Publications

Simplified Lame models are used to show effects of rock mechanical properties on stresses around wellbores and development of zones of plastic failure. Zones with unusually low values of Poisson's Ratio develop tangential stresses near the wellbore which are tensile. Zones with unusually high values of Poisson's Ratio have high compressive stresses near the wellbore indicating a tendency of the wellbore to collapse. These zones are detected and the mechanical properties of the rock are determined in situ with open-hole logs. These results indicate fracture pressures, wellbore pressure necessary for hole stability, and troublesome sand production zones.