Research And Implementation Of Sandwich Land Piezoelectric Geophone Based On Piezoelectric Ceramic Process

With the exploitation of LPG resources on land,especially shallow oil,oil resources have been declining,and people have to turn their attention to deep geology,sea or shallow sea transition zones.However,due to the filtering effect of the near surface loose layer,the high-frequency signals from the deeper strata reach the surface with very weak energy and are not easily received by existing detectors.It is impossible to improve the performance of the high frequency signal simply by combining multiple detectors in parallel.At the same time,as a hydrophone used in offshore transition belts,because it uses piezoelectric materials for the reception of hydroacoustic signals,it has different working principles from the traditionally used circular speed detectors,and subsequent data processing results will also be different.The high frequency signal acquisition can be improved by designing the sensor structure of piezoelectric materials and the new charge amplifier circuit,this paper mainly does the following aspects of research.Firstly,after introducing the development status of the geophone,the influence of the traditional products on the exploration of high-frequency signals,and the problem of the mixed acquisition of the speed detector and hydrophone in the shallows transition zone,this paper proposes the topic of sandwich land piezoelectric geophone.Secondly,a kind of charge amplifier is designed,and the structure of the sandwich type piezoelectric detector and kernel is designed.By comparing the parameters of the chip,the main chip of the charge conversion amplifier and the fine-tuning amplifier are determined.At the same time,the decoupling capacitance and anti-drift capacitance are designed.Through the series combination of new piezoelectric ceramics and the structure design of the geophone kernel,the higher charge output and voltage output of the system are realized.Finally,the parameters of piezoelectric ceramic combination are tested and analyzed by means of instrument or software respectively,and the parameter stability of piezoelectric ceramic combination is verified.The software is also used to simulate the input and output relationship of the charge amplifier and verify the amplification relationship of the amplifier circuit at all levels.This paper compares the characteristic curves of the speed geophone and the sandwich land piezoelectric geophone by curve chart,and shows the ability of the geophone to improve the high frequency signal in the high frequency segment.The scanning frequency of the speed geophone and the sandwich land piezoelectric geophone is verified by using the vibration table scanning curve.By taking the output value of the sweep curve,the sensitivity of the latter at some frequencies is higher than that of the former.At the same time,it also verified that the frequency of the sandwich land piezoelectric geophone is about 6 dB.