Abstract:

The Shigang, Chajian and Wubao fault systems in Subei basin represent, laterally, combined characteristics of a major fault with main linear shift zone, horsetail splays and en echelon lambda-type structures, and, vertically, structural features of cone-like fracture, forced monocline and fractured main shift zone. Shear and compressive fracture planes can be observed in rocks beside the faults. Based on the above characteristics, it is believed that the Shigang, Chajian and Wubao fault systems are of discrete-type right lateral strike-slip faults. Stress analysis indicates that Subei basin has experienced both agents of extension and right lateral strike-slip, while right lateral wrench movement is the main cause of strike-slip faults, which has been controlled by Tanlu fracture zone. It is the features of discrete-type right lateral strike-slip of the Shigang, Chajian and Wubao fault systems that control the formation and distribution of oil and gas traps, as well as the migration and accumulation of oil and gas in Subei basin.

Key words: strike-slip fault, discrete-type, right lateral, genetic mechanism, hydrocarbon accumulation, Subei basin