石油学报 ›› 2012, Vol. 33 ›› Issue (2): 264-268.DOI: 10.7623/syxb201202011

• 油田开发 • 上一篇    下一篇

低渗透油藏非线性渗流新模型及试井分析

姜瑞忠 1 李林凯 2 徐建春 1 杨仁锋 3 庄 煜 1   

  1. 1 中国石油大学石油工程学院 山东青岛 266555;2威德福(中国)能源服务有限公司 天津 300457;3中海油研究总院 北京 100027
  • 收稿日期:2011-08-22 修回日期:2011-10-29 出版日期:2012-03-25 发布日期:2012-05-17
  • 通讯作者: 姜瑞忠
  • 作者简介:姜瑞忠,男,1964年4月生,1987年毕业于西南石油学院,现为中国石油大学(华东)教授、博士生导师,主要从事油气田开发方面的教学和科研工作。
  • 基金资助:

    国家重大科技专项(2011ZX05051)和国家自然科学基金项目(No.51174223)资助。

A nonlinear mathematical model for low-permeability reservoirs and well-testing analysis

JIANG Ruizhong 1 LI Linkai 2 XU Jianchun 1 YANG Renfeng 3 ZHUANG Yu 1   

  • Received:2011-08-22 Revised:2011-10-29 Online:2012-03-25 Published:2012-05-17

摘要:

基于毛细管模型,结合边界层理论,通过引入描述低渗透储层渗流的特征参数c1 c2,建立了低渗透油藏渗流新模型,解释了启动压力梯度和非线性渗流产生的根本原因。根据新模型给出了考虑动边界影响的试井模型,并采用数值方法求解,分析了无因次特征参数c1Dc2D 对试井曲线的影响。结果表明:新模型的压力和压力导数曲线上翘,上翘幅度比拟启动压力梯度模型要小。考虑动边界影响的试井曲线上翘幅度比不考虑时要小。c1D c2D 是决定曲线形态的特征参数。当c1D c2D 之和不为常数时,随着 c1D 或 c2D 增大,上翘幅度增大;当 c1D c2D 之和为常数时,随着 c1D 增大,c2D 减小,上翘幅度增大。对于封闭边界和定压边界在试井曲线上的压力响应,新模型与达西模型一致。

关键词: 低渗透油藏, 渗流模型, 非线性渗流, 试井, 启动压力梯度

Abstract:

Based on a capillary model and integrated with the boundary layer theory, we proposed a new mathematical model for seepage in low-permeability reservoirs by introducing two parameters c1 and c2 that could characterize seepage of low-permeability reservoirs. This model well explained origins of a start-up pressure gradient and nonlinear seepage. According to the new model, a well-testing model considering the influence of moving boundaries was established and solved with the finite difference method, an impact of dimensionless characteristic c1D and c2D parameters on well-testing curves was investigated as well. The results show that pressure and pressure derivative curves for both the new model and a pseudo pressure gradient model are upward compared with the Darcy model though the upward degree for the new model is gentle. And c1D and c2D are characteristic parameters that determine the shape of well-testing curves. The upward degree increases with an increase of c1D or c2D when the sum of c1D and c2D is not a constant, while the upward degree increases with an increase of c1D but a decease of c2D when the sum of c1D and c2D is a constant. On well-testing curves, a pressure response to the new model is in agreement with that to the Darcy model both for closed boundaries and for constant pressure boundaries.

Key words: low-permeability reservoir, flow model, nonlinear seepage, well testing, threshold pressure gradient