task 7 system conceptual design & analysis report rpsea project 1502 coiled tubing ... ·...

RPSEA 08121-1502-01 - TASK 7 FINAL REPORT

TASK 7

SYSTEM CONCEPTUAL DESIGN & ANALYSIS

REPORT

RPSEA PROJECT 1502

Coiled Tubing Drilling & Intervention System

Using Cost Effective Vessels

DOCUMENT NUMBER: 1502-003

March 17, 2011

Charles R. Yemington, PE

Project Manager

Nautilus International LLC.

400 N. Sam Houston Pkwy. East, Suite 105

Houston, TX 77060


LEGAL NOTICE

This report was prepared by Nautilus International LLC. as an account of work sponsored by the Research

Partnership to Secure Energy for America, RPSEA. Neither RPSEA members of RPSEA, the National Energy

Technology Laboratory, the U.S. Department of Energy, nor any person acting on behalf of any of the

entities:

a. Makes any warranty or representation, express or implied with respect to accuracy,

completeness, or usefulness of the information contained in this document, or that the use of

any information, apparatus, method, or process disclosed in this document may not infringe

privately owned rights, or

b. Assumes any liability with respect to the use of, or for any and all damages resulting from the

use of, any information, apparatus, method, or process disclosed in this document.

This is a final report. The data, calculations, information, conclusions, and/or recommendations

reported herein are the property of the U.S. Department of Energy.

Reference to trade names or specific commercial products, commodities, or services in this report does

not represent or constitute and endorsement, recommendation, or favoring by RPSEA or its contractors

of the specific commercial product, commodity, or service.


ABSTRACT

This report describes the results of the HAZID undertaken by Nautilus International and their

associated contractors for the RPSEA Project 1502 on the Self Standing Riser (SSR) and associated

Coiled Tubing operations. The HAZID was undertaken on the 13th October 2010 at the offices of

Baker Hughes in Houston. The Risk Ranking of the Hazards took place on the 24th and 29th October

2010. Mr F J Deegan of Riskbytes Inc., an experienced subsea HAZID facilitator, facilitated the HAZID

and produced the report. The HAZID addressed a number of issues raised by members of the HAZID

team on the design and operation of the Self Standing Riser, its interface with both the DP vessel

and the proposed associated Coiled Tubing operations. The Self Standing Riser system presents

novel and challenging features which could possibly present hazards to the successful operation of

the system once it had been installed and commissioned, and it was one of the objectives of the

HAZID to identify these issues and identify the associated risks. The HAZID review process followed

a classical HAZID approach as outlined in the Ref 2 Loss Prevention in the Process Industries by F P

Lees. The overall HAZID review identified 43 HAZID recommendations to address hazards identified

by the HAZID team.

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RECORD OF REVISION

REV DATE DOCUMENT STATUS ORIGINATOR CHECKED ISSUED

C 2/27/2012 Issued for use (minor text edits) C. Yemington TH C Yemington 0 3/17/2011 Issued for use C. Yemington KM / TW C Yemington B 12/06/2010 Issued for Review and Comment C. Yemington KM / TW C Yemington A 09/03/2010 Issued for HAZID Review C. Yemington KM / TW C Yemington

Administrator

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3/13/2012

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Issued for use (remove Volume 1)

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D. Beach

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C.Yemington


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RPSEA PROJECT 1502 TASK 7 OPERATIONAL PLANNING REPORT

TABLE OF CONTENTS 1.0 EXECUTIVE SUMMARY ……………………………….……….………………………...3 GENERAL....................................................................................................................4

1.1 Scope..................................................................................................................4 1.2 Acronyms & Abbreviations ..................................................................................5

2.0 SSR MOBILIZATION PROCEDURES ........................................................................6 2.1 SSR Preparatory Work ........................................................................................6 2.2 Load Out & Sail Away for Installation ..................................................................8

3.0 SSR INSTALLATION PROCEDURES ......................................................................12 4.0 MOBILIZATION PROCEDURES FOR INTERVENTION .............................................17

4.1 Preparatory Work for Down-Hole Intervention ..................................................17 4.2 Intervention Vessel Load Out Procedure..........................................................18

5.0 ONSITE ACTIVITY FOR DOWN-HOLE WORK .........................................................20 6.0 CONTINGENCY & OPTIONAL SCENARIOS ............................................................24 7.0 SYSTEM LEVEL OFFSHORE MAINTENANCE ........................................................27

7.1 Maintenance of Riser & Riser Installation Equipment.......................................27 7.2 Maintenance of Operations Equipment............................................................28

8.0 RELIABILITY ANALYSIS ..........................................................................................29 8.1 System Level FMEA & Fault Logic Diagram ....................................................29

9.0 VALIDATION OF FUNCTIONAL CAPABILITY .........................................................35 10.0 ESTIMATED OPERATING COSTS...........................................................................37

10.1 SSR Installation Assumptions & Cost Estimate ..........................................38 10.2 Intervention Assumptions & Cost Estimate ..................................................39


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1.0 EXECUTIVE SUMMARY The procedures in this Operational Planning report provide an overview of steps for operations, maintenance, and contingencies. The procedures were used to validate planned equipment for deck handling, deployment, and down-hole work. Preliminary procedures were used as the basis for the Task 8 HAZID and were then updated for this report by incorporating HAZID recommendations. The results of the work were then used as the basis for cost estimates. The estimates show that the work has met the project objective of saving half the cost of using a MODU for the same work.

The seafloor shutoff device, the CT BOP, and the near surface shear and seal device provide well control during down-hole operations. Closed tree valves isolate the reservoir at all other times including during riser installation and retrieval.

The procedures and specifications include provisions for safely resolving known contingencies including hydrate formation, control system malfunctions, structural failures, equipment failures, and down-hole problems. The steps for both routine and emergency disconnection and vessel departure show the practicality of safely disconnecting within seconds in an emergency, or routinely disconnecting to run from weather or to move away from the tree before transferring personnel or equipment.

The equipment configuration allows using either a single large vessel for riser installation and down-hole work or two small vessels. A vessel optimized for construction work can install and recover the Self Supporting Riser (SSR) and a vessel optimized for work in the presence of hydrocarbons can then be used for the well intervention work. If the down-hole project is too extensive for a small vessel, a larger foreign flag vessel can work through a previously installed SSR. If two vessels are used, only one of them need be on hire at any one time. It is therefore not necessary for one type of equipment and personnel to standby while the other works. System maintainability has been structured so that either vessel can do maintenance on all underwater equipment. Advantages of using two smaller vessels include their lower day rate, and improved efficiency is when two vessels are optimized for the two very different kinds of work. The cost of complying with the Jones Act is reduced by a factor comparable to using a readily available US Flag supply boat to install the riser before the intervention vessel arrives. This avoids the cost of a separate supply boat and avoids the expense and safety hazards associated with transferring equipment between vessels at sea.

A single large vessel can be used to both install and work through the SSR when attractive for scheduling or economics, or to expand the weather window or allow additional work scope for the vessel. The Q4000 is an example of a suitable larger vessel, having both installed the Anadarko demonstration SSR and done down-hole work.

The equipment and procedures can be used for both Coiled Tubing and wire line work, and the service contractor can switch back and forth between the two. For instance, operations can quickly switch between Coiled Tubing for down-hole work and wire line to recover and replace the crown plugs of a horizontal tree.


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GENERAL

1.1 Scope This final report on Operational Planning presents an overview of plans, procedures, and costs for equipment staging, vessel load out, and offshore operations. The primary focus is on safe procedures for mobilization and offshore operations. Onshore and offshore maintenance are addressed in Section 8. Sections 9 and 10 address reliability analysis and validation of functional capability.

The procedures in this report have been updated after drafts were used as the basis for the Task 8 HAZID. Procedures for mobilization and operations are based on the system described in the Task 5 Design Basis Document and more fully defined in the Task 6 report. The SSR is recovered by reversing the installation procedures, so separate p recovery are not presented.

The procedures and conclusions in this report are widely applicable, and are not significantly influenced by differences in water depth, current profile, type of vessel used, or the nature of the down-hole work.

SSR mobilization and installation procedures incorporate lessons learned from installation of the demonstration SSR for Anadarko. Equipment design and installation methods have been optimized by iterative definition. Existing field proven tools are used to the greatest extent practical. Examples include drill pipe for the riser and conventional tongs and slips for running the riser. These items are arranged in a novel way to facilitate use on a vessel that is relatively small and therefore subject to greater motions. The installation equipment is being defined more fully as part of the Task 9 work.

