The Development Of Three Component Digital Geophone Based On Time-division Sampling Technology

The main part of energy consumption in the world are oil and gas, their level ofreserves and exploration Closely related with the level of a country’s economicdevelopment. Nowadays, One of the most common and effective way of oil and gasexploration is seismic exploration, the performance of detector used in seismicexploration directly determines the quality of seismic exploration instruments, theconventional seismic prospecting method and equipment has been relatively mature,and also has achieved fruitful results. But in the geological structure where is extremelycomplex mountain region, under the effect of different factors, makes the dataacquisition of seismic becomes very difficult, and the data quality is not good enoughfor interpretation. Therefore, complex mountainous seismic exploration proposed newrequirements to seismic exploration instruments and methods.To meet the need of seismic exploration in complex mountain region, this paperrelies on the "the development of multi-wave and broadband seismic data acquisitionsystem under complicated mountainous condition which belongs to important scientificinstruments equipment developed special for NSFC, and the "nuclear geophysicalprospectingtechnologyinstrument development and application research" belongingtothe National Science Fund for Distinguished Young Scholar. This paper start from thedevelopment of three-component seismic geophone, based on the time-divisionsampling technology, carry out the research of MEMS inertial sensor in the applicationof seismic geophone Orientation detection, the study of the digital hardware filter anddetector low ripple power supply design and some other aspects, the main keytechnologies and methods involved in the paper and the achievements so far are asfollows:(1) Time-sampling technology used in the application of three-channel seismicdata acquisition. With using the technology of sampling frequency conversion, simpleinterpolation and extraction to the sampled data, and then through the correspondingdigital filter, the sampling sequence can make the appropriate changes in the frequency.This method replaces the traditional three-channel parallel data acquisition circuit,reduced the number of discrete device in the system, improved the stability of the system to some extent, and reduced the cost and power consumption of the system aswell.(2) Research of three-component geophone attitude orientation based on MEMSinertial sensor combination. Internal integration low-cost inertial sensor group includetri-axial MEMS gyroscope, tri-axial MEMS electronic compass and tri-axial MEMSaccelerometer, with simple data fusion algorithm to get the attitude of the detectorinformation. After information the detector attitude was read by MCU, we can providea reference for the installation of the detector, and provide more data for later dataprocessing either, contrast with the method of traditional energy approximateestimation, this one is more easier and reduce the difficulty of the later data processing.(3) Development of data acquisition circuit based on hardware digital filterCS5378. Compared with the traditional scheme, the scheme of seismic data acquisitionwhichprovidebyCirrus Logic Inc,not onlyshortentheR&D andtestingcycle,but alsohave excellent quality, such as dynamic range of the detector, noise level control, powerconsumption, etc which are the traditional scheme can never catch up with. Although,the scheme of Cirrus Logic Inc cost more, but with time-sampling technology, we cannot only improve the performance of detector, at the same time, we can control the costof the detector at the same time.In general, this paper use the scheme combined time-sampling technology withCirrus Logic set piece design a three-component geophone, not only improve theperformance of the detector, and makes the cost at the same level with the traditionalschemes. At the same time, consider with the successful application of MEMS inertialsensors in the field of attitude detection, put it inside the detector, make it become amodule to get the attitude information of the detector. And cooperate with RS485interface and Ethernet transmission interface, makes the detector can adopt differentways according to the circumstance and the data collection station communication anddata exchange, improve the network capacity of detector and its adaptability incomplex environment. In this paper, the research improved the hardware equipment incomplex mountainous seismic exploration environment adaptability from the threecomponent geophone level, and bring forward a new way to the design of threecomponent digital geophone, provides a certain reference for design of threecomponent digital detector in the future.