Unique Completion Techniques Utilized In A Multi-Zone Waterflood Project

Publication Rights Reserved This paper is to be presented at the 39th Annual Fall Meeting to be held in Houston, Tex., on Oct. 11–14, 1964, and is considered property of the Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of the Journal of Petroleum Engineers or the Executive Secretary. Such abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in JOURNAL OF PETROLEUM TECHNOLOGY or SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted on request, providing proper credit is given that publication and the original presentation of the paper. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. The problem confronted in the initiation of the Adell Field Multi-zone Lansing-Kansas City Waterflood was isolation of injection because of the behind-the-pipe communication between the various producing intervals. This problem is common to producing operations in Western Kansas because of past drilling and completion procedures. In general, past waterflooding practices for the Lansing-Kansas City reservoir make no particular effort to control injection, disregarding reserves left in the intervals receiving inadequate water input. The potential secondary reserves in the Adell Lansing-Kansas City Field were sufficient to justify something better than uncontrolled water injection. To gain maximum secondary recovery, nine new input wells were drilled around the periphery of the field. By the use of a specific type of drilling mud, casing cementing procedure, and completion program, injection of water was controlled into the zones proposed for waterflooding. Introduction The Adell Field, Sheridan County, Kansas, is a multi-zone Lansing-Kansas City lime reservoir which has produced over 5 million barrels of primary oil since discovery in 1945., Fig. 1. Pilot waterflood operations proved the feasibility of secondary recovery and the seriousness of the communication problem. Approximately 3 million barrels of secondary oil were predicted, providing each zone of the Lansing-Kansas City reservoir could be effectively waterflooded. To assure maximum effective waterflood operations, the isolation of injection appeared necessary. The use of existing producing wells for injection was deemed unsound, because of the cost and difficulty involved with behind-the-pipe repair. Severe communications existed in the producing wells causing the foreseeable problem of isolation of water injection into the desired intervals. At this point, further investigation was made of the exact nature of the communication problem, beginning with core samples of the Lansing-Kansas City shales. Laboratory analyses of these shale samples showed a high percentage of calcareous material. The samples disintegrated in fresh water, salt water and acid, but were stable in oil and oil-water emulsions. This knowledge gave thought that communication existed because of the hydration and sloughing of the shale sections separating each Lansing-Kansas City zone, when the wells were drilled and cemented with conventional water-based fluids. This was confirmed by the character of caliper logs run through the Lansing-Kansas City formation. The decision was then made to proceed with the planned waterflood operations by drilling nine injection wells, Fig. 2. The drilling program was designed to minimize shale hydration by use of an inverted emulsion mud and use of salt cement with a fluid loss additive during casing setting operations. Nine injection wells were drilled in the above manner, with final completion made by perforating one-foot intervals in six prospective waterflood zones.