SSR mobilization and installation procedures are followed by corresponding procedures for down-hole intervention. Intervention procedures focus on aspects of CT operations that are different from conventional work from a production platform. The primary difference is in use of a riser extension and a Motion Isolation System that allows work from a small vessel. Aspects of down-hole operations that relate only to conventional CT equipment and tools or are unique to the specific well or planned down-hole tasks are beyond the present scope.

Operations procedures are necessarily at a high level because details depend on the specific down-hole tasks to be done, the vessel selected for the work, and preferences of the client and the CT service contractor. Equipment arrangements shown are representative, and other options and alternatives that may be appropriate for a particular well or vessel.

The procedures allow different vessels to be used for riser installation and down-hole operations. Since only one vessel is needed at any one time, this allows use of smaller, lower cost vessels for a substantial reduction in day rate. Larger, more capable multipurpose vessels can be used without significant change to the procedures.


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The reliability analysis originally planned for Task 8, was included in Task 7 as preparation for the formal HAZID review and is therefore included in this report.

Cost estimates for offshore operations are in Section 11.

1.2 Acronyms & Abbreviations BOP Blow Out Preventer CT Coiled Tubing CTES Coiled Tubing Engineering Services, Division of NOV DP Dynamic Positioning FMEA Failure Modes & Effects Analysis HPU Hydraulic Power Unit HSE Health, Safety, Environment MODU Mobile Offshore Drilling Unit MSDS Material Safety Data Sheet NDT Non Destructive Test OD Outside Diameter PPE Personal Protective Equipment psi Pounds per square inch psia Pounds per square inch absolute RADS Riser Assembly & Deployment System ROV Remotely Operated Vehicle SSR Self Supporting Riser SSD Seafloor Shutoff Device TBD To Be Determined USCG U.S. Coast Guard


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2.0 SSR MOBILIZATION PROCEDURES This section focuses on work to be done before sail away. Vessel specific procedures can be prepared only after the vessel is contracted so procedures in this document are necessarily at a high level. Work following contracting begins on two paths, one for installation and recovery of the riser and the other for down-hole operations.

2.1 SSR Preparatory Work Planning for mobilization, preparation of the SSR hardware, and staging at dockside are addressed in this section. Categories of preparatory work are primarily:

• Permits, procedures, certifications, safety plan, QC plan for installation, & engineering documentation

• Preparation of SSR components • Equipment Spares and Consumables for SSR Installation • Vessel with supplies, provisions, and consumables • Dock and dockside support services for vessel load-out • Personnel

Permits & Documentation The riser contractor and down-hole service contractor will support the operator in obtaining permits to install the riser on the tree.

Procedures, Offshore Maintenance Plan, and a Safety Plan for riser installation are prepared by the SSR installation contractor for approval by the client. Procedures are to include details for preparation, testing, and use of the Seafloor Shutoff Device (SSD) and active deck equipment. Procedures are to detail deck handling of components, operation of the Riser Assembly and Deployment System (RADS), and contingency operations in the event of closing weather window, equipment failure, or other interruption.

Certifications for riser components and handling aids are to be provided by the equipment suppliers. The riser contractor provides engineering and QC documents including drawings, torque specifications, component traceability by serial number, and modeling results for riser performance in the anticipated current profile.

The installation contractor, in cooperation with the vessel owner, is to obtain approval from the vessel classification agency for his deck fastening and load test plan.

Each contractor is to have an approved safety program. In addition, a safety plan specific to mobilization and offshore operations for the particular task is to be submitted for review and comment. All relevant Material Safety Data Sheets shall be provided with the safety plan.

The QC plan for installation shall include requirements for inspection, record keeping including pass/fail-testing criteria, and verification of as-left conditions including valve positions and connection interfaces. Qualification and training requirements for offshore personnel are to be included in the plan.


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A detailed mobilization plan is required and must include a deck layout drawing with sufficient detail to show routing of electrical cables, lines for hydraulics and other fluids, and protective covers where these lines cross walkways or equipment thoroughfares. The mobilization plan is to include equipment lists and checklists for items to be loaded onto the vessel and for all necessary dockside activities.

Each hardware item is to be permanently marked with a part number and serial number to be used in the installation tally and also used for cross reference to records from manufacturing, testing, inspection, and prior use. All active items are to be function tested before mobilization and all interfaces are to be subjected to fit check as part of System Integration Test.

All riser components required for the specific job are to be staged at the dock. Each item is to be protected at all times from the environment, temperature extremes, tampering, and loss or damage. All items are to be staged with handling aids suitable for lifting and offshore use. Slings with current certification records are to be provided for each item.

Special equipment is required to enable a work boat or light construction vessel to run riser joints, buoyancy modules, and other elements of the riser. The Riser Assembly and Deployment System (RADS) is an assembly of these tools designed for ease of mobilization. It includes tongs, slips, moon pool guides, and associated equipment to restrain joints and heavy equipment as they are moved on deck. Hydraulic Power Units; vans for controls, spares and tools; and compressors and/or liquid nitrogen are also required.

Spares and tools per the Offshore Maintenance Plan must be staged and shown to be ready.

Consumables such as pipe dope, coating repair kits, and hydraulic fluid may require special handling and storage if flammable, toxic, or detrimental to the environment.

The vessel should be US flag to comply with Jones Act requirements for transporting the riser without an intermediate stop in a foreign country.

Vessel survey must confirm adequacy and appropriateness of vessel condition, onboard equipment and safety features, and compliance with requirements of the classification agency, the USCG, and the client. Certification of cranes and lifting devices must be verified, including recent load tests, condition of safety brakes and stops, and suitability for the particular requirements of SSR installation and recovery.

Training and license status for key vessel personnel must be verified.

The DP system should be surveyed for function and condition of thrusters, engines, generators, and controls. The deck structure, particularly around the moon pool, should be surveyed to verify load capability. Vessel survey also includes suitability of accommodations, communications, and navigation equipment. The ROV system requires verification of load test of launch and recovery system, ROV condition including spares, availability and condition of tools.


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Dock facilities must be mutually agreeable to the key stake holders. Considerations include location, water depth, safety record, security, dock conditions, and availability of dockside services. Required services include provisions for staging equipment and lifting equipment from trucks and onto the vessel, supply of fuel and potable water, and basic yard functions such as welding and nondestructive testing. Storage is required for any vessel item that can not remain onboard during riser installation.

A suitable shore crane with appropriate certification is needed for unloading trucks and lifting equipment to the vessel. Welding services and non-destructive test services are required for sea fastening of equipment.

All personnel required for vessel mobilization and offshore operations must be contracted and made available at the dock along with their tools and supplies. This includes welders, nondestructive testing technicians, and offshore personnel including manufacturer’s representatives for the tree and the active SSR components.

Personnel must be verified to have suitable safety training, Transportation Worker’s Industry Credential (TWIC) cards, and any special certifications required by the vessel or the operator. Section 11 includes a tabulation of personnel used for cost estimating purposes.

2.2 Load Out & Sail Away for Installation The vessel has the highest day rate of the items required so all other items should be staged and standing by when the vessel arrives at the dock.

A typical deck arrangement for load out is shown in Figure 3.1.

Riser Joints Crane Assembly & Deployment System

Gas Umbilical ROV System Buoys SSD ROV Vans

Riser Vans FIGURE 3.1 TYPICAL DECK ARRANGEMENTS FOR 260 FT INSTALLATION VESSEL

A preliminary listing of equipment with weight and dimensions is shown in Table 3.1. Weights and outline dimensions are shown for the larger items.


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TABLE 3.1 PRELIMINARY EQUIPMENT LIST FOR VESSEL LOAD-OUT EQUIPMENT ITEM ON

CONSTRUCTION VESSEL OUTLINE

DIMENSIONS ON DECK

WEIGHT

Riser joints 6 5/8 “drill pipe 2’w x 4’h x 32’ long rack per 1000’ depth

33,000# per 1,000’ depth

Buoyancy modules 16’ h x 14’ OD 21,000# each RADS 30’ h X 28’ X 28’ TBD SSD & tree interface TBD HPU for SSD & tree 8’h x 8’w x 20’ 20,000# Stress joint/isolation valve/connector assembly

40’h x 5’w x 5’ L TBD

HPU for CT BOP 8’h x 8’w x 20’ 20,000# Control umbilical for SSD & tree with connectors & installation equipment (if used)

25’h x 25’L x 8’ reel 100,000# for 10,000’

Umbilical reel for air hose for buoys

TBD

Test line & pump for SSR pressure test

TBD

Vans for controls & spares 8’h x 8’ x 20’ TBD Gas supply for buoys 8’ x 12’ Consumables including pipe dope, cleaning fluids, coating repair kit, & hydraulic fluid

6’h x 8’ x 8’ 3000#

Specialty PPE DP beacon ROV tools for function & override of SSD & connectors

Clips for sea fastening QC inspection aids Riser extension joints

Vessel load-out is to be supervised by the installation contractor with oversight by the Client Representative. Representatives of equipment suppliers are to participate to ensure that their equipment is handled properly and left in fully operable condition.

