Long Term Stability Of Proppants Exposed To Harsh Shale Reservoir Conditions

Abstract

Abstract Laboratory experiments under reasonable Haynesville Shale reservoir temperature conditions have shown that an uncoated ceramic proppant and shale samples changed significantly in key physical properties. Proppant tensile strength was reduced significantly and Brinell Hardness of the shale was also reduced significantly from long-term exposure to broken fracturing fluid. The water chemistry of the fluid changed substantially during the entire 6 month time at temperature test period. It was concluded that the time dependency of these changes may have important implications for well drawdown practices for similar reservoirs, fracturing materials, and conditions. SPE 131782 presented an early progress report on these experiments, using single proppant crush, proppant type and a single fracturing fluid chemistry. The purpose of this paper is to present the next progress report. New experiments have used both low and high-pH make-up water. Tests completed since the first report and including results from both coated and uncoated sand and different ceramic proppants will be reported. Changes in water chemistry from the laboratory experiments have been compared to long-term post-fracturing water chemistry changes in Haynesville Shale wells. Results show good agreement between the chemistries of the produced water and the water sampled from the laboratory tests.