Seismic signatures of reservoir transport properties and pore fluid distribution

Journal Article · Mon Aug 01 04:00:00 EDT 1994 · Geophysics; (United States)

DOI:https://doi.org/10.1190/1.1443680· OSTI ID:7091430

Akbar, N ^[1]; Mavko, G; Nur, A; Dvorkin, J ^[2]

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1. Saudi Aramco, Dhahran (Saudi Arabia)
2. Stanford Univ., CA (United States). Dept. of Geophysics

The authors investigate the effects of permeability, frequency, and fluid distribution on the viscoelastic behavior of rock. The viscoelastic response of rock to seismic waves depends on the relative motion of pore fluid with respect to the solid phase. They consider wave-induced squirt fluid flow at two scales: (1) local microscopic flow at the smallest scale of saturation heterogeneity (e.g., within a single pore) and (2) macroscopic flow at a larger scale of fluid-saturated and dry patches. They explore the circumstances under which each of these mechanisms prevails. They examine such flows under the conditions of uniform confining (bulk) compression and obtain the effective dynamic bulk modulus of rock. The solutions are formulated in terms of generalized frequencies that depend on frequency, saturation, fluid and gas properties, and on the macroscopic properties of rock such as permeability, porosity, and dry bulk modulus. The study includes the whole range of saturation and frequency; therefore, the authors provide the missing link between the low-frequency limit and the high-frequency limit given by Mavko and Jizba. Further, they compare their model with Biot's theory and introduce a geometrical factor whose numeric value gives an indication as to whether local fluid squirt or global mechanisms dominate the viscoelastic properties of porous materials. The important results of their theoretical modeling are: (1) a hysteresis of acoustic velocity versus saturation resulting from variations in fluid distributions, and (2) two peaks of acoustic wave attenuation--one at low frequency and another at higher frequency (caused by local flow). Both theoretical results are compared with experimental data.

• OSTI ID: 7091430
• Journal Information: Geophysics; (United States), Journal Name: Geophysics; (United States) Vol. 59:8; ISSN GPYSA7; ISSN 0016-8033
• 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
58 GEOSCIENCES
580000 -- Geosciences
DATA ANALYSIS
ELASTICITY
FLUID FLOW
FUNCTIONS
GEOLOGIC DEPOSITS
GEOPHYSICAL SURVEYS
MECHANICAL PROPERTIES
MICROSTRUCTURE
MINERAL RESOURCES
NATURAL GAS DEPOSITS
PERMEABILITY
PETROLEUM DEPOSITS
POROSITY
RESERVOIR ROCK
RESOURCES
RESPONSE FUNCTIONS
SEISMIC SURVEYS
SEISMIC WAVES
SURVEYS
TENSILE PROPERTIES