The Riser Assembly & Deployment System is illustrated schematically in Figure 3.2. It is the heaviest single lift for mobilizing the SSR installation vessel. This unit, together with a deck crane, provides the tools and equipment needed to assemble the SSR.


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FIGURE 3.2 SCHEMATIC OF RISER ASSEMBLY AND DEPLOYMENT SYSTEM

Table 3.2 is a high level procedure for mobilization, beginning with all equipment staged at the dock and ending with the vessel loaded and provisioned. A typical deck arrangement is shown in Figure 3.1 above.

TABLE 3.2 SSR INSTALLATION VESSEL LOAD-OUT PROCEDURE

STEP VESSEL LOAD-OUT ACTIVITY 1. Inspect vessel for acceptance. This may include DP trials, vessel general

condition, safety gear, and other items per requirements of USCG, the client, and insurance carriers. Review adequacy of communications systems, fuel, lubricants and provisions. Plan to take on supplies as needed.

2. Board crew for equipment load-out. Hold kickoff meeting and safety briefing for personnel involved in load-out. Verify that all appropriate Material Safety Data Sheets are readily available onboard.

3. If necessary, offload any vessel equipment that is not needed for SSR installation to free up deck space or provide access or improve safety.

4. Lift Riser Assembly & Deployment System (RADS) and set it over the moon pool. Remove and stow the lifting slings.

5. Obtain hot work permit and begin welding sea fastening clips, starting with the RADS frame and continuing as additional equipment is loaded.

6. Use deck crane to temporarily install moon pool guide rails and fit check rails to walls of moon pool. Caution: Vessel should not maneuver in shallow water while guide rails are installed. Guide rails are to be removed and stowed prior to vessel transit.

7. Lift HPU, control van, and spares van from dock and sea fasten. 8. Lift and set consumables pallets on deck and sea fasten. 9. Connect hoses and cables for Riser Assembly & Deployment System (RADS).

Install safety covers over lines, inspect whip checks. 10. Fill and bleed hydraulic lines and fill HPU fuel tank. 11. Function test active features of umbilical reel drive and RADS including moon

pool cover, tongs, etc. while proceeding with other mobilization tasks.


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STEP VESSEL LOAD-OUT ACTIVITY 12. Lift and sea fasten Seafloor Shutoff Device (SSD) & tree interface assembly.

NOTE: This assembly can be set on the moon pool cover to avoid deck handling while the vessel is offshore.

13. Lift and set umbilical reel(s). 14. Connect umbilical to HPU and control consoles. Test controls functions for

Seafloor Shutoff Device (SSD) via consoles and umbilical. 15. Lift and sea fasten riser joint racks with joints. 16. Lift and sea fasten seafloor stress joint/connector assembly. 17. Lift and sea fasten other specialty joints that can not be stowed in the rack with

the standard joints. 18. Lift and sea fasten buoyancy modules. 19. Lift gas supply equipment & sea fasten. 20. Connect & test gas supply system. 21. Lift and sea fasten other equipment on the manifest. 22. Finish third party verifications, including NDT of sea fastening welds, any load

tests, etc. 23. Verify suitable window for weather and sea state. 24. Board any offshore personnel not yet onboard. 25. Verify that all mobilization checklists have been completed and vessel has

been fueled and provisioned. 26. Dismiss and demobilize all personnel who are not required offshore. 27. Cast off and motor to site.


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3.0 SSR INSTALLATION PROCEDURES Table 4.1 is a high level overview of procedural steps to be done offshore prior to start of installation work.

TABLE 4.1 ON-SITE PREPARATORY OPERATIONS

STEP VESSEL ACTIVITY 1. Notify host platform of arrival. 2. Perform DP checks. 3. Dive ROV for ‘as found’ inspection of tree and associated infrastructure and for

measurement of current in water column. Set acoustic beacon for DP. 4. Plan riser assembly location with respect to tree location. 5. Hold kickoff meeting & safety briefing for installation crew. 6. Verify that weather window and current forecast are suitable for SSR

installation. 7. Perform pre-installation checklists for equipment, including activation and

function test of hydraulic power units, Riser Assembly & Deployment System (RADS), control consoles, umbilical reel drive, and gas supply system. Install guide rails in moon pool.

8. Take up station, preferably 20% of water depth from seafloor infrastructure to mitigate dropped object hazard to tree, flowline, etc.

Figure 4.1 shows the general arrangement of components in the SSR.

Buoyancy

Riser Casing Extension

Seafloor Shutoff Device

Tree

FIGURE 4.1 EQUIPMENT LOCATIONS IN TYPICAL SSR ASSEMBLY Table 4.2 is a high level overview of procedural steps for assembling the SSR and making it ready to relocate to the tree or a temporary anchor. The installation steps in can be reversed at any time during assembly to recover the components of a partially assembled riser in the event of closing weather window or other problems that might interrupt the installation.


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TABLE 4.2 ASSEMBLE SSR FROM 6 5/8” DRILL STRING OR CASING

STEP SSR ASSEMBLY ACTIVITY 1. Release sea fastenings and the transfer the tree interface/Seafloor Shutoff

Device (SSD) assembly to the Riser Assembly & Deployment System (RADS). NOTE: This is the heaviest assembly, and it can be set in the RADS at the dock to reduce the requirements for offshore handling of equipment.

2. If the stress joint is not already attached to the Seafloor Shutoff Device (SSD), lift stress joint/connector assembly and engage the connector to the top of the SSD.

3. If umbilical is to be installed with the SSR, feed tree control umbilical through umbilical guide on RADS & connect to Seafloor Shutoff Device.

4. Function test Seafloor Shutoff Device through umbilical. 5. Verify that SSD valves are left in correct position. Valves are normally left open

to allow riser to flood as it is assembled and lowered. 6. Inspect and test to verify readiness of controls connector for ROV installation of

umbilical jumper to tree. 7. Use HPU and control panel to charge SSD accumulator to at least seafloor

ambient seawater pressure to avoid negative pressure on accumulators. 8. Use winch wires or crane to lift SSD clear of the moon pool cover and open

moon pool cover. 9. Lower SSD into moon pool while paying out umbilical. 10. Close moon pool cover around upper part of stress joint and hang stress joint

below moon pool cover. 11. Upend next joint, secure to Riser Assembly & Deployment System (RADS)

cross bar, & land joint in box of stress joint assembly. 12. Close tongs and thread joint to stress joint assembly. 13. Inspector is to record data on connection and tally the serial number of the

joint. 14. Open tongs and slips and use crane to lower assembly while paying out

umbilical. 15. Hang assembly in slips. 16. Use ROV to release winch wires (if used) and recover wires 17. Repeat above joint installation steps to install subsequent drill string joints.

ROV with banding device may be used to secure umbilical to joints as they are lowered.

18. Continue per engineering documentation until the required number of joints has been installed below the lowest buoyancy module.

19. Transfer a buoyancy module to the RADS, using equipment to prevent module motions with respect to the vessel. Use supports on the moon pool cover to align buoy’s guide sleeves with the moon pool guide rails.

20. Remove handling equipment and attach winch wires to buoyancy module. 21. If the joint that goes through the buoy was not previously installed, lift it and

secure it in the joint guide on the cross bar of the RADS, and lower buoy joint into the central sleeve of the buoy and land its pin in box of previous joint.

22. Close tongs and make up threads between buoy joint and previous joint. 23. Open tongs and disconnect crane line. 24. Inspect buoy and update tally with serial numbers of buoy and buoy joint. 25. Lift assembly with winches and release slips.


