Seismic signal acquisition transmission apparatus used for Earth physical exploration

Abstract

The invention belongs to the geophysical exploration field. In order to provide an acquisition transmission node capable of transmitting high capacity earthquake data reliably at high speed, the invention employs a technical scheme and provides a seismic signal acquisition transmission apparatus used for Earth physical exploration. Data format transmitted on a twisted pair of the apparatus which is a node is that synchronization information is periodically inserted into command information. The apparatus also comprises an acquisition clock extraction module, a command decoding module, an analog-to-digital converter and a gain and self-check controller. A bit synchronization clock extractor, a transponder, the acquisition clock extraction module, a node main controller, the gain and self-check controller, a data reception and transponder and a data device are realized on an FPGA chip. In a phase-locked loop circuit, a phase frequency detector PFD, a proportion integration filter, a crystal voltage controlled oscillator VCTCXO are in series connection in order. The invention mainly is applied to Earth exploration.

Description

technical field [0001] The invention belongs to the field of geophysical exploration, in particular to a seismic signal acquisition and transmission device for geophysical exploration. Background technique [0002] The seismic data acquisition and recording systems used in my country's offshore oil and gas field exploration are all imported from abroad, such as: the MSX system of the US I / O company, the SYNTRAK960 system of the French SERCEL company and other instruments and equipment. The VME bus structure of the advanced industrial computer has a large volume, relatively backward technology, small amount of collected data, and slow transmission speed. [0003] The number of acquisition channels supported by the acquisition nodes of some existing seismic acquisition systems is small. For example, in the 408UL system developed by the French SERCEL company, one acquisition node can only acquire data of one channel, which leads to a system with the same number of channels. Man...

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Problems solved by technology

[0002] The seismic data acquisition and recording systems used in my country's offshore oil and gas field exploration are all imported from abroad, such as: the MSX system of the US I / O company, the SYNTRAK960 system of the French SERCEL company and other instruments and equipment. The industrial computer VME bus structure is relatively large, the technology is relatively backward, the amount of collected data is small, and the transmission speed is slow

[0003] The number of acquisition channels supported by the acquisition nodes of some existing seismic acquisition systems is small. For example, in the 408UL system developed by the French SERCEL company, one acquisition node can only acquire data of one channel, which leads to a system with the same number of channels. Many acquisition nodes reduce the reliability of the system, and the cost of the system is very high

In the acquisition board designed by the University of Science and Technology of China, the downlink command line, power line and synchronous acquisition clock line are transmitted separately, so that there will be many transmission lines in the system and the system volume is large; in addition, they use optical fiber as the transmission medium to realize Although the transmission of data can bring the advantage of increasing the transmission capacity, it also brings two disadvantages: on the one hand, the optical fiber is easy to break, which makes the system failure rate high and the system reliability is reduced; on the other hand, the photoelectric transceiver module Large volume, large heat dissipation and high cost are not conducive to the miniaturization of detection cables (see literature [1] Wang Chao, Song Kezhu, Tang Jin. Design and implementation of high-performance underwater seismic data acquisition system [J]. Journal of Jilin University ( Engineering Edition). 2007, 37(1): 168-172)

The disadvantage is that the acquisition and transmission nodes are separated, which increases the volume of the system; and each acquisition node can only acquire seismic signals of 4 channels, the integration of acquisition channels is not high, and the system is bulky

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