Geology and shale gas resource potentials in the Sichuan Basin, China

The organic-rich shales in the Sichuan Basin in China include Pre-Cambrian Sinian to Middle Permian marine shales deposited in passive margin to foreland settings, Upper Permian transitional shales deposited in a coastal swamp setting, and Triassic and Jurassic lacustrine shales deposited in a foreland setting. Regional shale property mapping, analysis of geochemistry, mineralogy and petrophysics based on sample tests, reservoir characterization of potential shale intervals, and recent exploration and production (E&P) results reveal that: Pre-Cambrian to Middle Permian marine shales, especially the Lower Silurian Longmaxi shale, deposited during transgressive systems tract to early highstand systems tract period have significant reservoir storage, high TOC, high maturity, high brittle mineral content and high gas content, and are similar to the Barnett shale in USA to hold a huge amount of shale gas. The coal-associated Upper Permian transitional shales and Triassic to Jurassic lacustrine shales are relat...