Sonatrach's Wellheads

INTRODUCTION TO HYDROCARBON EXPLOITATION Development Phase

Introduction to Hydrocarbon Exploitation Development Phase Well Heads

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Introduction

Drilling Engineering - Wellhea ds

All Surface equipment topping off the architecture of a well. It consists of Hangers, Christmas tree and all other hardware suspended with respect to safety and reliability of a well.

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September – October 2005

INTRODUCTION TO HYDROCARBON EXPLOITATION Development Phase

Drilling Eng inee ring - We llhead s

Introduction

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Drilling Engineering - Wellhea ds

Changes in Wellhead Changes in wellhead during a drilling operation are described based on the following  Drilling 17 ½” Hole  Casing 13 3/8”  Drilling 12 ¼” Hole  Casing 9 5/8”  Drilling 8 ½” Hole  Casing 7”  Drilling 6” Hole  Completions

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September – October 2005

INTRODUCTION TO HYDROCARBON EXPLOITATION Development Phase

Drilling Eng inee ring - We llhead s

Drilling 17 ½” Hole  The initial architecture of well consists of bell nipple or conductor.  Only if there is shallow gas-Diverter is used  Surface casing is run in and cemented right to the surface.  Wait on Cement and then mount the Casinghead housing.  Diverter – Its an annular type BOP . – Working pressure is low – Functions to divert any blow out to a flare. ©2005 Abalt Solutions Limited. All rights reserved

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Drilling 17 ½” Hole

Drilling Engineering - Wellhea ds

Casing Head Housing – First Component screwed, welded or forged to surface casing. – In the event casing string gets stuck on the way down, connection can be made only after pipe is cut off and welded. – Bore in upper part of housing can be cylindrical or tapered to support casing hangers and seals for next casing string. – The surface casing and housing support all the casings and BOPs anticipated.

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September – October 2005

INTRODUCTION TO HYDROCARBON EXPLOITATION Development Phase

Drilling 17 ½” Hole

Drilling Eng inee ring - We llhead s

 Assembling BOP – The Wellhead is complete for this drilling phase with mud cross and Operator’s recommended BOP. – Wear bushing locked with locking flange and radial threaded rods inside casing head housing to protect bore from erosion. ©2005 Abalt Solutions Limited. All rights reserved

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Drilling 17 ½” Hole

Drilling Engineering - Wellhea ds

 Pressure Tests – Wellhead must be pressure tested Whenever anything is assembled Whenever anything is dismantled Periodically according to Operator All valves and pair of pipe rams are tested by pumping into annulus via kill line

– Tested using Tester cup – Tool screwed on to end of DP and to 10 to 30m into casing. – All valves and pipe rams are tested

Tester plug – Plug with O rings are rested in casing head – Pipe rams, annular and accessories can be tested. ©2005 Abalt Solutions Limited. All rights reserved

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September – October 2005

INTRODUCTION TO HYDROCARBON EXPLOITATION Development Phase

Drilling Eng inee ring - We llhead s

Drilling 12 ¼” Hole  Drilling with 12 ¼” bit.  9 5/8” casing is run and then cemented up to desired height from shoe.  Wear bushing is removed from casing-head housing.  Casing tensioned and anchored placing weight of 9 5/8” on casing spider and disconnecting flanges between mud cross and CHH.  Lift BOP Structure.  Place Casing Hangers in between 9 5/8” casing and bore of the casing head housing.

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Drilling 12 ¼” Hole  Casing Hangers

Drilling Engineering - Wellhea ds

– Devices to anchor and hang casing strings in the CHH. – Each has slips to hang the casing into tapered section of CHH. – Contains rubber ring sealing assembly. – Types Separate Packers and Hangers Hangers and incorporated packers Automatic hangers. ©2005 Abalt Solutions Limited. All rights reserved

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September – October 2005

INTRODUCTION TO HYDROCARBON EXPLOITATION Development Phase

Drilling 12 ¼” Hole  Casing Head Spools

Drilling Eng inee ring - We llhead s

– Also supports casing strings. – 2 Flanges of different sizes and working pressures Lower flange-same dimension and working pressure as casing-head housing. It has a cylindrical bore and seal system. Upper part-cylindrical or tapered to accommodate casing hangers of next string

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Drilling 8 ½” Hole

Drilling Engineering - Wellhea ds

 Principle is same as preceding phase  Casing string anchored after wear bushing has been removed.  Casing cut-off according to the components that will be assembled on top of 7” string.  Testing/Pack-off flange is connected

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September – October 2005

INTRODUCTION TO HYDROCARBON EXPLOITATION Development Phase

Drilling 8 ½” Hole  Tubing Head Spools

– Identical to double flanged casing-head spools and suspend tubing.

 Tubing Hangers

Drilling Eng inee ring - We llhead s

– Consist of threaded hanger with seal on tapered outside part which corresponds to tubing head. – Held by screws on upper flange of tubing head. – Length of tubing is screwed on to upper female part of hanger. – For dual completions, special tubing head must be used.

