Method for detecting interface orientation of dielectric layer based on fractional-turn coil

Abstract

The invention provides a method for detecting the interface orientation of a dielectric layer based on a fractional-turn coil. The method comprises the steps of: employing an axisymmetrically windingcircular transmitting coil and an asymmetrically winding receiving coil which is coaxial and parallel with the transmitting coil, wherein the receiving coil can completely eliminate direct-coupled electromotive force generated by the transmitting coil for the receiving coil under an infinite uniform medium, and only receive a signal reflected by a transmitting signal through a stratum interface; calculating a reflection field received by the receiving coil by adopting a mirror image method, acquiring a total electric field at the receiving coil according to a field superposition theory, and calculating an induced electromotive force of the receiving coil by adopting Gaussian integration. and realizing high-precision measurement of the interface orientation of the layer interface accordingto change rules of amplitude and a phase angle of the induced electromotive force. By adopting the method, the reflection field at the layer interface is calculated by adopting the mirror image method, and a non-axisymmetric model is converted into an axisymmetric model, so that the calculated model can realize high-precision measurement of the azimuth of the layer interface by adopting a rapid algorithm of the axisymmetric model, and real-time inversion of the dielectric layer information is of great significance.

Description

technical field [0001] The invention relates to the technical field of well logging, in particular to a method for detecting the orientation of a medium layer interface based on a fractional-turn coil. Background technique [0002] With the rapid development of detection technology, long-distance detection and imaging systems have become a hot topic, especially for aircraft, radar, underwater submarines and geological exploration and other fields, the imaging of three-dimensional vector fields and medium detection have become very important research contents. Especially in a complex environment, the signal received by the measurement system is seriously interfered by the background signal, and there are large errors in the long-distance detection of the distance and orientation information of the object / medium, which makes the rapid response system unable to accurately identify the measured object. In the process of long-distance edge detection, the reflection signal of the ...

AI Technical Summary

Problems solved by technology

For the detection of the position of the layer interface, because the shielding coil of the traditional logging instrument cannot completely eliminate the direct coupling electromotive force in the medium, the direct coupling signal accounts for a large proportion of the induced electromotive force generated by the receiving coil, and the proportion of the reflected signal is small. Especially when the layer interface is far away, the reflection signal attenuation of the layer interface is serious, so that the azimuth and distance of the layer interface cannot be effectively analyzed through the amplitude and phase angle of the induced electromotive force, and the conductivity of the formation can be calculated through the induced electromotive force

[0004] On the other hand, due to the existence of the layer interface, the layer interface will reflect the electromagnetic wave emitted by the transmitting coil of the instrument, so that the induced electromotive force generated by the traditional circular symmetrical receiving coil will weaken the signal

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