低效稠油CO2复合吞吐参数优化

针对部分埋藏深、渗透率低、高温高盐等无法热采或化学驱的稠油油藏,部分油田采用了“CO2+增溶剂”的复合吞吐生产方式,并取得了一定效果。目前关于CO2吞吐方面的物模模拟实验无法满足复合吞吐的研究需要。本研究建立了一套基于吞吐补偿系统的CO2复合吞吐的物理模拟方法,开展了室内CO2 吞吐物理模拟实验,研究了增溶剂注入量、CO2注入量、注入方式等因素对吞吐效果的影响,同时进行了现场试验并进行了跟踪评价。结果表明：增溶剂注入浓度为5-10%、CO2与化学剂注入质量比为1:2.5~1:5、采用两段塞注入方式,提高采出程度最高。该方法有效的模拟了复合吞吐过程中的注入、焖井和产出过程,完全满足CO2复合吞吐的工艺参数优化的研究要求。

Study on optimization of CO2 compound huff and puff parameters for low-efficiency heavy oil

For some heavy oil reservoirs with deep burial depth, low permeability, high temperature and high salinity, which cannot be thermally recovered or chemically flooded, some oil fields have adopted the "CO2 + chemical agent" compound huff and puff method, and achieved certain results. The current physical simulation experiments on CO2 huff and puff cannot meet the research needs of compound huff and puff. In this study, a physical simulation method of CO2 compound huff and puff based on huff and puff compensation system was established. Physical simulation experiments of CO2 huff and puff were carried out in the laboratory. The effects of the solubilizer injection volume, CO2 injection volume and injection method other factors were studied. At the same time, the field tests and follow-up evaluations were carried out. The results show that when the injection concentration of solubilizer is 5-10%, the mass ratio of CO2 to chemical agent is 1:2.5~1:5, the two-slug injection method is adopted, and the recovery degree improve to the highest degree. This method effectively simulates the injection, soaking and production processes in the complex huff and puff process, and fully meets the research requirements of the CO2 complex huff and puff parameter optimization.