论文部分内容阅读
用5μm微管、人造岩心及天然岩心研究了CO2气体的流动特性及与岩心作用后对渗透率的影响规律.结果表明,CO2气体在微管中的流动速度明显比N2快;CO2在饱和水的岩心(含碳酸盐)中流动时,其渗透率随着注入量的增加而增大,表明CO2的溶蚀作用导致了岩心孔径的增加,用扫描电子显微镜(SEM)也验证了溶蚀扩孔作用.CO2气体在微管中具有较高的流速是由于尺度效应和压缩效应的综合反映,而其在水中溶解引起的界面层水分子扩散速度增大,导致孔隙壁面的水膜厚度减小,其水溶液流动的有效孔径增大.上述两种结果表明,CO2在驱油过程中具有良好的注入能力,是低渗储层开发过程中能量补充的一种很好的驱替流体,但也造成其在地层中窜流或散逸的可能性增大.
The flow characteristics of CO2 gas and its influence on permeability after core action were studied by means of 5μm microtubes, artificial cores and natural cores.The results show that the flow rate of CO2 gas in microtubules is significantly faster than that of N2, CO2 in saturated water (Including carbonate), its permeability increased with the increase of injection amount, indicating that the dissolution of CO2 led to the increase of core diameter. The corrosion reaming was also verified by scanning electron microscopy (SEM) The higher flow velocity of CO 2 gas in microtubules is due to the combination of scale effect and compression effect, and the diffusion rate of interfacial water molecules caused by its dissolution in water increases, resulting in the decrease of water film thickness on pore wall, The effective pore size of the aqueous solution flow increases.The above two results show that CO2 has a good injection ability in the oil displacement process and is a good displacement fluid for energy supplement in the development of the low permeability reservoir but also causes It is more likely to flow or escape in the formation.