The relationships between the velocities, attenuations and petrophysical properties of reservoir sedimentary rocks

Journal Article · Tue Feb 01 04:00:00 EST 1994 · Geophysical Prospecting; (United States)

DOI:https://doi.org/10.1111/j.1365-2478.1994.tb00204.x· OSTI ID:7115908

Best, A I; McCann, C; Sothcott, J ^[1]

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1. Univ. of Reading, Berkshire (United Kingdom). Postgraduate Research Inst. for Sedimentology

The authors have measured the velocities and attenuations of compressional and shear waves in 29 water-saturated samples of sandstones and shales at a confining pressure of 60 MPa and at frequencies of about 0.85 MHz. The measurements were made using a pulse echo method in which the samples (diameter 5 cm, length 1.5 cm to 2.5 cm) were placed between perspex buffer rods inside a high-pressure cell. The velocity of each seismic wave was determined from the travel time difference of equivalent phase points (corrected for diffraction effects) of the signals reflected from the top and from the base of each samples. Attenuation was determined in a similar way by comparison of the diffraction corrected amplitudes of the signals. The attenuation data are presented as quality factors'': Q[sub p] and Q[sub s] for compressional and shear waves respectively and shear waves respectively. The results show that Qs is strongly correlated with V[sub s], that Q[sub p] is weakly correlated with V[sub p], and that Q[sub p] is strongly correlated with Q[sub s] [center dot] Q[sub p] is strongly dependent on the volume percentage of the assemblage of intra-pore minerals, whether they are clays or carbonates. It is concluded that the attenuation mechanism is due to the local fluid flow arising from the differential dilation of the solid rock frame and the intra-pore mineral assemblage, which is a results of their very different elastic moduli.

• OSTI ID: 7115908
• Journal Information: Geophysical Prospecting; (United States), Journal Name: Geophysical Prospecting; (United States) Vol. 42:2; ISSN GPPRAR; ISSN 0016-8025
• 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
ATTENUATION
DATA ANALYSIS
GEOLOGIC DEPOSITS
GEOPHYSICAL SURVEYS
MINERAL RESOURCES
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
RESERVOIR ROCK
RESOURCES
SEISMIC SURVEYS
SEISMIC WAVES
SURVEYS
WAVE PROPAGATION