Abstract: The Ordovician reservoir in Tahe Oilfield experienced many tectonic reconstructions and was characterized by multiple hydrocarbon charging. Based on 105 Ordovician core samples from 10 wells of Tahe Oilfield, systematic analysis of fluid inclusions was employed to study the complex hydrocarbon charging histories. The results of fluorescence observation on petroleum inclusions and microthermometry of both petroleum and aqueous inclusions indicated that the Ordovician reservoir of Tahe Oilfield experienced five thermal fluid activities corresponding to four times of petroleum charging and one time of gas charging. Comprehensive analysis of fluid inclusion and the burial history curve shows that the four times of hydrocarbon charging happened in the late Hercynian, the Indo-Sinian and Yanshan, the early Himalayan and the middle Himalayan respectively. The gas charging happened in the late Himalayan. The integrated information suggests that the critical moment for petroleum charging is in the late Hercynian.

Key words: Tahe Oilfield, Ordovician reservoir, fluid inclusion, homogenization temperature, hydrocarbon charging, petroleum charging moment

摘要： 塔河油田奥陶系储层经历过多次构造运动的改造,具有多期油气充注特征.对采自该油田10口井的105块奥陶系岩心样品的流体包裹体进行了系统分析,揭示了这种复杂的油气充注过程.对各期次流体包裹体的均一温度、盐水包裹体的盐度以及油包裹体的荧光强度等测试结果的综合分析表明,塔河油田奥陶系储层经历过5期热流体活动,且分别对应于曾发生过的4期油充注和1次晚期天然气充注过程.结合埋藏史分析可知,4期油充注分别发生于海西晚期、印支—燕山期、喜山早期和喜山中期,天然气充注发生于喜山晚期.根据原油物化性质和分布特征,最终确定出塔河油田奥陶系储层的主成藏期为海西晚期.

关键词: 塔河油田, 奥陶系储层, 流体包裹体, 均一温度, 油气充注过程, 成藏期