The effect of pore fluid on the stress‐dependent elastic wave velocities in sandstones

2002 ◽  
Author(s):  
Colin M. Sayers ◽  
De‐Hua Han
Keyword(s):  
Elastic Wave ◽  
Pore Fluid ◽  
Wave Velocities ◽  
Stress Dependent

scholarly journals Ultrasonic moduli for fluid-saturated rocks: Mavko-Jizba relations rederived and generalized

Geophysics ◽  
2009 ◽  
Vol 74 (4) ◽  
pp. N25-N30 ◽  
Author(s):  
Boris Gurevich ◽  
Dina Makarynska ◽  
Marina Pervukhina
Keyword(s):  
Elastic Wave ◽  
Bulk Modulus ◽  
Quantitative Model ◽  
Pore Fluid ◽  
Porous Rocks ◽  
Laboratory Measurements ◽  
Shear Moduli ◽  
Wave Velocities

Mavko and Jizba propose a quantitative model for squirt dispersion of elastic-wave velocities between seismic and ultrasonic frequencies in granular rocks. Their central results are the expressions for the so-called unrelaxed frame bulk and shear moduli computed under an assumption that the stiff pores are drained (or dry) but the soft pores are filled with fluid. Mavko-Jizba expressions are limited to liquid-saturated rocks but become inaccurate when the fluid-bulk modulus is small (e.g., for gas-saturated rocks). We have derived new expressions for unrelaxed moduli of fluid-saturated porous rocks using Sayers-Kachanov discontinuity formalism. The derived expressions generalize the established Mavko-Jizba relations to gas-saturated rocks, reduce to Mavko-Jizba results when the pore fluid is liquid, and yield dry moduli when fluid-bulk modulus tends to zero. We tested this by comparing our model and the model of Mavko and Jizba against laboratory measurements on a sample of Westerly granite.

Assessing rock brittleness and fracability from radial variation of elastic wave velocities from borehole acoustic logging

2016 ◽  
Vol 64 (4) ◽  
pp. 958-966 ◽  
Author(s):  
Xiao-Ming Tang ◽  
Song Xu ◽  
Chun-Xi Zhuang ◽  
Yuan-Da Su ◽  
Xue-Lian Chen
Keyword(s):  
Elastic Wave ◽  
Radial Variation ◽  
Acoustic Logging ◽  
Wave Velocities ◽  
Rock Brittleness

scholarly journals Experimental Investigation of Wave Velocity-Permeability Model for Granite Subjected to Different Temperature Processing

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Guanghui Jiang ◽  
Jianping Zuo ◽  
Teng Ma ◽  
Xu Wei
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Wave Velocity ◽  
Pore Fluid ◽  
Rock Matrix ◽  
Permeability Model ◽  
Wave Velocities ◽  
Before And After ◽  
Different Temperatures ◽  
Increasing Temperature

Understanding the change of permeability of rocks before and after heating is of great significance for exploitation of hydrocarbon resources and disposal of nuclear waste. The rock permeability under high temperature cannot be measured with most of the existing methods. In this paper, quality, wave velocity, and permeability of granite specimen from Maluanshan tunnel are measured after high temperature processing. Quality and wave velocity of granite decrease and permeability of granite increases with increasing temperature. Using porosity as the medium, a new wave velocity-permeability model is established with modified wave velocity-porosity formula and Kozeny-Carman formula. Under some given wave velocities and corresponding permeabilities through experiment, the permeabilities at different temperatures and wave velocities can be obtained. By comparing the experimental and the theoretical results, the proposed formulas are verified. In addition, a sensitivity analysis is performed to examine the effect of particle size, wave velocities in rock matrix, and pore fluid on permeability: permeability increases with increasing particle size, wave velocities in rock matrix, and pore fluid; the higher the rock wave velocity, the lower the effect of wave velocities in rock matrix and pore fluid on permeability.

Elastic Wave Velocities in Laminated Media

1954 ◽  
Vol 26 (5) ◽  
pp. 949-949
Author(s):  
J. E. White ◽  
F. A. Angona
Keyword(s):  
Elastic Wave ◽  
Wave Velocities
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