Characteristics of transfer zones under the influence of pre-existing faults and regional stress transformation: Wenchang A subsag, Zhujiang River Mouth Basin, northern South China Sea

A transfer zone in rift basins preserves important information on regional tectonic evolution and plays significant roles in hydrocarbon accumulation. Based on the systematic analysis of 3D seismic data and hydrocarbon accumulation conditions, the geometry, kinematics, and reservoir control of a large synthetic overlapping transfer zone in the south of the Wenchang A subsag in the Zhujiang (Pearl) River Mouth basin were investigated. Results indicate that the development and evolution of the transfer zone was controlled by the interaction between pre-existing faults and regional stress transformation. The intense rifting of the main faults of the transfer zone controlled the development of source rocks and fault-controlled slope break paleogeomorphology. The strike-slip overprint since the Oligocene is conducive to the formation of a large-scale fault-anticline trap, and the secondary faults in the transfer zone contribute to the hydrocarbon transportation. The conjugate intersection area of the NE- and NW-trending faults offers more opportunity for hydrocarbon migration and accumulation.