超低渗透油藏注水方式研究

Study on water injection in ultra low permeability reservoir

从超前注水的机理入手,结合数值模拟与实际动态,对比了不同注水时机下油水井间的压力剖面,优选了超低渗透油藏的注水时机,并在最优注水时机下,分析了不同注水方式对地层压力波及范围的影响; 基于超低渗透油藏具有启动压差大、应力敏感性强、孔喉细小等特性,分析了不同超前注水方式下油井和水井压力升幅和压力波及范围,在岩石不破裂的情况下,进行不同超前注水方式的筛选与组合,反阶梯温和注水能够得到最优的开发效果。以长庆油田BMZ区块为例,进行了不同注水方式的开发效果分析,当采用反阶梯温和注水时,预测平均单井产油量在前20个月都明显高于非超前注水。

This article starts from the mechanism of advanced water injection, combining with the numerical simulation and actual production data, it contrasts the pressure profiles between the water injection well and oil well under the different water injection timing, then, optimizes the water injection timing in ultra low permeability reservoirs, and under the optimal water injection timing , it analyzes the effect on transmission of pressure by different ways of advanced water injection. Based on low permeability reservoirs property of start-up pressure gradient, stress the sensitive, thin pore throats, we analyze the effect on the lifting amplitude of oil wells, water wells and reservoir pressure by the different ways of advanced water injection. At the condition of the maximum of spread coefficient and under the rock breakdown pressure, screening and combining different ways of advanced water injection, we found that, it could be able to get the best development performance in ultra low permeable reservoir by anti-step mild water injection. Taking Changqing BMZ oilfield as example, the development effect has been analyzed under different water injection, and we evaluated the development effect of the method of anti-step mild water injection, which has certain directive significance to make the technology policy.