利用基于模型的层析速度反演进行低幅度构造成像

发布时间：2018-10-31 09:37

【摘要】：基于层位的层析反演在低信噪比地区无法进行层位解释,在划分速度界面时也无法保证模型精度,局限性较大;基于网格的层析反演不容易收敛到实际速度模型,且模型没有地质意义的约束,有时会产生不符合地质规律的反演结果。为此,基于模型的层析反演方法,借鉴了层位约束和全局反演优点,以地质层位为基础建立模型,在横向上沿地质层位网格进行参数更新,在纵向上层位间网格更新尺度随着模型的地质层位而变化,既解决了薄层速度建模问题,又能得到精准的高、低频速度分量和各向异性参数。其次,基于模型的层析反演将模型中地质层位的深度作为一个变量纳入层析反演数据空间,可以同时反演速度结构与反射点位置(或反射层深度),具有更高的反演精度。将基于模型的层析反演方法应用于YM工区实际资料,并通过各向异性叠前深度偏移处理,提高了速度模型精度,解决了该区低幅度构造成像问题。
[Abstract]:Tomographic inversion based on layer can not be interpreted in low signal-to-noise ratio region, nor can it guarantee the accuracy of the model when dividing the velocity interface. The mesh based tomography inversion is not easy to converge to the actual velocity model, and the model has no constraints of geological significance, and sometimes the inversion results do not conform to the geological laws. Therefore, the tomography inversion method based on the model, drawing lessons from the advantages of horizon constraint and global inversion, establishes the model based on the geological horizon, and updates the parameters along the geological horizon grid horizontally. The scale of mesh renewal in the vertical upper layer varies with the geological layer of the model, which not only solves the problem of thin layer velocity modeling, but also can obtain accurate high and low frequency velocity components and anisotropic parameters. Secondly, based on the model, the depth of the geological layer in the model is included as a variable in the data space of the tomography inversion, which can simultaneously retrieve the velocity structure and the reflectance point position (or the depth of the reflection layer), which has higher inversion accuracy. The model based tomography inversion method is applied to the actual data of YM area, and the accuracy of velocity model is improved by anisotropic prestack depth migration, and the problem of low amplitude structural imaging in this area is solved.
【作者单位】：中国石油大学(华东)地球科学与技术学院;中国石油塔里木油田公司勘探开发研究院;帕拉代姆技术(北京)有限公司;
【基金】：国家重大科技专项课题(2011ZX05001-002-003、2011ZX05001-001-006)联合资助
【分类号】：P631.4

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