AVA Positive Phase Media, Inverse Modeling Study

With depth in oil and gas exploration, study of theoretical seismic wavepropagation phase media gradually strengthened, and the effect of oil and gasexploration gradually emerging, mainly for two-phase fluid properties of the medium,and the frequency of the slow compressional wave velocity, porosity, saturation andpermeability studies to directly find the reservoir, which are based on the researchobjectives idealized model for the two-phase medium-The subject of this study is thepositive phase medium AVA, inverse modeling studies, which mainly theoreticalZoeppritz equation phase media, conducted a two-phase medium forward calculationreflection and transmission parameters AVA curves and sensitivity analysis, use AVAcurve forward calculation of synthetic seismograms forward, and ultimately the useof synthetic seismograms forward to strike the inversion of elastic parameters andlithology parameters-The forward not only to analyze the impact of variousparameters on oil and gas exploration, and prepare for the inversion, thus obtainingthe elastic parameters and seismic lithologic parameters of concern-The main resultsof this study are as follows:(1) both the upper and lower curves for the two-phase medium model AVA forwardcalculation and analysis of comparativeBy the calculation of two-phase medium Zoeppritz equations, draw two-phaseisotropic medium medium AVA characteristic curve, the model of which is givenmainly to two, the first model for the upper aqueous lower oil reservoir, the first twomodels for the upper aqueous lower oil reservoir on each curve comparison andanalysis, the difference between the two, thus reflecting the seismic wave propagationin different phase media model-(2) analysis of the sensitivity of each of the elastic parameters AVA curveElastic parameters fixed by the elastic parameters in addition to the need to changethe outside of the changes to the elastic parameters need to be changed to forwardcalculation AVA curve, through comparative analysis of the elastic parameters of thesensitivity of the AVA curve-Inversion effect depends on the chosen parameters, sothe selected parameters to meet the high sensitivity of the inversion angle region goodeffect not only fast, but fast convergence easily overflow characteristics-Thus optimizing the inversion parameters, choose a reasonable inversion algorithmsprovide support-So the choice of parameters inversion highly sensitive area, savingtime greatly beneficial AVA inversion-(3) Synthetic seismogram phase mediaObtained by the use of forward modeling and seismic reflection coefficientconvolution of seismic waves recorded synthesis and synthetic seismic records toanalyze results of various seismic wave propagation in two-phase medium-(4) AVA inversion phase mediaAs the use of synthetic seismograms surface observation data, using the modifiedleast squares inversion of elastic parameters to the geological structure of the layers,such as multi-wave velocity, porosity, fluid velocity, density of the solid medium, thefluid density-Error analysis and inversion analysis of the accuracy of the two-phasemedium AVA inversion of the parameters-...