Geomechanics in heavy oil

An enlightening article on the role of geomechanics to optimize SAGD recovery of heavy oil.

SPE article 97905-PA explores the use of geomechanics, which examines the behavior of rock formations under stress conditions, to optimize heavy oil recovery. Thermal heavy oil recover methods such as SAGD create higher pressure and temperatures within the reservoir rock and formation fluid. SAGD can reduce the effective rock stress and weaken the oil sand causing any number of production problems.

The geomechanical response to increased formation fluid pressure can alter rock porosity, permeability, and mobility – this in turn can have significant impact on the growth pattern of the SAGD steam chamber and heavy oil recovery efficiency. Stresses occurring naturally in the rock or induced through SAGD will also determine the direction of the steam chamber growth. Operators that can measure and anticipate geomechanical response can better optimize the orientation and spacing of their wells to increase production.

The article also introduces some new ideas for monitoring SAGD such as the use of satellite radar interferometry to assess caprock integrity and monitor steam chamber growth; once reservoir caprock integrity is lost the SAGD process cannot be contained within the reservoir which may require expensive recompletion and drilling programs to remediate.

The application of geomechanics to better understand and anticipate reservoir behavior is another key to improving heavy oil planning, prediction, and recovery .

Kambiz.