Polymer Flooding Enhanced Oil Recovery Evaluated with Magnetic Resonance Imaging and Relaxation Time Measurements

Magnetic resonance imaging (MRI) and magnetic resonance (MR) T-2 lifetime measurements were employed to monitor oil displacement by waterflooding and polymer flooding in two different rock core plugs. In situ oil saturation profiles were determined from the MRI measurements. Water-wet and oil-wet core plugs saturated with crude oil and mineral oil showed different oil saturation profile changes and T2 relaxation time variations during core flooding. The T2 log mean ratio is proposed to normalize T2 trends from different rock/fluid samples. The polymer stripping mechanism in the oil-wet rock core plugs was consistent with in situ oil saturation profile changes and relaxation time trends observed during oil displacement.