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STEP SSR ASSEMBLY ACTIVITY 26. Open the moon pool cover. Verify guide sleeves on buoy are engaged to guide

rails in the moon pool. 27. Lower assembly on winch wires while paying out umbilical. 28. Close moon pool cover and hang assembly in slips. 29. Repeat steps above for any drill string joints between buoyancy stations. Use

acoustic telemetry or ROV to monitor buoy and buoyancy. Monitor buoyancy instruments as module is lowered and use ROV deployed hose to de-ballast buoyancy. Caution: Proper de-ballasting is required while lowering. The submerged weight of the riser will increasing as the gas in the buoys is compressed due to lowering. De-ballast as appropriate to keep the assembly heavy in water while preventing suspended load from exceeding the rating of the lowering system.

30. Repeat above buoyancy module installation steps for station 2 buoys. 31. As components are assembled and lowered, continue to pay out umbilical for

SSD/tree and continue to de-ballast buoys while monitoring the instruments. 32. Install uppermost buoy(s) per buoy installation steps above. 33. Secure tree control umbilical to top buoy. 34. Use winch wires to lower assembly until submerged below wave zone and hold

with lower end of SSR above seafloor infrastructure. ROV to observe lower end of SSR to ensure adequate elevation above potential interference.

The final step of riser assembly is illustrated in Figure 4.2.

FIGURE 4.2 ASSEMBLING UPPERMOST BUOY TO THE SSR Table 4.3 lists procedural steps for maneuvering the assembled SSR from the assembly location to the tree, connecting the SSR to the tree, and completing required testing. The SSR can be relocated from the tree by reversing these steps.


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If the tree is not ready for the riser, or if the operator prefers, the SSR installation vessel can connect the SSR to a temporary anchor. The intervention services vessel can then follow these steps to relocate the SSR to the tree. The intervention vessel can also use these steps to relocate the SSR from one tree to another or relocate the SSR to a temporary anchor when down-hole work is completed.

TABLE 4.3 RELOCATING & TESTING ASSEMBLED SSR

STEP SSR RELOCATION AND TEST ACTIVITY 1. Review current profile and plan DP move to tree location. 2. Notify host platform of readiness to land and engage the riser. 3. Verify that tree has been shut in and made ready for removal of the tree cap

and connection of the SSR. 4. Request and receive Lock-Out-Tag-Out certificate from host platform showing

that tree has been made safe for entry and that swab valve is closed. 5. Use ROV to remove tree cap & inspect interface for the SSR. 6. Check instruments to verify that hook load on winch wire(s) is appropriate for

relocating and landing SSR. Trim buoyancy if necessary. 7. With SSR held at a safe elevation above the seafloor by winch wire(s) or heave

compensated crane wire, begin DP move along safe route to tree. 8. Use ROV to guide connector on bottom of the SSD onto tree hub and close

and latch connector. 9. While SSR buoyancy is ballasted to make riser heavy in water, test connection

to tree by pulling with lift wire(s) to tension SSR to standalone tension. 10. De-ballast SSR to standalone tension while slacking tension in lift wire(s). 11. Disconnect lift wire(s). 12. Pay out umbilicals while moving vessel to standoff location for final testing of

SSR. 13. Increase SSR tension for ultimate load test by de-ballasting buoyancy until

SSR tension is typically 1.25 to 1.5 times maximum operational tension. . 14. Hold at load test tension for required time and then ballast to operational

tension in SSR. 15. Use ROV to connect pressure test line to connector cap atop SSR. 16. Fill SSR with fluid (if not already filled) and then pressurize SSR for internal

pressure test. Hold till pressure is shown to stabilize. Perform ROV video inspection of SSR during pressure test. NOTE: If test is being done with SSR connected to tree, coordinate with host platform and verify that Seafloor Shutoff Device (SSD) is open so that pressure test will be done against swab valve, thus also testing the connection between the SSR and the tree.

17. Depressurize SSR and trim buoyancy to survival condition. Use ROV to measure water depth to connector hub on top of riser.

18. Close Seafloor Shutoff Device valves to isolate SSR from tree. Charge SSD accumulators to 3000 psi above ambient pressure (3015 psia plus ambient seawater pressure).

19. Use ROV to disconnect pressure test line from SSR and recover the line. 20. Use ROV for ‘as left’ inspection of tree and riser. 21. Terminate umbilical with protective sealing caps, attach buoys, and secure and

abandon upper ends of umbilicals.


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STEP SSR RELOCATION AND TEST ACTIVITY 22. Proceed to assemble and wet park riser extension per procedure below, or

recover acoustic DP beacon and notify host platform of readiness for departure and prepare deck for vessel transit.

The structural, casing segment of the riser extension can be assembled by the SSR installation vessel and wet parked by hanging it from a buoyancy module of the SSR, per the steps in Table 4.4.

TABLE 4.4 STEPS TO ASSEMBLE & WET PARK STRUCTURAL RISER EXTENSION STEP RISER CASING EXTENSION ASSEMBLY & WET PARK ACTIVITY 1. With SSR secured to tree or anchor, take up station 20% of water depth away

from SSR and seafloor infrastructure to reduce dropped object hazard. 2. Lift the lowest joint of the structural casing segment of the riser extension

(including connector) and set it in Riser Assembly & Deployment System (RADS) with upper part secured in joint restraint of cross bar.

3. Test the ROV operable connector and prepare connector for deployment. 4. Lift the joint with crane, open moon pool cover, lower connector and joint into

moon pool, close moon pool cover, and hang joint in slips. 5. Lift next joint of riser extension, secure it in joint restraint of RADS crossbar,

and use tongs to thread it to the previous joint. 6. Repeat above step for additional joints as required by documentation. 7. Lift riser extension joint that has syntactic foam and set it in RADS for

assembly, thread with tongs, open moon pool cover, lower assembly, close moon pool cover, and hang assembly in slips.

8. Lift upper most joint of riser extension to RADS and use tongs to thread it to the assembly. Total length of extension is to suit as-installed depth of the SSR.

9. Secure top of riser extension to line from constant tension winch, and lower to hang-off depth.

10. Maneuver vessel on DP to position the riser extension near the SSR. 11. Maneuver vessel and use ROV assistance to guide the extension to the

attachment location on the buoy. 12. Use ROV to secure the top of the riser extension to the buoy and secure the

bottom of the riser extension to the casing. 13. Use ROV to release lowering line from the riser extension and recover wire. 14. Use ROV to inspect the riser extension and upper part of SSR. 15. Notify host platform of readiness for departure, recover DP beacon, and

prepare deck for vessel transit.


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4.0 MOBILIZATION PROCEDURES FOR INTERVENTION The mobilization procedures for installation and intervention can be worked in parallel if a single vessel is used. If separate vessels are used for SSR installation and intervention, the equipment addressed in this section does not need to be mobilized until after the SSR has been installed.

4.1 Preparatory Work for Down-Hole Intervention The down-hole service contractor will coordinate preparations specific to reentry and work over, including engineering, detailed procedures for down-hole work, vessel selection. Depending on the planned work, the vessel may require provisions for hydrocarbons on deck. Primary categories of preparation are:

• Permits, procedures, certifications, safety and QC plans, & engineering documentation

• Preparation of equipment that interfaces to the SSR • Preparation of CT equipment and consumables • Vessel with supplies, provisions, and fuel • Dock facility and dockside support • Personnel

Requirements that are the same as discussed in Section 3.1above have been omitted from the following discussion.

The riser contractor will support the operator and down-hole service contractor in obtaining permits and assist in preparing procedures that involve interface to the SSR. Contingency operations for use in the event of a closing weather window or other interruption are to be detailed.

SSR interface equipment consists primarily of the Motion Isolation System and the emergency disconnect segment of the riser extension.

The emergency disconnect segment includes the Near Surface Shear and Seal device, the emergency disconnect connector, and a retention valve for the riser extension. This segment is preferably assembled and tested onshore. It is installed by the intervention vessel so that it can be recovered for maintenance during down-hole operations.

The baseline plan is for the structural casing extension to be wet parked by the SSR installation vessel as part of the riser installation. Alternately, it can be assembled by the CT vessel.

The injector, CT reel, pumping equipment, and other items of CT equipment are mobilized to the intervention vessel. The choke and kill lines, if used, are preferably reeled. Other CT equipment can be used in the same configuration as for working from a production platform and routine preparations are appropriate. The need for cement or other consumables such as drilling fluids depends on the specific tasks to be done. The intervention vessel is expected to have bulk storage tanks suitable for the necessary consumables.


