MDT Applications in CBM

HamidReza PourabedReservoir Engineerhpourabed@slb.com

1

Agenda

• Mini-DST (Pressure, Permeability, Skin, PI)

• Mini-Frac (Minimum Horizontal Stress)

• Long Spacing MDT configuration

2

MDT (Modular Dynamic Tester)

3

• MDT modularity helps to customize tool string based on job objectives

• There is a main flowline throughout the tool

• Each module may have its own flow line isolated from main flow line by valves

• Module functionalities are customized to achieve the objective of the specific module task

The Modular Dynamics Tester (MDT) is an open hole wireline instrument primarilyused for measuring vertical pressure distribution in a reservoir, as well as forrecovering formation fluid samples.

Primary Objective of Formation Tester

4

FormationPressure

Dual Packer Module (PA)

5

Now we can use 2xPA to increase the spacing even more than 11m

Interval valve

Strain gauge

Quartz gauge

1m1.6m2.5m3.4m0.4m

Inlet Port

Bypass flowline

• Pressure Test in CBM• Mini-DST • Mini-Frac• Sampling

Packer Diameter Max Temp. Pressure Hole Diameterin DegC psi Min (in) Max (in)5 175 20,000 6 7⅕

6 ¾ 175 20,000 7 ⅞ 9 ⅝8 ⅟2 175 20,000 12 ⅟4 14

Pump Module

6

• Pump-In

• Pump-Out

• Pump between modules

Flexible Pump Rate

7

Pump Displacement

Unit

Stroke Size

Min. Flow Rate (Rough Estimation)

Max. Flow Rate (Rough Estimation)

Min. Flow Rate (Rough Estimation)

Max. Flow Rate (Rough Estimation)

B/D B/D cc/sec cc/sec

Standard 485 2.3 19.6 4.3 36

High Pressure

366 1.8 15.2 3.3 28

Extra-High Pressure

170 1.3 10.9 2.4 20

MDT MINI-DST

8

IPTT (Mini-DST)

9

• Determination of:– Pressure

– Permeability

– Skin

– Rate Dependent Skin

– Productivity Index

– AOFP

What is Mini-DSTPr

essu

rePu

mp

rate

PRESSURE TRANSEINT

IPTT (Mini-DST) Example

11

LONG SPACING CONFIGURATION

12

Long Spacing Configuration

13

Lower Pumpout Module

Single Probe Module

Gamma Ray and Telemetry

Upper Exit Port

Lower Exit Port

Upper Pumpout Module

1m

3.4m

7.5m

9.9m

11.4m

Long Spacing Configuration

14

Pressure Derivative Plot

15

K.H= 14.4 mD.mH= 9mK=1.6 mDSkin=-1.49

Multi-Seam Tests

16

Tota

lZo

ne 2

Zone

1

Build-Up(Both Zones)

Build-Up(Zone 1)

Build-Up(Zone 2)

Build-Up(Zone 1)

Build-Up(Zone 2)

Multi-Seam Tests

17

Tota

lZo

ne 2

Zone

1

1E-3 0.01 0.1 1 10Time [min]

0.1

1

10

Pres

sure

[psi

]

test 1-430.8m-442.2m_Bottom Packer_PAQP_Zone 2 Rate.ks3 - Analysis 2test 1-430.8m-442.2m_Top Packer_PAQP2_Zone 1 Rate.ks3 - Analysis 2Test4 (Repeat of Test 1).ks3 - Analysis 3 (ref)

Current Available Long Spacing Configurations

19

Mini-DST Limitations/ Challenges

• Packer to be seat over good calliper Sand/Shale formations (<20% ovality)

• Pressure differential Limitations – Depend on Packer Type and hole Size

• 1200psi for 8.5in hole

• 500 psi for long Spacing MDT

• Maximum Pump Rate (~19 BB/D)– Closed Chamber Test using air cushion empty

sample chamber

20

MDT MINI-FRAC

21

Mini-Frac

22

• Geomechanical Applications:– Wellbore Stability

– Sand Production

– Design of Hydraulic Fracturing

• Well Trajectory and Completion Design

• Reservoir Management– Understand Initial Natural Fracture

Distributions

– Understand Fractures Created By Water Injectors

– Understand Time Dependent Effects

What is Mini-FRACPr

essu

rePu

mp

rate

Fracture Initiation Pressure

Fracture Propagation Pressure

Fracture Closure Pressure

Before After

Mini-FRAC & GeomechanicsPr

essu

re

Fracture Initiation Pressure (Pi)

Fracture Propagation Pressure

Fracture Closure Pressure (σh)

Pr: Pore pressure (reservoir pressure)T: Tensile strength

Mini-Frac Limitations/Advantages• Maximum Differential Pressure

– Depend on wellbore• 3500 psi for 8.5in hole

• Pump Rate against Cleats permeability may limit Injection pressure

• Higher chance of closure observation in adjacent sand/shale

• Flow Controller module for flow back test• Multi-Rate pump for Step Rate/Down test• No need for injection surface facility• Mini-Frac/DST at the same run/same station• IFT and Mini-DST test at same station

25

MDT Support• Pre-job Planning• Real-Time Monitoring and Interpretation

(InterACT)

• Post Job Interpretation Report• Post Job Presentation/SQ Meetings

26

MDT Long Spacing Added Values

27

Features Conventional DST MDT Long Spacing Advantages

Accurate downhole Rate Measurement NO YES

Accurate Permeability & Skin Estimation

Real-Time control over RateMulti-Rate Drawdown

Rate Dependent Skin estimationProductivity Index EstimationHigh resolution Build-up Data,

Hence successful test in low perm coals

Faster and More reliable test results

Multi-Coal Test in one descent

No (sometimes Yes if previous test did not add too much of cushion head and straddle Interval won't need to be

changed)

Yes (Unlimited)

Real-time Data Yes YesOptimizing test time/ Faster and

more reliable test resultsTechnical Support (Prejob

design, Real-time monitoring, Post Job free Interpretation)

Partially Yes. Yes

Flexible Straddle Interval in one descend

NoYes (Currently 1m, 1.6m, 2.5m,

3.4m, 7.5m, 9.9m, 11.4m/11.9m)

Flexible Straddle Interval in one descend

Yes currently up to 11.9m Testing Thick coals

No YesMulti-Seam Test in one Inflation

(higher resolution Perm/Skin estimation)

No Yes Vertical Interference testEnough signal to Noise ratio

in super permeable coalsYes

Yes (Using empty SC configured with 100 psi air cushion)

DST, IFT and DFIT test in one run/at each station

No Yes

Surface facility for Injection Test

Yes No

Downhole Sampling and Contamination Monitoring

No Yes

Questions are welcomed

28