杏71区块扶余油层超前注水技术界限

Technical Limit of Advanced Water Injection in Fuyu Reservoir ofX71 Block

摘要: 超前注水是提高低渗透油藏开发效果行之有效的技术，但油层渗透率和压力系数发生改变时，油藏采收率随之变化。为确定超前注水措施实施的技术界限，通过室内进行超前注水模拟实验，研究实施超前注水后岩心的驱油效率、渗透率和微观孔隙结构参数的变化，并在此基础上，结合数值模拟，分析得出低渗透油藏超前注水开发的压力系数范围和渗透率范围，为超前注水技术的推广提供指导。研究结果表明，岩心的渗透率越低，驱油效率对压力越敏感性越强，因而确定杏71试验区实施超前注水油层的压力系数应小于1.1，实施超前注水油层的渗透率应介于1.22× 10⁻³~7 × 10⁻³ μm²之间。

Abstract: Advanced water injection is an effective technology to improve the development effect of low permeability reservoirs, but its recovery changes with the permeability and pressure coefficient of reservoirs. In order to determine the technical limit of the implementation of advanced water injection measures, the indoor advanced water injection simulation experiment is carried out to study the changes of oil displacement efficiency, permeability and micro pore structure parameters of the cores after the implementation of advanced water injection. Then combined with numerical simulation, the pressure coefficient range and permeability range of advanced water injection development of low permeability reservoir are analyzed, which provides guidance for the popularization of advanced water injection technology. The results show that the lower the permeability of the core, the stronger the sensitivity of the oil displacement efficiency to pressure. Therefore, it is determined that the pressure coefficient of the reservoir with advanced water injection in X71 test area should be less than 1.1, and the permeability of the reservoir with advanced water injection should be between 1.22 × 10⁻³ μm² and 7 × 10⁻³ μm².