  Using an analogy to the classical Stefan problem, we construct evolution
equations for the fluid pore pressure on both sides of a propagating
stress-induced damage front. Closed form expressions are derived for the
position of the damage front as a function of time for the cases of
thermally-induced damage as well as damage induced by over-pressure. We derive
expressions for the flow rate during constant pressure fluid injection from the
surface corresponding to a spherically shaped subsurface damage front. Finally,
our model results suggest an interpretation of field data obtained during
constant pressure fluid injection over the course of 16 days at an injection
site near Desert Peak, NV.
