not to copy -- no disseminate without written agreement … · not to copy -- no disseminate...

Presentation JB – AG – JCN – JR 1 NOT TO COPY -- NO DISSEMINATE WITHOUT WRITTEN AGREEMENT


ENVIRONMENTAL DATA ACQUISITION


ENVIRONMENT METEOCEAN GEOHAZARDS GEOTECHNICS P

HA

SE

1

DESK STUDY

3D EXPLO

DESK STUDY

3D EXPLO DESK STUDY

LARGE SCALE / REGIONAL ASSESSMENT

NEW SURVEY NEEDED ?

DESK STUDY

PH

AS

E 2

METEOCEAN SURVEY

ENVIRONMENT. BASELINE SURVEY

HR SURVEYS SEABED SAMPLING

ONE CAMPAIGN ONE SURVEY

EIA & DESIGN PARAMETERS ASSESSMENT ON FOCUSED AREA

RESULTS REVIEWED WITH PROJECT TEAM

PH

AS

E 3

PRELIMINARY DRILLING / DEVELOPMENT

GEOTECH. SURVEY EIA LOCATION ASSESSMENT

FINAL SITE ASSESSMENT AND RECOMMENDATION

methodology



Comparative figure of various environmental conditions

Source: OTC paper 22161 / OTC Arctic Technology Conference / Houston 2011



Typical – Iceberg Management Techniques

Source: OTC paper 22103 / OTC Arctic Technology Conference / Houston 2011



Sakhalin 1 Project

“Orlan platform”




HA

SE

1

DESK STUDY

3D EXPLO

DESK STUDY

3D EXPLO DESK STUDY


NEW SURVEY NEEDED ?

DESK STUDY

PH

AS

E 2

METEOCEAN SURVEY






PH

AS

E 3




methodology



Meteo-oceano survey

As relevant, a meteo-oceano survey includes ….

- waves, swell, tides data on the location,

- winds data

- currents data.

Data can be available and purchased nearby Administration of the Country or

the Company (the Operator) must plan and perform such data acquisition

ample time in advance.



100 year Extremes K1 K2 K3 K4 K5

Hurricane Winter Loop/Eddy Run-Off Submerged

Max. Wave Storm Current Current Current

Waves

Hs (m) 12,7 7,6 3,6 4,3

Tp (s) 14,9 12,5 10 9,2

Hmax (m) 21,5 13,7 6,4 7,9

Thmax (s) 13,4 11,4 9 8,1

Dir. (°N / from) 155 110 87.5 - 177.5 110

Wind

Speed (m/s -1hr) 39,9 22,9 14,0 17,0

Dir. (°N / from) 155 110 87.5 - 177.5 110

Current (m/s)

0 m 1,3 0,5 1,74 1,25 0,26

30 m 1,3 0,5 1,72 1,25 0,26

60 m 1,3 0,5 1,70 1,25 0,26

75 m 0,6 0,5 1,66 1,25 0,26

90 m 0 0 1,62 1,25 0,26

100 m 0 0 1,60 1,25 0,26

King's Peak design criteria

EXAMPLE OF METEOCEAN DESIGN CRITERIA



METEOCEAN SURVEY

WATER COLUMN CURRENT PROFILE (ADCP) (to identify solitons, …) SALINITY, TEMPERATURE METEOCEAN CRITERIA FOR DRILLING RISER DESIGN

GOM & Gabon - Extreme Current Profiles

0 m

500 m

1000 m

1500 m

2000 m

2500 m

3000 m

0 0,5 1 1,5 2 2,5

Current Speed (m/s)

De

pth

K3

K4

K5

C2

C3

G1

ACDP (Acoustic Doppler Current Profiler)



Meteo-oceano survey

A meteo-oceano survey will be necessary and/or is compulsory, for ….

- the selection of the MODU

- the conduct of drilling operations;

More, permanent weather forecasts are necessary in difficult areas/rough seas

- for the safety of the operations,

- for the efficiency of the operations



Main use of meteo-oceano surveys

A meteo-oceano survey and, as relevant, permanent weather forecasts will be

necessary and/or is compulsory, for ….

