Origins and Differences in Condensate Gas Reservoirs between East and West of Tazhong Uplift in the Ordovician Tarim Basin, NW China  

作　　者：Yinglu Pan Bingsong Yu Baotao Zhang Guangyou Zhu 

机构地区：[1]State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences [2]Geological Exploration Institute of Shandong Zhengyuan,China Metallurgical Geology Bureau [3]Research Institute of Petroleum Exploration and Development,PetroChina

出　　处：《Journal of Earth Science》2017年第2期367-380,共14页地球科学学刊（英文版）

基　　金：financially supported by a Chinese National 973 Program (Nos.2011CB201100-03, 2006CB202302);Chinese National Oil and Gas Program (Nos.2011ZX05005-004-HZ06, 2011ZX05009-002-402)

摘　　要：The Ordovician of the Tazhong area in the Tarim Basin has suffered multi-cyclic hydrocarbon charging, making Tazhong a typical condensate gas district. In this paper, production and test data were gathered and a detailed comparison was conducted on the geology and the fluid distribution and characteristics between the eastern and western Tazhong area. Eastern and western regions exhibit significant differences in tectonic structure, fluid distribution, and physical-chemical properties of oil and gas. Compared with the eastern region, the western part has a greater development of discordogenic gas associated with strike-slip faults which, combined with the Tazhong No. 1 fault zone, control the fluid distribution. The eastern region is mainly controlled by the Tazhong No. 1 fault zone. Fluid have markedly homogeneous properties in the east, but are heterogeneous in the west. The origins of oil and gas are different between the east and the west. In the east, hydrocarbons are mainly from Ordovician source rocks and natural gas is mostly derived from kerogen pyrolysis. In the west, the hydrocarbons mainly originated from Cambrian source rocks, and the gas was mostly generated by crude oil cracking. In sum, the east region is dominated by primary condensate gas reservoirs, and the western region is dominated by secondary condensate gas reservoirs. Because of the different geological settings and fluid physical properties, differences in the condensate gas reservoirs in the eastern and the western Tazhong area have been analyzed, and appropriate formation mechanisms for condensate gas origins are established.The Ordovician of the Tazhong area in the Tarim Basin has suffered multi-cyclic hydrocarbon charging, making Tazhong a typical condensate gas district. In this paper, production and test data were gathered and a detailed comparison was conducted on the geology and the fluid distribution and characteristics between the eastern and western Tazhong area. Eastern and western regions exhibit significant differences in tectonic structure, fluid distribution, and physical-chemical properties of oil and gas. Compared with the eastern region, the western part has a greater development of discordogenic gas associated with strike-slip faults which, combined with the Tazhong No. 1 fault zone, control the fluid distribution. The eastern region is mainly controlled by the Tazhong No. 1 fault zone. Fluid have markedly homogeneous properties in the east, but are heterogeneous in the west. The origins of oil and gas are different between the east and the west. In the east, hydrocarbons are mainly from Ordovician source rocks and natural gas is mostly derived from kerogen pyrolysis. In the west, the hydrocarbons mainly originated from Cambrian source rocks, and the gas was mostly generated by crude oil cracking. In sum, the east region is dominated by primary condensate gas reservoirs, and the western region is dominated by secondary condensate gas reservoirs. Because of the different geological settings and fluid physical properties, differences in the condensate gas reservoirs in the eastern and the western Tazhong area have been analyzed, and appropriate formation mechanisms for condensate gas origins are established.

关 键 词：condensate gas reservoir origin Ordovician carbonate Tazhong area 

分 类 号：P618.13[天文地球—矿床学]