While drilling an anticline structure, at a depth of 4500 ft, (just above the productive formation), the pressure in a subsurface aquifer was measured as 2089 psia. At a depth of 4800 ft, oil contact was established. The pressure in the oil phase was measured to be 2228 psia. The well was drilled through the oil column and another measurement of pressure in a subsurface aquifer was taken. At a depth of 5500 ft, the pressure in the water phase was observed to be 2549 psia. Using this information, calculate the depth of oil water contact. PVT analysis reports the density of oil to be 44.64 lb/ft If we had not measured the pressure in water, and instead would have relied on standard equation (with p=62 lb/ft and C=14.7) to estimate the pressure in the water phase, how much difference would have occured in our estimate of oil water contact?