subsea well intervention: learning from the past - planning for the future

1 - Classification: Internal 2010-10-18

Subsea well intervention;Learning from the past – planning for the future

UTC 2010

Trond Inge Ramsnes

2 - Classification: Internal 2010-10-18

Beautiful but demanding

3 - Classification: Internal 2010-10-18

Optimising reservoir recovery from subsea fields

• Increased fluid handling capacity

• Reduced wellhead pressure

• Integrated Operations

• Identify

−Drainage points

−Well intervention needs and opportunities

Ambition: increase subsea

recovery Cost effective drainage & well intervention

4 - Classification: Internal 2010-10-18

4

Cumulative wells – Statoil NCS

0

100

200

300

400

500

600

700

1980 1990 2000 2010

Dry trees

Wet trees

5 - Classification: Internal 2010-10-18

5

Learning from the past – planning for the future

RLWI

Cat B

TT riser

2⅞” CT

• Platforms only to date

• Spoolable connectors

• Sweep cleanouts

TT Drill

TTML

• TTRD platforms and subsea

• CTD (Gullfaks)

• Safe & efficient operations

• Full technical capability including MPD

• Solid base for delivery of through tubing technology

• Backup to RLWI

• Cost efficient• Data collection• Light perforating• Light mechanical wireline

• TTRD• CTD• CT/WL intervention

• Maintain motherbore production

• Access by-passed reserves

• Gullfaks, Veslefrikk

2000

2002

2003

2004

2009

2013

6 - Classification: Internal 2010-10-18

6

Impact of well intervention – mature asset

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

No activity Drill New Maintenance

Oil

Sm3 /D

7 - Classification: Internal 2010-10-18

Addressing challenges – realising opportunities

Scale build-up in the upper completion

Equipment problems SCSSV

Access problems

Restricted production

Water influx

Wellbore scaling

Access problems

Restricted production

Formation damage (scale, fines, etc.)

Restricted production

“Fishes”

Access problems

Restricted production

Water holdup

Wellbore sanding

Access problems

Restricted production

Completion integrity issues

Milling or high pressure jetting to remove scale

Straddles or patches to repair tubing

Wellbore cleanout, fill removal with long or reverse circulation

Selective zonal isolation, mechanical or chemical

Heavy duty fishing with simultaneous removal of fill

Wellbore unloading with nitrogen

Formation matrix or fracture stimulation

Milling and underreaming to remove wellbore scale

Perforating long sections

8 - Classification: Internal 2010-10-18

Category ARLWI

Category BFull range intervention & TTD

Category CDrilling and completion

•Wireline / tractor only

•Limited bhalength

•Full range of through tubing services

•Limited live well through tubing services

High pressure light weight

riser (8-5/8”)

Low pressure marine riser (21”) standard

HP concentric riser and SSTT required for live well intervention

9 - Classification: Internal 2010-10-18

Cat B – fit for purpose concept

Lightweight HP riser system (through tubing)

Full DP or mooring assisted station keeping options

Topside system sized for through tubing operations (2⅞” & 3½” drillpipe)

Integrated high capacity coiled tubing package (2 ⅞” / 3½”)

Full handling of live well returns

Semi-submersible rig hull type

10 - Classification: Internal 2010-10-18

LRP/EDP stack on BOP carrier SBOP In rack-back area

Key components in riser system

11 - Classification: Internal 2010-10-18

Operational Limitations

•WSOG

•Position reference

•Propulsion

•Riser system limitations

•Wellhead limitations

•Drift-off / drive-off

•”Zero Moment Position”

•RMS system used as advisory system for rig positioning

Fatigue monitoring / management

12 - Classification: Internal 2010-10-18

Experience with TT Riser System• Pilot operation with new system offshore

− new equipment and procedures

• stepwise and constrained progress.

• Improve cleaning after milling and drilling operations.

• No wear of the high pressure riser detected

• RMS

− High focus – used actively

− Relatively nice weather – low utilization

− High angles in Upper Flex Joint

13 - Classification: Internal 2010-10-1813 - Classification: Internal 2010-04-12

Protecting Horizontal XT (HXT) – used on all pipe runs

HORIZONTAL XMAS TREE

PIGGY BACK WEAR SLEEVE

TUBING HANGER NIPPLE PROTECTOR

14 - Classification: Internal 2010-10-18

Existing production tubing

Production packer

Whipstock

Through Tubing Sidetrack

SSD

CHOKE

Production from ’motherbore and new sidetrack simultaneously

Through Tubing Drilling (TTD)drilling through existing tubing (completion)

Reservoir

15 - Classification: Internal 2010-10-18

Operational experience Åsgard P-4

< 300

kSm3

< 100

kSm3

< 50 kSm3

Decreasing target volume

Increasingtargetcount

& reserves

Additional reservesCat B enabled

15

16 - Classification: Internal 2010-10-18

P-4 AH Actual Drilled Wellpath – Geological Cross Section

Not

Ile 2 & 3Ile 2 & 3

Ror

Tilje 3Tilje 3

TVDMSL

Tilje 1 & 2

Tilje 4, 5, 6

Ile 1

Garn 3 & 4

Garn 1 & 2

T1T1 T2T2 T3T3 T4T4 T5T5

Kick off3871mMDGarn 3

P-4 H mother bore

P-4 AH actual

Drilled a world record of 1744m 5 ¾” TTRD sidetrack

17 - Classification: Internal 2010-10-18

Production P-4

Initial production

approx. 20 000 boe/d

18 - Classification: Internal 2010-10-18

Status Category B Services

• 3 Contractors carrying out FEED (Front End Engineering and Design) in the period March - September 2010;

− Aker Oilfield Services

− Helix WellOps

− Saipem

• Bid process ongoing – bid due mid October

• An 8 years “Cat B Services Contract” will be awarded this year

− Operations commencement Q3 2013

19 - Classification: Internal 2010-10-18

Subsea well intervention;Learning from the past – planning for the future

Trond Inge Ramsnes

Project Leader Well Intervention

trira@statoil.com, tel: +47 51 99 00 00

www.statoil.com

Thank you