1. a) Starting with Darcy's law, show that PI= 7.08x 10* */ B,In(r/ r)+S for radial steady flow. [5] b) The initial reservoir pressure of dry reservoir was 4200 psia, with temperature of 180 F. The reservoir has been producing for some time. Two pressure surveys have been made at different times [5] PIZ (psia) 4600 3700 G, (MMScf) 2800 Assuming the reservoir rock has a porosity of 12%, the water saturation is 30 % and the reservoir thickness is 15ft. How many acres does the reservoir cover?