Pre-Stack Seismic Data Reservoir AVO Parameter Inversion And Application

Amplitude variation with offset(AVO technology)is a new technique to search oil and gas directly which developed in the most recent decades. Its basic principle is the reflection coefficient changes along with the incident angle changes, which means the reflection coefficient is a function of incident angle. Its theoretical basis is the Zoeppritz equation and its approximations.The AVO parameter inversion may divide into single-wave and the multi-wave AVO inversion. Single-wave AVO inversion mainly uses the P-wave or PS-wave to carry on parameter inversion. But multi-wave AVO mainly refers combination P-wave with PS-wave or other types waves to carry on the union parameter inversion. In actual inversion process, the main step is to carry on AVO simulation and to take the restraint condition using the log information, then carries on the restraint inversion to an actual AVO angle collection,which can extract rock parameter exactly, and then direct forecasts oil gas.This article is in the foundation of AVO simulation and carries on Single-wave AVO inversion with the restraint of log information to extract Poisson's ratio profile from real seismic data. Firstly, the arcticle introduces the geophysics basic of AVO inversion, which includes full Zoeppritz equation and its approximations, and also explains their characteristics and the condition of using. Secondly, this article introduces the AVO characteristics of three petroliferous rocks, and then uses the approximation of Zoeppritz equation to calculate the reflection coefficient and then gets the synthetic AVO simulation records. Thirdly, this article introduces the algorithm of AVO inversion the Chaos Simulation Annealing basic principle and its the characteristic and the application effect. Finally this article which uses the Chaos Simulation Annealing algorithm, combining AVO simulation, to transform a CDP collection into an angle collection and extract wavelet,has carried on the simulation data and the real data inversion. Looked from the inversion effect that, the above algorithm carries on the inversion which has the well speed and good effect, showed this method is effective feasible.