Evaluate wellbore stability for a horizontal well that you will need in order to exploit in a tight-gas reservoir subjected to a strike-slip stress state.

The horizontal well lies at 8,000-ft true vertical depth (TVD) where it is estimated that Shmin = 50 MPa, SHmax= 70 MPa, lithostatic (overburden) stress gradient of 1 psi/ft and Pp= 0.6Sv. The unconfined compressive strength (UCS) of the rock is 8,500 psi, the rock internal friction coefficient is 1, and tensile strength, is 800 psi, given the large density of pre-existing fractures (PEFs). Determine the mechanical stability limits on wellbore pressure (i.e. Pw,shear and the pressure at which longitudinal DITF initiation occurs) for the horizontal well that is drilled parallel to SHmax, assuming theta = 23.