Some Results of Fracturing with the Single-Point Entry Technique

Abstract

Abstract Fracturing with the single-point entry technique is discussed for the Big Piney and Patrick Draw fields, Wyo., and the Bijou field, Colo. In the single-point entry technique, the wellbore is notched at a selected point. The well is fractured and then is produced by way of the single fracture. The results indicate that fracturing treatments can be performed more easily through the single entry than through perforations, and the production histories available thus far indicate that wells fractured with the single-point entry technique have higher productivities than those fractured by conventional wellbore preparation. Introduction The single-point entry technique of fracturing for well stimulation per se was first used in the Big Piney field, Wyo., in June, 1959. This technique of fracturing, in which the wellbore is notched for the fracture placement and a single, high-flow-capacity fracture is used for the production stimulus, was originally considered to have its greatest potential in secondary recovery schemes and in the control of gas and/or water coning. However, during the development of the techniques for notching the wellbore and for selection and placement of the fracture propping agent, it became apparent that for a number of reservoirs conventional fracturing techniques did not provide the well stimulation that the single-point entry technique would provide. Thus, the mechanics of the technique was adapted for use as a production stimulus during primary recovery. Since June, 1959, single-point entry fracturing has been used in several hundred cases for well stimulation. In a majority of the cases, a comparison of the results with those obtained by conventional fracturing in a perforated interval cannot be made because the available data are insufficient. However, sufficient data are available for three fields in the Rocky Mountain area to allow an evaluation of the usefulness of the single-point entry technique in performing fracturing operations. These fields are the Big Piney and Patrick Draw fields in Wyoming and the Bijou field in Colorado. Also, for the Patrick Draw field, productivity index data are available to enable a comparison of the results of fracturing to be made, and sufficient production history on the Big Piney field makes it possible to compare the performance of the wells fractured conventionally with those wells fractured by the single-point entry technique. In this paper, fracturing operations in the three fields listed are discussed as case histories.