Analyses of 85 recent waterfracs performed in the Barnett Shale by Chief Oil and Gas strongly demonstrate that well productivity has been improved by increasing the mass of sand utilized. Productivity was not improved with larger fluid volumes. Increased net pressures were also found to improve well production. Results have encouraged Chief to further increase sand mass by 25% without increasing fluid volume. Higher sand concentrations have improved well production and have not posed any placement difficulties for this operator.
Chief Oil and Gas, LLC has an active drilling and completion program in the Barnett Shale, Newark East Field, Ft Worth Basin near Ft Worth, Texas, USA. This Mississippian age gas producing reservoir consists of naturally fractured shale. Most hydraulically induced fractures have been observed to be more of a network of fractures, referred to as fracture fairways, than the usual ‘planar’ fractures. These fairways apparently result from opening many of the natural fractures allowing for production. All wells must be hydraulically fractured for economic production. The Barnett Shale hydraulic fracturing trend in the last few years has been to water frac with small concentrations of sand. The water frac treatments reported on here have varied from approximately 600,000 to over 1,500,000 gallons and 120,000 to over 400,000 pounds of sand. Most of the wells have been completed in the lower Barnett with a lesser number in the upper and lower. Results from both types of completions are included in this work.
Production histories versus treatment volume and pounds of sand are presented as well as production decline data. Results indicate a much better correlation of production history with sand quantity than with fluid volume.
Author(s): Gerald R. Coulter, Coulter Energy Int'l; Edward G. Benton, Clifford L. Thomson, Chief Oil and Gas, LLC
Paper Number: SPE 90891