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An algorithm for estimating saturation level during magnetization

IP.com Disclosure Number: IPCOM000242360D
Publication Date: 2015-Jul-09
Document File: 2 page(s) / 15K

Publishing Venue

The IP.com Prior Art Database

Abstract

One of the major goals of the project is to increase the signal to noise ratio of the measurement. Improving and optimizing the performance of the transmitter antennas will certainly increase the magnetic field and induced eddy current in the formation and consequently raise the formation signal strength. In this document, an algorithm to estimate the level of magnetization for switchable ferromagnets is proposed. The mathematical model proposed by Jiles and Atherton is employed to accurately represent the hysteresis behavior of the ferromagnetic core. In the sense of accurate fitting of the measurement data into the J-A model, a modification to the mathematical model is essential for this kind of switchable magnets. A finite element model of the Z-transmitter has been developed and level of magnetization in the switchable magnet is estimated.

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RES4-58512-US

Title:  An algorithm for estimating saturation level during magnetization

Abstract: One of the major goals of the project is to increase the signal to noise ratio of the measurement. Improving and optimizing the performance of the transmitter antennas will certainly increase the magnetic field and induced eddy current in the formation and consequently raise the formation signal strength.  In this document, an algorithm to estimate the level of magnetization for switchable ferromagnets is proposed.  The mathematical model proposed by Jiles and Atherton is employed to accurately represent the hysteresis behavior of the ferromagnetic core.  In the sense of accurate fitting of the measurement data into the J-A model, a modification to the mathematical model is essential for this kind of switchable magnets.  A finite element model of the Z-transmitter has been developed and level of magnetization in the switchable magnet is estimated.

Detailed Description:  Magnetic components are essential components in a wide variety of electromagnetic sensors in LWD/MWD and wireline tools.  Accurate modeling of behavior of these magnetic materials is important to predict the design performance of the sensor.  For the project, the transmitter is a switchable magnet.  Changes in the magnetic moment and external magnetic field produced by the magnets excite eddy currents in surrounding conductive medium.  These currents in turn generate a secondary magnetic field to be measured by a receiving sensor.  Based on its application, the magnetic material for the transmitter needs to be a ferromagnetic material with high residual as well as high saturation magnetization.  Therefore, the magnetic behavior is desirable to be close to rectangular shape.  In this document, an algorithm to estimate the level of magnetization for such a switchable magnet is proposed as following: 1.  In order to predict and analyze the performance of the sensor, it is required to accurately represent t...