part 5 perforating techniques

PerforatingPerforating TechniquesTechniques

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CONTENTS

1. Introduction

2. Gun System

3. Gun Types

4. Gun Conveyance

5. Perforating Environment

6. Factors Affecting The Productivity

7. Safety

8. Conclusion. 3

Introduction

4

Perforating Gun

Shaped Charge Bullet

5

ShapedShaped ChargeCharge GunGun ComponentsComponents

Charge Carrier

Explosive Charge

Detonating Cord

Detonator

6

GunGun SystemSystem

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The Liner ¾

The Case ¾

The Explosive ¾

Shaped Charge Components

GunGun systemsystem8

JeJett PenetratinPenetratingg MechanismMechanism

1. Detonation Waves.

2. Liner Collapse

3. Jet Formation

4. Slug Formation

Gun system9

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The Shaped Charge

Shaped Charge Design Parameters

¾Liner Size

¾Liner Geometry

¾Explosive Properties

¾Case Material

¾Charge Size

¾Design Optimization.

GunGun systsystee1mm1

ThThee BulleBullett GunGun

Gun Components:

¾ Gun Body

¾ Igniter

¾ Propellant Charge

¾ Combustion Chamber

¾ Barrel and Bullet

Gun sys1t2em

Gun Types

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Gun Types

Reusable

Shaped Charge Gun Bullet Gun

Expendable(Reusable Hollow Carrier Gun )

Gun Typ14

es

ReusableReusable GunGun (Reusable(Reusable HollowHollow CarrierCarrier Gun)Gun)

Charge

Port Plug

Carrier

Gun Typ15

es

ExpendableExpendable ShapedShapedChargeCharge GunGunExpendable

Hollow Carrier

Charge

Strip

Dome (Recess)

Carrier

Gun Typ16

es

RecoveredRecovered expendableexpendable hollowhollow carriercarrier gungun

Gun Typ17

es

ExpendableExpendable ShapedShaped ChargeCharge GunGun

Expendable hollow carrier

Fully expendable Semi expendable

Charge

Strip

Dome (Recess)

Carrier

18Gun Types

BulletBullet GunGun

z Is not common in use

z Bullet penetration decreases substantially in high strength formation & high strength casing

z The most important applications are:- Hydraulic Fracturing

- Injection Wells

19Gun Types

Gun Conveyance

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GunGun ConveyanceConveyance

1. Wire Line Conveyed Perforating

2. Tubing Conveyed Perforating

3. Coiled Tubing Conveyed Perforating

21Gun Conveyance

ents :

22

1.1. WireWire LineLine ConveyedConveyed PerforatingPerforating

Gun String Compon

1. Cable Head

2. Measurement Devices

3. Auxiliary Weights

4. The Gun

Applications :

1. Completion of Relatively Short Zones.

2. Very High Reservoir Temperature.

3. When the Well May be ShotOverbalanced..

4. Perforating for Squeeze.

WireWire LineLine ConveyedConveyed

PerforPerforaa23tingting

22.. TubingTubing ConveyedConveyed PerforatingPerforating

Gun String Component :

1. Radioactive Sensor.

2. Packer.

3. Firing Head.

4. The Gun.

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rocedure :P

¾ Make up the String

¾ Run String to Depth

¾ Positioning

¾ Installing Surface Equipments

¾ Shot the Gun

¾ Retrieve the String

25TubingTubing ConveyedConveyed PerforatingPerforating

Applications:

1. Large Intervals or Multi Zones Wells

2. Gravel Packed Wells

3. Wells Containing Sour Gases (H2S)

26TubingTubing ConveyedConveyed perforatingperforating

33.. CoiledCoiled TubingTubing ConveyedConveyed PerforatingPerforating

Coiled tubing is high-strength yet ductile steal

tubing ,usually( 1.25-1.5 inch OD).

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Gun String Component

1. Tubing Real

2. Goose neck

3. Injector

4. Stripper

28CoiledCoiled TubingTubing ConveyedConveyed PerforatingPerforating

Application:Used in highly deviated or horizontal wells.

Advantages:

1. Saving Time

2. Minimizing Cost

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PerforatingPerforating EnvironmentEnvironment

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Perforating Environment

Underbalance Overbalance

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Underbalanced-Pressure Perforating

¾ Formation pressure is higher than well bore pressure

¾ Perforating is made after well equipments have been run in

¾ Level of underbalance should be optimized

32PerforatingPerforating EnvironmentEnvironment

Problems

¾ Mechanical Failure of Formation

¾ Movement of Formation Fines

¾ Blowing of The Gun String up The Hole

¾ Casing Collapse

¾ Other Tubular Damage

PerforatingPerforating EnvironmentEnvironment33

Advantages

¾ Provides optimum perforation cleanup and minimum skin

¾ Eliminates the risk of formation damage as a result of completion fluid

¾ Perforations are not plugged by the completion fluid

PerforatingPerforating EnviEnvirr3oo4nmentnment

Overbalanced-Pressure Perforating

¾ Well pressure is higher than formation pressure

¾ Perforations are made Before well equipments have been run in

¾ Wellbore fluid should be selected carefully

¾ Small amount of solids can decrease productivity

¾ Level of overbalance pressure should be minimum


Disadvantages¾ Formation damage results from fluid

invasion¾ Perforations are plugged by the

completion fluid¾ It’s difficult to get all the perforations

behave actively¾ A lot of rig time is required to clean the

perforations¾ Wellbore fluid must be filtered


Advantages

¾ Provides good well performance with clean well fluid and minimum level of overbalance.

Used in the cases of :

- Long Interval

- Over-pressured Gas Reservoir


Factors Affecting The Productivity

of Perforated System

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FactorsFactors AffectingAffecting TheThe ProductivityProductivityofof

1.

PerforatedPerforated System:System:

Number of Effective Perforation

2. Perforation Penetration

3. Characteristics of The DamagedZone

Perforation

4. Number of Shot Directions

5. Perforation Diameter

39Factors Affecting The Productivity

1. Number of Effective Perforations

¾ Are the perforations open to flow

¾ Can be measured by:

- Flow Meter

- Spinner Survey

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2. Perforation Penetration

¾ Increasing penetration length increases productivity

¾ Penetration depends on :

-The Explosive Load

-Shape and Type of Cone Penetration

-The Clearance Between Gun and Casing

Factors Affecting The

Produc4t1ivity

ClearancClearancee EffectEffect

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3-Characteristics of The Damaged

Perforation Zone

Depends on :¾ Formation Type (lime,s.s,…) & Fluid Type¾ Porosity and Permeability¾ Type of Shaped Charge¾ Direction and Level of Differential Pressure

FactorsFactors AffectingAffecting TheThe ProdProduu4cc3

tivitytivity

4. Number of Shot Directions

¾ Angular phasing other than 0 degree increasesproductivity

¾ Going from one direction to two shot direction increases the productivity index by 20%

FactorsFactors AffectingAffecting TheThe

ProducProductt4iivv4ityity

PhasingPhasing (180(180 00 )) Phasing (900)

45Factors Affecting The Productivity

5. Perforation Diameter

¾ Increasing entry hole diameter increasesproductivity index

¾ Perforation diameter depends on :

-Charge Cone (angle,etc )

-Clearance Between Gun and Casing

46FactorsFactors AffectingAffecting TheThe ProductivityProductivity

part 5 perforating techniques

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