Relationship of pore structure to fluid behavior in low permeability gas sands. Final report
This is the final report of a three-year project concerned with the pore structure of low permeability gas sands. The report is divided into five sections: (1) Pressure Sensitivity of Permeability, (2) Effects of Fluid, Confining Pressure, and Temperature on Absolute Permeabiities of Low Permeability Sandstones, (3) Effect of Acid Leaching and Presence of Fractures, (4) Adsorption, and, (5) Mathematical Modelling and Correlations. In the first section, a data base of core properties is developed with measurements of permeability vs. confining pressure for three suites of cores as the main feature. The third section describes an initial investigation into (a) the effects of removing carbonate cement by leaching cores with acetic acid, (b) the effects of calcite-filled fractures on permeability and pressure sensitivity. Dramatic increase in permeability and decrease in pressure sensitivity were observed to result from leaching. For cores containing calcite-filled fractures, it was found that the fracture was neither a permeability barrier to flow across the fracture or a highly conductive region for flow along the fracture. Results presented in the fourth section on relationships between relative pressure and amount of adsorption provide careful information about the existence and extent of microporous material contained in tight gas sands. The fifth section on mathematical modelling presents results in which the diffusive contribution to flow is calculated for crack-shaped pores in series, and for two- and three-dimensional networks. 93 figures, 20 tables.
- Research Organization:
- New Mexico Inst. of Mining and Technology, Socorro (USA). New Mexico Petroleum Recovery Research Center
- DOE Contract Number:
- AS19-80BC10216
- OSTI ID:
- 6711802
- Report Number(s):
- DOE/BC/10216-13; ON: DE84012721
- Country of Publication:
- United States
- Language:
- English
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Relationship of pore structure to fluid behavior in low permeability gas sands. First annual report
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Related Subjects
SANDSTONES
FRACTURES
LEACHING
PERMEABILITY
POROSITY
ACETIC ACID
ADSORPTION
CORRELATIONS
DRILL CORES
EXPERIMENTAL DATA
MATHEMATICAL MODELS
MICROSTRUCTURE
NATURAL GAS DEPOSITS
PRESSURE DEPENDENCE
TEMPERATURE DEPENDENCE
CARBOXYLIC ACIDS
CRYSTAL STRUCTURE
DATA
DISSOLUTION
FAILURES
GEOLOGIC DEPOSITS
INFORMATION
MINERAL RESOURCES
MONOCARBOXYLIC ACIDS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SEPARATION PROCESSES
SORPTION
030200* - Natural Gas- Reserves
Geology
& Exploration