flower Garden Banks National Marine Sanctuary The operations proposed in this EP will not be conducted within the Protective Zones of the Flower Garden Banks or Stetson Bank.


Offshore Alabama

11 Lease Stipulations Information

OCS-G 19939, 26252 & 26253 are not a part of any Biological Sensitive Area or Shipping Fairway. OCS-G 19939 & 26253 are located in Military Warning Area EWTA-1. OCS-G 19939, 26252 & 26253 are designated as having a high potential for containing archeological properties. OCS-G 26252 & 26253 leases were assigned to Shell Gulf of Mexico Inc. April 30, 2008. SGOMI acquired deep rights below 16,500’ SSTVD to OCS-G 19939 on August 3, 2010. Lease Stipulation No. 6, Protected Species, is addressed in the following sections of this plan: Section 6h, Threatened or endangered species, critical habitat, and marine mammal information Section 10b, Environmental Monitoring Information, Incidental takes Section 12b, Environmental Mitigation Measures Information, Incidental takes Section 18, Environmental Impact Assessment

12 Environmental Mitigation Measure Information

(12a) Impacts to Marine and coastal environments The proposed action will implement mitigation measures required by laws and regulations, including all applicable Federal & State requirements concerning air emissions, discharges to water, and solid waste disposal, as well as any additional permit requirements and Shell policies. Project activities will be conducted in accordance with the Regional Oil Spill Response Plan. The EIA attached as Section 18 to this plan discusses impacts and mitigation measures. (12b) Incidental Takes We do not anticipate any incidental takes related to the proposed operations. Shell implements the mitigation measures and monitors for incidental takes of protected species according to the following notices to lessees and operators from the Minerals Management Service: NTL No.2007-G03 “Marine Trash and Debris Awareness and Elimination” NTL No.2007-G04 “Vessel Strike Avoidance and Injured/Dead Protected Species Reporting”

13 Related Facilities and Operations Information

(13a) Related OCS Facilities and Operations Information regarding Related Facilities and Operations Information, transportation systems, & produced liquid hydrocarbon transportation vessels are not included in this EP as such information is only necessary in the case of DOCDs


Offshore Alabama

14 SUPPORT VESSELS AND AIRCRAFT INFORMATION (14a) General

Type Maximum Fuel Tank Storage Capacity (Bbls)

Maximum No. In Area at Any Time

Trip Frequency or Duration

Crew Boats 1040 2 Twice per week

Offshore Support Vessels 9750 3 Twice per week

Tug Boats 7100 2 3 days

Anchor Handling Vessel 11850 3 20 days

Helicopter 22 1 Once per day

(14d) Solid and Liquid Wastes Transportation

Type of Waste Approx.

Composition

Total Amount

Name/Location Rate Transport Method

Synthetic drilling mud

12,000 bbls/well

Newpark Environmental Services Inc. Ingleside, TX

200 bbls/day

Below deck storage tanks on Offshore Support Vessels

Synthetic based cuttings w/ ROC

greater than 6.9%

75 bbls/well

Newpark Environmental Services Inc. Ingleside, TX

4 bbls/day Cutting boxes on barges

Chemical products and general

hazardous waste

330 bbls/well

Safety Kleen System Inc. Denton, TX

or Lamp Environmental Industries

Hammond, LA

4 bbls/day Drums on Offshore Support Vessels

Non-hazardous Trash and debris (Non-recyclables)

450 bbls/well

Newpark Environmental Services Inc.

Ingleside, TX or

Bridge City, TX

7 bbls/day Storage bins on Crew Boat

Used Oil & Glycol 85 bbls/well

U. S. Filter New Orleans, LA


Batteries, lamps, glass, mercury

7 bbls/well

Lamp Environmental Industries, Inc.

Hammond, LA

0.1 bbls/day Storage bins on Crew Boat

Oil Filters, rags, pads, empty drums,

cooking oil

20 bbls/well

Omega Waste Management Inc Patterson, LA

0.25 bbls/day

Recycled

Trash and debris (recyclables)

200 bbls/well

Omega Waste Management Inc 1900 Hwy 90 West Patterson, LA

or

ARC New Iberia, LA


(14e) Vicinity Map


Offshore Alabama

15 ONSHORE SUPPORT FACILITIES (15a) General

Name Location Existing/New/Modified

Fourchon Port Fourchon, LA Existing

Boothville PHI Heliport Boothville, LA Existing

The onshore support bases for water and air transportation will be the existing terminals in Boothville and Fouchon. The Fouchon boat facility is operated by SOI and is located on Bayou LaFourche, south of Leesville, LA approximately 3 miles from the Gulf of Mexico. The Boothville heliport is operated by SOI and is located on La State Highway 23 in Boothville, La (15b) Support Base Construction or Expansion None planned. (15c) Support Base Construction or Expansion Timetable None planned. (15d) Waste Disposal

