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Methods to obtain better results with hydraulic fracturing in low permeability sandstone formations are constantly being developed. Fracturing techniques employed are often cyclic in nature, catalyzed to a large extent by gas and oil prices and corresponding costs of the stimulation treatments. "Optimization" of the fracturing approach may often seem arbitrary and raise the question: "Optimum …. Compared to what?" Technology for improvements in hydraulic fracturing results is advancing at a rapid pace from the 3-D Seismic measurements used to define pay structure all the way to improved real-time mapping of fracture propagation. Extensive data gathering projects, however, are frequently big budget items and require dedication of manpower and resources. Therefore, such data measurement often tends to be reserved for projects of a regional scope. This paper discusses several case studies of fractured wells in the Cotton Valley formation in East Texas and describes systematic changes in fracturing techniques used to improve treatment success. Comparisons of production data (short term and long term) are used to illustrate the degree of improvement. Readily available information (open hole logs, RA Tracer Logs, and PLT logs) was used systematically in this study. |
