New Treatment for Improving the Productivity of Shale Reservoirs Using Thermochemical Fluids

Abstract

Shale reservoirs are characterized with very low productivity due to the high capillary pressure and the ultra-low rock permeability. This article presents an effective treatment to improve the hydrocarbon productivity for shale reservoirs by injecting thermochemical fluids. In this study, several measurements were carried out to determine the effectiveness of the presented treatment. Coreflood, rate transient analysis (RTA), and nuclear magnetic resonance (NMR) measurements were performed. The gas productivity was estimated, before and after the treatment, utilizing the gas flowrates and the pressure drop across the treated rocks. The improvement in gas productivity due to thermochemical fluids was estimated by calculating the productivity index (PI) and the absolute open flow (AOF) before and after the chemical injection. Also, the changes in the pore size distribution, due to chemical injection, were studied using NMR measurements. Results showed that thermochemical treatment can improve the gas productivity by 44%, increase the AOF by 450%, and reduce the capillary pressure by 47%. Also, NMR measurements showed that fractures were induced in the shale rocks after the treatment, which will improve the shale productivity. Ultimately, this study introduces, for the first time, the use of thermochemical fluids to improve the hydrocarbon productivity for shale reservoirs.