特低渗透油藏水平井井网极限注采井距的确定

Limit injection-production well spacing of horizontal well in ultra-low permeability reservoir

 吕栋梁 徐伟 唐海 唐瑞雪

 （西南石油大学石油与天然气工程学院，四川 成都 610500）

 (School of Oil and Natural Gas Engineering, Southwest Petroleum University, Chengdu 610500, China)

 为了确定特低渗透油藏水平井注采井网的极限注采井距，考虑低速非线性渗流段，运用二参数运动方程建立非线性渗流模型，将其引入到Comsol仿真软件建立的物理模型中。采用试算法，不断调整注采井距，直至水驱前缘在到达采油井时的压力梯度等于启动压力梯度，最终得到极限注采井距。以新疆油田某特低渗透油藏为例进行分析，结果表明：随着水平井长度的增加和裂缝间距的减小，极限注采井距增加，但增加不是无限的，存在一定的临界值；水平井注水￣水平井采油、水平井注水￣压裂水平井采油、压裂水平井注水￣压裂水平井采油这3种井网形式的极限注采井距依次增大；在油田开发初期，可以优先采用压裂水平井注水￣压裂水平井采油的井网形式。

 In order to determine the limit-injection production well spacing of horizontal well injection production wells in ultra-low permeability reservoirs, many methods are used. Considering the low velocity non-linear flow section, the non-linear seepage model is established by using the two parameter equation. The physical model of Comsol simulation software is introduced. By trial and error method, the pressure gradient of the water drive front in the oil production well is equal to the starting pressure gradient. Taking a practical special low permeability reservoir in Xinjiang Oilfield as an example, the result shows: with the increase of the horizontal well length and the decrease of the crack spacing, the limit injection-production well spacing is increased, But the increase is not infinite, there is a certain critical value. The largest limited injection-production well distance is in the condition of water injection by fractured horizontal well and production by fractured horizontal well. The minimal distance is horizontal well water injection and oil production. The best injection-production well pattern is fractured horizontal well water injection and oil production in the development of new reservoir.

10.6056/dkyqt201605020