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论文类型：期刊论文

发表时间：2016-11-01

发表刊物：JOURNAL OF VISUALIZATION

收录刊物：SCIE、Scopus

卷号：19

期号：4

页面范围：603-614

ISSN号：1343-8875

关键字：CO2 flooding; Asphaltene precipitation; Permeability reduction; X-ray micro-CT imaging; Kozeny-Carman equation

摘要：In the present study, three types of experiments on immiscible CO2 flooding in porous media were conducted and high-resolution images of asphaltene precipitation obtained using X-ray micro-CT scanner. It was found that the effective oil mobility is reduced due to the adsorption of deposited asphaltene onto the rock which blocks the pore throats, whereby the formation wettability is changed and both the effective porosity and permeability are reduced. The deposited asphaltene cannot be redissolved or displaced by the reinjected crude oil, and the formation damage is irreversible. In addition, the porosity-based permeability model was applied to study the effective permeability reduction that results from porosity reduction. The porosity-based permeability was calculated based on the Kozeny-Carman equation and experimental data. The effective permeability variation rate obtained by the porosity-based permeability model agreed well with the results obtained by Darcy's law, which demonstrates that the method is feasible in evaluating the effective permeability variation rate based on the porosity of the cores acquired from micro-CT images.