川北阆中地区震旦系-寒武系油气成藏条件与过程

川北阆中地区CS1井钻揭震旦系—寒武系地层中发育良好的烃源岩及多套储盖组合，储层含气性较好，揭示良好的勘探前景。为取得进一步勘探突破，本次研究以盆地模拟技术为手段，基于实钻井数据、实验分析资料、地震解释成果等开展研究，深化油气成藏过程认识，指明下步勘探方向。结果表明：（1）研究区筇竹寺组烃源岩发育，热演化程度高，储层以震旦系灯影组四段与下寒武统龙王庙组为主，纵向上储盖组合发育。输导体系主要以断裂和裂缝为主。（2）筇竹寺组烃源晚三叠世末—中侏罗世为生液态烃高峰，晚侏罗世为生气态烃高峰。其中，灯四段油气充注位于中—晚三叠世和中侏罗世；寒武系油气充注为中—晚侏罗世。（3）对关键生排烃期的古构造和油气运聚分析认为，灯四段成藏期古构造呈现整体北倾、东高西低，逐渐转变为东低西高到两凹一隆。油气运聚趋势表现为由西向东、南北分区到向南调整；龙王庙组成藏期古构造从东倾逐渐转变为东北倾，油气运聚趋势表现为由东向西、南北分区，最后到西南调整。有利区预测表明灯四段勘探前景更优。

Study on Conditions and Process of Hydrocarbon Accumulation in Sinian and Cambrian in Langzhong Area, North Sichuan

In Langzhong area, well CS1 was drilled and exposed in the Sinian to Cambrian with well-developed source rocks and multiple sets of reservoir and cap assemblages, and the reservoir gas measurement showed a good result, showing a good exploration prospect. Based on actual drilling data, testing and analysis data, seismic interpretation results and so on, the study was carried out by means of basin modeling technology to deepen the understanding of hydrocarbon accumulation process and point out the next exploration direction. The results show that: (1) The source rocks of the Qiongzhusi Formation in the study area are well developed and the thermal evolution degree is high. The reservoirs are mainly composed of the fourth member of the Sinian Dengying Formation and the Lower Cambrian Longwangmiao Formation, and the reservoir-cap assemblages are developed vertically. The transport system mainly consists of fractures and fractures. On the whole, there are basic conditions for hydrocarbon accumulation. (2) The source of the Qiongzhusi Formation was the peak of liquid hydrocarbon from the end of Late Triassic to the middle Jurassic, and the peak of gas hydrocarbon from the late Jurassic. Among them, the fourth member of the Dengying Formation was charged in the middle to late Triassic and middle Jurassic. The Cambrian oil and gas charging occurred in the middle to late Jurassic. (3) According to the analysis of the paleo-tectonics and hydrocarbon migration and accumulation in the key hydrocarbon generation and expulsion periods, the paleo-tectonics of the fourth member of Dengying Formation showed an overall north dip, high in the east and low in the west, and gradually changed to low in the east and high in the west to two depressions and one uplift. The oil and gas migration and accumulation trend is adjusted from west to east and from north to south. The paleo-tectonics of the Longwangmiao Formation in the pool-forming period gradually shifted from east to northeast, and the trend of oil and gas migration and accumulation was divided into east to west and north to south, and finally adjusted to southwest. Four and two favorable areas are proposed in the distribution of the fourth member of Dengying Formation and Longwangmiao Formation, among which the resource prospect of the fourth member of Dengying Formation is the best.