Geological characteristics and distribution patterns of hydrocarbon deposits in the Bohai Bay Basin, east China

The Bohai Bay Basin in east China is a Meso-Cenozoic continental fault-bounded basin with abundant petroleum resources. Based on analyses of sedimentation history and tectonic and thermal evolution, the vertical and horizontal distribution patterns of oil and gas are discussed in this paper. The basin has characteristics of multiple cycles of depression and uplift and each depression has its own sedimentary system and pattern of oil generation. The main source rocks are of Lower Tertiary sediments characterized by multi-cyclic sedimentation. Multiple source-reservoir-caprock associations were developed. Abrupt changes of sedimentary facies and the development of numerous faults caused the formation of various types of oil and gas reservoir that constituted multiple oil and gas accumulation zones based on individual structure zones. These accumulation zones are mainly distributed around the centre of source rock deposits and are restricted in the areas where source rocks are distributed.