南堡1号构造中浅层油气富集主控因素分析

为了准确定位断裂附近油气藏的空间位置，从油源断裂优势运移通道和被断裂破坏后盖层垂向封闭能力2方面入手对南堡1号构造中浅层横向、纵向油气富集主控因素进行了详细研究，结果表明：①油源断裂有效断面脊作为优势运移通道控制了油气横向富集部位，南堡1号构造中浅层主要油气储量均分布于有效断面脊附近；②火山岩类（脆性）盖层被断裂破坏后垂向封闭能力可用盖层残余有效厚度（H′）来评价，南堡1号构造馆三段火山岩盖层残余有效厚度垂向封闭油气阈值(Ho）约为79～93m，当H′>Ho时，油气主要在盖层下部富集，而当H′

Main Controlling Factors on the Hydrocarbon Accumulation in the Middle-Shallow Layer of 1st Structure,Nanpu Sag

To pinpoint the location of reservoir near fault,the work of dominant migration pathway of oil source faults and vertical sealing capability of caprock after broken by fault was carried out to study main controlling factors for horizontal and vertical hydrocarbon accumulation in middle-shallow layer of 1st structure,Nanpu Sag.The results show that:(1)effective fault plane ridge of oil source fault is the dominant migration pathway,which controlled lateral hydrocarbon enrichment site.The major oil and gas reserves in middle-shallow layers of 1^ststructure of Nanpu Sag,are located near the effective fault plane ridge;(2)vertical sealing capability of volcanic rock(brittle)caprock after broken by fault can be evaluated by the relict effective thickness of caprock(H′),and the threshold value(Ho)of NgⅢ volcanic caprock in vertical hydrocarbon sealing is about 79-93m.In the 1^st structure of Nanpu sag,hydrocarbon mainly accumulates at the bottom of the caprock when H′>Ho,and the sealing ability of caprock is limited when H′>Ho.Leakage of hydrocarbon exist both above and below the caprock,so the relict effective thickness of caprock controls the layers where hydrocarbon transports and accumulates vertically.Integrate the above two aspects,we can quickly determine a three-dimensional favorable area where hydrocarbon accumulated near fault,which reduce the risk of exploration .