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Personnel required for installation of the Motion Isolation System on the vessel consist primarily of hydraulic and electrical technicians and an engineer. Third party services are required for welding and non-destructive test of sea fastenings. In addition to personnel required by the client, a crew of 5 is assumed for 24 hour operation of the down-hole intervention equipment. Section 11 includes a tabulation of personnel used for cost estimating purposes.

FIGURE 5.1 TYPICAL DECK ARRANGEMENTS FOR CT VESSEL 4.2 Intervention Vessel Load Out Procedure The CT reel is the heaviest lift. The motion isolation system is lighter, but requires more man hours for installation. Table 5.1 lists steps for mobilization:

TABLE 5.1 INTERVENTION VESSEL LOAD OUT PROCEDURE

STEP VESSEL LOAD-OUT ACTIVITY 1. Inspect vessel for acceptance. Include DP trials, vessel general condition,

safety gear, and other items per requirements of USCG, the client, and insurance carriers. Review adequacy of communications systems, fuel, lubricants and provisions. Plan to take on supplies as needed.

2. Board crew for equipment load-out. Hold kickoff meeting and safety briefing for personnel involved in load-out. Verify all appropriate MSDS are readily available onboard.

3. Use dock crane to lift Motion Isolation System (MIS) and set it over moon pool. Remove and stow the lifting slings.

4. Obtain hot work permit and begin welding sea fastenings, starting with the MIS frame and continuing as additional equipment is loaded.

5. Lift & sea fasten Motion Isolation System HPU and van for controls and spares 6. Connect MIS power and control lines. Install safety covers where lines cross

walkways and inspect whip checks. 7. Fill and bleed hydraulic lines, fill HPU fuel tank, and function test the MIS. 8. Lift jumper reels & sea fasten. 9. Connect reel power & controls. Test reel drives. 10. Lift gas supply equipment & sea fasten. 11. Connect & test gas supply system.


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STEP VESSEL LOAD-OUT ACTIVITY 12. Lift and sea fasten CT reel drive and reel. 13. Lift and sea fasten HPU for CT equipment. 14. Lift and sea fasten injector. 15. Lift and sea fasten preassembled emergency disconnect segment of the riser

extension. This segment includes the Near Surface Shear & Seal, the emergency disconnect connector, the blind shear retention valve, and end connectors.

16. Finish third party verifications, including NDT of sea fastening welds, any load tests, etc.

17. Lift and sea fasten packer stripper and diverter. 18. Take on consumables and vessel supplies. 19. Verify suitable window for weather and sea state. 20. Board any offshore personnel not yet onboard. 21. Verify that all mobilization checklists have been completed and vessel has

been fueled and provisioned. 22. Dismiss all personnel who are not required offshore. 23. Cast off and motor to site.


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5.0 ONSITE ACTIVITY FOR DOWN-HOLE WORK This section covers offshore work for down-hole operations and is limited to those aspects that differ from CT work from a platform. Differences consist primarily of interfaces between the riser, the vessel, and deck equipment. Aspects of down-hole operations that relate only to conventional CT equipment and tools or are unique to specific down-hole tasks are beyond the present scope.

It is assumed that a riser extension will be used and that, as shown in Figure 6.1, the structural casing extension has been hung off from the SSR buoyancy as part of riser installation. Alternately, the intervention vessel could assemble the extension. Some CT equipment configurations do not require a riser extension.

Figure 6.1 is representative of the well site configuration when the intervention vessel arrives.

Buoyancy

Riser Casing Extension

Seafloor Shutoff Device

Tree

FIGURE 6.1 SSR AS FOUND BY INTERVENTION VESSEL Table 6.1 lists the steps for entering the field and preparing for work by installing the active component segment of the riser extension and installing or connecting the control umbilical. Appropriate tests are conducted and then, if necessary, vessel trims SSR buoyancy to suit the intervention plan.

TABLE 6.1 ON-SITE PREPARATORY OPERATIONS

STEP VESSEL ACTIVITY PRIOR TO DOWN-HOLE OPERATIONS 1. Notify host platform of arrival and arrange for transfer of control of the tree and

well. 2. Hold kickoff meeting & safety briefing for crew. 3. Perform DP checks. 4. Dive ROV to check current profile and set acoustic beacon for DP. 5. Use ROV for ‘as found’ inspection of SSR, tree and local infrastructure.

Observe and record status of all indicators on Seafloor Shutoff Device (SSD), tree, and CT BOP.


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STEP VESSEL ACTIVITY PRIOR TO DOWN-HOLE OPERATIONS 6. Verify that weather window and current are suitable for planned tasks. 7. Work off checklists for deck equipment, including activation and function test of

hydraulic power units, Motion Isolation System (MIS), control consoles, gas supply, and other deck equipment.

8. Install or connect umbilical for control of tree and SSD. NOTE: Umbilical may have been preinstalled by the SSR installation vessel, in which case the upper end is to be connected to the vessel as part of system activation.

9. Connect umbilical and conduct deck tests for the emergency disconnect segment of the riser extension.

10. Lift the emergency disconnect segment of the riser extension and deploy it through the wave zone.

11. Maneuver vessel on DP2 to take up station over the SSR. 12. Lower the emergency disconnect segment while paying out umbilical and use

ROV to guide it to the hub atop the SSR. 13. Use ROV to engage the connector between the SSR hub and the emergency

disconnect segment. 14. Close the Near Surface Shear & Seal and pressure test SSR to verify integrity

of the connection to the SSR. 15. Lower constant tension line or heave compensated line and use ROV to secure

it to the structural casing segment of the riser extension. NOTE: It is assumed that the structural casing segment was hung from an SSR buoyancy module as part of SSR installation.

16. Use ROV to unlatch the structural casing segment of the riser extension from SSR.

17. Lift upper end of the structural casing segment of the riser extension through the moon pool and hang it from the Motion Isolation System (MIS). Connect packer stripper and diverter to the top of the structural casing segment. NOTE: If SSR has been relocated the water depth may be different. If so, hang riser extension in Motion Isolation System (MIS) and use deck crane to add or remove pup joints as required.

18. Use lift line to lower structural casing segment and use ROV to guide it to the hub atop the emergency disconnect segment which was installed previously.

19. Land the structural casing segment of the riser extension on the hub and use ROV to latch connector.

20. Bring SSR to vertical by maneuvering vessel to coordinates of tree while maintaining specified tension in the winch line.

21. Adjust Motion Isolation System (MIS) to mid-stroke and secure riser extension to the MIS.

22. Transfer the tension to the MIS and disconnect the lift line. 23. Increase hydraulic pressure to load test the riser extension and connector.

(SSR was previously load tested to higher tension.) Then adjust tension to nominal for operations.

24. Use ROV and umbilical reel drive to install tree/SSD control umbilical if it was not installed by SSR installation vessel.

25. Use ROV and gas line to trim buoyancy of SSR to operational tension in SSR.


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Figure 6.2 shows the system with the riser extension and umbilicals connected and with the injector on the Motion Isolation System.

FIGURE 6.2 SYSTEM READY FOR CT OPERATIONS Table 6.2 includes steps to engage the CT deck equipment to the riser and make ready for entry through the tree. Details of the procedure will depend on the specific tasks required by the project. Vessel motions relative to the SSR are the primary difference from onshore CT operations.

TABLE 6.2 DOWN-HOLE INTERVENTION OPERATIONS

STEP DOWN-HOLE OPERATIONS 1. Connect the CT contractor’s well control equipment, including the CT BOP and

the stripper packer, to the top of the riser extension. Connect hydraulic hoses and test the well control equipment.

2. Position the injector and connect it to the stripper packer. Connect hydraulic lines and function test the injector.

3. Hang tools and feed tubing into the injector. 4. Open CT BOP and the Near Surface Shear and Seal device and run coiled

tubing through stripper packer and down to the Seafloor Shutoff Device (SSD). 5. Circulate appropriate fluids to flush water from SSR as necessary. 6. Establish pressure balance to prevent hydrate formation. 7. Coordinate with host for handover of tree control. 8. Use ROV to connect control umbilical jumper from the SSD to the tree.


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STEP DOWN-HOLE OPERATIONS 9. Conduct appropriate tests and proceed to enter tree and run tubing for down-

hole work. Note: Wire line through the SSR may be used to retrieve crown plugs from horizontal trees. Plugs for production tubing sizes up to and including 4 inches may be pulled through 6 5/8 inch drill pipe SSR. All other components of the baseline riser are suitable for pulling crown plugs for 5 inch production tubing, but casing larger than the 6 5/8” drill pipe must be used if it is necessary to pull crown from a tree with production tubing5 inches or larger.

