界面张力协同作用下胺类对CO2-EOR过程中CO2/油MMP的影响机理研究

It is very helpful to reduce the green house gas in air and to exploit the usage of captured CO2 by using CO2 for EOR　which can fulfill the storage of CO2 at the same time. Due to the great differential of mobility in the stratum, it is very easy to form fluid channeling therefore leading to a poor oil recovery efficiency. Usually a high pressure is adapted in CO2-EOR to ensure CO2 and oil forming a miscible fluent to increase the oil recovery efficiency, which will definitely brings up the energy consume and the amount of CO2 and to limit the capture and reusing of CO2.In this project, a great idea is brought out that introducing amine to CO2 to form a mixed gas fluent to displacing oil, which can not only reducing the burden of separating CO2 from amine during the capture process, but also to form in situ surfactant by using alkaline gas reacting with the acidic components in oil there by reducing the MMP and forming G/O emulsion to block the channel using the swelled oil. In this research, the IFT of mixed gas and oil, MMP and the EOR　efficiency of mixed gas will be studied, the influence of the structure of amine, the composition of mixed gas and MMP on the oil recovery efficiency will be analyzed. A novel model calculating the MMP will be build considering the influence factors such as the composition of gas and oil, especially the IFT.

CO2-EOR在利用CO2提高原油采收率的同时实现CO2的存储，对于降低空气中的CO2含量以及综合利用CO2具有十分重要的意义。由于CO2和原油在地层中的流度比差别大，导致过早的出现窜流，降低采收率。为了利用混相提高采收率，需在较高的压力下进行驱油，能耗及CO2用量较大，不利于CO2的再利用。本项目拟利用含有一定量胺类的CO2进行驱油，一方面胺类与原油中酸性物质反应形成原位界面活性物质，降低油/CO2-胺混合体系的界面张力，促进其混相进而降低该体系的MMP；另一方面在较低的界面张力下使CO2进入油相，使原油膨胀以增强对窜流的封堵；还可降低CO2捕获后与胺类分离的负荷。该研究拟通过测定油和CO2-胺混合体系的IFT、最小混相压以及驱油效果，考查混合体系的IFT、MMP与其组成、结构的关系以及其与驱油效果之间的关系及作用规律，并结合界面张力的影响建立预测MMP的模型。

CO2 与油相的混相压（MMP）的研究对于CO2提高采收率过程具有十分重要的意义。CO2-胺体系的性质也对CO2 EOR过程具有十分重要的影响。为了预测CO2-油的MMP，提出了四种不同的理论模型对含有不同杂质的CO2-EOR过程中MMP进行了预测，对于影响NMMP的不同因素进行了考察。结果表明，所建立的模型能很好的预测CO2-EOR体系的MMP，改进后的模型的准确度也得到了显著的提高。采用细管实验测量了体系的MMP，与预测结果一致。同时也对混有有机胺的CO2体系的性质进行了研究。为了更接近于驱油实际，对CO-EOR过程中，多孔介质在不同的温度和压力下对驱油剂CO2、胺的扩散性能进行了研究。研究表明，岩层的迂曲度对于其扩散有显著的影响，会降低扩散系数，需要进一步提高温度和压力来改善其影响。考虑从了迂曲度所建立的预测模型的预测结果能更好的反映其在实际驱油扩充中扩散。