The Use of Injection/Falloff Tests and Pressure Buildup Tests To Evaluate Fracture Geometry and Post-Stimulation Well Performance in the Devonian Shales

Abstract

ABSTRACT This paper summarizes a series of experiments performed on the Gilbert Exploration Emma Preece No. 1 well in Martin Co., KY which have led to a better understanding of fracture geometry and post-stimulation well performance in the Devonian Shales. The Preece well, like many Devonian Shale wells, was perforated and stimulated with a single treatment over a large, perforated interval (727 ft). Post-fracture well tests performed after initial completion indicated little improvement over pre-fracture well performance. In 1989, the treated interval was sub-divided into four distinct zones to further evaluate the fracture treatment using isolation, communication, nitrogen injection/falloff, and flow/buildup tests. Results of these tests indicate (1) that the large completion interval was not uniformly stimulated by the fracture treatment and (2) that reservoir quality was different for each perforated interval, indicating the completion interval should be treated as a layered reservoir. These results help explain the apparent short fracture half-length and the less-than-expected flow rates for this well following stimulation.