Pore-level mechanisms of residual oil formation during miscible displacement

Journal Article · Tue Mar 01 04:00:00 EST 1994 · Journal of Colloid and Interface Science; (United States)

DOI:https://doi.org/10.1006/jcis.1994.1096· OSTI ID:7279455

Mohanty, K K ^[1]; Gupta, A ^[2]; DeRuiter, R A ^[3]

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1. Univ. of Houston, TX (United States). Dept. of Chemical Engineering
2. Univ. of Oklahoma, Norman, OK (United States). School of Petroleum and Geological Engineering
3. ARCO Exploration and Production Technology, Plano, TX (United States)

Miscible flooding of oil from porous sedimentary formations by the injection of high-pressure solvents incorporates a complex interaction of heterogeneity, fingering, multiphase flow, and phase behavior. The objective of this work is to identify pore-scale mechanisms that lead to formation of a residual oil saturation in so-called miscible floods in the absence of water shielding. Oil displacements are carried out in two high-pressure, two-dimensional, transparent micromodels, which are simplified analogs of porous rocks. Displacement mechanisms are visualized for different solvents. Results show that the interaction of bypassing and phase behavior can lead to an immiscible residual with so-called first-contact miscible solvents. An equimolar mixture of ethane, propane, and n-butane (C[sub 2]C[sub 3]C[sub 4]) recovers all the oil in one-dimensional flow, but can leave a nonzero residual in dead-end pores of micromodels. Ethane develops multicontact miscibility with this oil in one-dimensional flow. Three hydrocarbon phases appear during the oil displacement by the methane-diluted equimolar mixture of ethane, propane, and n-butane. Capillary-driven flow recovers oil out of dead-end pores in ethane- and methane-diluted equimolar C[sub 2]C[sub 3]C[sub 4] displacements. The interaction of viscous fingering and phase behavior can also contribute to miscible flood residuals in multiple contact displacements.

• OSTI ID: 7279455
• Journal Information: Journal of Colloid and Interface Science; (United States), Journal Name: Journal of Colloid and Interface Science; (United States) Vol. 163:1; ISSN 0021-9797; ISSN JCISA5
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
ENERGY SOURCES
ENHANCED RECOVERY
FLOW MODELS
FLUID INJECTION
FOSSIL FUELS
FUELS
MATHEMATICAL MODELS
MICROSTRUCTURE
MISCIBLE-PHASE DISPLACEMENT
OIL SATURATION
OIL WELLS
PETROLEUM
PORE STRUCTURE
RESERVOIR ROCK
RESIDUAL PETROLEUM
SATURATION
WELLS