Abstract:

Strike-slip basins are commonly complex, mainly because of its complicated fault system and tectonic style. Based on systematic structural interpretation with 3D seismic data and analysis on regional geology and drilling data, the fault system and tectonic style of the Yitong Graben are studied. It is shown that the fault system of the Yitong Graben mainly composed of EW strike extensional normal faults and NE strike wrench faults, and reflects a right lateral strike-slip stress field. There are four evolution types of faults, and well matched with the basin formation and evolution. The main tectonic style of the graben is the “basement involved”, and is strike-slip and pull-apart origins, and can be subdivided into 5 types. There is only one dominant tectonic type in each fault depression. The difference of the tectonic styles is the main reason which causes each fault depression to have its own oil distribution law.

Key words: fault, fault depression, tectonic style, the Yitong Graben