Name/Location Type of Waste Amount Rate Disposal

Method Newpark

Environmental Services Inc

Ingleside or Bridge City, TX

Synthetic Drilling Mud 12,000 bbls/well 200 bbls/day Recycled

Newpark Environmental Services Inc


Synthetic based cuttings w/ ROC greater than 6.9%

75 bbls/well 4 bbls/day Land farmed

Safety Kleen System Inc Denton, TX

Chemical products and general hazardous waste Paint, solvents, unused

chemicals, etc

330 bbls/well 4 bbls/day Hazardous waste disposal

Newpark Environmental Services Inc


Non-hazardous Trash and Debris Non-Recyclables

450 bbls/well 7 bbls/day Land farmed

U. S. Filter New Orleans, LA

Used Oil & Glycol 85 bbls/well 10 bbls/day Recycled

Lamp Environmental Industries, Inc. Hammond, LA

Batteries, lamps, glass, mercury

7 bbls/well 0.1 bbls/day Recycled

Omega Waste Management Inc

Patterson, LA

Oil Filters, rags, pads, empty drums, cooking oil

20 bbls/well 0.25 bbls/day Recycled

ARC ew Iberia, LA

Non-hazardous Trash and Debris

Recyclables

200 bbls/well 3 bbls/day Recycled


Offshore Alabama

(16) Sulphur Operations Information

Information regarding Sulfur Operations Information is not included in this EP as such information is only necessary in the case of DOCDs. .

17 Coastal Zone Management Act (CZMA) Information

Coastal Consistency

ALABAMA

COASTAL ZONE MANAGEMENT

CONSISTENCY CERTIFICATION

Supplemental Exploration Plan Type of Plan

Mississippi Canyon 391 Mississippi Canyon 392 Mississippi Canyon 348 Area and Blocks

OCS-G 26252 OCS-G 26253 OCS-G 19939 Lease Numbers

The proposed activities described in detail in this Plan will comply with Alabama's approved Coastal Resources Program and Alabama's Coastal Area Management Program Policies.

SHELL GULF OF MEXICO INC. (SGOMI) Operator

______________________________ Sylvia A. Bellone Certifying Official

12/21/2010 Date


Offshore Alabama

Coastal Zone Management Consistency Information For the State of Alabama

In accordance with Subpart E of 15 CFR 903 “Consistency for Outer Continental Shelf (OCS) Exploration, Development and Production Activities” and as required by 15 CFR 930.58, Shell Gulf of Mexico Inc. is hereby providing the following information in support of the Environmental Impact Analysis submitted as Attachment 18 of our Initial Exploration Plan for the above mentioned leases. 15 CFR 930.58 identifies necessary data and information to be furnished to the State agency. The information is as follows:

A. CONSISTENCY CERTIFICATION A Coastal Zone Consistency Certification for activities that affect the State of Alabama is provided in Attachment 17 (c) of the above-mentioned EP. B. OTHER INFORMATION (1) As proposed the EP provides for the drilling wells beginning approximately March 1, 2011. The proposed activity is located approximately 72 miles from the nearest shoreline. Shell Gulf of Mexico Inc will utilize a shorebase in Fourchon, Louisiana for water support and PHI’s Boothville terminal for air traffic for the proposed activities. (2) As per NTL 2008-G04, the following items have been identified as being required:

! A discussion of the method of disposal of wastes and discharges is provided in Attachment 15(d) of the above-mentioned EP.

! Oil Spill Information is provided in Attachment 9 of the above-mentioned EP. ! All operations are covered by Shell Gulf of Mexico Inc.’s Regional Oil Spill Response Plan,

which has been approved by MMS. The Plan is available upon request.

(3) Following is an evaluation that includes findings relating the coastal effects of the proposed activities and associated facilities to the relevant enforceable policies of the Alabama’s Coastal Management Program: All activities shall be consistent with Alabama’s coastal management program and shall comply with all relevant rules and regulations. Pollution shall be prevented or reduced at the source; pollution that cannot be prevented shall be recycled in an environmentally safe manner; pollution that cannot be prevented or recycled shall be treated in an environmentally safe manner; and disposal or other release into the environment shall be employed only as a last resort and should be conducted in an environmentally safe manner. All activities comply with all applicable provisions of the administrative code. No activities are planned within special management areas. Activities will be carried out avoid unnecessary conflicts with other uses of the vicinity.

