Characteristics and Main Controlling Factors of Fractures within Highly-Evolved Marine Shale Reservoir in Strong Deformation Zone

Based on the systematical observations of cores, thin sections, and scanning electron microscope (SEM) together with testing data characteristic parameters, this paper discussed characteristics controlling factors fractures, their control shale gas accumulation in Lower Cambrian Niutitang Formation black reservoir Well YX1 northern Guizhou Province. The results show that macro structural fractures are common Formation, which can be divided into shear (e.g., high dip-angle low slip fractures), tensional tension-shear fractures. Non-structural microfractures organic-related inorganic mineral-related Most were filled types fillings diverse. staggered relationships confirm complexity tectonic movement study area. formation is mainly controlled by major fault. influence mineral composition content, mechanical properties, brittleness, organic matter content rocks from external manifestation sedimentary environment. Affected diagenetic evolution, matter-related not common. Compared other reservoirs China abroad, organic-rich characterized both “geological sweet spots” “engineering spots”; however, strong deformation faulting have led to loss damage overpressure Therefore, it suggested small-scale caused movements but without large penetrating faults, most favorable for reservoirs. complicated setting Guizhou, pressure should taken account.