以渤海湾盆地南堡凹陷典型油藏为例,通过地质方法探讨了"毛刷"状油藏的成因,进而揭示出断层封闭能力的有限性,最后采用物理模拟实验的手段对其进行了验证。研究结果表明,断层下盘遮挡圈闭中呈"毛刷"状分布的油气藏是由断层封闭能力的近一致性造成的;断层存在着不严密的封闭,只能对有限的油气柱高度起封闭作用,达到最大油气柱高度后将保持动态平衡不再增加;在一定的断层封闭能力下,断层遮挡圈闭中的含油气面积受储层倾角影响,即储层倾角越小,含油气面积越大,油气储量也就越大。
The paper discussed the geological forming cause of reservoirs which distribute like brushes, brought forward the limitation of fault-sealing, and validated it by physical simulation experiment. Through the comparison between measured data and calculated data of oil column height sealed by fault, it is believed that the fault-sealing for oil and gas is limited. When hydrocarbon column height reaches the threshold, oil will spill from the top of reservoir along fault, and the scale of reservoir will remain invariable. When the sealing capacity of fault is settled, the area of oil and gas in fault-screened traps is controlled by the obliquity of reservoirs. The area of oil and gas increases with the decrease of reservoirs obliquity.