致密油气藏裂缝介质压力敏感分析与计算方法

发布时间：2018-04-03 08:31

本文选题：致密油气藏　切入点：裂缝变形　出处：《大庆石油地质与开发》2017年02期

【摘要】：致密油气藏裂缝介质的压力敏感性对油气藏开发效果具有显著影响。基于物质守恒理论,通过理论推导建立了基质和裂缝的压力敏感方程;同时,通过开展单条裂缝压力敏感渗流物理模拟实验,研究裂缝变形特征和介质渗透率变化特征,并利用实验结果验证了压力敏感裂缝性介质渗透率模型的合理性。研究表明:建立的基质和裂缝压力敏感方程是关于流体压力的函数,能够解决常规压力敏感方程中变形系数确定困难的问题,增强了压力敏感方程在实际致密油藏开发中的适应性。实验中发现流体压力下降,基质块发生膨胀使得基质块之间的裂缝闭合,开度变小,介质渗透率变小;流体压力升高时,基质块发生收缩,使得基质块之间裂缝开启,开度增大,介质渗透率变大。对比实验模拟结果与基于实验参数的渗透率模型的计算结果,验证了渗透率模型的合理性。通过研究,揭示了致密油藏裂缝介质的压力敏感变形机理,又为裂缝介质的渗透率表征奠定了基础。
[Abstract]:The pressure sensitivity of fractured medium in tight reservoirs has a significant effect on the development of oil and gas reservoirs.Based on the material conservation theory, the pressure sensitive equations of matrix and fracture are established by theoretical derivation, and the characteristics of fracture deformation and medium permeability change are studied through physical simulation experiment of single fracture pressure sensitive seepage.The rationality of the permeability model of pressure sensitive fractured medium is verified by the experimental results.The results show that the matrix and fracture pressure sensitive equation is a function of fluid pressure and can solve the problem of determining deformation coefficient in the conventional pressure sensitive equation.The adaptability of pressure sensitive equation in the development of real tight reservoir is enhanced.It was found in the experiment that the fluid pressure decreased, the expansion of the matrix block made the cracks between the matrix blocks close, the opening became smaller, the medium permeability became smaller, and when the fluid pressure increased, the matrix block shrank, which made the cracks between the matrix blocks open.The permeability of medium increases with the increase of opening.The rationality of the permeability model is verified by comparing the experimental simulation results with the calculated results of the permeability model based on the experimental parameters.The mechanism of pressure-sensitive deformation of fractured medium in dense reservoir is revealed, which lays a foundation for the permeability characterization of fractured medium.
【作者单位】：中国石油大学石油工程教育部重点实验室;
【基金】：国家自然科学基金项目“各向异性裂缝页岩气藏渗流机理与理论研究”(51374222) 国家重点基础研究发展计划“陆相致密油高效开发基础研究”课题五之专题一“致密油藏产能预测方法”(2015CB250905)
【分类号】：TE31

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