In microfluidic studies of improved oil recovery, mostly pore networks with uniform depth and surface chemistry are used. To better mimic the multiple porosity length scales and surface heterogeneity of carbonate reservoirs, we coated a 2.5D glass microchannel with calcite particles. After aging with formation water and crude oil (CRO), high-salinity Water (HSW) was flooded at varying temperatures and durations. Time-resolved microscopy revealed the CRO displacements. Precise quantification of residual oil presented some challenges due to calcite-induced optical heterogeneity and brine–oil coexistence at (sub)micron length scales. Both issues were addressed using pixel-wise intensity calibration. During waterflooding, most of the ultimately produced oil gets liberated within the first pore volume (similar to glass micromodels). Increasing temperature from 22 °C to 60 °C and 90 °C produced some more oil. Waterflooding initiated directly at 90 °C produced significantly more oil than at 22 °C. Continuing HSW exposure at 90 °C for 8 days does not release additional oil; although, a spectacular growth of aqueous droplets is observed. The effect of calcite particles on CRO retention is weak on flat surfaces, where the coverage is ~20%. The calcite-rich pore edges retain significantly more oil suggesting that, in our micromodel wall roughness is a stronger determinant for oil retention than surface chemistry.
Wednesday 12 October 2022
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- Mon 5 Dec 2022Colloquium Prof. Kislon Voïtchovsky, December 8, 16.00-17.00, Ravelijn building RA 2502
- Mon 5 Dec 2022PhD Defence Saravana Kumar, December 9, 14.45 hrs Waaier 3
- Wed 21 Sep 2022Dr. S.J.A. De Beer and Prof.Dr. F.G. Mugele receive OTP grant from NWO-TTW
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- Thu 31 Mar 2022Newly granted NWO-TTW project