1. Lesson 8 Offshore Drilling
PETE 406
Lesson 8
Offshore Drilling

2. Content Inland barges (submersible) Jackup rigs Platform rigs
Wildcats
Shallow water templates
Cantilevered over platform
Platform rigs
Floaters - semi’s and drillships

3. Inland barge Used in swamps, bays, inland water, shallow offshore.
Floated and towed to location
On location these rigs are submerged
Well is drilled
Personnel and supplies are brought in by boat.

4. Noble Drilling’s Cecil Forbes A Jack-Up Rig
Jackup rigs
Noble Drilling’s Cecil Forbes A Jack-Up Rig

5. Jackup rigs Independent legs or mat supported
Some are self propelled to location, but most moved by tugs
On location survey boat surveys location

6. Jackup rigs Legs jacked down to sea floor Hull picked up above water
Rig “pre-loaded”
Seawater pumped out
Jacked up to working “air gap”
Well drilled

7. Jackup rigs Used for both wildcat and development
Shallow water up to ’ WD
Derrick may be fixed or cantilevered

8. Platform rigs
Tendered

9. Platform Rig
Self contained

10. Platform Rig Operations similar to land except: Limited storage space
Crew lives on location
Cementing operations simpler

11. Floating rigs
Semi-submersible
Drill ships

12. Sonat’s George Washington A Semi-Submersible Rig

13. Zapata’s Trader A Drillship

14. Semi-submersible
Marine Riser
Subsea BOP stack

15. Drilling from Floating Vessel
Rig move
Hole opener pulled from storage and prepared for use
Structural casing is measured and brought on deck
Inspect and test riser and BOP system

16. Drilling from Floating Vessel
Water depth at new location verified
Tide tables obtained
Choke manifold inspected and tested
Site surveyed and marked with buoys

17. Drilling from Floating Vessel
Anchor boats on location
Heading adjusted and anchor setting begins

18. Drilling from Floating Vessel

19. Drilling from Floating Vessel
Anchor lines tensioned

20. Drilling from Floating Vessel
Well prepared for spudding
Temporary guide base (A) set
36” Structural hole drilled to 80’ to 200’ BML
30” Structural casing (B) run and cemented with permanent guide base (C) attached C B A

21. k 26” Conductor hole drilled to approx. 1000’ BML
Can be drilled with or without riser
20” conductor casing run and cemented. k

22. lling
Wellhead installed with conductor casing

23. While WOC riser and stack are N/U and latched onto the wellhead
Control pods

24. Surface hole drilled to 3000’ to 5000’ BML
Surface casing is run and cemented through riser and BOP’s

25. Floating Drilling Float collar drilled out and casing tested
Float shoe drilled out and 5’ to 15 feet of new formation drilled
Hole is circulated and conditioned
Casing seat is tested

26. Intermediate hole drilled to just above target zone and logged
Intermediate casing set, cemented and tested
Intermediate casing drilled out
Hole circulated and conditioned
Casing seat tested

27. Production hole drilled to TD and logged
Production casing or liner run and cemented
Well completed and tested

28. Floating Drilling After testing, hole prepared for abandonment
P&A, PNA
TA, T&A, TNA
Perfs squeezed, and cement plugs set according to regulatore rules and regulations

29. Floating Drilling Riser and BOP retreived
Casing cut approx. 10’ BML if PNA
Temporary and permanent guide base retrieved
Anchors pulled
Vessel under way to next location