basics of well completion-ep

Oil Exploration & Production

At the end of this presentation, you will be able to:

•Define completion•Describe the process of completion•List and define the different types of completion•Describe surface control equipments•Define subsea completion

Completion

Agenda


• After exploratory drilling confirms the presence of an oil or natural gas reservoir, the hydrocarbons are brought to the surface.

• Once the design well depth is reached, the formation is tested and evaluated to determine whether the well is to be completed for production, or plugged and abandoned.

• This decision is taken based on the information available on reservoir characteristics.

• To complete the well production, casing is installed and cemented, and the drilling rig is dismantled and moved to the next site.

• A service rig is brought in to perforate the production casing and run production tubing along with downhole equipments.

• The installation of surface safety equipments takes place and production begins.

30’’ CASING

20’’ CASING13 3/8’’ CASING

7’’ LINER

RESERVOIR

SEA BED

PLATFORM

Production casing (9 5/8)

Downhole Equipment

Safety Equipment

Introduction

Completion Process

Completion


Well completion creates a dependable pathway to the surface for the hydrocarbons.

Once the well is drilled, it has to be made readyfor the safe and efficient production of oil.

The term ‘completion’ describes the assembly of Down hole tubulars and other safety equipments that is required to enable the safe and efficientproduction of oil or gas from the well after it has been drilled.

Completion Process

What is Completion?

Completion


Well completion activities include:

• Conducting drill stem test • Setting production casing • Running production tubing along with downhole

equipments• Installing surface safety equipments• Starting production flow

If it is decided that the well will not be completed,then it will be plugged and abandoned.

Well Completion Activities

Completion Process

Completion


Well completion activities include: • Conducting drill stem test • Setting production casing • Running production tubing along with

downhole equipments• Installing surface safety equipments• Starting production flow


Conducting Drill Stem Test (DST)To determine the potential of a producing formation, the operator may order a drill stem test (DST). The DST crew makes up the test tool on the bottom of the drill stem, then lowers it to the bottom of the hole. Weight is applied to the tool to expand a hard rubber sealer called a packer. Opening the tool ports allows the formation pressure to be tested. This process enables workers to determine whether the well can be produced.

Completion Process

Completion


Well completion activities include: • Conducting drill stem test • Setting production casing & perforation • Running production tubing along with downhole



Setting Production Casing

Production casing is the final casing in a well. It can be set from the bottom to the top. Sometimes a production liner is installed. This casing is set the same as other casings, then cemented in place.

Completion Process

Completion


30’’ CASING

9 5/8’’ CASING


PRODUCTION TUBING

SEA BED

PLATFORMBOP

GASOILWATER

RESEVOIR


GASOILWATER

30’’ CASING

9 5/8’’ CASING


7’’ LINER

PRODUCTION TUBING

RESEVOIR

SEA BED

PLATFORM

Only this casing is visible

from outside

Production casing (9 5/8)

WELL HEAD EQUIPMENT

BACK


Running Production Tubing and Downhole EquipmentsA well is usually produced through tubing inserted down the production casing. Oil and gas is produced more effectively through this smaller-diameter tubing than through the large-diameter production casing. Joints of tubing are joined together with couplings to make up a tubing string. Tubing is run into the well similar to casing, but it is smaller in diameter and is removable.

Completion Process

Completion

Well completion activities include: • Conducting drill stem test • Setting production casing & perforation • Running production tubing along with downhole




Installing Surface Safety Equipments

Though the tubings and downhole equipments are present in the well, production cannot start without installing surface control equipments. They are required to prevent uncontrolled oil flow out of the well.

Completion Process

Completion

Well completion activities include: • Conducting drill stem test • Setting production casing & perforation• Running production tubing along with downhole




Starting Production Flow

Production flow is started by ‘washing in’ the well and setting the packer. The pumping in of water or brine to flush out the drilling fluid is called washing in. Usually this is enough to start the well flowing. If this does not work then the flow might be started by pumping high-pressure gas into the well after setting the packer.

Completion Process

Completion

Well completion activities include: • Conducting drill stem test • Setting production casing & perforation• Running production tubing along with downhole


.



Downhole Equipment

The parts of a downhole equipment are:

Completion

Gas Lift Valve

Safety Valve

Hydraulic Control Line

Pump Out Plug

Packer

Completion Process


Well Head

The surface termination of a wellbore that incorporates facilities for installing casing hangers during the well construction phase is the well head.

It is a means by which the production tubing is hung, the Christmas tree and the surface flow-control facilities are installed, in preparation for the production phase of the well. The BOP also sits on top of well head.

