计算物理 ›› 2018, Vol. 35 ›› Issue (1): 55-63.DOI: 10.19596/j.cnki.1001-246x.7589

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分形低渗透缝洞型油藏非线性渗流规律

刘化普, 刘慧卿, 王敬   

  1. 中国石油大学石油工程学院教育部重点实验室, 北京 102249
  • 收稿日期:2016-11-21 修回日期:2017-03-12 出版日期:2018-01-25 发布日期:2018-01-25
  • 作者简介:刘化普(1993-),男,在读硕士生,研究方向为油藏工程及提高采收率技术,E-mail:liuhuapu@foxmail.com
  • 基金资助:
    国家科技重大专项(2016ZX05014003004)资助项目

Nonlinear Percolation Law in Low Permeability Fissure Cave Reservoir with Fractal Dimension

LIU Huapu, LIU Huiqing, WANG Jing   

  1. MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing 102249, China
  • Received:2016-11-21 Revised:2017-03-12 Online:2018-01-25 Published:2018-01-25

摘要: 引入分形理论,建立考虑低速非达西效应的分形三重介质缝洞型油藏数学模型,通过Laplace变换及Stehfest数值反演方法求出井底压力,借助Matlab编程绘制压力动态曲线,划分渗流阶段,分析渗流规律,进行非线性参数敏感性分析.最后结合实际算例,验证模型的正确性.结果表明:分形三重介质油藏渗流过程分为早期纯井储,过渡流,缝洞窜流,拟径向流,基质与溶洞、裂缝窜流及总体径向流6个渗流阶段;低速非达西效应对渗流的影响随时间的推移逐渐增大;启动压力梯度越大,总径向流阶段压力动态曲线上翘幅度越大;分形系数影响整个渗流过程,随着分形系数的增大,裂缝迂曲程度随之增大,致使渗流阻力增加,引起压力动态曲线整体上移幅度增大.

关键词: 缝洞型油藏, 分形, 三重介质, 非达西, 启动压力梯度

Abstract: Fractal approach is introduced. Mathematical model of fractal triple medium fissure cave reservoir with low velocity non-Darcy effect is established. By means of Laplace transform and Stehfest numerical algorithm, bottom hole pressure solution is obtained. Seepage characteristics analysis and nonlinear parameter sensitivity analysis are conducted. Finally, combined with actual well data fractal model is verified. It shows that seepage process of fractal triple medium fissure cave reservoir can be divided into 6 seepage stages. They are presence of wellbore storage, transition flow, channeling of caves to fractures, pseudo radial flow, channeling of matrix to fractures and caves, total radial flow, respectively. Furthermore, effect of velocity non-Darcy effect on percolation law is gradually increasing with time. The higher starting pressure gradient, the higher pressure dynamic curves in total radial flow stage bend upward. Fractal coefficient affects whole percolation process. With increase of fractal coefficient, fracture tortuosity and flow resistance increase and whole pressure dynamic curves move up.

Key words: fissure cave reservoir, fractal, triple medium, non-Darcy, starting pressure gradient

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