Perforating Presentation

8/11/2019 Perforating Presentation

1/29

SchlumbergerConfidential

Perforating

Manuel Enrique Nieves Plata

Especialista DSTTCP


2/29

3

1 February 2013


Basics


3/29

4

1 February 2013


What is Perforating?

A perforating gun is lowered into a

well and placed opposite a target

formation

The gun is fired by initiating an

electric or percussion detonator

Shaped charges housed inside the

gun pierce the casing, cement andformation

Fluids can now flow into the wellbore


4/29

5

1 February 2013

Schlumberg

erConfidential

History of Perforating in Oil Industry

Nitroglycerine: 1860s

Mechanical Cutter:before1932

Bullets: from 1932

Shaped Charge: from 1946

Wireline Perforating: from1946

Abrasive Jetting: from

1958

Tubing Conveyed: from


5/29

6

1 February 2013

Schlumberg

erConfidential

Shaped Charge History

Cavity effect Franz van Bader 1792

Rediscovered by Charles Munroe 1888

Known as Munroe effect in USA and

Neumann effect in Germany

Metal liner effect Early work in Germany, UK, Russia,

Italy , Japan (~1911 onwards)

Effective penetrators designed by Henry

Mohaupt (Switzerland, UK, USA),

Franz Thomenek (Germany) both late

1930s

First oil industry use ~1946-8 by

Mohaupt in USA

Powdered liners Schlumberger 1960s


6/29

7

1 February 2013

Schlumberg

erConfidential

Components of Shaped Charge


7/29

8

1 February 2013

Schlumberg

erConfidential

Explosives

High-energy chemicalreaction releasing gas

Characterized by Speed of reaction

Pressure generated

Sensitivity

Primary High Detonators

Secondary High

Detonators

Boosters

Detonating Cord

Shaped Charges


8/29

9

1 February 2013

Schlumberg

erConfidential

Oil Industry Explosives

RDX (Cyclotrimethylenetrinatramine) 8,750m/s

HMX (Octogen) 9,100 m/s

HNS (HexaNitroStilbene) 7,000 m/s

PETN, TATB, Nona, Tacot, PYX, SX-2

Lead Azide, Silver Azide

Flammable Solids Propellants

Low Explosives


9/29

10

1 February 2013

Schlumberg

erConfidential

How a Shaped Charge Works


10/29

11

1 February 2013

Schlumberg

erConfidential

How a Shaped Charge Works

FormationCasing

Gun


11/29

12

1 February 2013

Schlumberg

erConfidential

Hardware


12/29

13

1 February 2013

Schlumberg

erConfidential

Types of Shaped Charges

Deep Penetrating Pressed powdered metal

Long cones

Big Hole Solid liner

Parabolic

Good Hole

Reactive liners

Low debris:

Zinc or treated Steel

Determined by Liner Material andShape


13/29

14

1 February 2013

Schlumberg

erConfidential

Types of Guns

Capsule Exposed

Wireline

Carrier

Protected

Any conveyor

Special Guns

Pivot Gun

Side-Mounted Gun

OrientXact

Pump-over


14/29

15

1 February 2013

Schlumberg

erConfidential

Tubing ConveyedPerforating

Electronic

Firing Head

eFire (EFI)

Mechanical Firing HeadHDF (Percussion

Detonator)

TCP/DST string

PressureTransducer

Battery

ControllerCircuits

InitiatorCircuits

EFIDetonator


15/29

16

1 February 2013

Schlumberg

erConfidential

Wireline Perforating

Electrical Detonator

Secure Initiator (EFI)


16/29

17

1 February 2013

Schlumberg

erConfidential

Other Types of Deployment

Slickline

Completion

Coiled Tubing


17/29

18

1 February 2013

Schlumberg

erConfidential

Penetration


18/29

19

1 February 2013

Schlumberg

erConfidential

Perforation State

Crushed zone affects by production and injection

Fill, fines or debris affects injection


19/29

20

1 February 2013

Schlumberg

erConfidential

Cleanup Options

Surging Static

Underbalance

D namic Underbalance


20/29

21

1 February 2013

Schlumberg

erConfidential

PURE Dynamic Underbalance

PURE creates a fast DUB at the perforations

Increases effectiveness in cleaning perforations


21/29

22

1 February 2013

Schlumberg

erConfidential

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1-2500

-2000

-1500

-1000

-500

0

500

1000

1500

2000

2500

Perforation Dynamics

Time, sec

Test 7

Test 8

Initial overbalance = 500 psi

Test 9


22/29

Schlumberg

erConfidential

Perforation & PURE Timescale

1 : Gun positioned on depth

Shape Charge Detonation

Gun Pressure : Pg

Pw > Pg

PURE Condition : YES

Pr > Pw > Pg

Perforation Tunnel

&

Reservoir Pressure : Pr

Pressure

Pr

Time ms

Virgin Reservoir :

