Geological Characteristics of Deep Shale Gas and Their Effects on Shale Fracability in the Wufeng-Longmaxi Formations of the Southern Sichuan Basin, China

Abstract The deep shale gas reservoirs of the Wufeng-Longmaxi Formations in southern Sichuan Basin have strong heterogeneity and complex geological characteristics, resulting a poor fracturing effect low vertical production. Based on whole-rock X-ray diffraction analysis, scanning electron microscopy, gas-bearing experiments, rock mechanical parameter tests well logging elemental data, sedimentary environment, characteristics this are analyzed, fracability is evaluated. (1) type organic matter affected by factors such as sea level change, hydrodynamics, reducing environmental conditions, algae bioenrichment, tectonic stability, contents Type I II kerogens lowermost reservoir high. (2) pores between biogenic siliceous minerals (the framework) numerous provide space for occurrence gas. High-quality high brittle mineral content, Young’s modulus, Poisson’s ratio, an appropriate pressure, small net stress difference, fracability. (3) Multicluster perforation, temporary plugging near wellbore, multistage can be used Wufeng Formation-Longmaxi Formation, increasing near-wellbore hydraulic fracture complexity improving effect.