油气成藏动力学研究方法与应用

油气成藏过程的动力学研究是以一期油气成藏过程中从油气源到油气藏的统一动力环境系统为单元,定量研究油气供源、运移、聚集的机理、控制因素和动力学过程。以此为基础有望解决油气成藏定量的动力学研究中的几个关键问题。输导层概念的提出及砂岩输导层模型基本工作程序的建立,形成了可以利用通常的物性参数进行输导层量化表征的方法,实现了对油气运移通道的量化表征; 采用断层连通概率的概念对各种参数表征断层开启性的能力进行比较和评价,探讨了各种地质参数的有效性和代表性,建立起了断层启闭性表征参数的评价方法; 采用数值模拟方法,耦合运聚动力与输导体系,实现成藏系统内油气运移过程的模拟分析; 以运移途中烃损失量估算为基础,建立新的物质平衡方法,以模拟获得的运移路径为线索,评估油气在研究不同方向上的运移聚集量,展现油气运移的路径特征、运移方向及运移量,初步形成了以油气成藏动力学成因为基础的油气资源预测方法。

Dynamic studies on hydrocarbon migration and accumulation: Methodology and application

In this paper the authors present a thought of dynamic studies on hydrocarbon migration and accumulation,corresponding methods,as well as an example of application in the Chengbei Fault zone,the Huanghua Depression,The Bohai Bar Basin,China.The authors embark on dynamic studies on hydrocarbon migration and accumulation by defining a concept of hydrocarbon migration-accumulation system:in the duration of a whole hydrocarbon migration accumulation process,within an overpressure compartment,where hydrocarbon drained out of a source,migrated through carriers,and accumulated in pools.Based on such concept,some import problems associated to hydrocarbon migration accumulation process may be solved.Defining a concept of carrier formation,a working procedure was established to characterize quantitatively connectivity among sandy carriers with conventional property parameters,which offers a tool to achieve a quantitative characterization of hydrocarbon migration carriers.An index,the fault-connectivity probability(N_p),is proposed to evaluate the possibility that any part of a fault has been once serving as a migration path.Various geological parameters pertinent to faults are analyzed to assess their effectiveness for characterizing fault connectivity.The values of fault-connectivity probability can be contoured on a fault plane to characterize the variations of hydraulic connective capacity on the fault plane.By using a numerical simulator with inversion percolation method,the driving forces and resistences of carrier may be coupled to discribe migration pathways in various scale of carriers in basin.Based on mass balance analysising and hydrocarbon loss on pathways estimating,the flux of hydrocarbon in migration pathways may be estimated that permits us to assess quantity of hydrocarbon migrating and accumulating in different directions.