Question: A Volumetric Undersaturated Oil Reservoir Has A Bubble Point Pressure Of 4500 Psia. The Initial Reservoir Pressure Is 7150 Psia And The Volumetric Calculations Indicate The Reservoir Contains 650 MMSTB Of Oil Initially In Place. The Field Is A Tight, Naturally Fractured, Chalk Reservoir And Was Developed Without Pressure Support By Water Injection. …

A volumetric undersaturated oil reservoir has a bubble point pressure of 4500 psia. The initial reservoir pressure is 7150 psia and the volumetric calculations indicate the reservoir contains 650 MMSTB of oil initially in place. The field is a tight, naturally fractured, chalk reservoir and was developed without pressure support by water injection. The initial reservoir pressure is 3685 psi. The following additional data is available: Swi = 43%, cf = 3.3 * 10-6 psi“, Bw = 1. 0 bbl/STB, cw = 3 x 10-6 psi”, Pb = 4500 psia The field production and PVT data summarized below: Q. (STB/day) Q (MMscf/day) В. (bbl/sch) 44 230 79326 75 726 (psia) 7150 6600 5800 4950 4500 4350 4060 3840 3600 3480 3260 3100 2940 2800 70208 50 416 35227 26 027 27 452 20975 15753 14268 13 819 64.110 115.616 110.192 134.685 147.414 135.282 115.277 151.167 141.326 125.107 116.970 111.792 B. (bbl/STB) 1.743 1.760 1.796 1.830 1.850 1.775 1.670 1.611 1.566 1.523 1.474 1.440 1.409 1.382 RS (scf/STB) 1450 1450 1450 1450 1450 1323 1143 1037 958 882 791 734 682 637 0.000797 0.000840 0.000881 0.000916 0.000959 0.001015 0.001065 0.001121 0.001170 N (MMSTB) 0 8.072 22.549 36.369 43.473 49.182 58.383 64.812 69.562 74.572 78.400 81.275 83.879 86.401 RE (scf/STB) 1450 1450 1455 1455 1447 1576 1788 1992 2158 2383 2596 2785 2953 3103 2 Calculate the initial oil-in-place by using the Havlena-Odeh method and compare with the volumetric estimate of N.