Comparison of Conventional Hydraulic and Water/Nitrogen Foam Fracturing in Two Ohio Devonian Shale Gas Wells

摘要

The current natural gas supply problems in the United States are encouraging research into new or underdeveloped gas sources. One such source is the Devonian Shale sequence of Kentucky, West Virginia, Pennsylvania, and Ohio. These thick shale deposits contain large gas resources, but have not been fully exploited because of the severely restricted gas well flow rates. Shale wells must be artificially stimulated to improve gas deliverability to a commercial level, and research is under way to develop a stimulation method suited to the Devonian Shale. This report describes a performance comparison of two wells completed in the Shale near Youngstown, Ohio: one stimulated conventionally with hydraulic fracturing, the other with a nitrogen/water foam treatment. Both wells have comparable reservoir sections and received equivalently sized stimulation treatments. Drilling and fracture programs for both wells are discussed along with short-term gas production tests conducted to evaluate the fracture treatments. Early indications show that the foam fracturing method is better suited to the reservoir conditions found in the Devonian Shale, resulting in much faster fracturing fluid clean-up and higher initial gas production than the conventional water method. (ERA citation 01:010276)