Characteristics and major controlling factors of fracturing in an Archean buried-hill, Bozhong Sag, Bohai Bay Basin, China

Archaeozoic fractured buried-hill reservoirs have been found in the Bozhong Sag, Bohai Bay Basin, but the origin, stage and distribution of fractures are still unclear. The B-block is used as an example to explore the genesis and main controlling factors on fracture formation. Core and image log data, combined with regional geology, were used to comprehensively analyze the characteristics of fractures. High-angle shear fractures and low-to moderate-angle tensile fractures were developed in the area. Fracture development was mainly controlled by lithology. The lithologies in the study area from most fracture prone to least are monzonite, granodiorite, cataclastic rock and gneiss. This study has provided a basis for the prediction of potential reservoir areas in paleo-buried hills.