Subsurface rock fracture pressure

Subsurface Rock Fracture Pressure (Fracture Pressure Gradient). The subsurface rock fracture pressure can be approximated by utilizing the known pore pressure at the same depth. The relationship between rock fracture pressure p (psi) and pore pressure p (psi) is [34]... 

Subsurface tension fractures will form when the minimum effective stress (CTj) reduces to the tensile strength of the rock (-C,). This will occur when the minimum total stress (S3) is reduced by tectonic dilation, or pore fluid pressure is increased (Watts, 1987). These failure conditions can be summarised as follows ... 

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