10. Continue down-hole work to completion. For interruptions and contingencies, see Contingency & Optional Scenarios procedures below.

11. When down-hole operations are complete, pull tubing to just above SSD, close swab valve in tree, and close SSD to isolate SSR from tree. NOTE: For horizontal trees, replace crown plugs before closing SSD and flushing riser.

12. Use ROV to recover umbilical jumper which was installed previously between SSD and tree.

13. Return control of the tree to host for well startup and flow tests. 14. Circulate fluids from riser as appropriate. 15. Recover tubing to the CT reel and close the Near Surface Shear and Seal. 16. Relocate the injector, disconnect the riser extension from the motion isolation

system, and wet park structural casing segment of riser extension by reversing the installation steps.

17. Use ROV and lift line to recover the emergency disconnect segment of the riser extension from atop the SSR and replace cap on the top hub of the SSR.

18. Use ROV for as-left inspection of SSR and tree. 19. Notify host platform of readiness to depart, recover DP beacon, and prepare

deck for vessel transit.


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6.0 CONTINGENCY & OPTIONAL SCENARIOS Routine disconnection is accomplished by pulling the tubing from the SSR, closing the tree and/or Seafloor Shutoff Device, closing the near surface shear and seal and the retention valve above the disconnect, di parking the riser extension, and disconnecting the tree/SSD control umbilical. The vessel is then free to motor to run from weather. It is not necessary to wet park the riser extension prior to maneuvering on DP for tasks such as transferring equipment or personnel at a safe distance from the seafloor infrastructure.

TABLE 7.1 ROUTINE DISCONNECTION OF INTERVENTION VESSEL

STEP STEPS FOR ROUTINE DISCONNECTION OF INTERVENTION VESSEL 1. Pull tubing from well. 2. Notify host platform of intent to disconnect from riser. 3. Close Seafloor Shutoff Device or tree valves. 4. Pull tubing from riser. 5. Close the Near Surface Shear and Seal device. 6. Disconnect tree/SSD umbilical at the surface. Cap the umbilical, attach

buoyancy, and abandon umbilical. 7. Close the retention device at the lower end of the riser extension and

disconnect riser extension from the SSR. NOTE: At this point the vessel is free to maneuver on DP for objectives such as making transfers at a safe distance from the tree. Proceed to the following steps before making an extended transit.

8. Position ROV to assist with wet parking the riser extension. 9. Disconnect the hoses from the CT contractor’s well control equipment. Attach

a line to the top of the riser extension, take load on the line, and release riser extension from Motion Isolation System.

10. Disconnect the structural casing segment of the riser extension from the active segment, lift riser extension clear of the SSR, and maneuver vessel. Disconnect the return line from diverter and wet park riser extension on the SSR by reversing the steps used earlier to connect the extension between the SSR and the vessel.

11. Perform ‘as-left’ inspection, recover ROV, and depart.


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Emergency disconnection may be necessary in an extreme event such as DP drive off or fire on board. The Seafloor Shutoff Device is designed to close within 10 second or less. There is a delay on closure of the near surface shear and seal to allow the SSD to shear the tubing while it is in tension. The shearing isolation valve in the riser extension and the near surface shear and seal close simultaneously, and the disconnection releases as soon as they have time to function.

It is preferable to function the near surface shear and seal while leaving the SSD open. This reduces the disconnection time by 5 or 10 seconds, and can avoid fishing for cut tubing if slip rams have been installed below the buoyancy to support the tubing. The steps below can all be sequenced automatically.

TABLE 7.2 EMERGENCY DISCONNECTION FROM WELL

STEP STEPS FOR EMERGENCY DISCONNECTION WITH TUBING DEPLOYED 1. Initiate closure of the slip rams (if installed) below the riser buoyancy. 2. Close the Near Surface Shear and Seal device (and the Seafloor Shutoff

Device if required by the plan for the specific well). Either is sufficient to isolate the reservoir by shearing tubing and sealing. The shearing retention valve above the disconnection connector is automatically actuated simultaneously with the Near Surface Shear and Seal device.

3. Release the emergency disconnection connector. A time delay may be incorporated to ensure that the Near Surface Shear and Seal device and the shearing isolation valve close before the connector opens. NOTE: Shearing the tubing will remove load from MIS, which causes it to rise and lift the riser extension to separate the connector halves. The disconnection connector must be rated to open under tension. Since the load is removed suddenly the MIS will stroke up and lift connector clear of the SSR without a specific command from the controls. NOTE: The above steps shear the tubing on both sides of the emergency disconnect connector, thus providing redundant release of the vessel from deployed tubing to ensure disconnect from the riser.

4. Disconnect the umbilicals from the vessel and abandon then as the final action to fully separate the vessel from the SSR.

5. Take action appropriate to the emergency and notify host platform of incident. The riser may be relocated between wells or to an anchor. Riser buoyancy must be ballasted sufficiently to make the riser heavy in water, but the buoyancy may support the majority of the riser weight. This results in a high mass to weight ratio for the hook load, so a constant tension winch is sufficient for riser relocation and full heave compensation is not necessary. Any of a wide range of vessels is therefore suitable for riser relocation. Steps for relocation are listed in Table 7.3.

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TABLE 7.3 MOVE RISER FROM TREE TO TREE STEP STEPS FOR RELOCATION OF SSR BY INTERVENTION VESSEL 1. Verify that previous work has been completed, that CT has been pulled from

riser that SSD is closed, and that control of tree has been returned to the host. 2. Coordinate with host platform on plans to relocate the SSR. 3. Close Seafloor Shutoff Device and the Near Surface Shear and Seal device. 4. Verify that SSR buoyancy is in standalone condition, per engineering

documentation. Attach line to the top of the riser extension and release structural casing segment of the riser extension from Motion Isolation System.

5. Tension line while ballasting buoyancy to make SSR heavy in water, per engineering documentation.

6. Verify that SSR buoyancy is properly ballasted and then disconnect SSD from tree.

7. Lift riser clear of the tree and other seafloor infrastructure. 8. Maneuver vessel to the tree to which riser is to be moved. .

9. At the new well site, inspect the tree and remove the tree cap per appropriate steps of riser installation procedure ‘SSR RELOCATION AND TEST ACTIVITY’

10. Maneuver vessel on DP, adjust elevation of SSR, and position SSR above tree 11. Repeat appropriate steps of SSR installation procedure to land SSR on tree,

latch connector, and hook up controls to tree. 12. De-ballast SSR buoyancy and repeat pressure test and load test of SSR, as

appropriate to test connection to new tree. 13. Relocate riser extension per steps for down-hole intervention. If water depth is

significantly different it will be necessary to add or remove joints of the riser extension.

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7.0 SYSTEM LEVEL OFFSHORE MAINTENANCE Offshore maintenance consists of repairs and routine preventive maintenance that can not be done onshore. The need for offshore maintenance is reduced by emphasizing onshore preventive maintenance, redundancy, conservative design margins, and short service duration.

During installation of the SSR, all components can be retrieved to deck for repair or replacement.

During down-hole operations, all active components with the exception of the Seafloor Shutoff Device (SSD) can be recovered and repaired or replaced on the deck of the intervention vessel. An intervention vessel that has a suitable crane can recover the SSD by disconnecting the riser from the SSD, hanging the riser from the motion isolation system, and then recovering the SSD. Consistent with its role as the final line of defense for reservoir isolation, the Seafloor Shutoff Device is designed and built to high reliability and quality standards to minimize the likelihood that it will need to be recovered for repair.

The configuration and maintenance provisions discussed in this section apply to the baseline configuration. Other configurations may be used at the discretion of the down- hole service contractor and the client, and maintainability is one of several considerations when choosing the configuration. A detailed maintenance plan is to be prepared before mobilization, and is to include a comprehensive list of spares and tools needed to maintain, repair, or replace all components.

7.1 Maintenance of Riser & Riser Installation Equipment The SSR does not require inspection or maintenance while installed for up to one year. Equipment used to install the SSR is accessible for repair on deck, and all known failure modes can be repaired without jeopardizing the vessel or the SSR.

