Ultrasonic velocity and attenuation in water and brine-saturated sandstones

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:542896

Jones, S M; McCann, C; Astin, T R ^[1]

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1. Univ. of Reading (United Kingdom)

ULTRASONIC measurements of P- and S-wave velocity (V) and attenuation (1000/Q) have been made on fifteen different fully saturated sandstones over a range of effective pressures, using distilled water and two concentrations of brine as pore fluids. We found that the degree of change in V{sub p} per molar change in pore fluid salinity (V{sub p}/M) was dependent on the amount of clay present, and deviated from Biot predictions were generally smaller. There was not found to be any significant difference between P-wave attenuation in water and brine saturated rocks, but S-wave attenuation in brine saturated rocks was slightly greater than, or equal to, those in water saturated rocks over a wide range of values. These data are consistent with the observation that fresh water reduces the permeability of rocks to a much greater extent than brine. The results are applicable to field data, since pore water salinity may vary from zero in fresh water to over 300 000 ppm in some petroleum basins, where salinity generally increases with depth.

• OSTI ID: 542896
• Report Number(s): CONF-951013--
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
58 GEOSCIENCES
ATTENUATION
EXPLORATION
MATERIALS TESTING
PETROLEUM DEPOSITS
RESERVOIR FLUIDS
SANDSTONES
SEISMIC WAVES