Geomechanics for Drilling Engineers

Fundamental of Rock Mechanics

• Fundamentals of rock mechanics
• How is geomechanics used to design wells and support drilling?
• The stress tensor
• Experimental rock mechanics

The course will begin with an introduction to the fundamental aspect of rock mechanics and a review of experimental results that have been published in industry papers.  After this participants will see how geomechanics can be used to design wells and support drilling operations. Participants will then learn about the stress tensor in particular units, principal stresses, strain, resolving stresses on a plane, constructing Mohr's Circle and analyzing stress, elasticity and elastic properties, effective stress, and other rock mechanic fundamentals. Lastly the attendees will learn about experimental rock mechanics, uniaxial and triaxial testing, thick wall cylinder tests, scratch testing, true triaxial tests, and tensile testing.

Earth Stress and Pore Pressure

• Principal earth stresses
• Origins of pore pressure
• Methods to measure pore pressure

The second day will begin with participants taking a look at stress in the Earth, including principal earth stresses, regional and local stresses, the world stress map, Andersonian classification of faults, overburden stress, horizontal stress orientation, borehole breakouts, and drilling-induced tensile fractures.  Other topics that participants will learn about include image logs, horizontal stress magnitudes, leak-off tests, and fracture gradients. Participants will then examine the detailed origins of pore pressure, measurement methods, methods for estimation, vertical and horizontal methods, Eaton’s method, and a real-time pore pressure approach.

Mechanical Earth Model, Wellbore Geomechanics, and Wellbore Stability

• Concept and construction of the Mechanical Earth Model (MEM)
• Wellbore geomechanics
• Modes of rock deformation in the wellbore
• Wellbore deformation in fractured rock masses

The third day participants will focus primarily on the Mechanical Earth Model (MEM), wellbore geomechanics, and wellbore stability issues.  This day will begin with participants reviewing the concepts and construction of the MEM, including detailed data requirements and required input data types.  With a working MEM, the participant will then learn how to manage wellbore geomechanics and the state of stress in and around the wellbore.  Modes of rock deformation in the wellbore, the effects of well azimuth, and inclination will also be covered.  Participants will also learn about basic geomechanics calculations.  The day will end with participants reviewing wellbore deformation in fractured rock masses and non-classical rock failures.

Drilling Geomechanics

• Planning for wellbore stability
• Implementation of geomechanics while drilling
• Wellbore strengthening
• Drill bit mechanics

On day four participants will learn about downhole drilling geomechanics with particular emphasis being placed on planning for wellbore stability and integration of geomechanics into the drilling plan.  Participants will then investigate the intricacies of implementing real-time geomechanics while drilling.  Participants will also look at how geomechanics is used to provide wellbore strengthening in order to avoid mud losses in depleted formations.  To conclude this day, participants will review drill bit mechanics.

Geomechanics Case Studies

• Build Mechanical Earth Model (MEM)
• Design wellbore stability plan
• Field development plan

On the last day, participants will work in teams in order to put into practice the geomechanics knowledge and skills learned during the week to build an actual MEM.  Participants will then use the MEM to design a wellbore stability plan for a proposed high angle well from a field development plan.