Integrated modeling and optimization of CO2 enhanced oil recovery and storage under uncertainty

由于新发现的石油储量越来越少，提高石油采收率在石油工业中发挥着越来越重要的作用。轻、中油藏经过一次采油和二次采油后，剩余油一般在原含油的50~60%范围内。在轻、中油藏提高采收率方法中，高压注气混相驱在有利条件下取得了很大程度的成功。特别是，二氧化碳注入被认为是在不久的将来最有前途的EOR技术，因为它不仅大大提高了石油采收率，而且大大减少了温室气体的排放。自20世纪70年代以来，二氧化碳提高采收率已被用作提高采收率的商业方法，而二氧化碳储存的有限现场应用直到最近才开始。成功的二氧化碳提高采收率和二氧化碳封存过程离不开对油藏动态的持续监测。虽然监测结果与油藏模拟和建模同时集成是取得成功的最佳机会，但如何完成这项任务仍然是二氧化碳提高采收率和二氧化碳储存过程中的一个具有挑战性的问题。此外，CO2 EOR和CO2储存过程的优化与目前的CO2注入实践有很大不同。

Enhanced oil recovery (EOR) plays an increasingly important role in the petroleum industry since there are fewer newly discovered oil reserves. After primary recovery and secondary recovery, the oil remaining in the light and medium oil reservoirs is generally in the range of 50~60% of the original oil in place. Among the EOR methods for the light and medium oil reservoirs, miscible displacement by injecting high-pressure gases has been successful to a large extent under favorable conditions. In particular, CO2 injection is considered as the most promising EOR technique in the near future because it not only greatly enhances oil recovery but also considerably reduces greenhouse gas emissions. CO2 EOR has been used as a commercial process for enhancing oil recovery since the 1970's, whereas limited field applications of CO2 storage have been undertaken only recently. Successful CO2 EOR and CO2 storage processes result from continuous monitoring and surveillance on the reservoir performance. Although simultaneous integration of monitoring results and reservoir simulation and modeling represent the best chance for success, how to accomplish this task remains a challenging issue for a CO2 EOR and CO2 storage process. In addition, optimization of both CO2 EOR and CO2 storage processes differs significantly from current CO2 injection practices.