COASTAL RESOURCE USE POLICIES Coastal Development – All activities shall be conducted in a manner that minimizes significant

impacts to coastal resources. No adverse effects to Alabama’s coastal area are expected in association with the proposed activities.

Mineral Resource Exploration and Extraction – No conflicts with any other mineral resource

exploration and extraction are expected.

Commercial Fishing – All uses and activities shall be planned, sited, designed, constructed operated and maintained to avoid to the maximum extent practicable adverse disruptions to fishery migratory patterns.

Hazard Management- Effective emergency plans are in place, practiced, and updated as necessary.

The best practical techniques shall be utilized to prevent the release of pollutants or toxic substances into the environment.

Shoreline Erosion - All uses and activities shall be planned, sited, designed, constructed operated and

maintained to avoid to the maximum extent practicable adverse alteration of protective coastal features

Recreation – We have considered the general factors utilized by permitting authorities and have

determined that the proposed activities shall cause no adverse impacts on areas of public use or concern, and all uses and activities shall be planned, sited, designed, constructed operated and maintained to avoid to the maximum extent practicable adverse alteration of these areas. The MMS has regulations in place which explicitly prohibit the disposal of equipment, cables, chains, chains, containers or other materials which may pose an unreasonable risk to public health, property, aquatic life, wildlife, recreation, navigation, commercial fishing, or other uses of the ocean into offshore waters. Although marine debris gets lost from time to time, the impact on Gulf Coast recreational beaches is expected to be minimal. No impacts are expected to adversely affect Public access to tidal and submerged lands, navigable waters and beaches or other public recreational resources.

Transportation- Alabama’s transportation resources are not expected to be impacted, as shorebases in

Fourchon and Boothville, Louisiana will be utilized for the proposed operations. Also, boats will not travel through any sensitive coastal areas off of the coast of Alabama.

NATURAL RESOURCE PROTECTION POLICIES Biological Productivity - All uses and activities shall be planned, sited, designed, constructed,

operated and maintained to avoid to the maximum extent practicable adverse alteration of biologically valuable areas. All uses and activities shall be planned, sited, designed, constructed, operated and maintained to avoid to the maximum extent practicable reductions in long-term biological productivity of the coastal ecosystem. No impacts are expected to adversely affect the biological productivity of the area.

Water Quality - The proposed activities shall be carried out in conformance with applicable water

quality laws, standards, and regulations. All discharges shall be covered by an NPDES permit. There shall be no discharge of untreated produced water, drilling moods, or cuttings resulting from energy exploration and production activities to the coastal waters of Alabama. Produced waters that are discharged offshore are diluted and dispersed to very near background levels at a distance of 1,000 m and are undetectable at a distance of 3,000 m from the discharge point. The MMS regulations, the USEPA’s NPDES general permit, and the

USCG regulations implementing MARPOL 73/78 Annex V prohibit the disposal of any trash and debris into the marine environment.

Water Resources - All uses and activities shall be planned, sited, designed, constructed operated and

maintained to avoid to the maximum extent practicable detrimental discharges into coastal waters.

Air Quality - The proposed activities shall be carried out in conformance with applicable air quality

laws, standards, and regulations. Emissions from the proposed activities are not expected to have significant impacts on onshore air quality because of the prevailing atmospheric conditions, emission heights, emission rates, and the distance of these emissions from the coastline.

Wetlands and Submerged Grassbeds - All uses and activities shall be planned, sited, designed,

constructed operated and maintained to avoid to the maximum extent practicable reductions of natural circulation patterns within or into wetlands and submerged grassbeds. Pipeline and navigation canals are considered the most significant impacting factors to wetlands and neither is proposed in the EP. Proposed activities are not expected to have any adverse impact on seagrass communities.

Beach and Dune Protection - Effective environmental protection plans are in place, practiced, and

updated as necessary. No significant impacts to the physical shape and structure of barrier beaches and associated dunes are expected to occur. In the unlikely event of a spill contacting a barrier beach, sand removal during cleanup would be minimized.

Wildlife Habitat Protection - We have considered the general factors utilized by permitting authorities and have determined that the proposed activities shall cause no adverse impacts on wildlife habitat areas. All uses and activities shall be planned, sited, designed, constructed operated and maintained to avoid to the maximum extent practicable adverse alteration of wildlife habitats or coastal wildlife. Proposed activities are in OCS waters, so they are located away from critical wildlife and vegetation areas. Access routes from shorebase operations shall pose no adverse on these critical wildlife and vegetation areas. Endangered Species No impacts are expected to adversely affect wildlife and fishery habitat, especially the designated Critical Habitats of Endangered Species. Beach mice – Potential impacts include oil spills, oil-spill response activities, consumption of beach

trash and debris and coastal habitat degradation. No significant impacts to beach mice are expected to occur. Protective measures required under the Endangered Species Act should prevent any oil-spill response and cleanup activities from having significant impact to beach mice and their habitat.

