NMR-Based Analysis of Fluid Occurrence Space and Imbibition Oil Recovery in Gulong Shale

The Gulong shale oil reservoir is situated in freshwater to slightly saline lacustrine basins mainly consisting of a pure geological structure, which quite different from other reservoirs around the world. Currently, development relies on hydraulic fracturing, while subsequent shut-in period for imbibition has been proven be an effective method enhancing recovery. To clarify characteristics fluid occurrence space and variation during saltwater shale, this paper carried out porosity permeability tests cores analyzed recovery based nuclear magnetic resonance (NMR). In tests, T2 distributions were used correct measured by saturation obtain NMR porosity. Combined with identification fractures using micro-CT analysis parameters, it was found that related cores. Through testing T1-T2 maps before after oil, contained heavy light clay-bound water, they distributed regions maps. Finally, at stages analyzed, entered minuscule inorganic pores clay minerals process squeezed larger-sized containing through hydration expansion effect, thus expelling core achieving purpose enhanced