Abstract:

New ideas about geological structure, formation and development of Damintun Depression in Liaohe Oilfield were obtained from interpretation and correlation of the multipleblockjointed prestack time migration processing of 3D seismic data. Damintun Depression is a typical extensional half graben in EoceneOligocene time, with steep slope zone distributed in the eastern part of depression. Its slope occured in the western part of depression, and its center of deposition and subsidence located at Rongshengpu subsag. Structural evolution history of steep slope zone can be divided into four stages:rifting, transpressional strikeslip, depression and compressional inversion stages. Multiple structural styles and traps were formed after early extensional fault reformed by later transpressional fault system. These structural traps are near the petroliferous depression,and have the excellent accumulation conditions for reservoir. The flower structure, compressional anticline, reverse faultedblock and inversion structure in shallow layer through original extensional fault plane especially have the good exploration prospects. 

Key words: steep slope zone, strike-slip fault system, inversion structure, Damintun Depression, Liaohe Oilfield