断层对油气的相对封闭性和绝对开启性分析——以准噶尔盆地西北缘八区—百口泉区二叠系油气特征为例

ANALYSIS OF RELATIVE SEALING AND ABSOLUTE PERMEABILITY OF FAULT-TAKING PERMIAN HYDROCARBON CHARACTERISTICS OF THE REGION 8 AND THE BAIKOUQUAN AREA, NORTHWEST MARGIN, THE JUNGGAR BASIN FOR EXAMPLE

高岗 柳广弟 黄志龙

Gao Gang Liu Guangdi Huang Zhilong

油气资源与探测国家重点实验室(中国石油大学), 北京, 102249

State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum, Beijing 102249, China

通过对准噶尔盆地西北缘八区—百口泉区夏子街组和风城组断层油气藏油气特征的分析,探讨了断层的封闭性与开启性。对于断层油气藏来说,油气特征在平面上的差异与断层封闭性有密切关系。封闭性好的断层油气藏由于油气重力分异作用,从油气藏底部到顶部,原油溶解气和天然气中甲烷等轻组分含量将不断升高,原油密度和粘度会逐渐降低。而封闭性差的断层油气藏越靠近断层,轻组分越容易散失,从油气藏底部到顶部,原油溶解气和天然气中甲烷等轻组分含量将不断降低,原油密度和粘度逐渐升高。不同断层油气藏的各种成藏条件相同时,由于断层封闭性不同,油气总体特征发生变化。研究区断层油气藏上倾部位的断层在不同部位封闭性有差异,断层基本都有不同程度的绝对开启性,而封闭性是相对的。通过对比分析认为八区夏子街组和风城组油气藏的断层封闭性要好于百口泉区。

In this paper,according to the characteristic analysis of oil and gas of the Xiazijie and Fengcheng Formation in fault oil field of the region 8 and the Baikouquan area of the Northwest margin,the Junggar Basin,the authors discussed the fault's property of sealing and unsealing.Ordinarily,for the fault oil and gas accumulation,there is an intimate relation between the horizontal distribution features of hydrocarbon characteristics and the sealing property of the fault.In a strong sealing fault hydrocarbon reservoir,because of the gravitational force differentiation of oil and gas,the contents of dissolved gas in the crude oil and methane will gradually increase and the density and the viscosity of crude oil will decrease from the bottom to the top of reservoir.While in a poor sealing fault hydrocarbon reservoir,the righter hydrocarbons are easily lost near the fault.From the bottom to the top of the fault reservoir,the contents of dissolved gas in crude oil and methane will gradually decrease and the density and the viscosity of crude oil will increase.When different hydrocarbon reservoirs have same pool formation conditions,the characteristics of oil and gas will have a regularity alteration owing to the different sealing property.In the research area,there is different degree sealing to updip faults of the hydrocarbon reservoir.They have all absolute unsealing and relative sealing.For the hydrocarbon reservoir of the Xaizijie and Fengcheng Formation,there is a relatively better sealing in the region 8 than in the Baikouquan area.

国家重点基础研究发展计划(973计划)项目(2007CB209503)资助

https://doi.org/10.11781/sysydz201003218