CO_2驱注采井网流线分布规律研究

Study on streamline distribution of CO_2 injection-production well pattern

CO_2驱油技术可以有效解决注水开发中的问题,提高油藏采收率.用流线法求解CO_2驱组分数值模型可有效解决常规有限差分方法求解过程中计算效率低、数值弥散等问题.本文基于流线方法,建立了不同储层条件和不同井网条件下的CO_2驱理论模型,分析了CO_2驱注采井网流线分布规律.通过实例,分析了不同生产时间条件下的井网流线分布.结果表明流线分布图能直观描述注采井间的流动关系,流线密集区域一般分布在注入井和生产井的连线附近,说明流动能力强,驱油效果好.流线稀疏区域一般分布在远离注采井的区域或生产井之间的压力等势面上,说明剩余油较多.流线分布规律可为油田开发中后期井网调整提供依据.

C02 flooding technology can effectively solve the water injection problems in water flooding and enhance oil recovery. Solving the C0 2 injection compositional model by stream-line method can overcome the problems of poor computational efficiency and numerical dis-persion by conventional finite-difference method. The theoretical model of C0 2 flooding at different reservoir and well pattern conditions were established based on streamline method and the streamline distribution was analyzed. Through instance analysis, the streamline dis-tribution at different production stages was analyzed as well. The results indicate that the streamline distribution map can quantitatively describe the fluid flowing behavior among the injection and production wells. The streamline denser region is distributed near the connect-ing line between the injection and production wells, which indicates high flow capacity and displacement efficiency. The streamline is sparsely distributed on the pressure equipotential surface of the production wells or the region far from the injection and production wells, which demonstrates a great deal of remaining oil. The streamline distribution can provide beneficial basis for well pattern adjustment in later stage of oil exploitation.