A Review of Steam Soak Operations in California

Abstract

Thermal stimulation of oil producing wells by cyclic steam injection accounts for over 13 percent of the current oil production in California. Here is a description of some of the more important steam soak operations currently being conducted in 29 California oil fields through June, 1967. Introduction The tremendous upsurge in thermal stimulation of heavy oil producing wells by steam soak operations in recent years has reversed the 9-year decline trend of the total oil production rate in California. By the end of June, 1968, some 14,000 wells were actively involved in steam soak operations and over 139,000 B/D of additional oil were being credited to this thermal stimulation process. The total state production has increased from 795,238 B/D in Feb., 1962, production has increased from 795,238 B/D in Feb., 1962, to 1,026,000 B/D in June, 1968. The substantial increase in oil production in turn created a widespread search for projects that could benefit from steam soak operations. This review was conducted to determine those areas in the state where steam soak operations were being successfully applied, and to recognize, if possible, which type of heavy oil reservoir had responded most favorably to this stimulation method. It was hoped that the results of the review would provide some practical guidelines to be used along with theoretical considerations in selecting future steam soak projects. History The following summarizes very briefly the active steam stimulation projects in the State of California from the inception of this process in 1958 until June, 1968.1958 -- Shell Oil Co. began steam soak operations on a pilot basis in the Yorba Linda field.1961 - The success of the Yorba Linda experiment was evident and Shell expanded their steam soak operations to include properties in the Coalinga field. During this year, Tidewater Oil Co. started hot water injection in the Kern River field.1962 - Beiridge Oil Co. began steam soak and steam displacement operations in the South Beiridge field.1963 --A total of 29 steam projects were in operation.1964 - A total of 111 steam projects were in operation.1965 -By December of this year, there were 284 steam projects in California, of which 17 were steam displacement and 267 were steam soak or "huff and puff" operations.1966 -- By June of this year, there were a total of 339 steam projects in California, approximately 90 percent of which were cyclic steam soak operations. percent of which were cyclic steam soak operations.1967 - By June of this year, the number of projects had declined to 256.1968 - By June of this year, the number had further declined to 242. Table 1 summarizes these projects by fields as of July 1, 1967. All data are from C.C.O.P. records except for the number of generators in use. These figures were taken from miscellaneous published articles. The estimated additional oil production from steam stimulation was about 120,000 B/D by the end of June, 1967. Approximately 408 generators were in use at this time, so that the additional production amounts to 295 B/D/generator. JPT P. 25