The SSR is a passive structure designed to standards for similar equipment in production systems intended for 20 year life without maintenance. Structural failure early in the life of such components is rare. The primary failure modes result from fatigue, corrosion, and damage, all of which tend to be cumulative over long periods. The SSR is designed for a 20 year service life but normally installed for only a few weeks and never for more than a year or two before it is recovered and all components are then inspected and refurbished, de-rated, or scrapped. This allows frequent preventive maintenance onshore in a shop environment and minimizes the need for offshore maintenance.

Each component of the SSR has a serial number which is used to track its service life. A full history including manufacturing records, qualification testing, mobilization dates, location and nature of service and duration of each installation is to be recorded for each serial number. Records are to be updated each time the item is mobilized or recovered, and periodically if the item is idle. Items are to be taken out of service if they fail inspection and can not be fully refurbished, or if fatigue cycles approach the allowable limit. Allowable fatigue life is known from the design and manufacturing records and

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actual fatigue is calculated based on time in service, the position in the riser where the item was used, and the environmental or service characteristics that may contribute to fatigue during use.

Credible failure modes for air can buoys are primarily leaks and structural failure. As is required for surface vessels, the SSR is designed to survive the loss of any one buoyancy chamber. The risk of leakage is reduced by specifying the buoyancy modules to have no through-hull penetrations in the top or sides. Buoys are to be coated and have ample design margins for structural strength and corrosion allowance. Coating repair kits are to be used to repair any coating damage noted during installation.

Equipment used to install the riser has a wider range of failure modes, but is always accessible on deck. All known failure modes are amenable to repair without risk to the safety of the vessel or the riser. For example, the suspended riser can be held by the slips, the constant tension winches, or the crane if any one of these three ways to support the load should require maintenance. Spares and tools are mobilized for offshore maintenance and repair of installation equipment. Items most likely to require offshore maintenance are the tongs, constant tension winches, hydraulic power units, and controls.

7.2 Maintenance of Operations Equipment The Seafloor Shutoff Device (SSD) and the Motion Isolation System (MIS) are the only elements of the CT system that are custom built. Hydraulic components of the MIS are specified to be fully redundant so that no single failure will interrupt service and most components can be replaced while the system remains in service. The CT reel drive brake can be used to lock the reel if the hydraulic drive components require maintenance.

Because the SSD is installed by the SSR installation vessel and used by the CT intervention vessel it is the only active component that is not readily accessible for maintenance during operations. In addition to the onshore preventive maintenance referred to above, the SSD is specified with redundancy and ROV override capability for all functions. Valves, controls, and other active components are normally used only for testing while offshore so there is limited wear.

The intervention vessel installs all other active components, including the near surface shear and seal device, the retention valve, and the emergency disconnect connector, all of which are in the riser extension. These components can all be recovered to the deck of the intervention vessel by reversing the installation procedure.

If the controls for the SSD fail, the near surface shear and seal device can be used to contain reservoir pressure until the ROV can override the SSD. When used with a vertical tree, the tree can be used to isolate the reservoir after the tubing has been recovered or the ROV has been used to override the shear function of the SSD. If the SSD fails during work through a horizontal tree, the casing length between the service contractor’s well control equipment and the Near Surface Shear And Seal device can be used to inject wire line tools to reset the crown plugs.

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8.0 RELIABILITY ANALYSIS

8.1 System Level FMEA & Fault Logic Diagram This section was prepared by General Marine Contractors. Figure 9.1 through 9.4 introduce the analysis results that follow.

FIGURE 9.1 BLOCK DIAGRAM


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FIGURE 9.2 CRITICALITY ANALYSIS

FIGURE 9.3 QUALITATIVE APPROACH


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FIGURE 9.4 SEVERITY LEVELS

Criticality Matrix (By Item Criticality) Seafloor Shutoff Device

Item Criticality IV III II I A - Frequent B - Reasonably Probable

Seals controls - software

C - Occasional ball valve Accumulators Controls – Hardware

D - Remote Ram actuators BOP rams

E - Extremely Unlikely

Hardware/Spools Connector

Cat I: Catastrophic - death or national incident Cat II: Critical - severe injury or damage, mission loss Cat III: Marginal - minor injury or damage, delay of mission Cat IV: Minor - unscheduled maintenance/repair

CONFIDENTIAL RPSEA PROJECT 08121-1502 TASK 7 REPORT

This report is confidential and proprietary. Material contained herein is not to be used or disclosed without written permission from Nautilus International LLC and RPSEA.

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9.0 VALIDATION OF FUNCTIONAL CAPABILITY Functional capability has been validated at the feasibility level by senior engineering personnel and subject matter experts who have examined the system from different viewpoints including system architecture, prior practice, computer model analysis, procedure review, reliability analysis, and HAZID.

Validation is aided by the fact that both the SSR and Coiled Tubing intervention are established technologies. The SSR has been widely proven in service. A demonstration SSR was installed on a simulated wellhead in 3,500 feet of water in the Gulf of Mexico as part of the Anadarko development program. Inspection of the Anadarko SSR in November of 2010 showed that it is still in good shape after surviving hurricane and eddy current events since it was installed four years earlier.

Assembling the SSR from joints of 6 5/8” drill string allows use of conventional slips, tongs, and related tools for handling and assembly.

The CT equipment and methods are changed little from what has been used successfully on production platforms. The system is designed to work with a wide variety of vessels and does not depend on characteristics of a particular vessel.

New technology developed for this application is essentially the provisions for using the SSR and Coiled Tubing together. The three areas of departure from prior practice are being examined further in Task 9 of this project phase:

• The Riser Assembly and Deployment System consists of tools and equipment to safely and efficiently install the SSR from a low cost work boat or light construction vessel which may be subject to greater vessel motions than normally encountered on a MODU.

• The Motion Isolation System and the Riser Extension provide the riser/vessel interface needed to avoid CT fatigue and bring the riser up through the moon pool of a cost effective vessel that may be subject to greater vessel motions than normally encountered on a MODU.

• The Seafloor Shutoff Device with tree interface is a new assembly of proven components suitable to shear Coiled Tubing and isolate the reservoir as the final line of defense to prevent loss of well control.

The riser extension and Motion Isolation System still must be proven in service, but together with the SSR they create an environment in which existing, field proven CT equipment can be operated from a small vessel for down-hole intervention on deep water satellite wells. Further validation of functional capability will be approached on several fronts during the design and fabrication phases. This includes following good design practice, using field proven components, adhering to industry standards, conducting design reviews and technical readiness reviews, testing new components, and conducting comprehensive system integration tests. Detailed plans including measures to ensure good engineering practice will be included in the Phase 2 project plan. The following widely applicable guidelines will be enforced:

• Use existing, proven components and methods to the greatest extent possible • Change only what must be changed • Test each change to verify that it works and to identify unintended consequences


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• Plan new equipment carefully and document functional requirements • Adhere to industry standards and codes • Prepare and enforce a comprehensive Interface Management plan • Prepare comprehensive procedures and hold procedure reviews • Feed back the results of procedure reviews to the design staff • Require experienced, conscientious engineers • Maintain good Document Control practices • Conduct Failure Modes and Effects Analysis at key points in design • Conduct frequent and extensive cross discipline design reviews • Prepare and enforce a comprehensive QC plan • Require experienced fabricators and oversee fabrication activity • Maintain detailed manufacturing records • Conduct extensive Factory Acceptance Tests for components and end items • Conduct comprehensive System Integrations Tests • Protect equipment during storage and staging

Formal validation of readiness will include Technical Readiness Review. Full validation of the combination of the two well established technologies will come from offshore demonstration and subsequent usage.


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10.0 ESTIMATED OPERATING COSTS This task is to determine the operating cost of installing and using the SSR for well intervention with Coiled Tubing. A project goal is to achieve 50% of the cost of using a standard MODU in deep water Gulf of Mexico. The bottom line on the cost is “it depends on the application.” The cost estimates presented here are representative for the 4Q 2010. They show that by using this system we can achieve our goal. The mobilization cost shown here is for a hypothetical vessel of opportunity. Mobilization for a dedicated vessel would be much less. The day rate could be reduced significantly by using vessels that are under long-term contract to the client.

These costs do not reflect the total job cost. Depending upon the specific job, the work performed, the tools and materials used and the time to complete the work, the job may cost more or less than shown in the estimates. The estimates are for comparison of the two approaches.

