How much surface tank oil exists in the following oil field? area of the field 480 acres; average 30%, and carbonate reservoir thickness-50-ft, average porosity oil formation volume factor 1.25. (10) 18%, average connate water using excel plot depth (ft) vs. pressure (psi) plot for a fresh-water system (sg 1.0), for a salt- water system (sg 1.12) and for a drilling fluid system (sg 1.25). (15) 9. 10. show that the static pressure of a gas column at depth h (hz-h,) can be estimated by the following equation: (15) 0.01875gh avg avg p2 pressure at depth h2: p, pressure at depth h; g gas gravity (air 1.0) h2-h1 = true vertical depth interval, ft = zavggas compressibility factor for average pressure and tavg - average temperature of gas column, "r (460° +。f) between h2 and h1