Development and Application of "Frac" Treatments in the Permian Basin

Abstract

Published in Petroleum Transactions, AIME, Volume 204, 1955, pages 58–65. Abstract The "frac" method of well stimulation has been applied successfully to all producing formations in the Permian Basin area. During the five years since its development, many changes and improvements have been made in treating materials, procedures, and equipment. A number of fluid carrying agents, having different physical and chemical properties, have been developed to meet various well requirements. The current trend is toward larger gallonage treatments, employing higher injection rates. The use of "down-the-casing" techniques has greatly reduced high surface working pressures, attributable to friction losses resulting from injection through tubing. Petrographic studies of various Permian Basin formations, coordinated with laboratory and well log data have been found a valuable guide in planning frac treatments. A knowledge of the extent and orientation of naturally occurring fractures and planes of weakness in the formation, aid in predicting the ultimate drainage pattern resulting from the frac treatment. Introduction The South Permian Basin covers an area in West Texas and New Mexico about one-half the size of the state of Texas. This vast region has been called the "Permian Basin" for so long that the term will be used here. It includes an area south of the Matador Arch, approximately 250 miles wide and 300 miles long. Structural features of importance within the basin are the Northwest Shelf, Eastern Platform, Midland Basin, Central Basin Platform, and Delaware Basin. The principal producing formations include sand, limestone and dolomite, with lesser amounts of shale, anhydrite, chert, and. various silicates. All of the producing formations in the Permian Basin have responded to some type of frac treatment. Essentially, a frac treatment may be defined as the injection, into a formation, of a fluid carrying agent containing a particulated solid (usually sand), for the purpose of increasing production. The application of this method of well stimulation to many differing Permian Basin reservoirs has necessitated numerous changes and improvements in carrying agents, solids, service equipment, well equipment, and treating techniques.