层析反演静校正技术在鄂尔多斯盆地中黄土塬区的应用
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摘要
层析静校正是一种非线性模型反演技术,它利用地震记录的初至波时间,根据射线追踪方法反演地表及近地表不同介质的速度模型,建立与其相对应的表层结构模型,在此基础上分别求取激发点和接收点的静校正值。鄂尔多斯盆地南部的黄土塬区,地形起伏大,低速带速度和厚度纵横向变化剧烈,常规静校正存在较大的局限性,通过采用层析反演技术,解决了单炮记录初至不光滑、有效反射波不清晰、同相轴连续性差等问题,与折射静校正相比,不但很好地解决了区内不同波长的静校正问题,而且克服了由低、降速带厚度、速度等因素引起的构造形态扭曲现象,较好地改善了剖面同相轴的连续性,使解释的构造形态更趋于合理。
The tomographic statics is a kind of nonlinear model inversion technology,it uses first arrival time in seismic record,based on ray tracing method to inverse surface and near surface velocity models of different media,consequently establish corresponding surface structure models.On this basis,evaluate statics values of shot point and receiver point respectively.Since undulating relief in loess tableland in the southern Ordos Basin,velocity and thickness of low velocity zone are variable violently both longitudinal and transversal,thus general statics has rather large limitations.By the use of tomographic inversion technology,issues of single-shot record unsmoothed first arrivals,unclear usable reflections,poor phase axis continuity are solved.As compared with refraction statics,not only issue of different wavelength statics in the area can be solved,but also coped with contorted structural form caused by thickness,velocity factors of low deceleration zone,improved profile phase axis continuity better,thus make structural form interpretation more reasonable.
The tomographic statics is a kind of nonlinear model inversion technology,it uses first arrival time in seismic record,based on ray tracing method to inverse surface and near surface velocity models of different media,consequently establish corresponding surface structure models.On this basis,evaluate statics values of shot point and receiver point respectively.Since undulating relief in loess tableland in the southern Ordos Basin,velocity and thickness of low velocity zone are variable violently both longitudinal and transversal,thus general statics has rather large limitations.By the use of tomographic inversion technology,issues of single-shot record unsmoothed first arrivals,unclear usable reflections,poor phase axis continuity are solved.As compared with refraction statics,not only issue of different wavelength statics in the area can be solved,but also coped with contorted structural form caused by thickness,velocity factors of low deceleration zone,improved profile phase axis continuity better,thus make structural form interpretation more reasonable.
引文
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