Pr K

Formation damage

PURE Charge

Shape Charge

Cement

Casing

PURE Condition : Pr > Pw > Pg

With : Pg = Gun Pressure ( Atmospheric pressure before gun fired)

Pw = Wellbore Hydrostatic Pressure ( Underbalance below Pr)

Pr = Reservoir pressure

Pg

Pw

Comments:

Pw is below Pr and corresponds to a desired initial

underbalance pressure

Pg below Pw since Pg is at atmospheirc pressure

Pw

Wellbore pressure : Pw


23/29

Schlumberg

erConfidential


2 : Fire guns


Gun Pressure : Pg

Pw < Pg

Perforation Tunnel

&


Pressure

Pr

Time ms

Virgin Reservoir :

Pr K

Formation damage

Cement

Casing

Timing :

0-15 MicrosecondBirth of jet

High jet tip velocity - 7,000 m/sec.

Pressure in gun ( Pg) increases. Gun Swells

Pg

Pw

Comments:

Gun Pressure Pg is building up inside the Gun

because of gas pressure generated by explosive

deto cord,shaped charge ) combustion.

Gun starts to swell

Pw

Pg

PURE Condition : NO

Pr > Pw < Pg



24/29

Schlumberg

erConfidential


3 : Gun pressure released


Gun Pressure : Pg

Pw < Pg

Perforation Tunnel

&


Pressure

Pr

Time ms

Virgin Reservoir :

Pr K

Formation damage

Cement

Casing

Timing :

15-30 MicrosecondJet interaction with fluid

Jet creates a hole in gun body

Free communication in between inner gun and Wellbore fluid

Pg

Comments:

High gas pressure generated by explosives exits from

gun and gas expends creating a large spike in

pressure in the wellbore

Pw

Pw


PURE Condition : NO

Pr < Pw < Pg

Timing :


25/29

Schlumberg

erConfidential


4 : Creation of perforation tunnel


Gun Pressure : Pg

Pw < Pg

Perforation Tunnel

&


Pressure

Pr

Time ms

Virgin Reservoir :

Pr

Timing :

30-250 MicrosecondCreation of cavity in Rock

High impact pressure : 15 million psi

Jet creates perforation tunnel and allow communication in between

reservoir and wellbore

Pg

Comments: High impact jet on reservoir pulverizes formation

rock grains causing a change in the matrix rock that

results in a low-permeability crushed zone

immediately surrounding the perforation tunnels and

creating potential for migration of fine particles

The process also leaves some residual charge debris

inside the perforations. Gas fully expanded in wellbore

Pw

Pw

Reduced Permeability

Crushed Zone : Kc

Damaged Zone : Kd

PURE Condition : NO

Pr < Pw < Pg


Timing :


26/29

Schlumberg

erConfidential


5 : Wellbore fluid rushes in gun

Perforation Tunnel

&


Pressure

Pr

Time ms

Virgin Reservoir :

Pr

Timing :

300-500 Microsecond - End of penetration

1-5 MillisecondInitial response of wellbore fluid

Perforation tunnel and allow communication in between reservoir and

wellbore

Pg

Comments: Also the perforation process leaves a mixture of

crushed material in the tunnel (comminuted debris,

loose sands, charge debris) which can have a large

impact in injection efficiency

The process also leaves some residual charge debris

inside the perforations.

The fluid in the wellbore begins to notice that it can

expand inside the gun

Pw

Reduced Permeability

Crushed Zone : Kc

Damaged Zone : Kd


Gun Pressure : Pg

Pw > Pg

PURE Condition : NO

Pr < Pw > Pg

Loose sand

Pw

0

Timing :


27/29

Schlumberg

erConfidential


6 : Dynamic underbalance occurs ( DUB)

Perforation Tunnel

&


Pressure

Pr

Time ms

Virgin Reservoir :

Pr, K

Timing :

5-10MillisecondPURE Effect

First step : Tensile failure of crushed zone

Pg

Comments: Tensile failure is caused by exposure to the high

differential pressure between reservoir and wellbore.

When the peak strength of the flow exceeds the

strength of the rock damaged by perforating, tensile

failure will cause the weakened rock to be removed


Gun Pressure : Pg

Pw > Pg

PURE Condition :YES

Pr > Pw > Pg

0 10

Pw

Differential pressure

=

PURE DUBy

Timing :


28/29

Schlumberg

erConfidential


7 : Transport of failed material

Perforation Tunnel

&


Pressure

Pr

Time ms

Virgin Reservoir :

Pr K

Timing :

10-50 MillisecondPURE Effect

Second Step : Crushed zone removed from perforation tunnel

Perforation tunnel cleaned up

Pg

Comments :

Fines and perforation debris are removed from the

perforation tunnel by the subsequent flow into the

wellbore caused by the dynamic underbalance


Gun Pressure : Pg

Pw = Pg

PURE Condition : YES

Pr > Pw

0 10

Pw

20 30 40

50

Flow

period


29/29

30

Schlumberg

erConfidential

Documents

Perforating Presentation