Post on 14-Oct-2014
transcript
L3 - DRILLING & SUBSEA WELLHEADS
• EXPLORATION METHODS
• RESERVOIR MODELLING AND DRILLING PROGRAMME
• TYPICAL SUBSEA WELLS
• OFFSHORE DRILLING VESSELS
• DRILLING A SUBSEA WELL
• WELLHEADS – Design & Function
• WELLHEADS - Connection to BOPs and Trees
Mobile Drilling VesselsProduction Platform
Wildcat well
(dry hole)
Appraisal well
(at reservoir boundary)
Development wells
Original Exploration/Discovery well
Satellitewell
Xmas tree
Flowline
Note
Development wells may be vertical wells or more complex extended reach or horizontal wells
WELL TYPES
Reservoir engineering is defined as the application of scientific principles to drainage issues arising during the development and production of oil and gas reservoirs.
The science explores the engineering operations involved in analysing the production behaviour of oil and gas wells, including well performance engineering, reservoir aspects of well erformance, restricted flow into the wellbore, rate decline analysis, and fundamentals of artificial lift.
• Build reservoir architecture utilising G&G mapping
• Populate model with reservoir properties utilising G&G integration
• Evaluate production tests
• Flow analysis Water drive, gas injection,water flood, etc.
• Volumetrics
• Reservoir simulation
• Production history match
DEVELOPING THE DRILLING PLAN - Bottom Hole Targets
BRITANNIA FIELD - North Sea
450 m
200 m
1300 m
2600 m
3200 m
120 m
WELLHEAD
OUTER CONDUCTOR
INNER CONDUCTOR
INTERMEDIATE STRING
SURFACE STRING
SEA BED
171/2 ” HOLE
133/8” CASING
121/4” HOLE
95/8” CASING
81/2” HOLE
7” CASING
36” HOLE
30” CASING
26” HOLE
183/4” CASING
BLOWOUT PREVENTOR WHEN IN DRILLING MODE
XMAS TREE WHEN IN PRODUCTION MODE
A TYPICAL NORTH SEA CASING DESIGN
WELLHEAD FIXED TO TOP OF INNER CONDUCTOR
IN PRODUCTION MODE A 5½ “ PRODUCTION TUBING IS HUNG FROM THE WELLHEAD/TREE TO THE RESERVOIR. IT IS PACKED OFF THERE. WHEN THE CASING IS PERFORATED THE OIL FLOWS UP THE PRODUCTION TUBING AND THROUGH THE TREE
LINER
RESERVOIR
JOINT OPERATORS -CONOCOPHILLIPS AND
CHEVRONTEXACO
JACK UP
SEMI-SUBMERSIBLE DRILLI NG RIG
DRILLSHIP
OFFSHORE DRILLING RIGS
Legs sit on seabed
Shallow water
Shallow and Deepwater. Station keeping by Mooring Lines or Dynamic Positioning Thrusters
Normally Deepwater
Station keeping normally using Dynamic Positioning Thrusters
SEDCO EXPRESS
DRILL SHIP
PRIDE AFRICA & ANGOLA - Working in Deepwater Angola
OFFSHORE DRILLING SYSTEM
RUNNING WELLHEAD AND CEMENTING CASING
Casing lowered into funnel up capture on guidebase
RUNNING WELLHEAD AND CEMENTING CASING
Wellhead locked into housing
Subsea Wellheads / Purposes
• To support BOP and seal with well casing during drilling
• To support and sealthe subseaproduction tree
• To support and sealthe well casing
• To support and sealthe production tubing hanger
Subsea wellheads
• Most widely size used : 18” 3/4 (Nom. Bore)
• Other sizes: 13” 5/8 , 16” 3/4 (Brasil) and 21 ” 3/4
• 18” 3/4 x 15 Ksi now available
• Deepwater wellheads designedfor much higher bending and tension loads
Vetco H-4 mandrel profile
Cameron hub profile
Wellhead to casing hangerMetal Seal assembly
Wellhead to casing hangerMetal Seal assembly
Wellhead to casing hangerMetal Seal assembly
High strength load shoulder
Bypass Area
Passive Pre-loadedlockdown system
13 3/8” casing hanger
10 3/4” casing hanger
7” casing hanger – For Glenelg thetubing hanger is at this elevationand replaces the 7” casing hanger
18 ¾” HP wellhead housing
30” conductor
20” casing
13 3/8” casing
10 3/4” casing
C Annulus
B Annulus
A Annulus
TYPICAL SUBSEA WELLHEAD
• Provides a mechanicalconnection and sealingpreparation for the BOP stack and tree.
• Provides landing, locking, and sealingpreparations for the subsequently run casing hangers
Wellhead Housing Joint
Permanent Guide Base
Mounted to the lowpressure conductorhousing. structure withguideposts for guidingequipment onto or into the wellhead, or it may be a guidelineless style withfunnels.
GUIDE BASE WITH 4 STANDARD GUIDE POSTS
SUBSEA WELLHEAD