The well head is installed on top of the casing before starting to drill. It has two or three sections. Each section has two flanges to facilitate the connections at both the ends.

Surface Control Equipments

Completion

well head Sections

Flanges


Each well head section has three components:

•Casing Bowl•Casing Hanger•Tubing Head


Completion

Components of a Well Head


Each well head section has three components:•Casing Bowl•Casing Hanger•Tubing Head


Completion


Casing BowlThe casing bowl consists of heavy fittings that provide a seal between the casing and the surface. It also supportsthe entire length of casing that is run all the way down the well. This piece of equipment typically contains a grippingmechanism that ensures a tight seal between the head and the casing itself.

Sealing





Completion


Casing Hanger

This is the sub-assembly of a well head that supports the casing string when it is run into the wellbore. The casing hanger provides a means of ensuring that the string is correctly located and generally incorporates a sealing device or system to isolate the casing annulus from upper well head components.





Completion


Tubing Head

The tubing head is a well head component that supports the tubing hanger and provides a means of attaching the Christmas tree to the well head.


Tubing Hanger

The tubing hanger is a device attached to the topmost tubing joint in the well head to support the tubing string.

The tubing hanger is located in the tubing head, with both components incorporating a sealing system to ensure that the tubing conduit and annulus are hydraulically isolated.

The tubing hanger assembly supports the weight of the tubing string and seals the annulus from the upper well head and Christmas tree components. It also provides connections at the surface, which controls the flow of fluids out of the well.


Completion

Anchor bolts to hold tubing

hanger in place


1.5 m

20” Casing Terminates Here

Tubing hanger comes here

Production Casing (9 5/8”)

terminates here

A Section

B Section

C Section

30” Casing Remains Outside

Well Head

Anchor Bolts


Christmas Tree

The assembly of valves, spools, pressure gauges, and chokes that are fitted to the well head of the completed well is called a Christmas Tree. It is used to control the flow of oil through the tubing hanger.

The function of a christmas tree is to:•Prevent the release of oil or gas from an oil well into the environment•Direct and control the flow of formati on fluids from the well

When the well is ready to produce oil or gas, valves are opened and the release of the formation fluids is allowed through a pipeline leading to a refinery.


Completion


Oil which flows from the tubing

is diverted through thispipe to the main header

and from thereto the process platforms

Top part of the C-section of well head

Tubing hanger comes upto this point

Lower Master Valve

Upper Master Valve

Crown/ Swab Valve

Wing Valve



Well Head

Reservoir

Packer

Safety Valve

Gas Lift Valve

X-mas Tree

Tubing hanger

ProductionTubing

Perforation


Pump Out Plug Sump

Oil Well After Completion



Types of Completion

The types of completion include:

Natural CompletionsNatural completions are those in which little or no stimulation is required for production. Sandstone and carbonate systems with good permeability and mechanical stability are ideal for natural completions.

Stimulated CompletionsThese completions are generally applied to improve the natural drainage patterns of hard, low-permeability formations. It is used to remove barriers that prevent easy passage of fluids into the wellbore.

Sand-Control CompletionsSand-control completions support the formation while allowing the flow of fluids. They are performed in young, unconsolidated or less mechanically competent sandstones.

Completion Process

Completion


Completion

Subsea Completions

Subsea production systems are wells located on the sea floor, as opposed to at the surface. The safety equipments are installed underwater on the seabed.

They enable early production from deepwater, remote, and marginal fields.

The evolution of subsea well completions has attracted a lot of attention because they offer a means of producing field extremities not reachable by directional drilling from existing platforms.

They also offer production options where field economics do not justify the installation of one or more additional platforms.

Subsea Completion


Downhole Equipment

The tubings along with the downhole equipment are lowered into the 95/8’’ casing of the well. The parts of a downhole equipment are:

Completion

Gas Lift Valve

Safety Valve


Pump Out Plug

Packer

Packer

Packer is a device consistingof a sealing device, a holding or setting device and an insidepassage for fluids. It expandsexternally to seal the well bore. It helps in blocking the fluids through the annular space between the pipe and the well bore wall. Packers use flexible,electrometric elements that expand. It is set hydraulicallyfrom the surface.

X

Completion Process


Downhole Equipment


Completion

Gas Lift Valve

The gas lift valve is a device installed on a gas lift cylinder or mandrel. Thisdevice is used to control the flow of gas between the exterior and interior of well tubing. It consists of an inlet, outlet, a main valve, a main chamber and so on. The design of the side pocket is such that the components that are installed do not obstruct the flow of production. This enablesaccess to the well bore and theother components of completion.

