Multi-Component Induction Logging Response Feature And Exploration Characteristic Analysis Research

In the multi-component induction logging, Analysis of response feature is the basis of logging explanation, and response function can reflect the relationship of logging response and spatial distribution of electrical parameters.First, in the infinite homogeneous isotropic medium, derived the geometric factor expression reflecting space exploration characteristic, then made a simulation. Compared with the simulation diagram given in the references, the results were shown to be good match, so verified their correctness.Secondly, by analytical expression of electromagnetic field excited by magnetic dipole source of arbitrary orientation in the homogeneous uniaxial anisotropic medium, brought in the concept of transmission tensor connecting field and source, then pointed out that multi-component induction logging was to measure the transmission tensor in instrument coordinate system, illustrated the reason why multi-component induction logging was called tensor induction logging fundamentally. Based on this made a derivation and analysis to the forward response of multi-component induction logging, further defined the electromagnetic propagation resistivity logging response in the multi-component induction logging- phase difference and amplitude ratio, then drew the important conclusion that phase difference and amplitude ratio of cross-components were all independent of instrument rotation angle, after that analyzed the relationship of phase difference and amplitude ratio of cross-components and dip angle.Thirdly, derived response functions in isotropic medium by a new method, which showed that logging response were not only related to the change in electrical parameters, but also related to the change in derivatives of electrical parameters. Then simulated the response functions part reflecting electrical parameters change when lauching in z direction, receiving in z direction, and compared them with other two kinds of response functions. The results showed that the new response functions part reflecting the change in electrical parameters could reflect the sensitivity of logging response, but lower sensitivity range. The reason was that it was influenced by the change in derivatives of electrical parameters, but also demonstrated that it reflected the comprehensive nature of problem.Finally, in uniaxial anisotropy medium, derived two different sets of response functions with equivalent current source and equivalent magnetic current source. The first set of response functions were only reflecting the change in electrical parameters, but only for vertical wells; the second set of response functions were not only reflecting the change in electrical parameters, but also reflecting the change in derivatives of electrical parameters, but could be used in dip wells.