Laboratory study heterogeneity impact on microscopic residual oil distribution in tight sandstone cores during CO2 immiscible flooding. Issue 23 (2nd December 2019)

• Record Type: Journal Article
• Authors: Xiao, Pufu; Lv, Chengyuan; Wang, Rui; Cui, Maolei; Xu, Qingyan; Hu, Qichuan; Hu, Wei
• Is Part Of: Energy sources. Volume 41:Issue 23(2019)
• Page Start: 2895
• Page End: 2905
• Publication Date: 2019-12-02
• Subjects: CO2 flood -- asphaltene precipitation -- microscope pore throat structure -- tight sandstone reservoirs -- nuclear magnetic resonance; Natural resources -- Periodicals; Energy consumption -- Periodicals; Energy consumption -- Climatic factors -- Periodicals; Energy conversion -- Periodicals; Energy conversion -- Environment aspects -- Periodicals; Power (Mechanics) -- Periodicals; 333.7905
• DOI: 10.1080/15567036.2019.1582732
• Languages: English
• ISSNs: 1556-7036

Abstract

ABSTRACT: We use physical simulation experiment and nuclear magnetic resonance methods to investigate crude oil distribution after immiscible CO2 flooding schemes in tight sandstone cores. Experimental results indicate that water-wet cores lead to the highest final recovery factor in comparison with intermediate wet cores and weak oil-wet cores, and the recovery oil difference in clay micropore is mainly because of the heterogeneity, and the difference in medium pore and large pore is affected by asphaltene precipitation phenomenon. Therefore, it is important to enhance the recovery in the clay micropores and reduce the impact of cores permeability reduction caused by asphaltene precipitation. Based on this investigation on the residual oil saturation in pore throats, immiscible CO2 flooding can be a potential method to improve recovery efficiency in tight oil reservoir.