一种利用特征值性质的MT阻尼最小二乘反演

发布时间：2018-02-14 07:33

本文关键词： 阻尼最小二乘反演大地电磁特征值阻尼因子分辨率突变界面　出处：《石油物探》2017年06期 　论文类型：期刊论文

【摘要】：阻尼最小二乘反演的方法总会得到一个最终迭代方程,该方程系数矩阵的特征值对反演结果有重要影响:小特征值相对大特征值对模型修正量的贡献更大,能够得到更高的分辨率,但同时更加不稳定。为此,以一维层状介质的大地电磁阻尼最小二乘反演为基础,采用特定单位的电阻率参数和层厚参数进行运算,同时改进阻尼因子的自适应调节方法,可以巧妙地利用小特征值能提高模型空间分辨率的特点,得到一种改进的阻尼最小二乘反演方法,并与传统阻尼最小二乘法进行了对比。合成数据测试结果表明,该方法能够得到电性陡变的反演模型,弥补了平滑模型反演不能有效识别电性突变界面的不足,对电性变化较为剧烈的地电结构的识别具有较好效果,分辨率有一定提高。
[Abstract]:The damped least square inversion method always obtains a final iterative equation. The eigenvalues of the coefficient matrix of the equation have an important effect on the inversion results: the small eigenvalues contribute more to the correction of the model than the large eigenvalues. Therefore, based on the magnetotelluric damping least square inversion of one-dimensional layered media, the specific unit resistivity parameters and layer thickness parameters are used to perform the calculation. At the same time, by improving the adaptive adjustment method of damping factor, the small eigenvalue can be used to improve the spatial resolution of the model, and an improved damped least square inversion method can be obtained. Compared with the traditional damped least square method, the synthetic data test results show that the proposed method can obtain the inversion model of abrupt electrical change, which makes up for the deficiency that the smooth model inversion can not identify the electrical abrupt interface effectively. It has a good effect on the identification of geoelectric structures with sharp changes in electrical properties, and the resolution is improved to a certain extent.
【作者单位】：成都理工大学地球物理学院;地球勘探与信息技术教育部重点实验室;
【基金】：国家自然科学基金项目(41674078)资助~~
【分类号】：P631.325

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