c) A circular reservoir of radius 2000 ft, sand thickness 120 ft, porosity 22% and connate water saturation of 26 % had an initial pressure of 6200 psia, and a bubble point pressure of 4800 psia. It was produced until the pressure dropped to 3100 psia. During this interval 3 MMSTB of oil was produced. The initial formation volume factor was 1.35 bbl/STB and initial gas oil ratio was 800 scf/STB. The gas oil ratio at 3100 psia was 360scf|STB and gas volume factor was 0.005 cu.ft/SCF. The produced gas oil ratio was 3200 scf/STB. Calculate:- i. the initial STB of oil in the reservoir (2 marks) ii. the initial SCF of gas in the reservoir (2 marks) iii. the STB of oil in the reservoir at 3100 psia (1 marks) (1 marks) iv. the recovery factor at 3100 psia V. (2 marks) the SCF of produced gas (2 marks) vi. the SCF of free gas in the reservoir at 3100 psia