Seismic wave attenuation and dispersion induced by fluid flow within various cracks and a small amount of bubbly fluid

摘要

Hydrocarbon reservoirs usually contain pores and various cracks, which may contain a small amount of bubble fluid. In this study, based on the wave theory of basic porous medium, the influence of various factors on fluid pressure are investigated, and then the stress-strain relationship and Lagrangea??s equations with a dissipation function is utilized to derive the elastic wave equation of porous medium containing various cracks and a small amount of bubbly fluid initially. This elastic wave equation describes the influence of squirt flow induced by various cracks on seismic wave attenuation and dispersion, and the influence of the bubble linear vibration on seismic wave attenuation and dispersion effectively. Then, the seismic wave attenuation and dispersion of a given model is estimated and the matching of rock physics parameters are obtained in different frequency bands. The numerical results illustrate that the proposed approach is compatible with previous theory to explain the mechanics of the seismic wave attenuation and dispersion induced by fluid flow and can better describe the propagation of elastic waves in actual rock medium especially for the mechanics of the seismic wave attenuation and dispersion induced by fluid flow within various cracks and a small amount of bubble fluid.