L04 - CHRISTMAS TREES

L4 - X’MAS TREES • X’MAS TREES - DUAL BORE TREES - HORIZONTAL (SPOOL) TREES - VALVES & ACTUATORS - DEEPWATER TREES - ALL ELECTRIC TREE - DRILL THRU SPOOL TREE

18 ¾” HP wellhead housing

Wellhead to casing hanger Metal Seal assembly Bypass Area Wellhead to casing hanger Metal Seal assembly Passive Pre-loaded lockdown system

7” casing hanger – For Glenelg the tubing hanger is at this elevation and replaces the 7” casing hanger 10 3/4” casing hanger 13 3/8” casing hanger Wellhead to casing hanger Metal Seal assembly High strength load shoulder

H-4 Vetco Profile 10 3/4” casing 13 3/8” casing 20” casing 30” conductor A Annulus B Annulus C Annulus

TYPICAL SUBSEA WELLHEAD Cameron Profile

SUBSEA X’MAS TREE FUNCTIONS •

Basically a stack of valves installed on a subsea wellhead to provide a controllable interface between the well and the production facilities.

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Specific functions of a subsea Christmas tree : – Sealing the wellhead from the environment by means of the tree connector – Sealing the production bore and annulus from the environment – Providing a controlled flow path from the production tubing, through the tree to the production flow line. Well flow control by means of tree valves and/or a tree-mounted choke valve. – Providing access to the well bore via tree caps and/or swab valves. – Providing access to the annulus for well control, pressure monitoring, gas lift, etc. – Providing a hydraulic interface for the down hole safety valve. – Providing an electrical interface for down hole instrumentation, electric submersible pumps etc. – Providing structural support for flow line and control umbilical interface.

Horizontal / Spool Tree

Conventional Dual Bore Tree

VALVES PRODUCTION • Master Control Valve • Wing Valve • Swab Valve or Plug VALVES – ANNULUS • Control * Wing Valve • Swab Valve

2” Tubing

5 1/2 Tubing

TREE VALVES

CROSSOVER VALVE

5 1/2, 7” or 9 5/8 Tubing

FAIL SAFE HYDRAULIC ACTUATOR Gate Valve Slide

Bore with Gate in open position Valve stem moved by hydraulic fluid

Actuator Spring compressed If hydraulic pressure is lost to the actuator (by design, activated by the control system OR if in an emergency the umbilical is cut) then the spring returns the valve to a safe closed position

Dual Bore X’Tree • Designed to allow vertical access to the main production bore and to the annulus bore during installation and workover operations. • When a dual bore subsea Christmas tree is connected to a subsea wellhead it must interface with the tubing hanger previously installed in the wellhead. The tubing hanger and tree must be correctly orientated so that the production and annulus bores are properly aligned and sealed. • Accomplished by interaction of a pin and helix between the tubing hanger running tool and the BOP

DUAL BORE TREE SUBSEA X’MAS TREE MANUFACTURERS •

COOPER CAMERON

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FMC KONGSBERG

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VETCO GREY

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KVAERNER NATIONAL

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DRILQUIP

X’MAS TREE SCHEMATIC WITH CONTROL SYSTEM

Note all control functions pass through the Tree Cap. With Tree Cap removed the control functions can be taken over by a drilling rig.

DUAL BORE X’MAS TREES

OSENBERG Tree

DRIL QUIP Showing Protection frame

Horizontal X’Trees •

“Side valve tree” or SpoolTree™.

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Most obvious distinction from the dual bore tree: the production and annulus bores branch horizontally out of the side of the tree body /valves on a horizontal axis.

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No production or annulus swab valves. Access to the well bore by removing the internal tree cap, or a wireline plug within the internal tree cap.

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Other distinguishing features of the horizontal tree: 1. 2.

the tubing hanger is installed in the tree itself, rather than in the wellhead and the top of the tree is designed so the BOP may be landed onto the tree. This arrangement allows the tubing string to be recovered without first retrieving the tree.

HORIZONTAL TREE 5.5” TUBING WITH 4” PRODUCTION CHOKE & 2” GAS LIFT CHOKE

KEY PWV = PRODUCTION WING VALVE XOV = CROSSOVER VALV PMV = PRODUCTION MASTER VALVE AAV = ANNULUS ACCESS VALVE AMV = ANNULUS MASTER VALVE AWV = ANNULUS WING VALVE SCSSV = DOWNHOLE SUBSURFACE SAFETY VALVE DHPTT = DOENHOLE P & T TRANSDUCERS

CAMERON HORIZONTAL - SPOOL TREE

TREE PROTECTION

INSTALLATION USING GULDE WIRES

Tree being run on Guide wires from Drilling Rig with Running Tool

DEEPWATER GUIDELINELESS TREE

CAMERON ALL ELECTRIC TREE 1. ELECTRICALLY ACTUATED PRODUCTION GATE VALVE 2.

ELECTRICALLY ACTUATED ANNULUS GATE VALVE

3.

ELECTRICALLY OPERATED CHOKE

4.

ELECTRICALLY ACTUATED CHEMICAL INJECTION VALVE

5.

ELECTRIC SUBSEA CONTROL MODULE

6.

POWER REGULATION AND COMMUNICATIONS MODULE

RUNNING WELLHEAD AND CEMENTING CASING

Wellhead locked into housing

INSTALLING THE X’MAS TREE

Tree run in drill string using running tool

INSTALLING THE X’MAS TREE

Funnel down capture of tree on wellhead

RUNNING BOP AND TESTING

RUNNING BOP AND TESTING

RUNNING BOP AND TESTING

INSTALLING THE CASING

Drill bit passing through BOP

INSTALLING THE CASING

Drill bit enters top of tree – see tree bore protected by liner

INSTALLING THE CASING

Drill to required depth and retrieve drill