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The Application Of Pre-stack AVO Inversion In Q Area

Posted on:2017-04-01Degree:MasterType:Thesis
Country:ChinaCandidate:X F ZhangFull Text:PDF
GTID:2180330485491961Subject:Geophysics
Abstract/Summary:PDF Full Text Request
In recent years, seismic inversion has become one of the most widely used techniques in reservoir prediction. With the development of technology, both at home and abroad the oil gas bearing basin exploration focus gradually from structural trap to the stratigraphic and lithologic subtle traps transfer and exploration of lithologic oil and gas reservoirs has becoming more and more important as an important direction of oil and gas reserves increase.Coal bed methane is mainly absorbed, dissolved and free in three states, which exist in the coal or other reservoirs. The proportion of the coal bed gas is greater than the others, which is the main object of mining. The difficulty of prediction of reservoir and fluid characteristics in this area is summarized, which is mainly reflected in the thin thickness of coal seam, complex formation, high degree of fracture development and the complexity of the plane distribution of coal-bed methane. This thesis research the coal seam gas characteristics and formation characteristics of The Q area, and apply post-stack constrained sparse pulse inversion and pre-stack AVO inversion.According to the seismic data in Q area, this thesis firstly studies the inversion of the post stack wave impedance and its application to predict the reservoir in the study area. Because the post-stack constrained sparse pulse inversion method of limitations, the method is unable to forecast the plane distribution feature of fluid, so this thesis use post stack attribute and the pre-stack AVO inversion in order to get some better results. Pre stack inversion is based on the Zoeppritz equation, but the Zoeppritz equation is too cumbersome, and the physical meaning is not clear, so the future many researchers use different applicable conditions to simply and approximate the Zoeppritz equation. This thesis introduce the Zoeppritz simplified equations, and make applicability analysis for the specific characteristics of the study area coal seam gas of Zoeppritz approximate equation, and for the practical application of pre-stack inversion provides important theoretical basis.According to the quality of the road set data in the research area, and use Optimal stack for the pre-stack gathers of the study area. As one of the key techniques in pre stack inversion, the analysis and processing of the angle gathers is very important to the result of pre-stack AVO inversion.This thesis according to the actual situation of the study area of the inversion method to do the applicability analysis, use the post stack constraint coefficient pulse inversion and pre-stack AVO inversion method respectively to the study area reservoir and fluid character prediction, and carries on the analysis to the inversion result. The results show that the inversion of constrained sparse pulse inversion and pre-stack AVO inversion results have a certain guiding role for the prediction of reservoir and fluid characteristics in the study area.
Keywords/Search Tags:Post stack inversion, pre stack inversion, Zoeppritz equation, optimal stack
PDF Full Text Request
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