Analysis of Waterflood Performance - Block VI Ranger Zone, Wilmington Field, Calif.

Abstract

Abstract An engineering analysis of the performance of the Block VI Ranger zone water flood operation from its inception in July, 1956, to date is presented. Implications of this performance with respect to future potential of a full-scale project are interpreted. Details are given of the expansion program currently underway, together with a description of the cooperative plan of operation in effect with offset operators. The dual purpose to be accomplished in the flood is explained. The objectives are to effect an economic waterflood operation and to control subsidence of the overlying area through control of reservoir pressure. Reservoir engineering and mechanical problems connected with the operation are treated. Introduction The first waterflooding Operations in the Ranger zone of Wilmington field, Los Angeles County, Calif., were initiated in July, 1956, as a pilot operation on the Producing Properties, Inc., N–1 and S–1 leases in Fault Block VI. The project is situated near the most easterly extension of the field and in the region where the Ranger zone underlies the downtown area of the city of Long Beach. The N–1 and S–1 leases of Producing Properties, Inc. are communitized leases comprising approximately 346 acres of town-lot development. Because the drilling of oil wells is prohibited by city ordinance within the area of these leases, the development drilling was accomplished from drill sites located on the west berm of the Los Angeles County flood control channel. This strip, which is located approximately 1,400-ft west of the western limit of Fault Block VI, is 26-ft wide and 5,570-ft long. As will be seen later, the fact that all wells producing from the properties are slant holes drilled from the western drill site has created unique problems in waterflood planning and in interpretation of the results observed in the pilot operations to date. At the time pilot operations were commenced, a total of 65 producing wells existed on the two leases in Fault Block VI; cumulative production had reached 8,889,773 bbl of oil, 12,191,422 Mcf of gas and 398,214 bbl of water. The Parcel A properties of the city of Long Beach. operated by Richfield Oil Corp. and bordering the pilot area to the south, had reached a development of 20 wells and had produced 2,348,465 bbl of oil, 3,764,623 Mcf of gas and 79,607 bbl of water. Development drilling in Fault Block VI of the Ranger zone stops at Pine Avenue in the city of Long Beach, or at its linear projection. The oil-productive Ranger zone unquestionably extends to the east in substantial development beyond this arbitrary boundary. The pilot area is offset to the north by the E. C. Simmons N–3 lease which had two producing wells and had produced 141,315 bbl of oil, 218,046 Mcf of gas and 11,531 bbl of water. Thus, at the commencement of the pilot operation. cumulative production from the Fault Block VI Ranger zone had been 11,379,553 bbl of oil, 16,174,091 Mcf of gas and 489,352 bbl of water.