Study Of Pre-stack Seismic Direct Elastic Inversion Of Magmatic Rock In Ludong Area Of Junggar Basin

With the development of the pre-stack seismic data processing technology and pre-stack migration technology, the development of quantitative AVO technology has been promoted at home and abroad.This thesis based on the theory of pre-stack AVO technology and to explore a kind of pre-stack seismic direct elastic inversion method. The study of the thesis involves Carboniferous magmatic rock in Ludong area of Junggar Basin, The lithology is relatively more complicated, and the correct lithology is the basic guarantee for this study. The true values of well logging data is restored by environmental correction in Section of borehole collapse and the systematic errors between different wells are eliminated by Standardization of well logging data. In study area, some wells are lack of S-wave data, which is simulated by using Biot-Gassmann equation, and elastic parameters of rockphysics are calculated. Filter out elastic parameters which are sensitive on different lithology and fluid by the systematic analysis of rockphysics, and the rockphysics standard Scale has been established in order to identify differences in different lithology and fluid, and guide the pre-stack seismic direct inversion. Based on rockphysics, geological framework model is established using SSN1 well data, and pre-stack seismic CRP gather data is made, and the conclusions of rockphysics are verified. Key of the thesis is to calculate AVO reflectivity of pre-stack seismic, and accurate incident angle is obtained from Seismic velocity that is corrected, and the different AVO reflectivity is directly calculated with all the good pre-stack seismic CRP gather data using different Zeoppritz equation, and signal to noise ratio and resolution of seismic reflectivity is improved. Finally, the seismic AVO reflectivities were solved out by the method of well logging constrained sparse spike inversion, and the results of pre-stack seismic direct elastic inversion were obtained by the method of constrained impedance inversion. The thesis is based on the study of Carboniferous magmatic rock in Ludong area of Junggar Basin, the likely hydrocarbon source rocks is predicted with the method of direct elastic inversion of pre-stack seismic, which provides the base for study the accumulation and migration of oil and gas, and predicted the spatial distribution of acid magmatic rock reservoirs and natural gas in Carboniferous.The actual results predicted shows that the pre-stack seismic direct elastic inversion method has the high signal to noise ratio and reliable quality in density and shear modulus and other elastic parameter inversion. Pre-stack seismic direct elastic inversion is an exploratory study of quantitative AVO technique, and it is suitable prediction method for reservoir and oil and gas of magmatic rock in Junggar Basin.