Northwestward(NW) Faults And Its Relationship With Hydrocarbon Accumulation In The Eastern Part Of Zhanhua Sag

The northwestward (NW) faults play an important role in the hydrocarbon accumulation in the eastern part of Zhanhua sag, Jiyang Depression. Based on the large number of geological, seismic and regional tectonic data, this paper studied systematically the distribution and their evolution characteristics of main faults in the eastern part of Zhanhua sag and their effect on hydrocarbon accumulation. The fault controlling effect on the hydrocarbon migration and accumulation was also studied by combining the physical and numerical experiments of hydrocarbon migration and accumulation. The results will benefits to forecast the favorable petroleum exploration area of eastern part of Zhanhua sag.The two NW structural belts, Chengdao-Kendong and Kendong-Guxi burial hill belts, in the eastern part of Zhanhua sag are the result of multi-tectonic superposition and later stage faulted reform. All main NW faults underwent the process of thrust first and then extension reversal. The activities increase from the west Luoxi Fault, Guxi Fault to the east Chengbei-Wuhaozhuang Fault, with the active velocity 45m/Ma, 65m/Ma and 80m/Ma respectively.The oil and gas distribution and hydrocarbon accumulation models are different in the different structural positions and different types of structures. Most petroleum accumulated in the Neogene Guantao Group and Lower Palaeozoic burial hill drape structure belts. The fault acted as the conducting system and the neotectoinc movement played an important role on the petroleum formation and distribution. At the same time, the physical experiment of hydrocarbon migration showed the large dip angle of fault is favorable to hydrocarbon migration.Based on the above study results, the favorable petroleum exploration area of eastern part of Zhanhua sag are Zhuanghai, Gubei and Kendong burial hills and Chengbei, Gunan sags.