断盖配置渗漏油气时期确定方法及其应用

为了客观把握含油气系统中断裂处的油气纵向分布规律,在断盖配置渗漏油气机制及其渗漏油气时期构成研究的基础上,通过厘定断裂开始破坏泥岩盖层封闭时刻、断层岩开始封闭时刻和断裂活动停止时刻,确定断盖配置渗漏时期,并结合源岩排烃史,建立了一套确定断盖配置渗漏油气时期的方法,并将其应用于渤海湾盆地南堡凹陷南堡5号油田,研究F3断裂...

Determination method and application of leakage period for oil and gas of fault-caprock configuration

Objectives:In order to understand the objective distribution regularities of hydrocarbon near the faults in a petroliferous basin.Methods:The determining method of the hydrocarbon leakage period has been constructed based on the mechanisms and time units of leakage in fault—caprock configuration,which was established by determining the time when a fault starts to destroy the sealing of mudstone cap and seal hydrocarbon by forming some fault rocks and ceasing activity.Then by analyzing the F3 in the Oilfield-5 in the Nanpu Depression,Bohai Bay Basin,this method was applied to the determination of oil—gas leakage period of mudstone caprock configuration(Ed~2).Results:The results show that the destructive effect to the mudstone cap of Ed~2 is limited by F3 of the Oilfield-5 in the Nanpu Depression,only the fault—caprock configuration fails and oil—gas leakage occurs at the Point P2 and P8.The oil and gas leakage periods of P2 and P8 are about 16~7.4 Ma and 13.6~4.8 Ma respectively.Conclusions:There is few difference with the oil—gas leakage period of the fault—caprock configuration between P8 and P2.However,the oil—gas leakage period by fracturing at P8 was obviously shorter than P2,which is favorable for hydrocarbon accumulation under the mudstone caprock of Ed~2at P8.This analyzing is consistent with the current situation of petroleum exploration near F3,the situation shows that hydrocarbon was founded at P8instead of P2 under the mudstone cap of Ed~2,which means that this method is feasible for determining the period of oil and gas leakage.