A moving-coil low-frequency extended geophone

Abstract

The invention provides a moving coil type low-frequency expanded geophone, and relates to the technical field of seismic detection. The geophone comprises a casing, a top cover, a bottom cover, magnetic steel and a spring suspension system; the spring suspension system comprises a spring, a coil rack and a coil; the spring suspension system is fixed in an enclosed space between the top cover and the bottom cover, and the coil rack is connected to a differential capacitor detection system radially; the differential capacitor detection system comprises a sensor, a measurement and control circuit, an analog to digital conversion module and a storage module; the sensor is connected with the coil rack and the measurement and control circuit, the measurement and control circuit is connected with the analog to digital conversion module, and the analog to digital conversion module is connected with the storage module; and eight groups of differential capacitors are distributed between the internal diameter and the external diameter uniformly. The moving coil type low-frequency expanded geophone has the advantages that the differential capacitors are added to detect displacement signals, flatter low-frequency response can be obtained on the premise that original frequency response is not influenced, the structure is simple and reasonable, and the geophone can be popularized and applied widely.

Description

technical field [0001] The invention relates to the technical field of seismic detection, in particular to a moving-coil low-frequency extended geophone. Background technique [0002] Geophones are sensors used to detect ground motion. In the field of seismic exploration, as the depth of the exploration target layer increases, high-frequency signals attenuate severely, and low-frequency signals remain intact. The imaging of low-frequency seismic information can greatly improve the accuracy of deep strata description, thereby enhancing the ability of deep resource exploration. [0003] The moving coil geophone is the most widely used geophone at present. The traditional moving coil geophone is a velocity type geophone. Due to the limitations of the inherent mechanical system, this geophone has defects such as low sensitivity and narrow frequency band (>10Hz), and its low frequency response is severely attenuated, which has become a bottleneck restricting the development o...

AI Technical Summary

Problems solved by technology

The traditional moving coil geophone is a velocity type geophone. Due to the limitation of the inherent mechanical system, this geophone has defects such as low sensitivity and narrow frequency band (>10Hz), and its low frequency response is severely attenuated, which has become a bottleneck restricting the development of seismic exploration.

Its low-frequency response can be improved by electronic feedback and other technologies to make its response bandwidth as low as 3Hz, but this method has a certain degree of damage to high-frequency signals

[0004] CN201210422586 discloses a high-sensitivity geophone, which adopts a high-coercive force magnet, and reasonably uses the length proportional relationship between the length of the magnet and the weight adjustment space between the upper and lower wire racks, and uses pole shoes to effectively increase the adjustment between the upper and lower wire racks. The length of the heavy space is to realize the improvement of the sensitivity of the geophone; CN201510002339 discloses a magnetoresistive geophone, the geometric center of the magnetoresistance element is placed in the linear distribution area of ​​the magnetic field generated by the magnet; CN201410216312 discloses a new type Seismic detectors improve detection sensitivity through multiple sets of upper and lower magnetic steels, multiple coil frames connected in parallel, and the upper magnetic circuit assembly of the magnetic steels using paramagnetic assembly and reverse magnetic assembly. question

[0005] At present, there is no existing technology that can effectively compensate the attenuation of the low-frequency response of the geophone without compromising the measurement accuracy of the high-frequency signal.

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