The Southwest Antioch Gibson Sand Unit

Abstract

Introduction The Southwest Antioch Oil Field located in T2&3N - R2&3W, GarvinCounty, Okla., was discovered in February, 1946, by The Globe Oil & Refining Co. and The Vickers Petroleum Co. at their Melinda Gibson No. 1. Oilproduction was encountered at a depth of 6,525 ft in 14 ft of lowerPennsylvanian sandstone. The producing sand, locally called the "Gibson" or "ThirdDeese," is a sand bar deposit strung along the west flank of the PaulsValley uplift in a northwest-southeast direction. The oil reservoir is definedto the east by the edge of sand deposition along the uplift and to the west bythe gradation of sand into shale. Within the Antioch Unit, the sand dips from150 to 400'Ft per mile southwesterly and has a pay thickness varying from 10 to55 ft and averaging 28 ft. Several areas of Gibson production have been developed, including the Katiepool on the south, the Elmore Area of the Southwest Antioch Gibson Sand pool, the Southwest Antioch Gibson Sand pool proper, the Southwest Maysville pool andthe New Hope pool on the north. Production extends over a belt 22 miles long byabout two miles wide and is continuous except into the Katie and New Hopepools. It appears that drilling will soon prove these intervening areasproductive. To March 1, 1950, approximately 18,000 acres have been developedwith 450 Gibson wells. It is likely this count will ultimately reach 32,000acres with 800 wells. Reservoir The natural production of oil from the Gibson reservoir is primarily due tosolution gas expansion though gravity also plays a part. There is no indicationof water drive or evidence that an initial gas cap existed. Gibson oil has a stock tank gravity of 43? API and was saturated at theoriginal reservoir pressure of 2,925 psi. It contained 1,340 cu ft of gas perbbl in solution and had a high shrinkage of 70 per cent. Connate water amountsto 15 per cent. Reservoir temperature is 130'F. Porosity averages 15.5 per cent and permeability ranges from less than onemd to over 1,000. Based on measurement of 400 core plugs from 15 wells, 78 percent of the permeabilities fell within the 10 to 1,000 md bracket and averaged167. Primary oil recovery is estimated at 140 bbl per acre-ft or 22 million bblfor the present 137-tract unit. T.P. 3057