大牛地气田低渗砂岩渗透率有效应力研究

发布时间：2018-04-04 22:34

本文选题：有效应力　切入点：渗透率有效应力系数　出处：《西南石油大学》2015年硕士论文

【摘要】：在低渗透气藏开采过程中,由于微裂缝和孔隙形变的共同作用,导致有效应力表现出明显的非线性,经典的线性有效应力理论难以客观反映低渗气藏开发过程中渗透率随孔隙压力的变化规律,因此难以客观评价应力敏感性对低渗透气藏开发造成的影响。为此,本文通过对国内外有效应力理论与实验研究的调研,以低渗砂岩为研究对象开展渗透率有效应力和应力敏感性研究,并结合数值模拟分析低渗透气藏中应力敏感对开发的影响。主要完成的工作和取得的认识如下： (1)完成低渗砂岩的基本物性测试,并采用扫描电镜、铸体薄片和压汞实验等微观分析手段对部分岩样进行了微观特征分析； (2)根据渗透率有效应力定义和数据分析方法,提出获取渗透率有效应力系数的方法； (3)设计渗透率有效应力的实验方案并完成10块低渗砂岩的常规应力敏感性实验和渗透率有效应力实验； (4)结合渗透率有效应力实验数据计算实验岩心的渗透率有效应力系数,并分析渗透率有效应力系数随孔隙压力和围压的变化规律； (5)分析渗透率有效应力系数随Terzaghi有效应力的变化规律,并得到渗透率有效应力系数与Terzaghi有效应力的函数关系式； (6)对实验岩心的渗透率与有效应力关系进行分析,建立渗透率与有效应力的函数关系式并分析不同类型函数关系式的适用性； (7)基于不同有效应力理论和岩石应力敏感性评价方法,对实验岩心的应力敏感性进行评价； (8)采用数值模拟器分析应力敏感对开发的影响,并结合实例对压裂水平井产能进行评价。本次研究结合有效应力的定义和数据分析方法,建立了一套获取渗透率有效应力系数的方法。通过对渗透率有效应力的研究进一步深化对渗透率有效应力变化规律的认识并客观分析应力敏感性对低渗透气藏开发的影响,为准确评价储层岩石的应力敏感性以及合理高效地开发油气田提供科学依据。
[Abstract]:In the process of producing low permeability gas reservoirs, due to the joint action of microfractures and pore deformation, the effective stress shows obvious nonlinearity.The classical linear effective stress theory can not objectively reflect the variation of permeability with pore pressure during the development of low permeability gas reservoirs, so it is difficult to evaluate objectively the influence of stress sensitivity on the development of low permeability gas reservoirs.Therefore, through the investigation of effective stress theory and experiment at home and abroad, the research on permeability effective stress and stress sensitivity of low permeability sandstone is carried out in this paper.The influence of stress sensitivity on development in low permeability gas reservoir is analyzed by numerical simulation.The main tasks accomplished and the awareness gained are as follows:1) the basic physical properties of low permeability sandstone were tested, and some rock samples were analyzed by means of scanning electron microscope, casting sheet and mercury injection experiment.2) according to the definition of effective stress of permeability and the method of data analysis, the method of obtaining effective stress coefficient of permeability is put forward.(3) designing the experimental scheme of permeability effective stress and completing the conventional stress sensitivity experiment and permeability effective stress experiment of 10 low permeability sandstone;(4) combining the experimental data of permeability effective stress, the permeability effective stress coefficient of experimental core is calculated, and the variation law of permeability effective stress coefficient with pore pressure and confining pressure is analyzed.(5) the variation of permeability effective stress coefficient with Terzaghi effective stress is analyzed, and the functional relationship between permeability effective stress coefficient and Terzaghi effective stress is obtained.(6) the relationship between permeability and effective stress of experimental core is analyzed, the functional expression of permeability and effective stress is established and the applicability of different types of functional relationship is analyzed.Based on different effective stress theory and rock stress sensitivity evaluation method, the stress sensitivity of experimental core is evaluated.The influence of stress sensitivity on development is analyzed by numerical simulator, and the productivity of fractured horizontal well is evaluated with practical examples.Based on the definition of effective stress and the method of data analysis, a set of methods for obtaining effective stress coefficient of permeability is established.Through the study of effective stress of permeability, the influence of stress sensitivity on the development of low permeability gas reservoir is analyzed objectively.It provides a scientific basis for evaluating the stress sensitivity of reservoir rocks and developing oil and gas fields reasonably and efficiently.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE312

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