Nonlinear Inversion Of Two-phase Medium Reservoir Parameter

The two-phase medium theory can adequately account for the structure of medium, and the particularity of fluid and the effect relation between local and integral, So implement two-phase medium theory can accurately describe the structure of stratum and it's property., it can well adapt to the necessary for the more and more complex oil-gas reservoir exploration situation, the two-phase medium theory has been one of advanced and difficult geophysics research problems now. Chaos is an universal nonlinear phenomenon with stochastic property, ergodic property and regular property, whose ergodicity can be used as a kind of mechanism for optimization to effectively avoid the search being trapped in local optimum, so that chaos has been a novel and promising tool for global optimization. Chaos nonlinear inversion method is a good way for the complex two-phase medium reservoir.In this paper, I have built the geophysical reservoir model by considering the physical properties of rocks in the west of Sichuan area after studying new techniques and methods of two-phase medium theory and studying the propagation feature of waves in two-phase medium. I have forwarded wave field of isotropic and anisotropic medium separately based on the Biot and BISQ two-phase medium model equation, and then analyzed the propagation law and property of these seismic waves by using forward results. I have studied the law and property of reflection and transmission on the interface of two two-phase when the angle of incidence of the seismic wave is random and 90 degree based on Zoeppritz equation and reflection and transmission equation of two-phase medium, and discussed the simple expressions for normal incidence reflection coefficients form an interface between porous medium and then analyzed effects that frequency to reflection and transmission coefficients on this situation. Later, with stochastic property and ergodic property and regular property of chaos I have finished high effects chaos optimum algorithm. And realized the AVO inversion base on two-phase medium theory by using this chaos algorithm, according to the chaos research results, implemented the two-phase medium reservoir parameter inversion to get the porosity and permeability of reservoir. I have discussed the relation among attenuation property and velocity dispersive and elastic parameter of the fast and slow P wave based on the BISQ model, and then educed the bearing gas prediction method of the two-phase medium reservoir.Finally, I established systemically the series methods and technologies for bearing gas detection and nonlinear parameters inversions and wave field forward and wave field analysis based on two-phase medium theory to reservoir, it showed the better effect applying of the study results to the seismic data.