Minifrac AnalysisMinifrac AnalysisMinifrac AnalysisMinifrac Analysis

Minifrac Test ProcedureMinifrac Test ProcedureMinifrac Test ProcedureMinifrac Test Procedure

Formation Breakdown / permeability analysis from Formation Breakdown / permeability analysis from thin fluid pressure declinethin fluid pressure decline

Step-Rate Test/maximum matrix injection rateStep-Rate Test/maximum matrix injection rate Step-Down Test / prediction of near-wellbore frictionStep-Down Test / prediction of near-wellbore friction Proppant Slugs / remove NWF if it existsProppant Slugs / remove NWF if it exists Main Minifrac / for prediction of fluid loss Main Minifrac / for prediction of fluid loss Main Treatment design based on pre-frac injection Main Treatment design based on pre-frac injection

informationinformation

Formation Breakdown / permeability analysis from Formation Breakdown / permeability analysis from thin fluid pressure declinethin fluid pressure decline

Step-Rate Test/maximum matrix injection rateStep-Rate Test/maximum matrix injection rate Step-Down Test / prediction of near-wellbore frictionStep-Down Test / prediction of near-wellbore friction Proppant Slugs / remove NWF if it existsProppant Slugs / remove NWF if it exists Main Minifrac / for prediction of fluid loss Main Minifrac / for prediction of fluid loss Main Treatment design based on pre-frac injection Main Treatment design based on pre-frac injection

informationinformation

Time

Pre

ssu

re

1st Step Rate/ShutinBelow FEP

Modified Step-Rate Test ProcedureModified Step-Rate Test ProcedureModified Step-Rate Test ProcedureModified Step-Rate Test Procedure

x

x

xx

x

Rate

Pre

ss

ure

Fracture ExtensionPressure

Step-Rate Test AnalysisStep-Rate Test AnalysisStep-Rate Test AnalysisStep-Rate Test Analysis

Step-Down TestStep-Down TestStep-Down TestStep-Down TestR

ate

Bo

tto

mh

ole

Pre

ssu

reR

ate

Bo

tto

mh

ole

Pre

ssu

re

TimeTime

PP11

PP22

PP33

PP44

QQ11

QQ22

QQ33

QQ44

ISIPISIP PP44

PP33

PP22

PP11

QQ44 QQ33 QQ22 QQ11

Perforation friction f(QPerforation friction f(Q22))

Total frictionTotal friction

Bo

tto

mh

ole

pre

ssu

re -

IS

IPB

ott

om

ho

le p

res

sure

- I

SIP

Tortuosity f(QTortuosity f(Q0.50.5))

RateRate

• Perforation Friction Dominated RegimePerforation Friction Dominated Regime

Step-Down TestStep-Down TestStep-Down TestStep-Down Test

PP11

PP22

PP33

PP44 QQ11

QQ22

QQ33

QQ44

ISIPISIP

Rat

e B

ott

om

ho

le P

ress

ure

Rat

e B

ott

om

ho

le P

ress

ure

TimeTime

• Tortuosity Dominated RegimeTortuosity Dominated Regime

PP44

PP33

PP22

PP11

QQ44 QQ33 QQ22 QQ11

Perforation friction f(QPerforation friction f(Q22))

Total frictionTotal friction

Bo

tto

mh

ole

pre

ssu

re -

IS

IPB

ott

om

ho

le p

res

sure

- I

SIP

Tortuosity f(QTortuosity f(Q0.50.5))

RateRate

Main MinifracMain MinifracMain MinifracMain Minifrac Design minifrac volume to obtain stable geometry Design minifrac volume to obtain stable geometry

(injection time ~5-20 min) and short closure time (<30 (injection time ~5-20 min) and short closure time (<30 minutes).minutes).

Pump minifrac at expected job rates using frac fluid.Pump minifrac at expected job rates using frac fluid. Monitor pressure decline until after fracture closure by Monitor pressure decline until after fracture closure by

analysing pressure decline data with P vs. sqrt(time) plot analysing pressure decline data with P vs. sqrt(time) plot or G-function plot. or G-function plot.

Match decline curve using FracPro to match fluid Match decline curve using FracPro to match fluid efficiency, closure time, and pressure declineefficiency, closure time, and pressure decline

Design minifrac volume to obtain stable geometry Design minifrac volume to obtain stable geometry (injection time ~5-20 min) and short closure time (<30 (injection time ~5-20 min) and short closure time (<30 minutes).minutes).

Pump minifrac at expected job rates using frac fluid.Pump minifrac at expected job rates using frac fluid. Monitor pressure decline until after fracture closure by Monitor pressure decline until after fracture closure by

analysing pressure decline data with P vs. sqrt(time) plot analysing pressure decline data with P vs. sqrt(time) plot or G-function plot. or G-function plot.

Match decline curve using FracPro to match fluid Match decline curve using FracPro to match fluid efficiency, closure time, and pressure declineefficiency, closure time, and pressure decline

0

10

20

30

40

50

60

70

80

90

100

0 5 10 15 20 25

Time (min)

Hei

ght

(ft)

or

Rat

e (b

pm)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Eff

icie

ncy

Minifrac SimulationMinifrac SimulationMinifrac SimulationMinifrac Simulation

RateEff

Lower Ht

Upper HtLength

Intersection of vertical lineand imaginary straightline through early timedecline is the ISIP

Shut In

Intersection of vertical lineand imaginary straight linethrough the early timedecline is the ISIP

ISIP

Determination of ISIPDetermination of ISIPDetermination of ISIPDetermination of ISIP

HALLIBURTON MINIFRAC ANALYSIS 08-Jun-1994 15:44:05 Corrected Fluid Pressure Efficiency

Pressure Delta (psi) Pressure

0.00

08:09:40

2.00

08:11:40

4.00

08:13:40

6.00

08:15:40

8.00

08:17:40

10.00 12.00

08:21:40

14.00 16.00

08:25:40

18.00 1820

1920

2020

2120

2220

2320

2420

2520

Delta Time (min)

Closure Delta Time Time (min)

1964 1956 166 24.6% 08:13:59 4.32

The vertical cross hairshould intersect thedecline curve where itdeviates from the straightline.

