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论文类型：期刊论文

发表时间：2017-06-01

发表刊物：MAGNETIC RESONANCE IN CHEMISTRY

收录刊物：SCIE、PubMed

卷号：55

期号：6

页面范围：546-552

ISSN号：0749-1581

关键字：MRI; porous media; counter-current imbibition; oil recovery

摘要：Counter-current imbibition is a process whereby a wetting phase spontaneously imbibes into a porous media, displacing the non-wetting phase. This process is considered an important oil recovery mechanism during water flooding in fractured oil reservoirs. In this study, the dynamic process of counter-current imbibition for a natural reservoir sandstone core with an all-face-open boundary condition was monitored using magnetic resonance imaging (MRI). A series of images and relaxation time T-1 spectra were acquired. The movement of water spontaneously entering the core sample while oil escapes, the spatial distribution of oil and water, and the in situ saturation change of oil and water in porous media can be accurately detected using MRI. MRI assists the direct evaluation of the basic mechanisms of imbibitions. Experimental results suggest the remaining oil was trapped in some large pores because of the capillary pressure, and the oil recovery in some large-pore regions is lower than that in some small-pore regions at the end of imbibition. Experimental findings show a close agreement between conventional material balance and oil recovery determined from MRI. The in situ oil recovery data agree well with the empirical models. The observations from MRI images could provide test cases to enable the development of mathematical models and to facilitate the evaluation of the proposed imbibition mechanisms. Copyright (c) 2016 John Wiley & Sons, Ltd.