Elastic properties of unconsolidated porous sand reservoirs

Journal Article · Thu Dec 01 04:00:00 EST 1977 · Geophysics; (United States)

DOI:https://doi.org/10.1190/1.1440797· OSTI ID:5615029

Domenico, S N

The effect of compressive stress and pore fluid properties on elastic properties of unconsolidated sand reservoirs was determined by laboratory velocity and pore volume measurements on two specimens. These consisted of a naturally occurring very fine grained sand and glass beads, each with a porosity of approximately 38 percent. Compressional- and shear-wave velocities and pore compressibility were measured in the brine- and gas-saturated specimens over a differential pressure range of 400 to 5000 psi. Measured velocities increase with increasing pressure very closely as a power of pressure. Pore compressibility of the glass bead specimen exceeds that of the Ottawa sand specimen by a factor of approximately 1.3 and, accordingly, static frame (bulk) compressibility of the glass bead specimen also is substantially greater. Shear modulus increases nonlinearly with differential pressure, the shear modulus of the Ottawa sand specimen becoming increasingly greater than that of the glass bead specimen with increasing pressure. Poisson's ratio is moderately greater for the Ottawa sand specimen. Compressional- and shear-wave velocities also were measured with a brine-gas mixture in the reservoir pore space at various brine saturations and at differential pressures of 1500 aiH 4500 psi. Measured shear-wave velocities generally decrease moderately with increasing brine saturation, substantially in conformance with theoretical curves. Effective fluid compressibilities, derived from compressional-wave velocity measurements, in general are between theoretical values given by the weighted-by-volume average of the compressibilities (direct weighting) and of the incompressibilities (inverse weighting) of the gas and brine.

• Research Organization: Amoco Production Co., Tulsa, OK
• OSTI ID: 5615029
• Journal Information: Geophysics; (United States), Journal Name: Geophysics; (United States) Vol. 42:7; ISSN GPYSA
• Country of Publication: United States
• Language: English

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580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
BRINES
COMPRESSIBILITY
COMPRESSION
DATA
DATA FORMS
DENSITY
DISPERSIONS
ELASTICITY
EXPERIMENTAL DATA
FLUIDS
GASES
GRAPHS
INFORMATION
ISOLATED VALUES
MECHANICAL PROPERTIES
MIXTURES
NUMERICAL DATA
PHYSICAL PROPERTIES
SAND
SEISMIC WAVES
TENSILE PROPERTIES
VELOCITY
WAVE PROPAGATION