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Investigation On Seismic Data Prestack Reverse Time Migration Approach

Posted on:2015-03-25Degree:MasterType:Thesis
Country:ChinaCandidate:D S TianFull Text:PDF
GTID:2180330431994844Subject:Earth Exploration and Information Technology
Abstract/Summary:PDF Full Text Request
Seismic data migration result largely determines the exploration effectiveness and thediscovery of reservoirs. Based on two-way wave equation operator, reverse time migration(RTM) computation has high precision, and it overcomes limitation of dip and migrationaperture, adapts to image dramatic changes in the vertical and horizontal subsurface, and canimage diffracted wave, prism wave, rotation wave and other complicated seismic wave withhigh accuracy, which is the best approach for complicated construction imaging. Therefore,investigation on prestack reverse time migration approach has important significance andstrong practical value.Begin with GPU accelerating technology, the paper introduces CUDA computingplatform and its optimization, and gives the RTM implementation by GPU/CPU collaborativeparallel accelerating computation. Secondly, the paper researches on seismic wave fieldmodeling based on high-order finite difference, including difference scheme of two-way waveequation high-order finite difference, stability and numerical dispersion, boundary condition,etc. Thirdly, the paper focuses on reverse time migration, including basic principle of RTM,imaging condition, storage strategies, random boundary condition, and suppressionapproaches to the low-frequency noise in the imaging result. Then, apply the above reversetime migration approach based on GPU/CPU collaborative parallel accelerating computationto graben model, Marmousi model, Sigsbee model, and Salt-2d model, suppress thelow-frequency noise by Laplacian operator, analysis the imaging advantages by RTMapproach. Last, the paper analyses the influence factor of reverse time migration imaging.In order to obtain accurate subsurface construction, greatly shortening the seismic dataprocessing cycle, most geophysicists are constantly exploring high-precision, high efficiencyimaging algorithms. Theoretical analysis and model calculations demonstrate that, prestackreverse migration can image accurately, and can greatly improve the computational efficiencyby GPU accelerating technology. Therefore, reverse time migration has broad applicationprospect.
Keywords/Search Tags:reverse time migration, two-way wave equation, GPU/CPU collaborativeparallel accelerating computation, random boundary condition, Laplacian operator noisesuppression
PDF Full Text Request
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