四川盆地川西坳陷东坡沙溪庙组油气成藏关键时刻研究

Key moments for hydrocarbon accumulation in Shaximiao Formation on the eastern slope of West Sichuan Depression, Sichuan Basin

林小云 魏民生 丰勇 李璐 韩艳

Lin Xiaoyun Wei Minsheng Feng Yong Li Lu Han Yan

长江大学 油气资源与勘探技术教育部重点实验室, 武汉 430100 2. 长江大学 地球科学学院, 武汉430100 3. 中国石油大港油田分公司 第二采油厂, 天津 061103

Key Laboratory of Exploration Technologies for Oil and Gas Resources of Ministry of Education, Yangtze University, Wuhan, Hubei 430100, China 2. College of Geosciences, Yangtze University, Wuhan, Hubei 430100, China 3. Second Factory of Oil Production, Dagang Oilfield Company of CNPY, Tianjin 061103, China

四川盆地川西坳陷是印支期以来龙门山挤压推覆所形成的前陆盆地，中段东坡地区包含合兴场—高庙子、丰谷、永太、中江—回龙和知新场—石泉场共计5个三维地震勘探区块，涉及3个构造区带。通过研究烃源岩生烃演化史并对研究区6口井22块流体包裹体样品进行荧光观察、显微测温、测盐等系统分析，结果表明：上三叠统须家河组五段烃源岩于151~145 Ma进入生烃门限，130 Ma达到生烃高峰；研究区侏罗系沙溪庙组砂岩储层发生过3期与油气成藏有关的流体活动，分别发生在距今141~128 Ma（J3-K1），105~88 Ma（K1-K2），83~68 Ma（K2），成藏关键时刻主要在烃源岩的生烃高峰期130~68 Ma（K1-K2）。

The West Sichuan Depression in the Sichuan Basin is a foreland basin formed under the compressional thrusting of the Longmen Mountain. 3D seismic was obtained on five exploration blocks on the eastern slope of the central depression, including Hexingchang-Gaomiaozi, Fenggu, Yongtai, Zhongjiang-Huilong and Zhixinchang-Shiquanchang, covering three tectonic belts. The hydrocarbon evolution history of source rocks was studied, and 22 fluid inclusion samples from 6 wells were analyzed using fluorescence, homogenization temperature and salinity measurements. Source rocks in the fifth member of the Upper Triassic Xujiahe Formation entered the hydrocarbon generation threshold at 151-145 Ma, and reached a peak at 130 Ma. Three stages of fluid activities related to hydrocarbon accumulation took place in sandstone reservoirs in the Jurassic Shaximiao Formation at 141-128 Ma (J3-K1), 105-88 Ma (K1-K2) and 83-68 Ma (K2), respectively. The peak of hydrocarbon generation of source rocks at 130-68 Ma (K1-K2) is the key moment for hydrocarbon accumulation.

国家科技重大专项“海相碳酸盐岩油气资源潜力与大油气田形成条件、分布规律研究”（2011ZX05004-001）资助。

https://doi.org/10.11781/sysydz201701050