Experimental studies of CO2-brine-rock interaction effects on permeability alteration during CO2-EOR
Experimental studies of CO2-brine-rock interaction effects on permeability alteration during CO2-EOR
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DOI：
10.1007/s13202-020-00883-8
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发表时间：
2020-04-18
影响因子：
2.2
通讯作者：
Khosravi, Maryam
中科院分区：
文献类型：
--
作者：
Okhovat, Mohammad Reza;Hassani, Kamran;Khosravi, Maryam
通过CO2强化采油（EOR）在油藏中封存二氧化碳（CO2）是减少大气中这种气体的一种方法。在这些操作期间发生的不期望的化学反应可能影响储层结构和特性。在这项研究中，CO2-水-岩石相互作用对岩石渗透率变化和最终采收率的影响进行了实验评估，在碳酸盐岩注入CO2。研究了注入CO2提高采收率过程中流量、驱替方式和压力的影响。不同的情况下，混相/非混相驱油，二次/三次采油已被评估为不同水平的原生水矿化度和注入速度。结果表明，损害的严重程度与注入速度直接相关，但驱替类型从混相到非混相的变化降低了多孔介质中化学反应的强度。此外，在三次CO2注入中，由于较高的水饱和度，化学反应变得更加严重。有趣的是，化学反应水平的这种增长对渗透率降低的影响可以忽略不计，因为可能的反应的主要体积发生在粗糙和高渗透性的孔隙中。结果表明，在盐水较多的情况下，损伤更强烈。
Carbon dioxide (CO2) sequestration through CO2 enhanced oil recovery (EOR) in oil reservoirs is one way to reduce this gas in the atmosphere. Undesirable chemical reactions that occur during these operations can affect the reservoir structure and characteristics. In this study, the effect of CO2-water-rock interaction on the rock permeability alteration and final oil recovery has been evaluated experimentally during CO2 injection into a carbonate rock. The effect of flow rate, displacement type and pressure were investigated during CO2 EOR injection. Different scenarios of miscible/immiscible displacement, secondary/tertiary recovery has been evaluated for different levels of connate water salinity and injection rate. The results show that the severity of damage is directly related to the injection rate, however change in displacement type from miscible to immiscible reduce the intensity of chemical reactions in porous medium. Moreover, in the tertiary CO2 injection, the chemical reactions become more severe due to the higher water saturations. Interestingly, this growth in the level of chemical reactions has a negligible impact on permeability reduction, since the major volume of possible reactions occurs in coarse and high permeable pores. Results reveal that damage is more intense in the case of more saline water.