Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1755749 | Journal of Petroleum Science and Engineering | 2010 | 9 Pages |
Wettability controls fluid saturation and distribution in reservoir rocks, that in turn affects two-phase properties such as Nuclear Magnetic Resonance (NMR) response. We simulated the NMR response of two-phase systems during drainage and waterflooding in pore-scale networks representing sand packs and sandstones using a random walk method. Different wettabilities were studied and the simulation results were compared with previously published experimental measurements. In oil-wet media, we predict a slow decay with a broad T2 distribution because water in the center of the pores has a low bulk relaxivity; there is little surface relaxivity since the grain surfaces are covered by oil layers. This suggests a straightforward technique to indicate oil wettability in core samples.