Characteristics of Hydrocarbon Accumulation in the Paleozoic Donghetang Formation in the Southwestern Tahe Area  

作　　者：ZHOU Wen ZHAO Guanjun LIU Fei YE Bin LI Xiuhua HUANG Tingting ZHOU Qiumei DONG Guoliang 

机构地区：[1]State Key Laboratory of Petroleum Reservoir Geology and Reservoir Engineering,Chengdu University of Technology,Chengdu,Sichuan 610059,China [2]Drilling and Oil Recovery Research Institute,Sichuan Petroleum Administrator Bureau,Guanghan, Sichuan 618300,China

出　　处：《Acta Geologica Sinica(English Edition)》2011年第4期899-910,共12页地质学报（英文版）

基　　金：supported by State Key Laboratory of Petroleum Reservoir Geology and Reservoir Engineering and partly by Northwest Bureau of Petroleum of SINOPEC

摘　　要：The ancient structure characteristic,correlation of the oil and the hydrocarbon source rock characteristics,hydrocarbon migration trace,types and conditions of traps,migration passages and characteristic of hydrocarbon accumulation are researched in this paper.It is shown through the analysis that two main large tectonic activities after the Early Hercynian orogeny resulted in different tectonic patterns in the study area.Two main hydrocarbon infills occurred in the Donghetang Formation,the first occurred in the Early Hercynian resulting in the ancient hydrocarbon accumulation in the northern Tahe,the second infill was a large amount that occurred in places beneficial for hydrocarbon accumulation,such as structural traps and structural-stratigraphic traps formed in the Early Himalayan orogeny after migration along the faults through source rocks and other passages.Before the earlier period of the Himalayan orogeny,the petroleum mainly migrated to the north,whereas petroleum migrated to the south and southeast because of the structural reverse in the Himalayan orogeny,so the middle and later period of the Himalayan orogeny is the key period for hydrocarbon accumulation.The model of＂oil generation formed early,hydrocarbon accumulation controlled by the faults through source rocks and structures formed late＂is proposed.It is pointed out that the south of the research area is currently the beneficial district for hydrocarbon accumulation, which provides the basis for future petroleum exploration.The ancient structure characteristic,correlation of the oil and the hydrocarbon source rock characteristics,hydrocarbon migration trace,types and conditions of traps,migration passages and characteristic of hydrocarbon accumulation are researched in this paper.It is shown through the analysis that two main large tectonic activities after the Early Hercynian orogeny resulted in different tectonic patterns in the study area.Two main hydrocarbon infills occurred in the Donghetang Formation,the first occurred in the Early Hercynian resulting in the ancient hydrocarbon accumulation in the northern Tahe,the second infill was a large amount that occurred in places beneficial for hydrocarbon accumulation,such as structural traps and structural-stratigraphic traps formed in the Early Himalayan orogeny after migration along the faults through source rocks and other passages.Before the earlier period of the Himalayan orogeny,the petroleum mainly migrated to the north,whereas petroleum migrated to the south and southeast because of the structural reverse in the Himalayan orogeny,so the middle and later period of the Himalayan orogeny is the key period for hydrocarbon accumulation.The model of＂oil generation formed early,hydrocarbon accumulation controlled by the faults through source rocks and structures formed late＂is proposed.It is pointed out that the south of the research area is currently the beneficial district for hydrocarbon accumulation, which provides the basis for future petroleum exploration.

关 键 词：southwestern Tahe faults cutting through hydrocarbon source rock hydrocarbon igration trace model of hydrocarbon accumulation 

分 类 号：P618.130.2[天文地球—矿床学] U656.314[天文地球—地质学]