In the Rock Creek tight gas formation, production was improved with the use of CO2 energized fluids. In addition, higher conductivity proppants were shown to be beneficial, with EconoProp providing higher production rates than sand or RCS in most treatment sizes. Further corroborating the benefit of increased conductivity, it was noted that 20/40 ceramic proppant provided superior results to 30/50.
Gelled hydrocarbon has been used as a fracturing fluid from the early days of fracturing. Over the years, its use has diminished in the U.S. However, its use internationally continues to the present day in Canada, South America, Russia and East Asia. The paper will discuss the use of gelled oil fluids in Canada, particularly in low pressure tight gas wells, where the use of CO2-energized gelled hydrocarbon fluids has been very successful. The chemistry of these fluids and their application is discussed. The energized fluids have been used in a variety of formations and in wells of permeabilities from 0.1 mD to 10 Darcies, depths in excess of 3000 m and BHT from 10 to 110 ºC. Initial and longer-term production data from wells fractured with the energized fluid will be compared to wells fractured with conventional gelled hydrocarbon fluids to show the effectiveness of the system in tight gas applications.
The case study will include gas wells fractured and producing from the Rock Creek formation east of Edson, Alberta, Canada from 47-10W5 to 56-15W5 in the Western Canadian Sedimentary Basin (WCSB). Observations on proppant type and proppant amount are made in addition to comments on the fracturing fluid selection.
Author(s): BJ Services Co., D.V.S. Gupta, and T.T. Leshchyshyn, BJ Services Co. Canada
Paper Number: SPE 95061