断裂填充物封堵性演化阶段厘定:以贝尔凹陷大一段内F3断裂为例OA

[Objective]The unreasonable classification of the evolutionary stages of the sealing ability of fault-zone fillings prevents a reasonable explanation of the variations in petroleum distribution in different parts of fault traps.[Methods]To address this problem,we propose a method that evaluates and tracks the closure index and cement index for both fault-zone fillings and underlying reservoir rocks,and then comprehensively delimits the evolutionary stages of fault sealing by comparing the relative values of the closure index and cement index between fault-zone fillings and underlying reservoir rocks.The method was applied to the F3 fault in K1d1 of the Huhenuoren tectonic belt,Beier Depression,Hailar Basin.[Results]The results show that:The fault-zone fillings of the F3 fault in K1d1 are in the stage of non-closure sealing and non-cement sealing at measurement points 2,4,6,and 9-11,which is unfavorable for the accumulation and preservation of petroleum in K1n2,consistent with the absence of petroleum during drilling.The fault-zone fillings of the F3 fault in K1d1 at measurement points 1,3,and 5 are currently in the closure sealing stage.However,due to their evolutionary stages being non-closure sealing and non-cement sealing during the critical period of reservoir formation,no petroleum was obtained during drilling.The fault-zone fillings of the F3 fault in K1d1 at measurement points 7,8,and 12-15 are in the closure sealing and cement sealing stages,which favors the accumulation and preservation of petroleum in K1n2 and has bed to the acquisition of industrial oil and gas flous.[Conclusion]Therefore,the proposed method for delimiting the evolutionary stages of fault-zone fillings material sealing ability is feasible,providing important insights for assessing the sealing ability and formation timing of fault traps and enhancing the efficiency of oil and gas exploration.