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Drilling Engineering - Wellhea ds

Drilling 8 ½” Hole

Dual tubing hanger connection

Well head for 6 ½” Drilling ©2005 Abalt Solutions Limited. All rights reserved

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September – October 2005

INTRODUCTION TO HYDROCARBON EXPLOITATION Development Phase

Drilling Eng inee ring - We llhead s

Drilling 8 ½” Hole

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Drilling 6” Hole

Drilling Engineering - Wellhea ds

 The 7”casing is run in hole and cemented at top of pay zone.  Producing layer is drilled and completed by running 5” liner anchored in the 7” casing.  Casing is perforated and production packer set.  Tubing & hanger are run in.  After BOPs are dismantled, an adapter flange fitting on the tubing head & supporting lower part of master valves completes wellhead. ©2005 Abalt Solutions Limited. All rights reserved

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September – October 2005

INTRODUCTION TO HYDROCARBON EXPLOITATION Development Phase

Blowout Preventers

Drilling Eng inee ring - We llhead s

Pressure control devices that hold and maintain pressure during drilling operations.  Designed to: – Seal off the well when formations are encountered that contain pressure>hydrostatic pressure of drilling mud. – Allow mud circulation & density adjustment according to formation fluids under pressure.  Characterized by: – Make – Type – Nominal size – Working pressure ©2005 Abalt Solutions Limited. All rights reserved

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Blowout Preventers  Characteristics for each Preventer: – Maximum opening diameter allowing drilling bits to pass through. – Opening & closing ratios; ratio between pressure prevailing in well when the Preventer is closed or opened) and hydrostatic pressure required to close or open) the preventers.

Drilling Engineering - Wellhea ds

 Working pressure

– 1000;2000;3000;5000;10,000;15,000 & 20,000

 Nominal diameters

– 30”,29 ”,21 ¼”,20 ¾”,18 ¾”,16 ¾”,13

5/8 ”,11 ”

&7

1/6”

 Make – – – –

Cameron Shaffer Hydril Vetco Gray

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September – October 2005

INTRODUCTION TO HYDROCARBON EXPLOITATION Development Phase

Types of BOPs  Ram type preventers

Drilling Eng inee ring - We llhead s

– Pipe rams – Blind rams – Shear rams

 Annular type preventers  Rotating preventers  Inside preventers

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Types of BOPs  Ram preventers – Pipe Rams

Drilling Engineering - Wellhea ds

 Semi circular openings which match diameter of pipe sizes for which designed.  If more than one size of drill pipe is used, additional preventers must be used on stack.

– Blind rams  Designed to close when no pipe is used.  Will flatten drill pipe if inadvertently closed with drill string in hole, but will not stop flow from well.

– Shear rams  Designed to shear drill string.  Will cause drill string to drop in hole & stop flow from well.  Used mainly when all pipe rams and annular preventers have failed.

Courtesy :Cameron

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September – October 2005

INTRODUCTION TO HYDROCARBON EXPLOITATION Development Phase

Types of BOPs

Drilling Eng inee ring - We llhead s

Pipe rams

Shear rams

Blind rams ©2005 Abalt Solutions Limited. All rights reserved

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Types of BOPs

Drilling Engineering - Wellhea ds

 Annular Preventer – Sometimes called bag-type Preventer – Stops flow from well using a ring of synthetic rubber that contracts in the fluid passage. – Rubber packing conforms to shape pf pipe – Working pressures:  2000 psi  5000 psi  10,000 psi

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September – October 2005

INTRODUCTION TO HYDROCARBON EXPLOITATION Development Phase

Types of BOPs

Drilling Eng inee ring - We llhead s

 Rotating Preventer – This type of Preventer allows the drill string to be rotated & run in or out. – Placed above normal preventers and used for drilling under pressure when low density mud is required. – Used for drilling with air or gas as fluid

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Different BOP Stack combinations  According to IADC:

Drilling Engineering - Wellhea ds

Duty

Working Pressure (psi)

Stack

Light

2000

2-Ram or 1 Bag type

Low Pressure

3000

2-Ram and 1 Bag type

Medium Pressure

5000

2-Ram and 1 Bag type

High Pressure

10,000

3-Ram and 1 Bag type-5000 psi

Very High Pressure

15,000

3-Ram and 1 Bag type-10,000 psi

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September – October 2005

INTRODUCTION TO HYDROCARBON EXPLOITATION Development Phase Different BOP Stack combinations

Drilling Eng inee ring - We llhead s

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BOP Hydraulic Control Systems

Drilling Engineering - Wellhea ds

 Principles – All Bops and wellhead valves are hydraulically actuated & operated. – There is always one line on opening side & one on closing side. – Volume of fluid required to carry out a given number of emergency open/close functions should be specified by operator. – Pressure must be exerted to get a good seal. – Time required to close all BOPs must be calculated.

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September – October 2005

INTRODUCTION TO HYDROCARBON EXPLOITATION Development Phase

BOP Hydraulic Control Systems Several Air/Oil accumulators Set of hydraulic pumps Direct control manifold Remote controlled manifold

Drilling Eng inee ring - We llhead s

   

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BOP Hydraulic Control Systems

Drilling Engineering - Wellhea ds

 Operation – Hydraulic fluid discharged by pumps to accumulators compress a bladder filled with Nitrogen. – Pressure equilibrium between gas & fluid in accumulator. – Gas acts as a spring that expels the oil when circuit is opened by means of one of four way valves that selects the functions. – Hydraulic pumps start & stop automatically and main circuit is regulated at 1500 psi.

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September – October 2005