Closure from Sqrt(Time) PlotClosure from Sqrt(Time) PlotClosure from Sqrt(Time) PlotClosure from Sqrt(Time) Plot

Fracture Linear FlowFracture Linear FlowSlope = 0.50Slope = 0.50 Fracture Bilinear FlowFracture Bilinear Flow

Slope = 0.25Slope = 0.25

HALLIBURTON MINIFRAC ANALYSIS 08-Jun-1994 15:55:24 Corrected Fluid Pressure Efficiency

Pressure (psi)

0.1

08:09:46

1

08:10:40

10

08:19:39

10

100

400

Delta Time (min)

Slope Closure Delta Time Time (min)

166 174 1.00 24.6% 08:13:59 4.33

A slope of 1.0denotes wellborestorage

Wellbore Storage

Wellbore Storage on Log-Log PlotWellbore Storage on Log-Log PlotWellbore Storage on Log-Log PlotWellbore Storage on Log-Log Plot

HALLIBURTON MINIFRAC ANALYSIS 08-Jun-1994 15:54:36 Corrected Fluid Pressure Efficiency

Pressure (psi)

0.1

08:09:46

1

08:10:40

10

08:19:39

10

100

400

Delta Time (min)

Slope Closure Delta Time Time (min)

166 174 0.64 24.6% 08:13:59 4.33

Right end of movableline has been pulled into lay on the verticalcrosshair.

This portion of the curvecorresponds to the stright lineportion of the square root timeplot. Note the slope is 0.64which is greater than thetheoretical value of 0.5.

Fracture Linear Flow

Linear Fracture Flow on Log-Log PlotLinear Fracture Flow on Log-Log PlotLinear Fracture Flow on Log-Log PlotLinear Fracture Flow on Log-Log Plot

HALLIBURTON MINIFRAC ANALYSIS 08-Jun-1994 15:56:15 Corrected Fluid Pressure Efficiency

Pressure (psi)

0.1

08:09:46

1

08:10:40

10

08:19:39

10

100

400

Delta Time (min)

Slope Closure Delta Time Time (min)

166 174 0.35 24.6% 08:13:59 4.33

The last portion of thecurve occurs after thefracture has closed.

Bilinear Flow

Bi-Linear Flow on Log-Log PlotBi-Linear Flow on Log-Log PlotBi-Linear Flow on Log-Log PlotBi-Linear Flow on Log-Log Plot

HALLIBURTON MINIFRAC ANALYSIS 27-Jul-1994 10:15:53

Corrected Fluid Pressure Efficiency

Pressure Delta (psi) Pressure

0.00

08:09:40

0.20

08:12:04

0.40

08:15:04

0.60

08:18:36

0.80

08:22:38

1.00

08:27:10

1820

1920

2020

2120

2220

2320

2420

2520

G-Function (Moderate Efficiency)

Closure Delta Time Time (min)

1946 1937 172 27.9% 08:14:59 5.32

Closure from G-Function PlotClosure from G-Function PlotClosure from G-Function PlotClosure from G-Function Plot

HALLIBURTON MINIFRAC ANALYSIS 28-Jun-1994 14:41:53

Corrected Fluid Pressure Efficiency

CP 1st Dv CP 2nd Dv

Pressure Delta (psi) Pressure

0.00

10:22:05

5.00

10:27:05

10.00

10:32:05

15.00

10:37:05

20.00

10:42:05

25.00 30.00

10:52:05

35.00 3870

3970

4070

4170

4270

4370

4470

4570

4670

4770

Delta Time (min)

Closure Delta Time Time (min)

4110 4105 483 59.0% 10:39:22 17.30

Use of DerivativesUse of DerivativesUse of DerivativesUse of Derivatives

FracPro MatchFracPro MatchFracPro MatchFracPro Match

Main Treatment DesignMain Treatment DesignMain Treatment DesignMain Treatment Design After Matching Minifrac Tests, alter After Matching Minifrac Tests, alter

treatment schedule and predict treatment treatment schedule and predict treatment pressures/fracture growth.pressures/fracture growth.

Adjust treatment schedule based on Adjust treatment schedule based on design objectives. Normal objectives are design objectives. Normal objectives are to attempt to pack the fracture (except in to attempt to pack the fracture (except in low perm wells), obtain desired frac low perm wells), obtain desired frac length, and limit fluid volumes.length, and limit fluid volumes.

After Matching Minifrac Tests, alter After Matching Minifrac Tests, alter treatment schedule and predict treatment treatment schedule and predict treatment pressures/fracture growth.pressures/fracture growth.

Adjust treatment schedule based on Adjust treatment schedule based on design objectives. Normal objectives are design objectives. Normal objectives are to attempt to pack the fracture (except in to attempt to pack the fracture (except in low perm wells), obtain desired frac low perm wells), obtain desired frac length, and limit fluid volumes.length, and limit fluid volumes.