X

Completion Process

Gas Lift Valve

Safety Valve


Pump Out Plug

Packer


Downhole Equipment


Completion

Safety Valve

A safety valve is a device that is installed in the upper well bore toprovide emergency closure of thechannels that produce oil. The valve has a housing and a movable valve element thatcontrols the flow of fluid in the well.

X

Completion Process

Gas Lift Valve

Safety Valve


Pump Out Plug

Packer


Downhole Equipment


Completion


Hydraulic control line is a device filled with hydraulic fluid and connected to a hydraulic fluid source.

Hydraulic control line is used to operate the safety valve. When the control line is pressurized up to a certain pressure limit, the safety valve opens.Its one end connects at the top of the safety valveand the other end to a pressurizing panel at the surface. It is lowered along with the safety valve while loweringthe tubing string during completion.

X

Completion Process

Gas Lift Valve

Safety Valve


Pump Out Plug

Packer


Downhole Equipment


Completion

Pump Out PlugSince the tubing is open at the bottom, the packer cannot be set as thewhole tubing string needs to be pressurized to set it. So a pump out plug (POP) is used for this purpose.

A steel ball is dropped inside the tubing string from the surface. This goes all the way down and sits on the POP seat at the bottom.

When water is pumped from the top, the ball is pressed against the POP seat and forms a seal. When pressure in the tubing string reaches a certainlimit, the packer is set. This is indicated in the pumping unit in the form of a sharp fluctuation of the pressure reading.

Then the pressure is increased, further, to shear the POP seat pins. This is done to remove the steel ball. When the pins are sheared, the POP seat dropsalong with the ball into the well sump.

X

Well Sump

A well sump is the extra bore space below the perforatedzone that allows the collection of junk for example steel ball.

Completion Process

Gas Lift Valve

Safety Valve


Pump Out Plug

Packer


•In a traditional well, components such as valves control the flow of fluids.

•Screens or gravel packs stop sand from entering the well.

•Pipe joints and packers needed to ensure the well retains its integrity over its producing life.

•However traditional wells do not respond to changing conditions and all the fluids (oil,gas and water) have to be produced together and separated at the surface.


IQ for Intelligent Wells

•Intelligent Wells

•Automatic Surface Interaction/Continuous

•Monitoring/Automatic Flow control/Extensive

•Downhole communication

•Semi Intelligent Wells

•Manual Surface Interaction/Limited

•Downhole communication

•Conventional

•Limited Interaction


•Smart wells offer the possibility to respond to changing conditions.

•Smart wells combine existing state-of-the-art technologies such as wireless technologies,remote sensing capabilities, remote control mechanism and robotic tools.

•Remote sensors can immediately show what is going on in the down hole.

•Valves down the hole can be adjusted, controlling flow or shutting off production at one level and increasing it from another.

•Fluid processing can take place down the hole with gas and liquids being separated by devices such as hydro-cyclones

Smart Wells


Drivers

• Improved Reliability

• Optimum Production leading to longer well and reservoir life.

– Optimization of reservoir drainage

• No mechanical intervention is required freeing up resources.

• Lower Operating Cost

– Less number of work overs

– Decrease Water Production

– Better sand control

• Increase Reservoir Knowledge

– Monitoring of fluid/gas contact zone movements

– Improved reservoir characterization (saturation, structure,

pressure, temperature)


Smart Well •Packers

•Hydraulic or Electrical Control Lines

•Sensors

•Inflow Control Valves ICV

•Surface Control Unit (Monitoring and Remote Operation)


Examples of Controls in Intelligent Wells

Controlling Commingled production

Controlling Down Hole Water Separation

Controlling Down Hole Gas Separation and Re-injection


Application for Intelligent Wells

• Marginal Reserves

• Highly Deviated. Horizontal and MLW

• Deepwater Wells

• High Volume Wells

Shell has about 20 intelligent wells worldwide and is working to increase that number.

One of its showcase pieces is a well in the North Sea’s Brent field. The well produces oil but also has a perforated gas zone up hole that’s opened for a short period each year to meet a gas contract.


Oilfields

Data

Data

Data

Data

Extract

Clean

Transform

Load

Data Store

Data Warehouse

Interpret

Analyze

Communicate

Decide

Partners,Agencies

OperationManagement


Reservoir Management Team

Devise ProcessControl Methodologies

Life CycleCost andBenefits

ModelingProcessesRequiringReal time

Management

Down holeEquipment

Design

Monitor DynamicProduction Data

basics of well completion-ep

Documents

production liner

final casing

efficient production

casing sea bed

downhole equipments

term completion

process of completion

surface control equipments