Subsea well intervention: Learning from the past - planning for the future


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Subsea well intervention: Learning from the past - planning for the future

  1. 1. Subsea well intervention; Learning from the past – planning for the future UTC 2010 Trond Inge Ramsnes
  2. 2. Beautiful but demanding
  3. 3. Optimising reservoir recovery from subsea fields <ul><li>Increased fluid handling capacity </li></ul><ul><li>Reduced wellhead pressure </li></ul><ul><li>Integrated Operations </li></ul><ul><li>Identify </li></ul><ul><ul><li>Drainage points </li></ul></ul><ul><ul><li>Well intervention needs and opportunities </li></ul></ul>Ambition : increase subsea recovery Cost effective drainage & well intervention
  4. 4. Cumulative wells – Statoil NCS 0 100 200 300 400 500 600 700 1980 1990 2000 2010 Dry trees Wet trees
  5. 5. Learning from the past – planning for the future RLWI Cat B TT riser 2 ⅞ ” CT <ul><li>Platforms only to date </li></ul><ul><li>Spoolable connectors </li></ul><ul><li>Sweep cleanouts </li></ul>TT Drill TTML <ul><li>TTRD platforms and subsea </li></ul><ul><li>CTD (Gullfaks) </li></ul><ul><li>Safe & efficient operations </li></ul><ul><li>Full technical capability including MPD </li></ul><ul><li>Solid base for delivery of through tubing technology </li></ul><ul><li>Backup to RLWI </li></ul><ul><li>Cost efficient </li></ul><ul><li>Data collection </li></ul><ul><li>Light perforating </li></ul><ul><li>Light mechanical wireline </li></ul><ul><li>TTRD </li></ul><ul><li>CTD </li></ul><ul><li>CT/WL intervention </li></ul><ul><li>Maintain motherbore production </li></ul><ul><li>Access by-passed reserves </li></ul><ul><li>Gullfaks, Veslefrikk </li></ul>2000 2002 2003 2004 2009 2013
  6. 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 Oil Sm 3 / D No activity Drill New Maintenance
  7. 7. Addressing challenges – realising opportunities 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 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
  8. 8. Category A RLWI Category B Full range intervention & TTD Category C Drilling and completion • Wireline / tractor only • Limited bha length • 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. 9. 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” & 3 ½” drillpipe) Integrated high capacity coiled tubing package (2 ⅞” / 3 ½”) Full handling of live well returns Semi-submersible rig hull type
  10. 10. LRP/EDP stack on BOP carrier SBOP In rack-back area Key components in riser system
  11. 11. Operational Limitations <ul><li>WSOG </li></ul><ul><ul><li>Position reference </li></ul></ul><ul><ul><li>Propulsion </li></ul></ul><ul><ul><li>Riser system limitations </li></ul></ul><ul><ul><li>Wellhead limitations </li></ul></ul><ul><ul><li>Drift-off / drive-off </li></ul></ul><ul><li>” Zero Moment Position” </li></ul><ul><li>RMS system used as advisory system for rig positioning </li></ul><ul><ul><li>Fatigue monitoring / management </li></ul></ul>
  12. 12. Experience with TT Riser System <ul><li>Pilot operation with new system offshore </li></ul><ul><ul><li>new equipment and procedures </li></ul></ul><ul><ul><ul><li>stepwise and constrained progress. </li></ul></ul></ul><ul><li>Improve cleaning after milling and drilling operations. </li></ul><ul><li>No wear of the high pressure riser detected </li></ul><ul><li>RMS </li></ul><ul><ul><li>High focus – used actively </li></ul></ul><ul><ul><li>Relatively nice weather – low utilization </li></ul></ul><ul><ul><li>High angles in Upper Flex Joint </li></ul></ul>
  13. 13. Protecting Horizontal XT (HXT) – used on all pipe runs - Classification: Internal 2010-04-12 HORIZONTAL XMAS TREE PIGGY BACK WEAR SLEEVE TUBING HANGER NIPPLE PROTECTOR
  14. 14. Through Tubing Drilling (TTD) drilling through existing tubing (completion) Existing production tubing Production packer Whipstock Through Tubing Sidetrack Production from ’motherbore and new sidetrack simultaneously Reservoir SSD CHOKE
  15. 15. Operational experience Åsgard P-4 < 300 kSm3 < 100 kSm3 < 50 kSm3 Decreasing target volume Increasing target count & reserves Additional reserves Cat B enabled
  16. 16. P-4 AH Actual Drilled Wellpath – Geological Cross Section Not Ile 2 & 3 Ror Tilje 3 TVDMSL Tilje 1 & 2 Tilje 4, 5, 6 Ile 1 Garn 3 & 4 Garn 1 & 2 T1 T2 T3 T4 T5 Kick off 3871mMD Garn 3 P-4 H mother bore P-4 AH actual Drilled a world record of 1744m 5 ¾” TTRD sidetrack
  17. 17. Production P-4 <ul><li>Initial production </li></ul><ul><li>approx. 20 000 boe/d </li></ul>
  18. 18. Status Category B Services <ul><li>3 Contractors carrying out FEED (Front End Engineering and Design) in the period March - September 2010; </li></ul><ul><ul><li>Aker Oilfield Services </li></ul></ul><ul><ul><li>Helix WellOps </li></ul></ul><ul><ul><li>Saipem </li></ul></ul><ul><li>Bid process ongoing – bid due mid October </li></ul><ul><li>An 8 years “Cat B Services Contract” will be awarded this year </li></ul><ul><ul><li>Operations commencement Q3 2013 </li></ul></ul>
  19. 19. Subsea well intervention; Learning from the past – planning for the future Trond Inge Ramsnes Project Leader Well Intervention, tel: +47 51 99 00 00 Thank you