Lesson 8 Offshore Drilling PETE 406 Lesson 8 Offshore Drilling

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

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.

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

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

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

Jackup rigs Used for both wildcat and development Shallow water up to 350-400’ WD Derrick may be fixed or cantilevered

Platform rigs Tendered

Platform Rig Self contained

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

Floating rigs Semi-submersible Drill ships

Sonat’s George Washington A Semi-Submersible Rig

Zapata’s Trader A Drillship

Semi-submersible Marine Riser Subsea BOP stack

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

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

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

Drilling from Floating Vessel

Drilling from Floating Vessel Anchor lines tensioned

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

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

lling Wellhead installed with conductor casing

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

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

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

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

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

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

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