1887

Abstract

Summary

It is well known that acoustic wave propagation under pressure is very nonlinear and the elastic properties of rocks are hysteretic, which behavior is important for mechanical understanding of reservoirs during depletion. Pressure strongly influences the elastic parameters of rocks, thus wave velocities too. In this study longitudinal and transverse wave velocities measured in laboratory on sandstone samples under pressure are presented. The uniaxial loading of the samples was carried out by an automatic acoustic test system. Measurement data were processed by a joint inversion technique based on the developed petrophysical model which describes the relationship between acoustic P/S wave velocities and pressure for loading and unloading phases. After Birch we assume that the main factor determining the pressure dependence is the closure of pores. The advantage of the model is that it is not based on simple curve fitting, but gives physical explanation for the process with three-parameter exponential equations. The quality checked joint inversion results showed that the misfits between measured and calculated data are small, proving that the proposed petrophysical model can be applied well in practice.

Loading

Article metrics loading...

/content/papers/10.3997/2214-4609.201414208
2015-10-05
2020-09-26
Loading full text...

Full text loading...

References

  1. Birch, F.
    [1960] The velocity of compression waves in rocks to 10 kilobars, Part 1. Journal of Geophysics Research, 65, 1083–1102.
    [Google Scholar]
  2. Dobróka, M. and Somogyi Molnár, J.
    [2012] New petrophysical model describing the pressure dependence of seismic velocity. Acta Geophysica, 60, 371–383.
    [Google Scholar]
  3. Hashin, Z. and Shtrikman, S.
    [1963] A variation approach to the theory of the elastic behaviour of multiphase materials. Journal of the Mechanics and Physics of Solids, 11, 127– 140.
    [Google Scholar]
  4. Ji, S., Wang, Q., Marcotte, D., Salisbury, M.H. and Xu, Z.
    [2007] P wave velocities, anisotropy and hysteresis in ultrahigh-pressure metamorphic rocks as a function of confining pressure. Journal of Geophysical Research, 112, B09204.
    [Google Scholar]
  5. Walsh, J.B. and Brace, W.F.
    [1964] A fracture criterion for brittle anisotropic rock. Journal of Geophysics Research, 69, 3449–3456.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201414208
Loading
/content/papers/10.3997/2214-4609.201414208
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error