Journal : Acta Geophysica
Article : New petrophysical model describing the pressure dependence of seismic velocity

Authors :
Bogusz, J.
Centre of Applied Geomatics, Military University of Technology,,
Saibi, H.
Laboratory of Exploration Geophysics, Department of Earth Resources Engineering, Faculty of Engineering, Kyushu University, Fukuoka, Japan,,
Verbanac, G.
University of Zagreb, Faculty of Science, Department of Geophysics, Zagreb, Croatia,,
Mustasaar, M.
Department of Geology, University of Tartu, Tartu, Estonia,,
Dobróka, M.
Department of Geophysics, University of Miskolc, Egyetemvaros, Miskolc, Hungary,,
Abstract : Seismic data are increasingly applied to predict the characteristics of reservoirs, as their quality improves. Since the change of pressure is a major component in exploitation of reservoirs, a thorough understanding of the influence of pressure on seismic velocity is also important. In this study we introduce the first results of the developed petrophysical model which describes the pressure dependence of seismic velocity. The model is based on the idea that microcracks in rocks open and close under the change of pressure. Laboratory measurements are presented on several sandstone samples. Longitudinal wave velocities were measured at various incremental pressures increased from 0 to 20 MPa. During the measurements, the pulse transmission technique was used and the parameters of the model were determined by using a linearized inversion method. The inversion results proved that the proposed petrophysical model well applies in practice.

Keywords : pressure, seismic velocity, petrophysical model, microcraks,
Publishing house : Instytut Geofizyki PAN
Publication date : 2012
Number : Vol. 60, no. 2
Page : 371 – 383

