5. well completion

8/13/2019 5. Well Completion

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WELL COMPLETIONCASINGING. JOHN HARRY RAMIREZ

UNIVERSIDAD SURCOLOMBIANA


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OVERVIEW

Once the design well depth is reached, the formationmust be tested and evaluated to determine whetherthe well will be completed for production, or pluggedand abandoned.

To complete the well production, casing is installedand cemented and the drilling rig is dismantled andmoved to the next site.

A service rig is brought in to perforate the production

casing and run production tubing. If no further pre-production servicing is needed, the christmas tree isinstalled and production begins.


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WELL COMPLETION

Well completion activities include: Conducting

Drill Stem Test

Setting Production Casing

Installing Production Tubing

Starting Production Flow

Beam Pumping Units


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PURPOSE

Casing is cemented in place aids the drilling process in severalways:

Prevent contamination of fresh water well zones.

Prevent unstable upper formations from caving-in andsticking the drill string or forming large caverns.

Provides a strong upper foundation to use high-densitydrilling fluid to continue drilling deeper.

Isolates different zones in the drilled formations from oneanother.

Seals off high pressure zones from the surface, avoidingpotential for a blowout

Prevents fluid loss into or contamination of production zones.

Provides a smooth internal bore for installing productionequipment


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DESIGN

In the planning stages of a well a drilling engineer, usuallywith input from geologists and others, will pick strategicdepths at which the hole will need to be cased in order fordrilling to reach the desired total depth. This decision is oftenbased on subsurface data such as formation pressures,

strengths, and makeup, and is balanced against the costobjectives and desired drilling strategy.

With the casing set depths determined, hole sizes and casingsizes must follow. The hole drilled for each casing string mustbe large enough to easily fit the casing inside it, allowingroom for cement between the outside of the casing and the

hole. Also, the inside diameter of the first casing string mustbe large enough to fit the second bit that will continue drilling.Thus, each casing string will have a subsequently smallerdiameter.


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INTERVALS

Typically, a well contains multiple intervals ofcasing successively placed within the previouscasing run. The following casing interval is

typically used in an oil or gas well: Conductor casing

Surface casing

Intermediate casing (optional)

Production casing

Production liner


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CEMENTING

Cementing is performed by circulating a cement

slurry through the inside of the casing and out

into the annulus through the casing shoe at the

bottom of the casing string.


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Well completionallows the

flow of petroleum or natural gasout of the formation and up to

the surface.

It includes;

strengthening the well hole with

casing,

evaluating the pressure and

temperature of the formation,

installing the proper equipmentto ensure an efficient flow of oil

and natural gas out of the well.

WELL COMPLETION


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Installing casing in the well is an

important part of both the drillingand completion process.

WELL COMPLETION

Casing is used;

-to strengthen the sides of the well hole,-ensure that no oil or natural gas seeps out of thewell hole as it is brought to the surface

-to keep other fluids or gases from seeping into the

formation through the well.

Cement is then forced into the annulus btw the

casing and the borehole wall to prevent fluid

movement between formations.


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Some of the casing

strings:Drive or Structural Casing

Conductor Casing

Surface Casing

Intermediate Casing

Liner String

Production Casing

WELL COMPLETION

The production casing or oil string is the final casing formost wells. It provides a conduit from the surface of the

well to the petroleum producing formation.


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Casing must be perforated to allow liquids to flow into

the well. This is a perforated completion.

PERFORATING

The most common method of

perforating is using shaped-charged

explosives.

A perforating gunis lowered into thewell opposite the producing zone on a

wire line& fired by electronic means

from the surface. After perforations are

made, the tool is retrieved.

Perforations are simply holes throughthe casing and cement, extending intothe formation.


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The well is not produced through the casing. A small

diameter pipe, called tubing, is used to transmit oil or gasto the surface.

WELL COMPLETION

A device called packerthat

fits around the tubing is

lowered just above theproducing zone.

It expands and seals off the

space between the tubing and

the casing, forcing theproduced fluids to enter the

tubing to the surface.


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WELL COMPLETION

When casing is set, cemented and perforated and

when the tubing string is run then a collection of valves,

called Christmas treeis installed on the surface at the

top of the casing.

It contains tubes and valvesthat control the flow of

hydrocarbons and other fluids

out of the well.

Usually, once the Christmas

tree is installed, the well can

truly be said to be complete.


