Applied Oilfield Geomechanics

Course Description

3D geomechanical models are frequently used to assess the state of stress inside the Earth. Knowledge of the stress-state in a reservoir and the surrounding rock allows assessing the risk of reservoir compaction, wellbore failure, sanding, breach of seal integrity and fault re-activation amongst others. Three-dimensional seismic data and inversion models can be used in building geomechanical models and time-lapse (4D) seismic data provide a means of calibrating the dynamic behaviour of reservoir geomechanical models. The purpose of this course is to provide an overview of currently available workflows to build and run calibrated 3D and 4D geomechanical models, maximizing the use of seismic data.

By attending the course, participants will deepen their insight into each of the elements that comprise a 3D and 4D geomechanical model. Special attention is given to the way that seismic data assist in the process, what other data sources are required, how to calibrate geomechanical models and finally, how to interpret geomechanical models for a range of applications.

Course Objectives

The purpose of this course is to:

  1. Provide an overview of the currently available techniques of building and calibrating 3D and 4D geomechanical models;
  2. Demonstrate the interaction between rock properties, pore pressure and stress state;
  3. Apply the knowledge of stress state from geomechanical models to field development and reservoir management;
  4. Understand the limitations of current workflows and techniques and give a glimpse of the road ahead.

Course Outline

  • Introduction: Applications of geomechanics in the oilfield life-cycle;
  • Rock mechanical properties:
    • Elastic and strength properties;
    • How do you derive mechanical properties in practice.
  • Stress and strain tensors:
    • Workflow for building 3D and 4D geomechanical models;
    • Calibration of 3D geomechanical models using well-centric 1D geomechanical models;
    • Analysis and display of displacement vectors, strain tensors and stress tensors.
  • Case studies:
    • Building a 3D geomechanical model using seismic AVO inversion in an onshore tight gas reservoir;
    • Geomechanical controls on hydraulic stimulation;
    • Wellbore stability for inclined wells: Why inclined and horizontal wells behave differently from vertical wells;
    • Multiple uses of 3D and 4D geomechanical flow models: Applications in a deepwater carbonate and clastic fields;
    • Stress rotations during production and their impact on hydraulic stimulation.

Participants’ Profile

Geomechanics projects integrate data and models from many different subsurface disciplines, including geophysics, rock mechanics testing, geology, geomodelling, rock physics and reservoir engineering. The course is designed for practising geoscientists and engineers and demonstrates how their discipline knowledge contributes to geomechanical modeling.

The course is also beneficial to students of petroleum geoscience (geophysics and geology). Finally, the course also appeals to managers of subsurface teams, increasing the appreciation of the complexity of the subsurface workflows that his or her team needs to address.

Prerequisites

This course is aimed at geoscientists and engineers with an interest in geomechanics, be their background in geology, geophysics, rock physics, reservoir engineering or geomechanics. The course was developed mainly with a practicing geophysicist or geologist in mind. The course has an emphasis on making the physics behind the presented techniques accessible and clear and will appeal to curious and inquisitive people. This course is also suited for Master’s and PhD students as the course (material) is designed in such a way that the principles of geomechanics become clear.

Geomechanics is still a relatively new discipline in the oilfield environment and is not taught as part of most university Geoscience-programs. Therefore a lot of graphic examples are included in the course material to aid intuitive understanding.

About the Instructor

Jorg Herwanger is a Director at MPGeomechanics, a geomechanics consulting and software company he co-founded in July 2016. His work combines experimental observations and the development of mathematical models and workflows in seismic, rock physics and reservoir geomechanics. Working closely with clients and his team, he carries out 3D and 4D geomechanical projects, integrating 1D geomechanical models, seismic inversion methods, rock physics and pore pressure predictions into reservoir flow and geomechanical models. Previous companies he worked for included Ikon Science and Schlumberger. Before working in the upstream oil and gas industry, Jorg’s interest was in the development and computer implementation of tomographic methods to determine anisotropic electrical properties from observed crosswell data. He combined these newly developed techniques with anisotropic velocity tomography to detect and evaluate fractures. Jorg is a member of EAGE, SPE and SEG. He served as an EAGE Distinguished Lecturer from 2007-2009, and EAGE Education Tour (EET-5) Lecturer in 2011-2012, and was the 2016-2018 EAGE Education Officer on the EAGE Board. For the EET-5, Jorg wrote the eponymous book on “Seismic Geomechanics”. Jorg holds a Diplom degree from Technische Universitat Clausthal, Germany and a PhD from Imperial College, London, U.K., both in Geophysics.