Defining Geomechanics

Optimizing development of new reservoirs and revitalizing mature fields

Geomechanics is the study of how soils and rocks deform in response to changes of stress, pressure, temperature, and other parameters.

This science is central to understanding how drill bits remove rock, characterizing borehole stability, predicting the stability of perforation tunnels, and designing and monitoring stimulation programs. Geomechanics also helps engineers to model fluid movement and predict how fluid removal or injection leads to changes in permeability, fluid pressure, and in situ rock stresses that can have significant effects on reservoir performance.

Engineers use geomechanical modeling to predict and quantify these effects for life-of-reservoir decisions. The mechanical earth model (MEM) is a collection of the data needed to make quantitative and qualitative predictions of the subsurface geomechanical environment. These data include the stresses in the earth, pore pressure, rock elastic properties, strength and fabric, and nonnumerical data.

A Defining Series article “Geomechanics” provides an overview of how this science plays an important part in nearly all aspects of petroleum extraction—from exploration to abandonment—and across all scales.