断裂对盖层封气综合能力破坏程度的研究方法及其应用

发布时间：2018-08-16 14:55

【摘要】：为了研究断裂在油气成藏与分布中的作用,在分析盖层封气综合能力及其研究方法的基础上,利用天然气在剩余压力作用下通过盖层向外渗滤散失压力梯度的大小,表征盖层封气综合能力的好坏;依据被断裂破坏前后盖层封气综合能力差值与被断裂破坏前盖层封气综合能力的比值,建立了一套断裂对盖层封气综合能力破坏程度的定量研究方法。以渤海湾盆地南堡凹陷南堡5号构造东二段泥岩盖层为例,对NP5-2断裂对东二段泥岩盖层封气综合能力的破坏程度进行了定量研究。结果表明:南堡5号构造NP5-2断裂对东二段泥岩盖层封气综合能力的破坏程度较高,除L6测线处为弱破坏程度和L1、L5、L8测线处为中等破坏程度外,其余5条测线处均可达到较强和强破坏程度;且NP5-2断裂对东二段泥岩盖层封气综合能力的破坏程度西部强于东部,这与东二段泥岩盖层之下储气层中目前已发现的天然气主要分布在断裂东部相吻合。该方法用于定量研究断裂对盖层封气综合能力破坏程度是可行的。
[Abstract]:In order to study the effect of faults on the formation and distribution of oil and gas, on the basis of analyzing the comprehensive capping ability and its research methods, the gradient of leakage pressure of natural gas through percolation outside the caprock under the action of residual pressure is used. According to the ratio of the difference between the gas sealing ability of the caprock before and after the fracture failure and the comprehensive ability of sealing the gas of the caprock before and after the failure of the caprock, the gas sealing ability of the caprock is characterized. A set of quantitative study methods for the failure degree of comprehensive sealing ability of caprock by fault are established. Taking the mudstone caprock of the eastern member of Nanpu structure No. 5 in Nanpu depression, Bohai Bay Basin as an example, the damage degree of NP5-2 fault to the comprehensive gas sealing ability of mudstone caprock in the east member of the second member of Bohai Bay Basin is quantitatively studied. The results show that the NP5-2 fault of No.5 structure has a high degree of damage to the gas sealing ability of the mudstone caprock in the eastern member of the second member, except for the weak failure degree at the L6 survey line and the moderate failure degree at the L1 / L5 / L8 survey line. The other five lines can reach a stronger and stronger degree of failure, and the damage degree of the NP5-2 fault to the gas sealing ability of the mudstone caprock of the eastern member is stronger in the west than in the east. This coincides with the distribution of natural gas in the gas reservoir beneath the mudstone caprock of the eastern second member of the eastern member of the fault, which is mainly located in the eastern part of the fault. It is feasible to quantitatively study the damage degree of gas sealing ability of caprock by fault.
【作者单位】：东北石油大学地球科学学院;
【基金】：国家自然科学基金项目(41372153) 东北石油大学研究生创新科研项目(YJSCX2015-003NEPU)~~
【分类号】：P618.13

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