Petrophysical Input to Geomechanics Modelling


Petroleum geomechanics is defined as the interaction between the evolving earth stresses and the overburden and reservoir rock mechanical properties. A comprehensive understanding of rock mechanical behaviour is key to successful field appraisal and development. For example, 70% of the world’s oil and gas reserves are contained in reservoirs where rock failure and sand production will become a problem at some point. Wellbore stability issues have been estimated to cost the industry USD 8 billion annually.

A reliable and robust predictive geomechanical model—whether 1D or 3D—requires a variety of data from different sources. Around 80%–90% of data comes from “traditional” core and log petrophysics, but the importance of data quality control and a rigorous and consistent petrophysical interpretation is often overlooked by well construction and production engineers. For example, rock strength models are developed from the calibration of rock mechanics tests on core with wireline log responses. However, misinterpretation and poor practices have a significant impact on rock strength and the elastic properties used to evaluate wellbore failure and reservoir rock deformation under stress.

This seminar will describe the data acquisition and quality control of the key model input parameters for strength and stress models—rock mechanics tests, core-log strength calibration, vertical stress determination, horizontal stress estimation, and pore pressure. The seminar explains how geomechanics can help in assessing the risk of rock failure through the practical integration of petrophysics, well test data, and drilling data from fields throughout the world.

Learning Level


Seminar Length

One day

Why Attend?

You will learn:

  • How to recognise and prevent core damage and the common laboratory pitfalls in rock mechanics testing.
  • How to determine rock mechanical properties in the overburden and reservoir from well logs.
  • How to determine the principal in-situ reservoir stresses and how they are distributed around the borehole.
  • How to account for parameter uncertainties and natural variabilities in the geomechanical model.
  • How to calibrate and test geomechanical models against field data for sand failure analysis and wellbore stability studies.

Who Should Attend?

Petrophysicists, geoscientists, drilling, completion and production engineers who wish to expand their knowledge of geomechanics and how it impacts field development, well construction and completion decisions.


Colin McPhee (Director, Pelican Rocks) has over 40 years’ experience in geomechanics, petrophysics, core analysis, formation damage and sand management. Until he retired in December 2015, Colin was Global Head of Rock Properties with LR Senergy and previously worked for Helix-RDS, Edinburgh Petroleum Services, and Heriot Watt University. During this time, Colin gained a lot of practical and pragmatic experience by doing and managing over 400 geomechanics and core petrophysics projects across the world, and has become peer-recognised as an expert on reservoir rock properties for static, dynamic, and geomechanical models.

Colin has authored and co-authored more than 20 technical papers and co-authored the 2015 “Core Analysis: Best Practice” textbook. He has presented over 150 in-house and public training courses on geomechanics, core analysis, and sand management to about 3000 operator and service company professionals throughout the world. He is currently an Associate Professor at Aberdeen University where he lectures on the MSc course in Petrophysics and Formation Evaluation.

A regular presenter at industry conferences and workshops, Colin has also been actively involved in the technical committees for the Society of Petroleum Engineers (SPE) advanced workshops. He was a SPE Distinguished Lecturer for season 2010/11, SPE North Sea Section Regional Formation Evaluation Award winner for 2016, and former Technical Editor for SPE Formation Evaluation.