Geomechanics Applications to Drilling, Hydraulic

Fracture Design, Completion Integrity and Reservoir

Management

Mohammed Ahmed Mohiuddin

Principal Geomechanics Engineer

SPWLA –Kuwait Presentation

15 January 2013

Outline

Introduction

Workflows

Field examples

Discussion

2

Geomechanics …

Excavation

stress

pressure

temperature

other things…

Application of Geomechanics

During Production & Injection

Leakage of injected

gas/steam

Subsidence

Cap-rock integrity

Water-cut

Well construction trends

3D Geomechanics Workflow

6

Seismic

Framework

Model

Initial

Stress Model

t =0

t =10yr

Dynamic Mechanical Earth Model

Logs/Cores Framework

Model

1D MEM

Properties Model

Pore Pressure Model

Prediction

Surveillance

Monitoring

Design

Drill

Data audit

MEM construction

Wellbore stability analysis

DrillMAP

Drilling optimization

LWD data acquisition

PP & WBS model update

Drilling monitoring

Instability monitoring

Diagnosis & remedy

Model & database update

Recommendation

Communication

Future well planning

Evaluate

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Three Phase Process

Effects of Reservoir Depletion

Pp

sV

sh

Depletion

sV = constant

Pp-

pp

sV = constant

sh - sh Pp-

pp

sh

sv

sh sh

Injection and Loss of Fracture Containment

Compaction-Induced Well Integrity Problems

Compacting Reservoir

Worst at crest

Any stretch in overburden

causes extension in casing etc.

Shear & local plastic

deformation

Euler buckling

Slip on Fractures and Planes of Weakness

With Depletion (and Compaction and Stress Transfer)

High sh

region (low angle shear)

Flanks Shoulders Crest Shoulders Flanks

Reservoir

compaction

High

region Slip planes

in overburden

Lmst

Marl

Anhydrite

Natural Fracture Conductivity

Under shear and normal deformation

(s,

s

s

Fault Re-activation Due to Depletion/Injection

sH > sv

sn = sn - p

Log data

Drilling data

Mechanical property correlations

Coupled Modeler

Fault surfaces

Seismic horizons

Petrophysical property correlations

Petrel Model

Eclipse Model

14

Coupled Reservoir Geomechanics Modeling Workflow

Eclipse Reservoir Simulator

P, T

PVT Tables

K, f

VISAGE Geomechanical

Simulator

2-Way Coupling

4-D

Micro-seismic

Completions

Sector Model

Fault Stability

Toolkits

Completion

Integrity

1-D MEM

Field Example: Lack of BHP Increase from Injection Reservoir Simulation Without

Geomechanics Reservoir Simulation

With Geomechanics

Client expected to see large pressure

increase from injection

Instead small pressure rises and falls

from injection were observed

Field Example: Hydraulic Fracture Containment with

Produced Water Re-injection

Scenario 1 Scenario

Scenario 1 proposed by client

Scenario 2 recommended based on results from coupled reservoir geomechanics modeling

Field Example: Reservoir Compaction with Production

Geomechanics Prediction

Compaction determined by two independent methods difference of ~5 cm

Prediction helped in development planning & seismic inversion confirmed

prediction

4-D Seismic Inversion

Field Example: Prediction of Completion Failure

Excessive shear strains along well path

Successfully predicted wellbore integrity problems in formation where not previously expected

0

1000

2000

3000

4000

5000

6000

7000

0 1 2 3 4 5 6 7

Field data

No history match

Geomechanics

WBHP (psia)

Time (year)

Field Example: History Matching With Geomechanics

Two fracture sets were implemented Different fracture strike, spacing and

conductivity

Hydraulic Fracture direction

Sig H

Sig h

Vertical

Well

Fracture

Confinement

Horizontal

Well

Failure & deterioration of wellbore LWD resistivity images of breakouts and fractures

Ultrasonic and stand-off calipers

LWD resistivity for drilling fluid-shale interaction and mud invasion

Formation properties

Pore pressure

Real time link

LWD configuration for geo-steering

with Rotary Steerable System

Laterolog resistivity

Array resistivity Nuclear

Resistivity

& annular pressure

Density, porosity &

ultrasonic caliper

Annular Pressure While Drilling - Real time ECD at BHA

Cavings monitoring Cavings rate

Failure mechanism

Real Time & Time-Lapse Data While Drilling Phase

Example of Updating: Pre-drill Models Contains Uncertainty

Ref: Malinverno, A., Sayers, C., Woodward, M. and

Bartman, R. (2004) SPE 90001

Reducing Uncertainty Ahead of Bit

Mud Weights

Sonic

Pore P

Data

Ref: Malinverno, A., Sayers, C., Woodward, M. and

Bartman, R. (2004) SPE 90001

3D Geomechanics – The Differentiator http://www.slb.com/services/technical_challenges/geomechanics.aspx

Real-Time data has

tremendous value when

integrated within a

“predictive” environment