Perpustakaan Digital ITB

Residual oil saturation (Sor) represents the fraction of oil that remains trapped in the pore space after primary and secondary recovery in Enhanced Oil Recovery (EOR), commonly represented through the capillary desaturation curve (CDC) relating Sor to capillary number (NCa). Microfluidic technology enables direct pore-scale visualization of oil movement and trapping during flooding. This study evaluates the CDC through waterflooding experiments on a real structure micromodel, a two-dimensional replica of a Bentheimer sandstone core plug derived from µCT imaging, at nine sequential injection rates from 0.1 to 20 µL/min, using a MATLAB-based image processing algorithm to quantify fluid saturation and trapped oil ganglia radius. The resulting CDC shows an inverse relationship between NCa and Sor, with Sor declining progressively from 0.403 to 0.224 as NCa increases from 1.34 × 10?? to 2.67 × 10??. Increasing injection rate breaks large oil clusters into smaller fragments that become mobilized, narrowing the maximum trapped ganglia radius from 0.6–0.7 mm at low injection rates to 0.2–0.4 mm at high injection rates. Differential pressure is closely linked to this pore-scale desaturation process, with water relative permeability increasing significantly once NCa exceeds a critical range of approximately 2.67 × 10??. These findings provide porescale insight into oil mobilization in heterogeneous porous media, relevant for evaluating flow conditions in EOR strategy design.