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IQPC HPHT 2009 241109 final1
- 1. 18th Nov 2009 CulzeanHPHT: Lessons Learnt From Maersk Oil UK’s 1st HPHT Exploration Well & Issues Related to Appraisal Planning Jim Manson, Culzean Drilling & Completion Team Leader IQPC HPHT Conference
- 2. 22 June, 2016 2 PresentationOutline • Culzean Prospect Background Information • Culzean Exploration Well • Well Design Issues • Planning Issues • Results - High Level Summary & Lessons Learnt • Culzean Appraisal Well Planning • Appraisal Well Challenges & Objectives • Appraisal Well Design • Appraisal Keeper Wells? • Culzean Development Well Planning Issues
- 3. 22 June, 2016 3 PresentationOutline • Culzean Prospect Background Information • Location, Geology, History Timelines, Challenges • Culzean Exploration Well • Well Design Issues • Planning Issues • Results - High Level Summary & Lessons Learnt • Culzean Appraisal Well Planning • Appraisal Well Challenges & Objectives • Appraisal Well Design • Appraisal Keeper Wells? • Culzean Development Well Planning Issues
- 4. 22 June, 2016 4 10km 242km from Aberdeen to Culzean Heron Marnock Elgin, Franklin & Shearwater Jackdaw NO. UK. Culzean Prospect Location Culzean Prospect: 49.99% Maersk Oil NS UK Ltd 16.9% ENI UK Ltd 17.1% Nippon UK 16% BP
- 5. 22 June, 2016 5HPHTProvince with offset fields (After Winefield et.al. 2005) Culzean 22/25a-9z O/P circa 6500psi Temperature ~380 degrees F
- 6. 22 June, 2016 6 CulzeanSeismic Section West to East Source: United Kingdom Discovery Digest. Special thanks to CGG Veritas
- 7. 22 June, 2016 7 CulzeanProspect Timelines • Exploration well 22/25a-1 drilled 1986 by BP • Dormont until operatorship transferred to Maersk Aug 05 • Maersk Conceptual Planning/Discussions from 2002 • Provisional Casing Design – June 05 • Long Leads ordered May 06 • Exploration Well, 22/25a-9/9Z • Spud - May 08 • P& A – Dec 08 • Drilled utilising Ensco 101 HDJU Rig • Appraisal Well Planning Started Jan 09 • Planned Two Well Appraisal Campaign • 18 month planning phase • Planned Spud Appraisal 1 – Jul 10
- 8. 22 June, 2016 8 CulzeanExploration Well Challenges • Limited offset wells – 22/25a-1 well drilled in 1986 by BP. Littered by drilling problems, failed to reach TD. Extensive well control issues , including classic wellbore breathing. Limited detailed information on this well. • High geological uncertainty. • High Pressure Uncertainty - BHP Range 17.0 ppg to 18.5 ppg emw • ~380 deg F BHT. • Drill close to crest - Narrow window between PP & FG - potentially un-drillable! OVERALL CHANCE OF DRILLING SUCCESS =53% Breakdown of 47% Drilling Risk of Failure: Risks 1 to 3 – Potentially too narrow and un-drillable drilling window 1. Aquifer Overpressure Greater than Predicted = 20% 2. Sand above the target reservoir =2.5% 3. Fracture Gradient Less than Estimated =25% 4. Problematic Gas in Hidra =10%
- 9. 22 June, 2016 9 PresentationOutline • Culzean Prospect Background Information • Culzean Exploration Well • Well Design Issues • Well Objectives • Non DST/Finder Well Rational • Well Design Options • Planning Issues • Results - High Level Summary & Lessons Learnt • Culzean Appraisal Well Planning • Appraisal Well Challenges & Objectives • Appraisal Well Design • Appraisal Keeper Wells? • Culzean Development Well Planning Issues
- 10. 22 June, 2016 10 CulzeanExploration Well Well Objectives • Drill a safe and incident free well. • Reach well planned TD. • Penetrate all reservoir prospects. • Successfully log all reservoir prospects. • In success case, MDT pressures and samples over reservoir prospects. • No Coring • No DST to be carried out. • P&A.
