Paper: Drilling Engineering Review Of The 1973 74 Denver Unit Infill Program Wasson San Andres Field

Prior to the 1973-74 Infill Program, the Shell operated Denver Unit, Wasson San Andres Field, Gaines and Yoakum Counties, Texas (Fig. 1) included over 900 producing or injecting wells. Upon project completion in October 1974, the 1973- 74 Denver Unit Infill Program added 120 wells (14 injectors, 3 replacement wells, and 103 new producers) to this total. The 1973-74 program was sufficiently different from previous Denver Unit programs to require some changes in techniques and equipment. The most significant differences were cementing production casing to surface and drilling "intown" and/or directional wells. These changes and the large number of wells necessitated the review of all drilling program facets to optimize performance and reduce costs. This paper presents the more significant points of this review and was prepared to document the cost reduction methods and the experience gained for use in future programs. The items discussed individually represent small cost reductions but collectively resulted in reducing 1973-74 Denver Unit Infill Program expenditures by $250,000.