Petroleum Rock Mechanics

Drilling Operations and Well Design


  • Bernt Aadnoy, Department of Petroleum Engineering, University of Stavanger, Stavanger, Norway
  • Reza Looyeh, Lead Engineer, Chevron Limited, Pembroke Refinery, UK

Petroleum Rock Mechanics: Drilling Operations and Well Design covers the fundamentals of solid mechanics and petroleum rock mechanics and their application to oil and gas-related drilling operations and well design. More specifically, it examines the role of formation, strength of rock materials, and wellbore mechanics, along with the impact of in-situ stress changes on wellbore and borehole behavior. Practical examples with solutions and a comprehensive glossary of terminologies are provided. Equations are incorporated into well-known failure criteria to predict stresses and to analyze a range of failure scenarios throughout drilling, well operation, and well completion processes. The book also discusses stress and strain components, principal and deviatoric stresses and strains, materials behavior, the theories of elasticity and inelasticity, probabilistic analysis of stress data, the tensile and shear strength of rocks, wellbore stability, and fracture and collapse behavior for both single and multi-lateral wells. Both inexperienced university students and experienced engineers will find this book extremely useful.
View full description


Reservoir Engineers, Production Engineer, Drilling Engineers, Exploration Geophysicists


Book information

  • Published: May 2011
  • ISBN: 978-0-12-385546-6

Table of Contents



About the Authors

List of Symbols

Part One - Fundamentals of Solid Mechanics

    1 Stress/Strain Definitions and Components

         1.1 General Concept

         1.2 Definition of Stress

         1.3 Stress Components

         1.4 Definition of Strain

         1.5 Strain Components



    2 Stress and Strain Transformation

         2.1 Introduction

         2.2 Transformation Principles

         2.3 Two-Dimensional Stress Transformation

         2.4 Stress Transformation in Space

         2.5 Tensor of Stress Components

         2.6 Strain Transformation in Space



    3 Principal and Deviatoric Stresses and Strains

         3.1 Introduction

         3.2 Principal Stresses

         3.3 Average and Deviatoric Stresses

         3.4 General Interpretation of Principal Stresses

         3.5 Two-Dimensional Stress Analysis

         3.6 Properties of Strain



    4 Theory of Elasticity

         4.1 Introduction

         4.2 Materials Behavior

         4.3 Hooke’s Law

         4.4 Hooke’s Law in Shear

         4.5 Analysis of Structures

         4.6 Theory of Inelasticity

         4.7 Constitutive Relation for Rocks



    5 Failure Criteria

         5.1 Introduction

         5.2 Failure Criteria for Rock Materials

         5.3 The Von-Mises Failure Criterion

         5.4 Mohr-Coulomb Failure Criterion

         5.5 The Griffith Failure Criterion

         5.6 Hoek-Brown Failure Criterion

         5.7 Druker-Prager Failure Criterion

         5.8 Mogi-Coulomb Failure Criterion



Part Two - Petroleum Rock Mechanics

    6 Introduction to Petroleum Rock Mechanics

         6.1 Introduction

         6.2 Definition and Classification of Rocks

         6.3 Petroleum Rock Mechanics

         6.4 Why Study Stress in Rocks?

         6.5 Units of Measurement



    7 Porous Rocks and Effective Stresses

         7.1 Introduction

         7.2 Anisotropy and Inhomogeneity

         7.3 Anisotropic Rocks, Transversal Isotropy

         7.4 Porous Rock

         7.5 Formation Pore Pressure

         7.6 Effective Stress

         7.7 Formation Porosity and Permeability



    8 In-situ Stress

         8.1 Introduction

         8.2 Definitions

         8.3 In-situ Principal Stresses

         8.4 Measurement and Estimation of In-Situ Stresses

         8.5 Probabilistic Analysis of Stress Data

         8.6 Bounds on In-situ Stresses

         8.7 Stress Directions from Fracture Traces



    9 Rock Strength and Rock Failure

         9.1 Introduction

         9.2 Strength of Rock Material

         9.3 Empirical Correlations

         9.4 Formation Fracture Gradient

         9.5 Laboratory Testing of Intact Rocks

         9.6 Rock Tensile Strength

         9.7 Rock Shear Strength



    10 Stresses Around a Wellbore

         10.1 Introduction

         10.2 State of Stresses Around a Wellbore

         10.3 Properties of Rock Formation Around a Wellbore

         10.4 Equations Governing Stress Analysis

         10.5 Analysis of Stresses Around a Wellbore

         10.6 Isotropic Solution

         10.7 Anisotropic Solution



    11 Wellbore Instability Analysis

         11.1 Introduction

         11.2 Analysis Procedure

         11.3 Wellbore Fracturing Pressure

         11.4 Wellbore Collapse Pressure

         11.5 Instability Analysis of Multi-lateral Boreholes

         11.6 Instability Analysis of Adjacent Boreholes

         11.7 Instability Analysis of Underbalanced Drilling

         11.8 Shallow Fracturing

         11.9 General Fracturing Model

         11.10 Compaction Analysis for High-Pressure High-Temperature Reservoirs

         11.11 Breakthrough of a Relief Well into a Blowing Well

         11.12 Fracture Model for Load History and Temperature

         11.13 Effects of Flow Induced Stresses

         11.14 Sand Production Modeling



    12 Wellbore Instability Analysis Using Inversion Technique

         12.1 Introduction

         12.2 Definitions

         12.3 The Inversion Technique

         12.4 Geological Aspects

         12.5 Analysis Constraints

         12.6 Inversion from Fracture Data and Image Logs



    13 Wellbore Instability Analysis Using Quantitative Risk Assessment

         13.1 Introduction

         13.2 Deterministic Analysis Versus Probabilistic Assessment

         13.3 Why Probabilistic Assessment?

         13.4 Quantitative Risk Assessment (QRA)

         13.5 Quantitative Risk Assessment of Underbalanced Drilling



    14 The Effect of Mud Losses on Wellbore Stability

         14.1 Introduction

         14.2 Mud Losses During Drilling

         14.3 Interpretation of the Leak-off Tests

         14.4 Future Development for Wellbore Stability




Appendix A - Mechanical Properties of Rocks

Appendix B - The Poisson’s Ratio Effect

Appendix C - Model for the Stress Bridge

Appendix D - Glossary of Terms