- 11. 22 June, 2016 11 CulzeanExploration Well Non DST/Finder Well Exploration Rational • Chances of Exploration Success? • Extra cost to include DST considerations in casing design. • Final hole size drives well design. • HPHT DST standard tools – 5” OD • Test tools as close to perforations as possible ( well kill volumes & complexity if testing with a drilling liner) • Thus preferred 8 ½” hole x 7” liner at TD for DST well. • Heavier casing design required – HPHT Heavy vs HPHT Light • Increased loads – Increase casing specification – Increased costs (10 ¾” - 9 7/8” up to £1.0m more, 13 5/8” or 14” vs. 13 3/8”) • DST Long Leads ~£1m • Contingency tie-back string ~ £1m. • DST planning – manpower and hours • Total Cost Differential ~ £8m- £10m less for Non/DST Finder “Light” design
- 12. 22 June, 2016 12 CulzeanExploration Well Non DST/Finder Well Exploration Rational (Cont’d) Worked Example: Eg. Chance of Exploration Success - 1 in 7 or 14.3% Expected Cost to go to Development? Conclusion: Culzean Exploration - Non DST, P & A HPHT Light £49m/well HPHT Heavy £59m/well HPHT Light/Finder (£M) HPHT Heavy (£M) 7 Exploration Wells 343 413 Test Exploration Well 0 19 1 Appraisal Well 59 49 Test Appraisal Well 19 0 Total To Go To Development 421 481 60Cost Saving with Finder Exploration Concept
- 13. 22 June, 2016 13 22June, 2016 13 Culzean Exploration Well Design Options : HPHT “Heavy” vs HPHT “Light” 36” x 26” hole 26” x 20” Conductor set @ 3000ft 16” or 17 ½” hole 13 5/8” Intermediate casing set ~ 11,000ft to ~12,000 ft 12-1/4” hole 10 ¾” x 9 7/8” Production casing set ~14,000ft to ~15,000ft 8-1/2” hole 7” Test liner set @ TD ~17,000ft HPHT “Heavy” HPHT “Light” 36” x 26” hole 26” x 20” Conductor set @ 1900ft 16” or 17 ½” hole 13 3/8” Intermediate casing set ~ 5,000ft to ~6,500 ft 12-1/4” hole 9 7/8” Production casing set ~13,500ft to ~14,000ft TD in 8 1/2” hole
- 14. 22 June, 2016 14 22June, 2016 14 Casing Setting Depths - Contingency 8-1/2” hole 7” Drilling liner set @ ~14,400ft 5-7/8” hole 4 ½” Test liner set @ TD HPHT “Heavy” 16” or 17 ½” hole 13 5/8” Intermediate casing set ~ 11,000ft to ~12,000 ft 12-1/4” hole 10 ¾” x 9 7/8” Production casing set ~14,000ft HPHT “Light” 12-1/4” hole 9 7/8” Production casing set ~13,500ft to ~14,000ft 8-1/2” hole, 7 5/8” Drilling liner 6 5/8”” hole 6” by 7 5/8” SET , then 6” hole TD in 6 5/8” or 6” hole Culzean Exploration Well Design Options : HPHT “Heavy” vs HPHT “Light”
- 15. 22 June, 2016 15 CulzeanExploration Well HPHT “Heavy” Design Pro’s • 12 ¼” hole can be drilled deep into PTZ • Increased chance of higher FG at 9 7/8” shoe and TD in 8 ½” hole. Con’s • Slower to drill, heavier and more expensive design • Drilling hard abrasive Palaeocene & chalks in slower 16” or 17 ½” hole. • Increase volume OBM cuttings for containment
- 16. 22 June, 2016 16 ExplorationWell Planning HPHT “Light” Design – Chosen Exploration Well Design Pro’s • Slimmer, faster, cheaper design • Drilling hard abrasive Palaeocene & chalks in quicker 12 ¼” hole. • WBM 17 ½” section. • Possible further expandable liner option available just to reach TD objectives. • Possible further optimisation of deletion of separate 20” casing string. Con’s • Due to weak Palaeocene/Tor formations, 12 ¼” hole cannot be drilled deep into PTZ. • Less chance of TD in 8 ½” hole. • Not a problem – no DST or coring required.
