Fault characteristics and their controls on hydrocarbon accumulations in Neogene, Kendong area, Bohai Bay Basin

We studied the geometric and kinematic characteristicsof faults in the Kendong area of the Bohai Bay Basin, and analyzed their controls on hydrocarbon accumulations, based on basic geology, well drilling, testing, logging and 3D seismic data. The study area mainly developed on NNE, NEE and NWW oriented fracture systems. Affected by the early activity of Tanlu Fault, faulting in the western and southern parts of the study area was stronger than that of the eastern and northern parts in the Paleogene, but the reverse in the Neogene.Different types of fractures had different controlling functions on hydrocarbon accumulation elements. Tensile fractures mainly formed simple fault block traps, transtensional(torsion) fractures formed complex fault block and fault-lithological traps, and compresso-shear fractures formed anticlinal structural traps. Reservoirs controlled by faults generally followed a principle that sand bodies developed near extensional faults and away from torsion faults. Sealing of extensional faults, transtensional (torsion) faults, compresso-shear faults enhanced in order, and hydrocarbon usually accumulated near the oil source faults with better sealing conditions.