The following estimates are based on using different vessels for SSR installation and for down-hole intervention. As compared to MODU operations, this approach is comparable to using a supply boat to run and set the completion and work over riser for use by the MODU or intervention vessel. The two vessel option is most attractive for an ongoing business in which the SSR installation vessel installs, relocates, and recovers multiple risers so that mobilizations consists primarily of loading or offloading riser components. If a single vessel is used for both SSR installation and CT operations its higher day rate is partially offset by savings in mobilization and transit costs. For a single well intervention, if the down-hole work takes more than a week, having the installation vessel stand down during down-hole work can reduce the cost. Also, cost can be reduced if a vessel suitable for both SSR installation and intervention is available at a day rate of $300,000 or less and can install, test, use, and recover the riser in 3 days or less in addition to its anticipated mobilization and demobilization time.

The following costs are for ongoing but intermittent work. The costs would be higher for a first time demonstration, and lower for an activity level that justifies a dedicated vessel. The nominal vessel configuration will be more fully defined in a subsequent task of this phase of the project and this may affect the vessel cost. Cost estimates for design and fabrication of the SSR are included in the Task 6 final report. The SSR riser rental rate is based on the ability to recover those costs over the life of the riser and system.

The costs estimates below are for comparison to the cost of using a MODU and do not include costs such as engineering the down-hole work which would be essentially the same for either job. This cost estimate for mobilization and operations does not include tasks that are also required for MODU intervention, such as the following:

• Permitting • Client personnel for his engineering, QC, contracting, & logistics • Client offshore personnel, including onboard representation and HSE specialist • Use of client shore base in south Louisiana for equipment staging and dock


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• Host platform activity, including any equipment and personnel transfers or use of

regularly scheduled supply boat and helicopter service to the host platform • Consumables unique to a specific down-hole task, such as cement or well fluids.

10.1 SSR Installation Assumptions & Cost Estimate The SSR installation estimate starts with transport of equipment and personnel to the dock, and includes vessel load-out, transit, riser installation, standby for 3 days during down-hole work, and demobilization. If the down-hole work is expected to take a week or more, the installation vessel would do other work or demobilize and remobilize later for riser recovery.

The estimate is based on the following assumptions:

• Vessel has suitable crane, moon pool, and ROV • Transit time between dock and work site is approximately 12 hours • Down time for weather is assumed to typically be 20%. Larger vessels would be

able to work through higher sea state conditions for better availability. • Water depth is approximately 5,000 feet • A crew of approximately 45 people on board is estimated for 24 hour operations

for riser installation based on: • 13 owner’s crew including the captain, 4 DP officers, 2 marine engineers, 4

galley crew, and 2 stewards (included in vessel day rate) • 7 deck crew including riggers, crane operators, deck supervisor • 11 crew for SSR and umbilical installation & equipment maintenance,

including 4 techs for operation and maintenance of the RADS, 2 inspectors, 2 gas supply techs, 1 offshore superintendent, and 2 techs to represent equipment manufacturers

• 2 riser engineers • 7 ROV crew • 1 Contractor safety professional • 4 client personnel, including client representative, engineer, safety

professional, and tech from tree manufacturer

The estimates are for jobs that require 3 or more days of down-hole work. For jobs that require less than 3 days of down-hole work it is more cost effective to have the installation vessel standby offshore, rather than return to the dock and demobilize as shown in the cost estimate below for installation and recovery of the SSR.

SSR MOB & INSTALLATION – RISER INSTALLATION ON ONE WELL

Item Unit cost

Qty. Cost Remarks

Personnel travel 3,300 20 $66,000 Includes per diem & travel time at day rate

Equipment transportation 20,000 Personnel at dockside 45,000 2 days 90,000 Mobilization Offshore personnel day rate

28,000 4 days 112,000 Includes transit & 1 day for weather

Gas supply day rate 5,000 6 days 30,000 Vessel day rate for dock 70,000 6 days 420,000 Includes 2 days for


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time, transit, & ops weather & transit, plus 2

days at dock Fuel, lube, catering 7,000 6 days 42,000 Equipment disposition & vessel restoration

50,000

Installation vessel standby offshore during down-hole work

110,000 3 days 330,000 Day rate for vessel, equipment, & personnel for standby offshore

Day rate on riser 30,000 6 days 180,000 Engineering & management

60,000 1 60,000

Total $1,400,000

10.2 Intervention Assumptions & Cost Estimate The down-hole intervention estimate starts with transport of equipment and personnel to the dock and includes vessel load-out, transit, onsite preparations, down-hole work, return to the dock, demobilization, and vessel restoration. The cost would be lower for an intervention vessel that already has the required equipment onboard. The estimate is based on the following assumptions:

• Vessel has suitable crane, moon pool, and ROV • The down-hole task is a basic function that is not “consumables intensive” • Down time for weather is assumed to typically be 20%. Larger vessels would be

able to work through higher sea state conditions for better availability. Using the SSR offers fewer overall days of down time due to the advantage of not pulling riser during hurricane threats.

• Personnel estimates are based a crew of approximately 42 for 24 hour operations: • 13 owner’s crew including the captain, 4 DP officers, 2 marine engineers, 4

galley crew, and 2 stewards (included in vessel day rate) • 5 deck crew including riggers, crane operators, deck supervisor • 2 techs for SSR, umbilical, & MIS operations/maintenance • 2 gas supply techs • 6 crew for down-hole service contractor • 1 riser engineer • 7 ROV crew • 1 Contractor safety professional • 5 client personnel, including client representative, 2 engineers, safety

professional, and tech from tree manufacturer

The following costs are for ongoing but intermittent work. The costs would be higher for a first time mobilization, and lower for an activity level that justifies a dedicated vessel. Offshore time is based on 3 days of down-hole work plus 24 hours of transit and 24 hours of down time for weather. The Installation costs above add to the column for SSR cost.


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Costs in the MODU column include transferring the operator’s completion and work over riser from a supply boat, running the riser, and offloading the riser back to the supply boat. The MODU day rate came from average published rates at the end of 2010, and the spread cost includes supply boat and helicopter service. The one day allowance for MODU down time for weather is 11%, as opposed to the 20% allowance used for the smaller vessels needed with the SSR. While the MODU can work in higher sea states, transfer of the completion and work-over riser to and from supply boats is weather sensitive. MODU weather time during hurricane season could be much higher (a week or so) if it is necessary to pull the riser and run to avoid a storm and then reinstall the riser after the threat has passed.

DOWN-HOLE MOB & OPERATIONS - INTERVENTION FOR ONE WELL

Item Unit cost or day rate

Qty. SSR Cost

MODU Cost Including both riser & CT work

Personnel travel Includes per diem & travel time at day rate

3,500 20 $70,000 $35,000

Equipment transportation 15,000 35,000 Dockside equipment & personnel day rate Ready the day before the vessel arrives

35,000 2 days

70,000 20,000

Offshore personnel day rate (CT crew is in CT day rate) Includes transit & 1 day for weather

11,000 5 days

55,000 $50,000

Basic CT equipment & 6 man crew day rate

23,000 7 days

160,000 $160,000

Gas supply day rate 5,000 7 days

35,000

Vessel day rate for 2 days at dock, 1 day transit, 1 day weather, & 3 days down-hole work

85,000 7 595,000 $5,500.000 (based on 10 days at $550,000 including 1 day transit, 1 day weather, 5 days equip & riser transfers & riser running & 3 days down-hole work)

Fuel, lube, catering 10,000 7 70,000 $300,000 Riser day rate 30,000 3

days 90,000

Equipment disposition & vessel restoration

100,000 $100,000

Subtotal for CT ops $1,257,000 Total including riser installation & recovery

$2,660,000 $6,200,000

The above estimates for installation and removal of the SSR and 3 days of down-hole work total to $2,660,000. This is less than half the overall spread cost for 10 days for a


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MODU, allowing the MODU 1 day for transit, 3 days for down-hole work, 1 day for waiting on weather, and 5 days to transfer, install, test, recover, and offload the completion and work over riser and transfer consumables. Weather for the MODU includes allowance for supply boat runs and vessel-to-vessel transfers. The cost of using a MODU also includes the cost to mobilize and demobilize the completion and work over riser plus the ongoing spread costs such as supply boat and helicopter service and fuel.

For the stated assumptions, the MODU approach would cost approximately twice as much as the SSR approach for a job that requires 1 (24 hour) day of down-hole work. As shown in the table above for 3 days of down-hole work, the MODU approach costs about 2.3 times as much as the SSR approach. For jobs that require more than 3 days of down-hole work the cost ratio would favor the SSR even more strongly.

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