Patent ID: 9646115
Date: 2017-05-09
CPC Classifications: E21B,G01V,G06F

Claim:
1. A method to determine a drilling fluid density limit for maintaining a target amount of rock failure in a drilling operation, comprising: obtaining a geomechanical model of a portion of a subterranean formation traversed by a target borehole, wherein the geomechanical model comprises a formation pressure dependent on subterranean formation depth; generating, by a computer processor using a stress model dependent on the formation pressure, a depth of damage model of the target borehole based at least in part on a yield factor, wherein the depth of damage model describes a relationship between a drilling fluid pressure and a depth of damage resulting from the drilling fluid pressure, and the yield factor is representative of a ratio between applied stress and resistant stress, calculating, by the computer processor using the depth of damage model and the geomechanical model, the drilling fluid density limit as a function of the subterranean formation depth, wherein the target borehole is drilled based at least on the drilling fluid density limit.