The relative dip angle and anisotropy of the anisotropic formation are generally determined through an inversion process. We have studied the responses of the novel transient multicomponent induction logging method and find that all of the components measured in the instrument coordinate system have the same decay with time. However, the cross component decays much faster than the coaxial or coplanar components in the formation coordinate system. We adopt an algebraic time-domain method to calculate the dip angle and anisotropy coefficient and thereby avoid the inversion process. The accuracy and applicability of this pseudoinversion method are studied theoretically. Numerical results demonstrate that coaxial, coplanar, and cross components are used to calculate the apparent relative dip angle that yields the exactly true value at very early times and then goes through a transition deviating from the true dip and gradually approaches the true value again at late times. The apparent anisotropy is calculated by the coaxial and coplanar components and is equal to zero at early times and nonzero to the true anisotropy during the transition times. Moreover, by using realistic source dipole moments as well as adding random measurement errors, the practicality of this algebraic method is also investigated. Determination of the relative dip is still stable and valid. Determination of the anisotropy is more easily affected by measurement error and has some application limitations.

中文翻译：

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确定倾角和地层各向异性的新型瞬态多分量感应测井方法

各向异性地层的相对倾角和各向异性通常通过反演过程确定。我们研究了新型瞬态多分量感应测井方法的响应，发现在仪器坐标系中测量的所有分量都具有相同的随时间衰减。但是，在地层坐标系中，横向分量的衰减比同轴或共面分量的衰减快得多。我们采用代数时域方法来计算倾角和各向异性系数，从而避免了反演过程。理论上研究了该伪反演方法的准确性和适用性。数值结果表明，同轴，共面，交叉分量和交叉分量用于计算视在相对倾角，该倾角在很早的时候产生准确的真实值，然后经历一个偏离真实倾角的过渡，并在后期又逐渐接近真实值。表观各向异性由同轴分量和共面分量计算得出，在早期等于零，而在过渡时间等于真实各向异性。此外，通过使用现实的源偶极矩以及添加随机测量误差，还研究了这种代数方法的实用性。相对倾角的确定仍然是稳定和有效的。各向异性的确定更容易受到测量误差的影响，并且具有一些应用限制。