Case History Of A Multiple Zone Peripheral Waterflood

Abstract

Introduction This paper is a report on the conception of and resulting performance of a water flood operation which has been carried out in the Oscar field located in Jefferson County, Oklahoma. The operator of the project is the J. B. Stoddard Estate, who is a joint working interest owner with Continental Oil Company. The oil reservoirs affected by this water flood program involve three members of the Hoxbar sand of Middle Pennsylvanian Age which is found at depths of 1100 to 1200 feet subsurface. The individual sand members are designated locally as the "A", "B" and "D" sands. Figure 2 contained herein is a composite log which identifies all sands that are present in the area to a depth of approximately 1750 feet subsurface and shows both productive and non-productive zones. At the time of the initiation of water injection the "A", "B", and "D" sands had exhibited water encroachment, the configuration of the limit of water-free production varying with each sand member. The interpretation of water-free areas as of the time of the original study in 1953 are outlined on the isopachous maps of gross sand intervals included as Figures 3, 4 and 5. The purpose of this paper is to present basic data on each reservoir, the significance of the data which was available for study and the important part these data had in interpretation of conditions in the field, the operating procedures applied in the program and the resulting performance of the reservoirs under a peripheral water injection type program. DEVELOPMENT The J. B. Stoddard Estate - Continental Oil Company - W. D. Seay lease is located in Jefferson County, Oklahoma, immediately north of the Red River and approximately 15 miles northeast of Nocona. It is in the Oscar (Oklahoma) area of the old Nocona or Montague County, Texas, pool. The Hoxbar sands are productive over a considerable area in this region extending under the Red River into Oklahoma extending under the Red River into Oklahoma from the Montague County, Texas area. The first productive well drilled on the J. B. Stoddard Estate Continental Oil Company - W. D. Seay lease was located on a sand spit in the middle of the Red River and was completed in July, 1930. This well was drilled to a total depth of 1265 feet and completed in the "D" sand reservoir. The "B" sand was also present in this well at approximately 1100 feet, and in August, 1930, the No. 2 well was drilled on the same sand spit at a location 300 north of No. 1 and completed in this 1100 foot zone. Beginning in 1933 an intensive development program was commenced and by 1935 there were 30 producing wells on the lease. Again in 1937 active drilling was undertaken and by January, 1938 a total of 62 wells had been drilled, 59 of which were oil productive, one gas well completed in an 500 foot Cisco sand zone and two wells had been abandoned. Operations were assumed by J. B. Stoddard in 1944 as the result of the acquisition of a portion of the working interest, and additional development was initiated in 1946, continuing periodically through 1956, until a total of 83 producing wells, one dry hole, one gas well and 11 abandoned wells were on the lease. The W. D. Seay lease encompasses a total of 287 acres, of which approximately 200 acres were found to be oil productive. PRODUCTION HISTORY Figure 1 illustrates graphically the production history from all productive sands and by virtue of the fluctuations in producing rate shows the period in which development drilling took place.