启动压力影响下注采井间有效驱替规律

中国石油大学(北京)石油工程学院,北京 102249

油田开发; 低渗透; 启动压力梯度; 渗流场; 有效驱替; 注采井距

Effective displacement rules for interwell with threshold pressure
Chen Minfeng, Wang Zhaoqi, Zhang Qichen, and Chen Lu

Chen Minfeng, Wang Zhaoqi, Zhang Qichen, and Chen LuCollege Petroleum Engineering, China University of Petroleum(Beijing), Beijing 102249, P.R.China

oilfield development; low permeability reservoirs; threshold pressure gradient; pressure and velocity field; effective producing area; injector producer distance

DOI: 10.3724/SP.J.1249.2017.01091

备注

低渗透储层具有明显的启动压力梯度,导致注采井间的渗流场分布与常规条件存在一定差异.基于典型注采条件下的渗流特点和驱替过程分析,在产量方程中引入启动压力梯度,构建出考虑启动压力影响下一注一采定产渗流模型.通过推导得出注采井间压力场、速度场分布的数学表达式,并建立计算注采井间有效驱替面积、有效注采井距的方法,得到不同开发条件下井间渗流场分布和注采单元中有效驱替范围变化的规律.结合典型低渗透油藏参数进行的研究表明,根据有效驱替要求确定有效注采井距,并以此为基础部署开发井网,能在更大程度上有效驱动注采单元内的流体,进而提高低渗透油藏的开发效果.

Due to the existence of significant threshold pressure gradient, the flow in low permeability reservoirs is low-speed non-Darcy flow. Under these conditions, interwell flow filed has significant difference compared to the fields of conventional reservoirs. In view of the flow characteristics and displacement process analysis of a typical water flooding regime, threshold pressure gradient is introduced into the basic flow equation and combined with the condition that both production and injection wells are working in a constant rate. A mathematical model is established for one injector producer pair in infinite formation. According to the initial and boundary conditions, interwell pressure and velocity field distribution function are deduced from the model. Based on the mathematical description, interwell pressure and velocity field distribution and variation could be defined. The analysis shows that for the waterflood development of low permeability oilfield, only by taking effective flooding strategy, can the oil between the injection and production wells be effectively displaced to a greater extent and can the development effectiveness of low permeability reservoirs be improved.

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