松辽盆地南部致密砂岩储层油气成藏期次研究

Study on hydrocarbon accumulation stages of tight sandstone reservoirs in South Songliao Basin

于轶星 王震亮

中国石油大学（北京）资源与信息学院盆地与油藏研究中心，北京 102249 中国石油大学（北京）油气资源与探测国家重点实验室，北京 102249 西北大学地质学系，陕西 西安 710069

Basin and Reservoir Research Center, China University of Petroleum, Beijing 102249, China State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing 102249, China Department of Geology, Northwest University, Xi′an 710069, China

松辽盆地腰英台地区青山口组致密砂岩储层中虽已经发现了油气藏，但该区的致密砂岩储层油气成藏机理却存在众多疑问，尤其是油气充注时间和期次，更是关系到青山口组致密砂岩储层油气成藏机理的关键问题。文中应用目前比较成熟的流体包裹体综合测试分析技术，研究区致密砂岩储层内流体包裹体的分布特征和均一温度测试结果，结合圈闭形成史、烃源岩生排烃史等，对该区青山口组油气成藏期次进行系统研究。研究结果表明，腰英台地区青山口组储层在地质历史时期内有2次油气充注，分别在78 Ma和68 Ma，对应的地质时期为四方台组沉积期—明水组沉积期。嫩江组沉积末期的构造运动为青山口组油气活动提供了动力条件，明水组沉积末期的构造运动使得圈闭最终定型。研究区内青山口组烃源岩在四方台组沉积末期—明水组沉积期开始进入生烃门限，目前已进入油气成熟阶段。针对腰英台青山口组致密砂岩储层油气成藏期次的综合研究对该区油气勘探有一定的指导意义。

Although the hydrocarbon reservoirs have been found in the tight sandstone reservoirs of Qingshankou Formation of Yaoyingtai Area, Songliao Basin, the hydrocarbon accumulation mechanism of tight sandstone reservoir is under a cloud. Especially, the time and stage of hydrocarbon filling are the key point of hydrocarbon accumulation mechanism in the tight sandstone reservoir. The stages of hydrocarbon accumulation in Qingshankou Formation have been researched systematically with integrated testing and analyzing technique of fluid inclusions according to the testing result of the distribution characteristics and homogenization temperature of fluid inclusions within reservoir in the tight sandstone reservoir of the area, combined with the history of trap formation, history of hydrocarbon-generating and hydrocarbon-expulsing. The study results show that there were twice hydrocarbon filling, separately in 78 Ma and 68 Ma, within geological history period for the Qingshankou Formation reservoir in Yaoyingtai Area. The corresponding geologic epoch is the depositional stage of Sifangtai Formation to the depositional stage of Mingshui Formation. The tectonic movement in the depositional end of Nenjiang Formation provided the condition of hydrocarbon migration in Qingshankou Formation, and the tectonic movement in the depositional end of Mingshui Formation made the trap form ultimately. Source rocks in Qingshankou Formation reached the hydrocarbon generation threshold between the depositional end of Sifangtai Formation and the depositional stage of Mingshui Formation, and go into the peak stage now. The research on the hydrocarbon accumulation stage of tight sandstone reservoir in Qingshankou Formation of Yaoyingtai Area has an important significance for oil and gas exploration.