- - the selection of the MODU (sea behaviour of MODU to wave amplitudes

& frequencies, )

- - the conduct of drilling operations including ….

- monitoring of WOW (Waiting On Weather) periods,

- safety (stability of the JU, evacuation of personnel, efficiency of anchors, ….),

- rig orientation on location,

- moving periods,

- anchoring operations,

- running of CP or BOP and riser,

- crane operations,

- DST periods,

- logistics: supplies for the rig, helicopter flights ….



DW floaters: Relative heave motion response vs. Wave period

Source: TOTAL Offshore Reference Book

RIG SIZING AND SELECTION



HA

SE

1

DESK STUDY

3D EXPLO

DESK STUDY

3D EXPLO DESK STUDY


NEW SURVEY NEEDED ?

DESK STUDY

PH

AS

E 2

METEOCEAN SURVEY






PH

AS

E 3




methodology



LOOP

CURRENTS

UNDERWATER

CURRENTS

CARBONATES

DIAPIR

POCKMARKS

MUD VOLCANOES

UNSTABLE

SEDIMENTS

SLIDING

SEDIMENTS

FAULTS SHALLOW

WATER SANDS

SHALLOW

GAS

CURRENTS

DEEPWATER – MAIN GEOHAZARDS



Main use of site surveys

Site surveys will be necessary and/or is compulsory, for ….

- - Shallow gas hazards identification (onshore and offshore)

- - Presence of hydrates

- - Obstruction on sea bed (pipes, wrecks, …)

- - Rig station keeping studies (anchoring)

- - Preparation of procedures to install a Conductor Pipe (CP), a wellhead or

to drill the top-hole section of a well,

- - A requirement from Insurance Companies.



ROV --- AUV --- SWIMMER

ROV: (Remote Operated Vehicle)

for underwater works; widely used in support of offshore drilling activities;

rental daily rate: (approx) 4000 $/d)

- main system components: TMS (Tether Management System)

+ tether (= ombilical)

+ ROV (Remote Operated Vehicle).

AUV : (Autonomous Underwater Vehicle)

for survey works (video inspection, …) on pipelines

SWIMMER : R&D development stage

- for underwater surveys + works

- main system components:

docking station (to “park” AUV + ROV)

+ AUV (to support the ROV)

+ ROV linked to the AUV with a tether)



GEOTECHNICAL,GEOCHEMICAL, SEDIMENTOLOGY DATA ANALYSIS (SEABED SAMPLING, SURFACE SURVEY)

PENETROMETER (TO SET SENSORS TO 30/40m IN 6000m WD) ROV SEABED SURVEY

GEOHAZARDS

FROM 3D EXPLO SEISMIC (SHORT OFFSET TO 400M) FROM HR ,VHR, UHR SEISMIC

Ifremer ROV Victor 6000 seabed survey Multi beams side scan sonar seabed survey

Ifremer Penfeld penetrometer



1500

m

GIANT POCKMARK

CARBONATE MOUNTS

FLUID ESCAPE

CHANNEL

STRUCTURAL LINEAMENT

Hydrates in sediments

BSR

(HYDRATES)

400 m

* BSR = Bright Spot Reflector




HA

SE

1

DESK STUDY

3D EXPLO

DESK STUDY

3D EXPLO DESK STUDY


NEW SURVEY NEEDED ?

DESK STUDY

PH

AS

E 2

METEOCEAN SURVEY






PH

AS

E 3




methodology



GEOTECHNICAL DATA & REPORT

Soil investigation is essential for the design of any offshore structure, because

it is the soil that ultimately resists the enormous forces and moments present in

the piling, at the bottom of the ocean, created by the presence of platforms.

The soil can be boulders, clay, sand, silt, or a mixture of these.

