Geomechanics in Wellbore Stability
This course covers the basic principles of geomechanics as they apply to drill wells safely. Students will be able to learn and refresh rock properties, stresses and strength parameters which influence drilling parameters and how to evaluate or estimate them from the available log, lab and field or empirical data. It is especially useful for those who want to understand the wellbore stability mechanisms and the role of geomechanics but have not had the background education or hands-on experience in determining rock properties from the lab or log data, or in designing mud weights for vertical or inclined wellbores. The course describes the step-by-step procedure for developing a 1-D mechanical earth model (MEM) starting with log data and integrating available lab and drilling data (tight holes, loss circulation events, as well as LOTs/FITs, etc.) for calibration. Calibration of the model to drilling events and mud weight used is an important part of model development. The effects of well inclination, azimuth and reservoir depletion on safe mud weight window in isotropic and anisotropic stress fields will be discussed. Examples from case studies will be presented along the way that are relevant to the topics discussed. Download the daily agenda here (.pdf).
Introductory to intermediate
Students will be able to learn/refresh and apply the principles of geomechanics to wellbore stability, reduce NPT and drill wells safely. The following topics will be covered. Appropriate examples from case histories will be provided to reinforce the learning principles.
• Normal, shear and principal stresses and use of Mohr’s circle
• Effective stresses and shear failure criteria
• Understand the basics of in-situ or earth stresses and methods to estimate
• Elastic rock properties and rock strength, lab, log and empirical methods to estimate them
• Vertical and horizontal stresses from density logs, pore pressure and rock properties
• Near wellbore stresses
• Tensile rock failure and mud weight window
• Leak-off tests, Formation Integrity tests, minimum horizontal stress or closure stress evaluation
• Stress anisotropy and its effect on stable mud weight
• Effect of depletion on mud weight window
This course is recommended for members of Geology & Geophysics Operation teams, drilling, completion, reservoir, and production engineers, earth scientists, and asset managers.
0.8 Continuing Education Units
Dr. Mohammed Azeemuddin is a senior geomechanics specialist working for Chevron since 2008, based in Houston. He holds a BS in civil engineering, an MS in geotechnical engineering, and a PhD in geological engineering. He started his career as a Geotechnical engineer working for CH2M Hill, then worked as a research engineer/associate professor at King Fahdp University of Petroleum and Minerals, then was a senior geomechanics engineer with Baker Hughes. He specializes in static and dynamic rock properties, in-situ stress determination, wellbore stability, depletion related geomechanics, etc., and has authored/coauthored more than 20 technical publications. He has more than 25 years of experience in the oil and gas industry, academia and geomechanical projects worldwide.