Effect of pore structure on miscible displacement in laboratory cores

Journal Article · Mon Aug 01 04:00:00 EDT 1988 · SPE (Society of Petroleum Engineers) Reserv. Eng.; (United States)

DOI:https://doi.org/10.2118/15017-PA· OSTI ID:6687964

Bretz, R E; Specter, R M; Orr, Jr, F M

Observations of pore structure in thin-sections are related to the performance of stable, first-contact-miscible displacements in reservoir cores and then to simulations of displacement performance of CO/sub 2/ corefloods. Results of effluent composition measurements are reported for miscible displacements in seven core samples - three sandstones and four San Andres carbonates from west Texas or eastern New Mexico. Those displacements are interpreted by fitting the measured effluent compositions to the Coats-Smith (C-S) model, which represents the flow as occurring in flowing and stagnant fractions with mass transfer between them. Observations of thin-sections, including measurements of pore-size distributions and a simple measurement of spatial correlation of pore sizes, are also reported. Comparison of displacement results and thin-section data indicates that wide pore-size distributions and preferential flow paths are characterized in the C-S model by high dispersion coefficients and low flowing fractions. Simulations of the interactions of phase behavior and flow in nonuniform pore structures indicate that wide pore-size distributions and preferential flow paths can significantly increase residual oil saturations (ROS's) in CO/sub 2/ floods over those for uniform pore structures. Thus, heterogeneities observable at the scale of a thin-section have significant effects in laboratory core but much smaller effects in displacements at field scale. Large-scale heterogeneities present in field floods, however, probably cause similar increases in residual saturation in some fields.

• Research Organization: New Mexico Inst. of Mining and Technology (US)
• OSTI ID: 6687964
• Journal Information: SPE (Society of Petroleum Engineers) Reserv. Eng.; (United States), Journal Name: SPE (Society of Petroleum Engineers) Reserv. Eng.; (United States) Vol. 3:3; ISSN SREEE
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200 -- Petroleum-- Reserves
Geology
& Exploration
020300* -- Petroleum-- Drilling & Production
CARBON DIOXIDE INJECTION
DATA
DISPLACEMENT FLUIDS
DRILL CORES
ENHANCED RECOVERY
EXPERIMENTAL DATA
FLUID INJECTION
FLUIDS
GEOLOGIC DEPOSITS
GEOMETRY
INFORMATION
MATERIALS
MATHEMATICS
MINERAL RESOURCES
MISCIBLE-PHASE DISPLACEMENT
NUMERICAL DATA
OIL FIELDS
OIL SATURATION
PETROLEUM DEPOSITS
PHASE STUDIES
POROSITY
POROUS MATERIALS
RECOVERY
RESOURCES
SAMPLING
SATURATION
TECHNOLOGY ASSESSMENT