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Design

Criteria

Data Inputs to Formulating

Design Criteria

ReservoirParameters

Fluid

Characteristics

Rock

Characteristics

Production

Constraints

Well and

Completion Evaluation

ECAPETROL - ENGLISH COURSE


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Design Criteria

ReservoirParameters

Geological

Structure ContinuityDrive

Mechanism

Physical

Characteristics

Structural Trap

Stratigraphic Trap

Unconformities

Combinations

Salt Domes

Permeability Barriers

Permeability Contrasts

Isotropy

Water Drive

Gas Cap

Solution Gas

Combination

Size

Shape

Thickness

Pressure

Temperature

Water Depth



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Geological Structure

Fault or Structural

Trap Unconformity or

StratigraphicTrap

Gas

Oil

WaterWater

Oil

Impervious Shale

Impervious Shale

(IMPERMEABLE)



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Geological Structure

Anticline Salt Dome

Water

Oil

Salt

Water

Oil

Cap Rock



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Rock

Characteristics

LithologicalDescription

Physical

Properties ChemicalComposition

Clastic

ChemicalPrecipitate

Biochemical

Precipitate

Porosity

Permeability

Consolidation

Pore Size distribution

Fluid Saturation's

Grain Size & Shape

Wetability

Moveable Fines

Composition

Contamination

Clay Content

Cementaceous Material

Scale Forming Materials



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Fluid

Characteristics

PhysicalProperties

ChemicalProperties

Oil DensityGas Gravity

Viscosity

Pour Point

G.O.R.

W.O.R.

Surface Tension

Composition

WaxContent

Corrosive Agents

Asphaltenes

Toxic Materials

Scale



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Production Constraints

Legislative

Considerations

EnvironmentalPolitical

System

Technical

Factors

Productivity

Separator Capacity

& Pressure Rating

Export capacity

Workover

Considerations

Operational

Flexibility

Taxation

Investment IncentivesMarket Requirements

Ease of Access

Weather Conditions

Built-up Areas

Local Industries

Safety

Standards

Disposal of Gas

& Water

Company Objectives

Cash Flow

Preferred Payback period

Ultimate Recovery

Production profile



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Production Zone Preparation

Drilling Activities Completion ActivitiesEvaluation Activities

Hole Size

Deviation Programme

Formation Damage

(Drilling fluids)

Coring

Testing

Logging

Fluid

Sampling

Casing Schemes

Primary Cementation

Design Criteria



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Mechanical Completion

Completion

Programme

Completion Fluid

Perforating Programme

Space Out

Essential Production

Equipment

Wellhead

S.S.S.V

Packer

Ancillary String

Components

Improving Performance

Flow Couplings

Tubing Seals

Blast joints

Operational Flexibility

Nipples

Circulating Devices

S.P.M.

Installation Procedure Equipment Design &

Selection



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ProductionInitiation

Production Initiation Phase

Inducing Flow

Gas lift Nitrogen Injection

With Coil Tubing

Displace Fluid

Cushion

Clean Up Programme

Initial Rate & Subsequent

Rate of increase

Well Test

Evaluation

Stimulation Function

Restore

Permeability

Increase

Permeability

Extent

Matrix Wellbore

Type of

treatment

Acidization

Fracturing

Surfactant



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Integration of Well Completion Phase

1 Establish Design Criteria.

2 Preparation of Production Zone.

3 Design and Installation of Completion String.

4 Production Initiation & Remedial Measures.

5 Monitoring Well & Completion Performance.

Update Design Criteria

Well Workover



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Properties of Drilling Muds

- Viscosity

- Specific Gravity

- Filtrate

Functions of Mud

SKIN damage to formation in contact with

mud



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Functions of Casing

1) Support the bore hole and prevent caving

2) Isolateshallow unconsolidated zones

3) Provide support for wellhead and BOP equipment and subsequentcasing strings

4) Provide sufficient fracture gradient to allow drilling of next hole section



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Production Liner

Surface Casing

Intermediate Casing

Production Casing

Conductor Pipe



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Casing Depths

Depth 3P 3

Depth 1P 1 F 1

Depth 2 F2

P 2

1

2

3

Pressure

D

e

p

th

Pore Pressure

Fracture Pressure



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Purpose of Cementing

1) Strengthens(FORTALECER)and supports the casing

2) Protects against corrosion

3) Prevents fluid migration

4) Seals around casing shoe to allow control of

formation pressures while drilling ahead



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Liners

12 Reasons for running a liner shown on Page 27Know 3-4 of these



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ANY QUESTION SO FAR????

THANKS FOR LISTENING


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GLOSSARY

SHAPE: FORMA

WAX: CERA

CAVING: CAVERNA

ISOLATE: SEPARAR


5. well completion

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