Marine birds– Potential impact-producing factors for marine birds in the offshore environment include helicopter and service vessel traffic and noise, air emissions, degradation of water quality, habitat degradation, and ingestion discarded trash and debris from service vessels and OCS structures. Adverse impacts to endangered coastal and marine birds are expected to be sublethal.

Sea turtles – Potential impact-producing factors from the proposed activities that may affect sea turtles include water quality degradation from operational discharges, noise from helicopter and vessel traffic and operating platforms, vessel collisions, brightly lit platforms, and swallowing or getting tangled in OCS-related trash and debris. Routine activities are expected to be sublethal and unlikely to have significant adverse effects on the size and recovery of any sea turtle species or population in the Gulf of Mexico.

Sturgeon – Drilling mud discharges may contain chemicals toxic to sturgeon, at concentrations four or five

orders of magnitude higher than concentrations found a few meters from the discharge point. These discharges dilute to background levels within 1000m of the discharge point. No impacts from the proposed activities are expected.

Cultural Resources Protection - All uses and activities shall be planned, sited, designed, constructed operated

and maintained to avoid to the maximum extent practicable adverse alteration of cultural resources. No impacts are expected to adversely affect historical, architectural, or archaeological sites. Should any historical, architectural, or archaeological resource be discovered in the course of conducting authorized activities, the Alabama Department of Environmental Management and the Alabama State Historical Officer shall be notified.

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Supplemental Exploration Plan

OCS-G 19939, Mississippi Canyon Block 348 OCS-G 26252, Mississippi Canyon Block 391 OCS-G 26253, Mississippi Canyon Block 392

Offshore Alabama

19 Administrative Information

(19a) Exempted Information Description (Public Information Copies Only) The following attachments were excluded from the public information copies of this plan: 1b. OCS Plan Information form – Bottom hole locations & proposed total depth (2d) Oil Characteristics 3a. Geologic Description 3b. Structure Contour Maps 3c. Interpreted 2D or 3D seismic line(s) 3d. Cross Section(s) 3e. Shallow Hazards Report 3f. Shallow Hazards Assessment – confidential data 3g. High-Resolution Seismic Lines & Top Hole Progs 3h. & 3i. Stratigraphic Column with Time vs. depth table (19b) Bibliography A shallow hazard report prepared by Fugro Geoconsulting, Inc, for Mississippi Canyon 347, 348, 391, and 392 dated March 2009, Report No. 27.2208-5022. Fugro-McClelland Marine Geosciences Report for Mississippi Canyon 348 and Surrounding Area, September 1998, Report No. 0201-3614. Initial Exploration Plan for MC 391 & 392, N-09387, approved as of June 26, 2009.

RECORD of Plan Information Requests/Amendments Supplemental Exploration Plan S-07444

Mississippi Canyon Blocks 348, 391 & 392

12/21/2010 Shell submitted a Supplemental Exploration Plan for Wells B-J. 1/7/2011 Received an information request from BOEM. 1/12/2011 Shell provided the following changes in response to the 1/7/2011 information request:

! Changed OCS Number in cover letter ! Provided copy of pay.gov confirmation ! Plan Information Form - Corrected BHL for Location C (Page 5) ! Updated ESR/chemosynthetic maps to show 2000’ clearance circles

(Pages 77-80) ! ORSP - added specific wells associated with WCD numbers and statement

relating to certification submittal (Page 115) ! Removed Texas CZM Certification (Page 153-156) ! Sent Additional PI CD’s for Alabama CZM


! Updated Projected Generated Waste Table (Page 108) ! Updated Projected Ocean Discharges Table (Page 109) ! Updated Solid & Liquid Waste Transportation Table (Pages 148-

149)


! corrected the generated wastes (page 108), projected ocean discharges (page 109), solid and liquid waste (page 148-149) and waste disposal (page 151) changing all amounts to “per well”

! correcting the number for synthetic drilling mud in the waste disposal table (Page 151)

! added synthetic based cuttings to the waste disposal table (page 151)

shell ox exploration plan

Documents

subject plan

subject exploration

mississippi canyon block

public information ms

public information copies

approved plan n

surface operator of

freedom of information