致密油藏二氧化碳吞吐过程中低压区域对二氧化碳波及范围的影响

二氧化碳在油藏中的波及范围是影响致密油藏二氧化碳吞吐提高采收率效果的关键因素。如何扩大注入的二氧化碳在油藏中的波及范围是新的研究热点。运用油藏数值模拟软件，建立致密油藏二氧化碳吞吐的理论模型，通过监测吞吐过程中油藏压力及二氧化碳含量变化，发现压力平衡过程中存在限制二氧化碳波及范围的低压区域，在此基础上，分析了注入压力、焖井时间和吞吐轮次对二氧化碳波及范围的影响。研究结果表明：注入压力是影响二氧化碳波及范围的主要因素，吞吐轮次对二氧化碳波及范围的影响较小。

Study on the influence of low pressure area on the spread range of carbon dioxide in the process of carbon dioxide huff and puff in tight reservoir

The sweep scope of carbon dioxide in the reservoir is a key factor affecting the effectiveness of carbon dioxide huff and puff in tight oil reservoirs to enhance recovery. How to extend the sweep scope of the injected carbon dioxide in the reservoir is a new research topic. Using reservoir numerical simulation software, a theoretical model of carbon dioxide huff and puff in tight oil reservoirs was established. By monitoring the changes of reservoir pressure and carbon dioxide content during the throughput process, it was found that there is a low-pressure region that limits the sweep scope of carbon dioxide during the pressure equilibrium process, and on this basis, the effects of injection pressure, well stew time and huff and puff rounds on the sweep scope of carbon dioxide were analysed. The results show that the injection pressure is the main factor affecting the sweep scope of carbon dioxide, while the huff and puff rounds has less influence on the sweep scope of carbon dioxide.