QUESTION The figure below shows the pressure prognosis for a well under planning. The open hole below the surface casing shoe is planned to reach 10,000 ft. Given: Pore pressure gradient: 0.45 psi/ft Fracture pressure gradient: 0.8 psi/ft Depth 10,000 ft Reservoir gas gradient: 0.1 psi/ft 4,500 psi 8,000 psi a) Determine the minimum depth of the surface casing in order to get full well integrity, i.e., the formation below the shoe will NOT fracture if the well is full of gas. Ans. = 5,000 ft Pressure