Effect of pore fluid conditions at the borehole wall on borehole stability

In existing poroelastic borehole models, the pore fluid conditions at the borehole wall are simply assumed as: a constant pore pressure for penetrating models, or no flux across the wall for impermeable models. In reality, the pore fluid boundary conditions at the walls may be much more complicated. This paper presents the newly-developed poroelastic solution for inclined boreholes with time-dependent pore pressure or the pore fluid flow at the wall. The effects of the pore fluid boundary conditions on the borehole stability are also analyzed.