- 17. 22 June, 2016 17 PresentationOutline • Culzean Prospect Background Information • Culzean Exploration Well • Well Design Issues • Planning Issues • Results - High Level Summary & Lessons Learnt • Culzean Appraisal Well Planning • Appraisal Well Challenges & Objectives • Appraisal Well Design • Appraisal Keeper Wells? • Culzean Development Well Planning Issues
- 18. 22 June, 2016 18ExplorationWell Planning Planning • Maersk HPHT Experience • 1st Maersk UK HPHT Exploration well. • Gain knowledge & experience. • Hire/Recruit • Networking: HPHT Operators Forum, Conferences, Contacts? • Lead times – realistically >2 years, or more • G & G review prospect – ? years • Detailed casing/design iterations w/ G&G – 1year • Lead time on bespoke equipment – 1 year. • Integrated/Interdisciplinary Approach Essential. • Service Providers into Team early. • Management Of Stakeholders? • Partners, Management, All Disciplines, HSE, Well Examiner • Alignment, Inform, Draw on HPHT experience
- 19. 22 June, 2016 19 PresentationOutline • Culzean Prospect Background Information • Culzean Exploration Well • Well Design Issues • Planning Issues • High Level Summary & Lessons Learnt • Culzean Appraisal Well Planning • Appraisal Well Challenges & Objectives • Appraisal Well Design • Appraisal Keeper Wells? • Culzean Development Well Planning Issues
- 20. 22 June, 2016 20 CulzeanExploration Well - High Level Summary Highlights • Challenging Prospect -53% Chance of Drilling Success @ Crestal Location. • Achieved planned well TD, meeting ALL Well Objectives. • Close to not achieving objectives through PTZ! • Narrow PPFG window , Utilised contingency 7 5/8” Liner to open up. • Milestones: • 9 7/8” Casing on depth, Well Cemented, Coped with High PP on bottom and loss zone above. • 7 5/8” , As Above. Lowlights • 8 ½” Kick – Poor Offshore Practices and decision making – should have been better handled. • 17 ½” Hole – 13 3/8” Casing stood-up, section re-drill required.
- 21. 22 June, 2016 21 Justsome of the PPFG Models ! Depth Pressure (ppg) Pore Pressure Forties Lwr. Cretaceous Top Reservoir Fracture Gradient Point of Note: HPHT Geological Surprises • Expect surprises. • Multiple PPFG Models • Plan for the extremes of PPFG – cover all the bases! • Build in maximum flexibility in well design to achieve objectives. • Gathered some information, but still many unknowns on prospect. Culzean Exploration Well
- 22. 22 June, 2016 22 PresentationOutline • Culzean Prospect Background Information • Culzean Exploration Well • Well Design Issues • Planning Issues • Results - High Level Summary & Lessons Learnt • Culzean Appraisal Well Planning • Appraisal Well- Challenges & Objectives • Appraisal Well Design • Appraisal Keeper Wells? • Culzean Development Well Planning Issues
- 23. 22 June, 2016 23 AppraisalWell Planning Appraisal Well -Challenges & Objectives • Challenges • Crestal Locations • Still with major geological uncertainty • one appraisal, one exploration well. • Seismic formation top accuracy. • Pore pressure uncertainty • Aquire sufficient key data for ascertaining economic development • DST, Cores, Fluid Data, Log Data • Sufficient data to proceed to project sanction. • Aquire sufficient data for detailed development design.
- 24. 22 June, 2016 24 PresentationOutline • Culzean Prospect Background Information • Culzean Exploration Well • Well Design Issues • Planning Issues • Results - High Level Summary & Lessons Learnt • Culzean Appraisal Well Planning • Appraisal Well Challenges & Objectives • Appraisal Well Design • Appraisal Keeper Well? • Culzean Development Well Planning Issues
- 25. 22 June, 2016 25 AppraisalWell Design • Exploration Well HPHT ”Light” Design & 12 ¼” TD • Achieved ”All” well objectives, still had one more contingency hole size available. • However, went too deep into PTZ w/ shallow 13 3/8” shoe. • Weak zone(s) in Paleocene (Forties) and/or top Tor. • Design incompatible w/ drive 9 7/8” shoe as deep as possible into PTZ. • Exploration Well - Needed Contingency Liner Option to Negotiate PTZ. • Appraisal well - DST Required from multiple zones • Conclusion: HPHT ”Heavy” Design required with deep set 13 5/8” Casing. • Optimum setting depth for 9 7/8” shoe? As deep as possible, preferably the Valhall. • 13 5/8” shoe depth? To facilitate above.
