A well is located next to a fault, 250 ft distance and it is producing under a transient flow condition at a constant flow rate. Find the sand-face pressure of the well after 15 hrs. Given data Q well : 200 STB/day Initial reservoir pressure: 4200 psi Oil viscosity: 2.0 cp Bo : 1.2 bbl/STB Skin: 0 Ct: 20 x 10-6 psi-1 Thickness: 20 ft rw : 0.25 ft Porosity: 15% Permeability: 400 md