MEMS geophone

Abstract

The invention discloses an MEMS geophone which comprises a protection shell provided with an upper cover, an MEMS machine core arranged in the protection shell, and a tail cone arranged outside the protection shell. The MEMS machine core comprises a machine core shell fixed into the protection shell, a supporting frame arranged in the machine core shell, and a plurality of MEMD accelerometers arranged on the supporting frame. The supporting frame is cuboid. The MEMS accelerometers are capacitive accelerometers and include the X accelerometer, the Y accelerometer and the Z accelerometer, wherein the three accelerometers are vertically arranged on three adjacent side faces of the supporting frame respectively, and the side face where the Z accelerometer is located is the top face, facing towards the upper cover, of the supporting frame. The tail cone is arranged on a screw which penetrates through a base plate of the protection shell and abuts against the machine core shell. A coil with the fixed frequency is not used in the MEMS geophone, the recordable dynamic range is large, the response bandwidth is wide, the resolution ratio is high, and detection of all broadband elastic waves generated by an artificial seismic source is facilitated.

Description

technical field [0001] The invention relates to the technical field of seismic exploration equipment, and more specifically relates to a MEMS geophone. Background technique [0002] Seismic exploration is a geophysical exploration method that uses instruments to detect and record the propagation time, amplitude, and waveform of reflected waves and refracted waves caused by artificial earthquakes, so as to analyze and judge the stratum interface, stratum properties, and geological structures. and the main means of resources such as oil and gas in the ocean. [0003] At present, the commonly used seismic exploration equipment in the field of oil and gas exploration is a moving coil velocity detector, which fixes the moving coil on the spring coaxial with the magnet, and the spring and the coil move relative to the magnet through external vibration. The coil generates an induced electromotive force. However, in the above-mentioned movable coil velocity detector, due to the na...

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Problems solved by technology

However, in the above-mentioned movable coil velocity detector, due to the natural frequency of the spring, the maximum dynamic range that can be recorded by the entire movable coil velocity detector is about 60dB, the distortion of the received signal is large, the response frequency band is narrow, and the resolution is poor, which is not enough Detection of all broadband elastic waves generated by artificial sources

[0004] In addition, the above-mentioned movable coil velocity detector also has the defect of low sensitivity, which makes it difficult to collect weak signals in deep layers, which seriously affects the effectiveness of seismic exploration

Furthermore, in the above-mentioned movable coil speed detector, the coil is also affected by noise to generate vibration, and the anti-interference ability is weak. During the survey, several to dozens of detector combinations are needed to reduce the impact of noise interference on the test results, resulting in survey costs. high

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