强边底水油藏特高含水期CO2吞吐差异挖潜技术研究

冀东油田浅层强边底水油藏已整体进入特高含水开发阶段,剩余油高度分散、含油饱和度不均,不同油井CO₂吞吐效果差异大,难以实现油藏整体高效开发。考虑到油藏含油饱和度不同,差异设计CO₂吞吐段塞组合及开发政策,改善CO₂吞吐开发效果是十分必要的。利用二维物理模拟及油藏数值模拟,研究不同CO₂吞吐方式控水增油机理,定量评价不同CO₂吞吐方式适应含油饱和度界限,建立不同含油饱和度下吞吐注采参数差异化设计图版。研究结果表明:剩余油饱和度介于0.47~0.50之间时,CO₂吞吐技术经济综合效果最优;剩余油饱和度介于0.43~0.47之间时,CO₂+堵剂吞吐方式最优;剩余油饱和度介于0.375~0.430之间时,CO₂+表活剂+堵剂吞吐方式最佳。上述研究成果对特高含水油藏CO₂吞吐差异设计精准挖潜剩余油,实现油藏整体高效开发具有重要意义。

Study on Different Potential Exploitation Technology of CO2 Huff and Puff in High Water Cut Period of Strong Bottom Water Reservoir

The shallow strong edge and bottom water reservoir in Jidong Oilfield has entered the stage of ultra-high water cut development. The remaining oil is highly dispersed and the oil saturation is uneven. The effect of CO₂ huff and puff in different oil wells is different, which is difficult to achieve the overall efficient development of the reservoir. Considering the different oil saturations of reservoirs, it is necessary to design the slug combination and development policy of CO₂ huff and puff, so as to provide guidance for improving the development effect of CO₂ huff and puff. By means of two-dimensional physical simulation and reservoir numerical simulation, the mechanism of water control and oil increase in different CO₂ huff and puff methods is studied, and the oil saturation limit corresponding to different CO₂ huff and puff methods to oil saturation is quantitatively evaluated. The differential design chart of injection and production parameters under different oil saturation is established. The results show that when the residual oil saturation is between 0.47 and 0.50, the comprehensive economic effect of CO₂ huff and puff is the best. When the remaining oil saturation is between 0.43 and 0.47, the CO₂+plugging agent throughput method is the best. When the residual oil saturation is between 0.375 and 0.430, the CO₂+surfactant+plugging agent throughput is the best. The above research results are of great significance for the differential design of CO₂ huff and puff in ultra-high water cut reservoirs to accurately tap the remaining oil and realize the overall efficient development of reservoirs.