PHYSICAL MODELING FOR TRAVEL OF SEISMIC-W AVES IN POROUS AND FRACTURED MEDIA

Experiments on sheet models have shown that under gas-saturated fractu ring and porosity the magnitude of dissipation-caused attenuation decr ement is determined by the total surface of inhomogeneities rather tha n by their dimensions. On determining the fracture direction, the angu lar dependence of attenuation for a medium with oriented fractures app ears to be more informative than the velocity angular dependence. It h as been shown on three-dimensional models that the gas-saturated poros ity leads to a considerable (as compared with the continuum medium) in crease in attenuation decrement of shear and compression waves. The oi l-saturated porosity leads to an average increase in attenuation of co mpression waves and to a great increase in attenuation of shear waves. The water-saturated porosity leads to an insignificant increase in at tenuation of compression waves with a significant increase in attenuat ion of shear waves. The use of statistic processing in estimation of a n increment of the visual period of reflected waves provides informati on on porosity of submerged horizons and fluid saturation of pores.