- 26. 22 June, 2016 26 22/25a-9zFracture Pressure in Tor ft/hr 0.2 2 20 200 ohmm 200 0 low resistivity high ROP higher porosity weaker formation
- 27. 22 June, 2016 27 22June, 2016 27 Culzean Exploration Well Design Options : HPHT “Heavy” vs HPHT “Light” 36” x 26” hole 26” x 20” Conductor set @ 3000ft 16” or 17 ½” hole 13 5/8” Intermediate casing set ~ 11,000ft to ~12,000 ft 12-1/4” hole 10 ¾” x 9 7/8” Production casing set ~14,000ft to ~15,000ft 8-1/2” hole 7” Test liner set @ TD ~17,000ft HPHT “Heavy” HPHT “Light” 36” x 26” hole 26” x 20” Conductor set @ 1900ft 16” or 17 ½” hole 13 3/8” Intermediate casing set ~ 5,000ft to ~6,500 ft 12-1/4” hole 9 7/8” Production casing set ~13,500ft to ~14,000ft TD in 8 1/2” hole
- 28. 22 June, 2016 28 22June, 2016 28 Casing Setting Depths - Contingency 8-1/2” hole 7” Drilling liner set @ ~14,400ft 5-7/8” hole 4 ½” Test liner set @ TD HPHT “Heavy” 16” or 17 ½” hole 13 5/8” Intermediate casing set ~ 11,000ft to ~12,000 ft 12-1/4” hole 10 ¾” x 9 7/8” Production casing set ~14,000ft HPHT “Light” 12-1/4” hole 9 7/8” Production casing set ~13,500ft to ~14,000ft 8-1/2” hole, 7 5/8” Drilling liner 6 5/8”” hole 6” by 7 5/8” SET , then 6” hole TD in 6 5/8” or 6” hole Culzean Exploration Well Design Options : HPHT “Heavy” vs HPHT “Light”
- 29. 22 June, 2016 29 AppraisalWell Planning HPHT “Heavy” – Chosen Appraisal Design Pro’s • 12 ¼” hole can be drilled deep into PTZ • Thus increased chance of FG at 9 7/8” shoe enabling TD in 8 ½” hole. • Implications of 7” Drilling Liner • DST well kill distance from perforations. • DST well kill volumes. • DST multiple zone testing – mill packer or re-use. • 5 7/8” hole – limitations on logs , smaller core- limitations on modelling Con’s • Slower to drill, heavier and more expensive design • Drilling hard abrasive Palaeocene & chalks in slower 16” or 17 ½” hole. • Increase volume OBM cuttings for containment
- 30. 22 June, 2016 30 PresentationOutline • Culzean Prospect Background Information • Culzean Exploration Well • Well Design Issues • Planning Issues • Results - High Level Summary & Lessons Learnt • Culzean Appraisal Well Planning • Appraisal Well Challenges & Objectives • Appraisal Well Design • Appraisal Keeper Wells? • Culzean Development Well Planning Issues
- 31. 22 June, 2016 31 CulzeanAppraisal - Keeper Well? Prize? • ~£80m/appraisal well , P & A ? • + ~£80m/development well = £160m • Keeper – Potential to save £15m to £30m/development well? Issues? • Assumed dry tree development. • No fully qualified & field proven HPHT MLT equipment. • Integrity at MLT? ( multiple use, MTM seal, Incaloy material, verticality etc.) • Alternative Shallow or Deep Tie-back options? • Tie-back operations - Complex, multiple operations. Poor success in past. High risk of failure. • Uncertainty on appraisal prospect – Size? Shape? Variability? Compartmentalisation? Upside? Downside? • Appraisal surface location drives platform location? • High risk of non-use , and potential high later abandonment costs. • Early installation of wellhead jacket ? – time & cost! Conclusion? • Tie-back Low Chance of Success, High Chance of Cost Over-Run • P & A appraisal well. • Review Keeper options for further potential appraisal wells. Prize? • HPHT Mudline tie-back? Alternative Approach? Service Sector?
- 32. 22 June, 2016 32 PresentationOutline • Culzean Prospect Background Information • Culzean Exploration Well • Well Design Issues • Planning Issues • Results - High Level Summary & Lessons Learnt • Culzean Appraisal Well Planning • Appraisal Well Challenges & Objectives • Appraisal Well Design • Appraisal Keeper Wells? • Culzean Development Well Planning Issues
- 33. 22 June, 2016 33 DevelopmentWell Planning Issues • Timelines • Earliest spud of development wells on critical path to 1st hydrocarbons • Depletion drilling challenges? • Earliest installation of wellhead jacket? • Concurrent development planning with appraisal drilling. • Still many unknowns • Size, Productivity, Homogeneity, Connectivity • Fluids • Conceptual Casing & Completion Designs • All the issues & input parameters • HPHT Light vs. HPHT Heavy! • Knowledge & Experience?
- 34. 22 June, 2016 34 CulzeanHPHT: Lessons Learnt From Maersk Oil UK’s 1st HPHT Exploration Well & Issues Related to Appraisal Planning Jim Manson Culzean Drilling & Completion Team Leader ANY QUESTIONS?