Petrography and reservoir physics III: Physical models for permeability and formation factor

Journal Article · Tue Oct 01 04:00:00 EDT 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5848919

Erhlich, R; Etris, E L; Brumfield, D; Yuan, L P; Crabtree, S J ^[1]

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1. Univ. of South Carolina, Columbia (United States)

Permeability and formulation factor are physical properties of porous rocks useful for assessing reservoirs. Neither property varies consistently as porosity varies. The relationship of both properties to porosity is complex, being sensitive to the structure of the porous microstructure, i.e., the sizes of pore throats, the numbers and sizes of pores, and the relationships between pores and throats. Physical models to account for these factors require parameters that describe physically relevant properties of the microstructure. A partial characterization of the relationship between pore type and throat size. This relationship is derived by combining data obtained from thin sections, from which pore types are derived via image analysis, and mercury injection porosimetry, which quantifies throat size information. Parameters derived from such a combination are sufficient to construct simple physical models for permeability and electrical conductivity. These models assume a porous medium that has large numbers of flow paths parallel to the potential gradient, such that flow has little tortuosity. The contributions of each pore type to permeability and electrical conductivity are computed. A constant of proportionally is the same for all samples from a reservoirs, is required, and must have values ranging (for sandstones) from about 2.5 to 3.5 for permeability and 5.0 to 7.0 for conductivity. These values are consistent for an efficiently packed fabric. One result of such modeling is a physical model of Archie's cementation exponent m as the ratio of the logarithms of the cross sectional throat area to pore area (per unit area).

• OSTI ID: 5848919
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (United States), Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Vol. 75:10; ISSN AABUD; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EQUATIONS
FLOW MODELS
FUNCTIONS
GEOLOGIC DEPOSITS
GEOLOGIC MODELS
MATHEMATICAL MODELS
MICROSTRUCTURE
MINERAL RESOURCES
NATURAL GAS DEPOSITS
PERMEABILITY
PETROGRAPHY
PETROLEUM DEPOSITS
PHYSICAL PROPERTIES
POROSITY
RESERVOIR ROCK
RESOURCES