A Performance Study of the South Pampa Waterflood
Authors: Byrd Jack L. 
Published: December 2007

Considerable effort has been expended in trying to define the factors that control the success or failure of Panhandle floods. Most of the failures result from a lack of adequate reservoir data and from a failure to recognize or give sufficient weight to danger signals that appear during the primary producing life of the flood prospect.

Introduction
The Texas Panhandle field has produced more than a billion barrels of primary oil. This ranks the field second in the U. S. in terms of cumulative oil production. The amount of remaining oil in place is certainly enough to generate interest in the potential for additional recovery by secondary means. Numerous secondary projects have been attempted to exploit these reserves and there has been a wide variation of results. Some of this variation can be explained by different reservoir conditions, which should be expected in a field that is more than 100 miles long with production in five counties. Thus, each localized area must be evaluated on its own merit. Several successful waterfloods have been conducted in recent years. There have also been several failures. This paper discusses one of the failures. Considerable experimentation and research have been conducted by several companies attempting to define the factor or factors that control the success or failure of Panhandle floods. Basically, most failures result from the Panhandle floods. Basically, most failures result from the lack of sufficient reservoir data and the failure to recognize or to give sufficient weight to danger signals that may have occurred during the primary producing life of the flood prospect. It is hoped that this paper will help reduce future failures if only by creating an awareness that some potential causes of failure might be recognizable even potential causes of failure might be recognizable even though available data are limited.

Historical Data
The South Pampa Waterflood is located in western Gray County, Tex., immediately south of the city of Pampa. Oil production is from the Wolfcamp Pampa. Oil production is from the Wolfcamp Dolomite of Permian age. The productive interval is locally named Brown Dolomite and is the major productive zone in the Panhandle field. Most of the major productive zone in the Panhandle field. Most of the major secondary projects produce from this zone, though attempts have been made to waterflood underlying dolomite and Granite Wash sections. Two major cooperative gas cycling projects, as well as several smaller ones, have been in operation for more than 20 years. These projects cover only localized areas within the field and need be considered only in connection with waterflood operations within or immediately adjacent to these operations. Only a small portion of the South Pampa project had been portion of the South Pampa project had been subjected to gas injection prior to waterflooding. Initial injection into the South Pampa project was in July, 1964, utilizing a 20-acre, five-spot pattern. (Fig. 1 is a map of the project.) Development was limited on the east and west boundaries, because of the lack of offset cooperation. Originally there were 900 productive acres within the project boundaries, with the flood development limited to 535 acres. An additional 60 acres was subsequently developed. In all cases, producing wells were used as injectors. Fig. 2 depicts the project performance. Production prior to flood development was 280 BOPD and 320 prior to flood development was 280 BOPD and 320 BWPD - a water cut of 53 percent. Water production increased rapidly during the first year of operation and averaged 1,200 B/D in mid-1965, when the first oil stimulation occurred. Both oil and water production increased for several months, with the oil production increased for several months, with the oil production reaching a peak of 440 B/D in March, 1966. production reaching a peak of 440 B/D in March, 1966. Corresponding water production was 2, 1 00 B/D. By Oct., 1966, oil production had declined to 270 B/D, while water production had increased to 2,600 B/D. A preferential east-west direction of sweep was evident by this time, in at least part of the project. An injection pattern change was effected in early 1967 to attempt to compensate for the preferential direction of water movement.
JPT
P. 393