The Gas Research Institute’s Second Staged Field Experiment: A Study of Hydraulic Fracturing

Abstract

ABSTRACT The Gas Research Institute (GRI) is currently sponsoring a field-based research program to better understand the processes that control hydraulic fracture growth. In order to effectively conduct this research and validate the technologies under development, GRI has planned a series of Staged Field Experiment (SFE) wells. These SFE wells, which are drilled specifically for conducting research, are "staged" in the sense that a series of successively higher goals have been set for each well. These goals have been more completely described in previous publications.1 The first Staged Field Experiment was completed in 1987, the results of which have also been published.2,3 The first three SFE wells were planned to be drilled through the Travis Peak formation, while the fourth SFE well is scheduled to be completed in another basin containing significant gas reserves in a tight sand. The purpose of moving SFE No. 4 to another basin will be to apply and test any technologies developed in the GRI program in an entirely differently geologic environment. There are many research technologies that are being developed and tested in the SFE program, but the primary objective was to develop a fracture monitoring and fracture modeling system that could compute the shape and extent of a hydraulic fracture in real time. In order to obtain accurate and reliable input data for the fracture models, it was necessary to perform studies on geology, coring, logging, and well testing of tight gas sands. In an effort to substantiate and verify the models, additional research is being sponsored in the development of instrumentation and analysis techniques for measuring the dimensions of the fracture. The second Staged Field Experiment, officially known as SFE No. 2, was successfully completed in 1989. An extensive amount of data was collected on this well from two different intervals of the Travis Peak that were tested and fracture stimulated. The purpose of this paper is to summarize all of the data that were collected and the analyses performed on these data. As a result of the work performed on SFE No. 2, a great deal was learned with regard to the completion and stimulation of the Travis Peak formation. A new strategy with regard to completion and stimulation of wells was developed that utilizes the integration of openhole log and in-situ stress data. These results are presented for the Travis Peak. Hopefully, this same approach can be applied on most tight gas sands.