【作者】 刘超英；

【导师】 周瑶琪；

【作者基本信息】 中国石油大学 ， 地质资源与地质工程， 2007， 博士

【摘要】 箕状断陷盆地通常可以分为陡坡带、洼陷带和缓坡带等次级构造单元,不同构造单元具有不同的石油地质特征。惠民凹陷南部为缓坡带,根据缓坡带沉积发育特点和构造特征可进一步划分为宽缓型斜坡带和窄陡型斜坡带。钱官屯地区和曲堤地区分属这两种缓坡带,油气富集程度也存在较大差异。本文在综合前人研究成果的基础上,从输导体系研究入手,结合流体包裹体分析技术对该区成藏期次、成藏时间及古流体势进行了研究,总结了惠民凹陷缓坡带油气运移及聚集规律,为下一步的勘探工作指明方向。断层和储集砂体输导系统是造成该区不同类型缓坡带油气富集差异的主要原因。该区断层输导体系主要受断层的封闭性、活动强度、断面产状等因素的影响,利用断层活动速率、泥岩涂抹系数、断面压力定量研究上述因素对断层输导系统的影响;针对夏口断层的“S”形状讨论了油气沿断面优势运移时遵循“凸聚凹散”规律。从宏观沉积相空间展布特征、砂体厚度到微观分析砂体的孔渗性研究了连通砂体作为侧向输导体系在惠民南斜坡油气运移中的作用;针对该区广泛存在剥蚀,但油源却并不充足的特点,讨论了不整合输导系统对该区油气输导的局限性。系统总结了烃源岩排烃法、油藏饱和压力法与包裹体分析技术在油气成藏史研究方面的优缺点,着重利用流体包裹体分析技术研究了该区的油气成藏期次及时间。讨论了利用包裹体分析技术研究成藏史的3个必要条件,指出有机包裹体在此方面的缺陷,提出利用与有机包裹体同期的盐水包裹体进行研究的观点,在此基础上设计高温高压釜合成NaCl-H2O体系的包裹体实验,以此分析盐水包裹体的捕获机理,验证其显微测试技术的可靠性。通过以上分析研究,对研究区盐水包裹体进行测试,发现钱官屯鼻状构造带沙四段油气为明化镇中期一期充注,曲堤地区为东营末及明化镇两期成藏。由于受到现场资料的影响,对流体势的研究目前还局限在现今流体势的研究中,流体包裹体可用来较为准确的分析油气运聚时期的热液环境,本文尝试利用包裹体测温技术结合相关热力学计算,分析了明化镇时期惠民凹陷南斜坡的古流体势场,指明钱官屯和曲堤地区为该时期缓坡带上的有利油气运聚区,并结合前人利用含氮化合物等地球化学研究成果进一步验证了此观点。输导系统的类型和空间分布、大的构造背景、不同时期流体势的分布和不同次级断层的活动性和封闭性使得惠民凹陷南斜坡的油气分布有“分带性”和“不均衡性”的特点,本文从上述因素总结该区油气成藏规律和成藏模式,惠民凹陷南斜坡不同类型缓坡带油气聚集方式和聚集量存在着显著的差异,钱官屯和曲堤地区各自具有不同的阶段式运聚特点,钱官屯地区为宽缓型-侧向运移成藏模式,而曲堤地区为窄陡型-阶梯式运移的成藏模式,并针对此成藏模式特点进一步指明了该区有利勘探方向。更多还原

【Abstract】 The ramp zone is a special structural position which lies on the continental fault basin. It is beneficial to the oil&gas migration and accumulation directions and also conducive to the formation of oil and gas reservior. Qian guan tun and Qu di region which laid on South slop of Huimin Sag, can be divided into broad ramp zone and narrow ramp zone. They are both secondary tectonic units of the same ramp zone and in the oil favorable migration directions, but they are very different in oil and gas accumulation quantity. Based on the former research results, the paper took the transportation System as the main research direction and combined with the research results of fluid inclusions of different oil migration stages and paleo-fluid potential. As the result, the paper deeply concluded the rule of the oil&gas migration and accumulation of Huimin south slope belt and further enriched the theory of the ramp zone hydrocarbon migration and accumulation of the continental fault basin. So it gave direction to further exploration.The paper analyzed the effect between the transportation systems such as the fault, sand body and unconformity and the oil and gas migration on the south slop belt of Huimin Sag. Then it indicated that faults and connected sand bodies were main migration pathways in South slop belt. The sealing, activity inensity and tectonic profile of faults are important factors of fault Transportation System. In the paper, active velocities of faults, pressure of the fault surface, and the coefficient of shale smearing in the fault zone can be used to study the sealing, active intensity and active history of main fault in the south slop. The rule of“Convergent convexity and Divergent concavity”was abided when hydrocarbon migrated through fault surfaces. So the paper analyzed the tri-dimensional distribution of facies, the thickness and the microcosmic permeability of sand bodies and studied the connected sand of South slop belt as lateral migration path from the macro to micro. Though the Slop denude widespread, the unconformity only took action in the oil lateral migration of short distance because of lack of the oil source.By comparing relative merits between the history of hydrocarbon generation and the bubble point pressure of reservoir with the fluid inclusions in analysis the history of oil migration and accumulation, we mainly used the fluid inclusions to study the oil and gas accumulation periods and stages of the slop in the paper. By using the high temperature and pressure vessel,we got synthetic fluid inclusions (NaCl-H2O system). those fluid inclusions can be used to analysis the trapping mechanism of fluid inclusions in brine and certified the reliability of temperature micro-analytic techniques. Then based on the study of salt-inclusions which trapping in the oil migration period, it was concluded that the oil of Es4 in Qianguntun is filling at Minghuazhen stage and Qudi was filling in Dongying and Minghuazhen two stages.In addition, due to the impact of collected information, the study of fluid potential just limited to current fluid potential, and fluid inclusions can be used to accurately analysze the hydrothermal environment in the period of hydrocarbon migration and accumulation. In the paper, it analyzed the paleo-fluid potential of Minghuazhen period used the temperature micro-analytical techniques and thermodynamic calculation and got the conclusion that the Qianguantun and Qudi region is the oil favorable migration zone in Minghuazhen period. The research result of geochemistry such as Nitrogen compounds can also demonstrate the opinion.The characters of oil distribution on Huimin south slop are zonate and imbalance, and it is mostly affect by control elements of forming a reservior such as tectonic backgroud, fluid potential andⅡ,Ⅲfaults, in the same time, these elements alse affect the hydrocarbon migration and accumulation. There are many differences in the hydrocarbon accumulation model and the accumulation quantity in Huimin south slop. Qianguantun and Qudi zone had respective oil accumulation characteristics. Based on above research results, the accumulation model of Qianguantun region is board ramp and lateral migration style, and Qudi is narrow ladder migration style. In addition, the paper also pointed out the favorable exploration zone in Huimin South Slop.更多还原