强剩磁强退磁条件下的二维井中磁测反演

强剩磁、强退磁改变了总磁化强度的大小和方向，给磁测资料解释带来困难.为此，本文利用二维井中磁测数据反演磁化强度矢量的二维分布.首先利用井中磁测的磁异常模量反演磁化强度大小的分布.然后，在已知磁化强度大小分布的前提下，拟合磁场分量，反演磁化强度方向的分布.其中，磁化强度大小和方向均用共轭梯度法求解，并通过预优矩阵改善磁化强度大小的反演效果.理论模拟说明，该方法能准确获得磁化强度矢量分布.磁化强度矢量反演结果包括感磁、剩磁及退磁的影响，这为研究强剩磁、高磁化率矿床提供了一种有效方法.

2D inversion for borehole magnetic data in the presence of significant remanence and demagnetization

Significant remanence and demagnetization alter the intensity and orientation of total magnetization, which complicates interpretation of magnetic data. To deal with the problem, we propose a method of inverting 2D magnetization vector distributions using the 2D borehole magnetic data. We firstly invert the magnetization intensity distributions based on magnetic anomaly amplitudes of borehole magnetic data. With the known magnetization intensity distributions, subsequently, we invert the magnetization orientation distributions by fitting the magnetic component anomalies. Both magnetization intensity and orientation are solved by conjugate gradients. And a preconditioned matrix is utilized to improve the inverse quality of magnetization intensity. All synthetic examples involving significant remanence and high susceptibility demonstrate that this method is capable of accurately recovering the magnetization vector distributions. The magnetization vector distributions comprehensively include the influences of induced magnetization, remanent magnetization and self-demagnetization. Therefore, it provides an effective approach to study the ore deposits when high susceptibility and significant remanent magnetization are present.