Each project must acquire a site-specific soil report showing the soil stratification

and its characteristics for load bearing in tension and compression, shear

resistance, and load-deflection characteristics of axially and laterally loaded piles.

This type of report is developed by doing soil borings at the desired location, and

then performing in-situ and laboratory tests in order to develop data usable to the

platform or equipment design /selection by the drilling engineer.



Seabed survey

As relevant, a seabed survey includes ….

- a bathymetry survey to identify any obstacles on the seabed (rocks,

wrecks, ….) or irregularities of the sea bottom (side scan sonar)

- a “geotechnic” (rock mechanism) survey

- to identify shallow formation lithology (clay, sand, shale …)

- to estimate soil cohesion vs. depths *

- a Seismic High Resolution (0 to approx 500m / Ref to surface casings

setting depths) to evaluate drilling hazards due to shallow gas.

( * e.g. evaluation of JU-leg penetration on the drilling site)



Soil survey (for JU-leg anticipated

penetration)

Very good fondation Good fondation Hazardeous fondation

Shales are more

and more compacted

Sand layer is

enough thick

pen

etr

ati

on

A Anticipated penetration




penetration)

Thick shale

layer

A Anticipated penetration

JU on a non-

secured

fondation

Maxi penetration

allowed 20m

Forbidden

location

e.g. thick clay layer

on compacted

shales

p

en

etr

ati

on




penetration)

Cu* (being measured) vs depth ….

then,

-- The loading capacity of the

formation can be calculated,

and,

-- Leg penetration can be estimated

(Cu = Shale cohesion coefficient)



SOIL SURVEY FOR JACK-UP INSTALLATION

Mat supported – slot type

For very soft seabed formation

and flat sea bottom



SOIL SURVEY FOR JACK-UP INSTALLATION

Spud can

D =

1 t

o 2

m

D =

10

to

20

m



SOIL SURVEY FOR JACK-UP

INSTALLATION

Jetting system

(for retrieving JU-leg out of

its foot print)

Spud can Nozzles for jetting system



SOIL SURVEY FOR

ANCHORING PATTERN

for a semi-submersible

WD on location: 115m

Chain length out: 1200m



Suction anchors are used in ultra-deepwater for

systems requiring taut or semi-taut preset mooring

systems.

This system uses a suction caisson as the anchor.

The caisson is cylindrical in shape with the bottom

end open. Embedment of the anchor is

accomplished by using an ROV to pump water out

of the top of the caisson until it is fully penetrated

into the seabed. The process is simply reversed to

recover the anchor.

Advantage of the suction anchor mooring system

-- anchor's ability to hold at higher uplift angles, thereby

reducing the circumference of the mooring pattern

-- suction anchor system provides excellentperformance

in ultra-deepwater and allows a platform to significantly

extend its water depth capability.

-- another significant advantages of the suction anchor

is the ability to target an exact location, its soil-holding

properties,

-- it reduce the weight of the mooring leg on the rig.

Suction anchor mooring system



Slides were prepared for presentation and information to Students of Schools and Universities only.

References

Slides presented were prepared with illustrations from the following referenced documents:

- API Standards and Recommended Practices,

- Neal J. Adams, Drilling Engineering , PennWell Books, Tulsa, Oklahoma, 1985,

- (Halliburton) - Petroleum Well Construction – J Willey & Sons

- Miscellaneous books from “Chambre Syndicale de la Recherche et de la Production du Pétrole et du gaz naturel”

- IFP Drilling data handbook

- Miscellaneous documentation from TOTAL Drilling Division

- Halliburton Completion Services

- Miscellaneous books from IFP

- Leading Edge Advantage Ltd (Under Balance Drilling).

- Miscellaneous documentation from web-sites: O&GJ, World Oil, SPE

- Transocean, Saipem, Pride Drilling Contractors

- Baker Hughes, Schlumberger, Weatherford, Wild Well Control Service Companies

- Cameron, Hydril, Companies.

not to copy -- no disseminate without written agreement … · not to copy -- no disseminate...

Documents