: Best, A.I. (1997), The effect of pressure on ultrasonic velocity and attenuation in near-surface sedimentary rocks, Geophys. Prosp. 45, 2, 345-364, DOI: 10.1046/j.1365-2478.1997.00344.x.
Biot, M.A. (1956a), Theory of propagation of elastic waves in fluid-saturated porous solids. I. Low frequency range, J. Acoust. Soc. Am. 28, 2, 168-178, DOI: 10.1121/1.1908239.
Biot, M.A. (1956b), Theory of propagation of elastic waves in fluid-saturated porous solids. II. Higher frequency range, J. Acoust. Soc. Am. 28, 2, 179-191, DOI: 10.1121/1.1908241.
Birch, F. (1960), The velocity of compressional waves in rocks to 10 kilobars, Part 1, J. Geophys. Res. 65, 4, 1083-1102, DOI: 10.1029/JZ065i004p01083.
Darot, M., and T. Reuschlé (2000), Acoustic wave velocity and permeability evolution during pressure cycles on a thermally cracked granite, Int. J. Rock Mech. Min. Sci. 37, 7, 1019-1026, DOI: 10.1016/S1365-1609(00)00034-4.
Dobróka, M. (1987), Love seam-waves in a horizontally inhomogeneous threelayered medium, Geophys. Prosp. 35, 5, 502-516, DOI: 10.1111/j.1365-2478.1987.tb00832.x.
Dobróka, M., and N.P. Szabó (2005), Combined global/linear inversion of welllogging data in layer-wise homogeneous and inhomogeneous media, Acta Geod. Geoph. Hung. 40, 2, 203-214.
Dobróka, M., and N. Szabó (2011), Interval inversion of well-logging data for objective determination of textural parameters, Acta Geophys. 59, 5, 907-934, DOI: 10.2478/s11600-011-0027-z.
Dobróka, M., Á. Gyulai, T. Ormos, J. Csókás, and L. Dresen (1991), Joint inversion of seismic and geoelectric data recorded in an underground coal-mine, Geophys. Prosp. 39, 643-665, DOI: 10.1111/j.1365-2478.1991.tb00334.x.
Duffy, J., and R.D. Mindlin (1957,) Stress-strain relations and vibrations of a granular medium, J. Appl. Mech. 24, 585-593.
Gassmann, F. (1951), Elasticity of porous media, Vierteljahr. Naturforsch. Ges. 96, 1-23 (in German).
Gyulai, Á. (1989), Parameter sensitivity of underground DC measurements, Geophys. Trans. 35, 3, 209-225.
Hassan, A., and S. Vega (2009), A study of seismic velocities and differential pressure dependence in a Middle East carbonate reservoir. In: Proc. 79th SEG International Exposition and Annual Meeting, 25-30 October 2009, Houston, USA, DOI: 10.1190/1.3255765.
He, T., and D.R. Schmitt (2006), Velocity measurements of conglomerates and pressure sensitivity analysis of AVA response. In: Proc. 76th SEG International Exposition and Annual Meeting, 1-6 October 2006, New Orleans, USA, DOI: 10.1190/1.2369894.
Holt, R.M., A.-K. Furre, and P. Horsrud (1997), Stress dependent wave velocities in sedimentary rock cores: Why and why not?, Int. J. Rock Mech. Min. Sci. 34, 3-4, DOI: 10.1016/S1365-1609(97)00059-2.
King, M.S. (2009), Recent developments in seismic rock physics, Int. J. Rock Mech. Min. Sci. 46, 8, 1341-1348, DOI: 10.1016/j.ijrmms.2009.04.008.
Menke, W. (1984), Geophysical Data Analysis – Discrete Inverse Theory, Academic Press, London.
Nur, A., and G. Simmons (1969), The effect of saturation on velocity in low porosity rocks, Earth Planet. Sci. Lett. 7, 2, 183-193, DOI: 10.1016/0012-821X(69)90035-1.
Prasad, M. (2002), Acoustic measurements in unconsolidated sands at low effective pressure and overpressure detection, Geophysics 67, 2, 405-412, DOI: 10.1190/1.1468600.
Prasad, M., and M.H. Manghnani (1997), Effects of pore and differential pressure on compressional wave velocity and quality factor in Berea and Michigan sandstones, Geophysics 62, 4, 1163-1176, DOI: 10.1190/1.1444217.
Prasad, M., and R. Meissner (1992), Attenuation mechanism in sands: Laboratory versus theoretical (Biot) data, Geophysics 57, 5, 719-710, DOI: 10.1190/1.1443284.
Sengun, N., R. Altindag, S. Demirdag, and H. Yavuz (2011), P-wave velocity and Schmidt rebound hardness value of rocks under uniaxial compressional loading, Int. J. Rock Mech. Min. Sci. 48, 693-696, DOI: 10.1016/j.ijrmms.2011.02.007.
Singh, R., C. Rai, and C. Sondergeld (2006), Pressure dependence of elastic wave velocities in sandstones. In: Proc. 76th SEG International Exposition and Annual Meeting, 1-6 October 2006, New Orleans, USA.
Stacey, T.R. (1976), Seismic assessment of rock masses. In: Proc. Symp on Exploration for Rock Engineering, 1-5 November 1976, Johannesburg, South Africa.
Stewart, R.D., M.N. Toksöz, and A. Timur (1983), Strain dependant attenuation: observations and a proposed mechanism, J. Geophys. Res. 88, 546-554, DOI: 10.1029/JB088iB01p00546.
Szalai, S., and L. Szarka (2008), Parameter sensitivity maps of surface geoelectric arrays, I. Linear arrays, Acta Geod. Geoph. Hung. 43, 419-437, DOI: 10.1556/ageod.43.2008.4.4.
Toksöz, M.N., C.H. Cheng, and A. Timur (1976), Velocities of seismic waves in porous rocks, Geophysics 41, 4, 645-621, DOI: 10.1190/1.1440639.
Toksöz, M.N., D.H. Johnston, and A. Timur (1979), Attenuation of seismic waves in dry and saturated rocks. I. Laboratory measurements, Geophysics 44, 4, 681-690, DOI: 10.1190/1.1440969.
Walsh, J.B., and W.F. Brace (1964), A fracture criterion for brittle anisotropic rock, J. Geophys. Res. 69, 16, 3449-3456, DOI: 10.1029/JZ069i016p03449.
Winkler, K.W., and A. Nur (1982), Seismic attenuation: Effects of pore fluid and frictional sliding, Geophysics 47, 1, 1-15, DOI: 10.1190/1.1441276.
Wyllie, M.R.J., A.R. Gregory, and G.H.F. Gardner (1956), Elastic wave velocities in heterogeneous and porous media, Geophysics 21, 41-70, DOI: 10.1190/1.1438217.
Wyllie, M.R.J., A.R. Gregory, and G.H.F. Gardner (1958), An experimental investigation of factors affecting elastic wave velocities in porous media, Geophysics 23, 3, 459-493, DOI: 10.1190/1.1438493.
Yu, G., K. Vozoff, and D.W. Durney (1993), The influence of confining pressure and water saturation on dynamic elastic properties of some Permian coals, Geophysics 58, 1, 30-38, DOI: 10.1190/1.1443349.
Qute : Bogusz, J. ,Saibi, H. ,Verbanac, G. ,Mustasaar, M. ,Dobróka, M. ,Dobróka, M. , New petrophysical model describing the pressure dependence of seismic velocity. Acta Geophysica Vol. 60, no. 2/2012