Numerical investigation of the influence of discontinuity orientations on fault permeability evolution and slip displacement

Abstract A pre-existing plane of weakness along the fault is comprised a particular pattern joints dipping at different orientations. The stress state, partially defined by orientation fault, determines potential slip failure and hence evolution permeability. Here influence on permeability was investigated direct fluid injection inside with three sets orientations (45°, 60° 110°), through coupled hydromechanical (H-M) model TOUGHREACT-FLAC3D. tendency magnitude induced seismicity also evaluated comparing resulted distance timing. simulation results revealed that decreasing dip angle increases corresponding in normal circumstance. Also, changing associated changes concurrently noticeable manner. Permeability enhancement after onset observed angles, while condition highest enhancement. Joints 145° (very high dip) 30° low did not trigger shear seismic However, intermediate angles (135°, 50° 70°) yielded varying orders magnitude. large excitation increasing during deformation noticeably joint but decreases as increases. Article highlights injection-induced largely influenced spatial With slight change direction, there an possibility for to approach critical state failure. Stress elevation point controlled fault/joint planes respect direction maximum principal stress.