Patent ID: 9746575
Date: 2017-08-29
CPC Classifications: G01V

Claim:
1. An induction type broadband 3-component borehole magnetic measuring sensor able to accurately and precisely measure a broadband magnetic field about a broadband frequency and x, y and z axes within a borehole in a borehole electromagnetic tomography system, wherein the borehole electromagnetic tomography system exploring includes a transmitter deployed in one borehole of a pair of parallel boreholes, a receiver deployed in the other borehole of the pair of parallel boreholes to receive a signal from the transmitter, and a surface unit deployed on a surface to receive and analyze signals received from the transmitter and the receiver, and explores an underground environment for geological features or resources buried therein, the measuring sensor comprising: a communications unit performing communications with the surface unit; a power unit supplying power; a control unit controlling overall operations of the measuring sensor; a 3-component fluxgate magnetometer measuring an angle of the measuring sensor to with respect to north within the borehole, as well as a degree of inclination of the measuring sensor within the borehole; a 3-component accelerometer detecting state information about the measuring sensor including a current position, a direction and an incline; a 3-component magnetic sensor comprising an analog/digital converter unit converting an analog sensor signal to a digital signal, wherein the 3-component magnetic sensor detects a 3-component broadband magnetic field about x, y and z axis directions; assuming that the z axis direction is parallel to a lengthwise direction of the casing, the x axis direction is perpendicular to the z axis direction, and the y axis direction is perpendicular to both the x axis direction and the z axis direction, the 3-component magnetic sensor comprises: a z-component sensor detecting a magnetic field in the z axis direction, the z-component sensor comprising a vertical coil module including a rod-shaped or cylindrical core and a plurality of coils wound on the core; an x-component sensor detecting a magnetic field in the x axis direction, the x-component sensor comprising a plurality of rod-shaped or cylindrical horizontal coil modules that are connected in parallel and arranged facing in a diametrical direction of the casing such that the plurality of horizontal coil modules is directed perpendicular to the vertical coil module, a diameter of each of the plurality of horizontal coil modules being smaller than a diameter of the casing; and a y-component sensor detecting a magnetic field in the y axis direction, the y-component sensor comprising a plurality of the rod-shaped or cylindrical horizontal coil modules that are arranged in a direction perpendicular to directions of the coil modules of the x-component sensor and the z-component sensor; a casing housing the communications unit, the power unit, the control unit, the 3-component fluxgate magnetometer, the 3-component accelerometer and the 3-component magnetic sensor; and pressure connectors deployed on both ends of the casing.