Research On The Development Of AD Conversion And Data Storage System In Wireless Acquisition Node Of Seismic Exploration Data

Seismic exploration is one of the most important and effective methods to solve oil and gas exploration problems in geophysical exploration.In view of the shortcomings of traditional cable seismic data acquisition system,the development of wireless seismic data acquisition system is a research hotspot.In this thesis,under the framework of the wireless acquisition system of seismic exploration data designed by the research group,the research on AD conversion and data storage system of the wireless acquisition node of seismic exploration data is carried out.The research and development work of AD conversion,data storage and data transmission through wireless network technology of single-component seismic exploration data wireless acquisition nodes is completed,and the corresponding functions of wireless acquisition nodes of three-component seismic exploration data are completed.The data acquisition end adopts a moving coil geophone,and the analog converter is sampled and converted by the AD converter ADS 1282 with an accuracy of up to 32 bits and the highest sampling rate can be set to 4000Hz to meet the high precision and high resolution seismic exploration data acquisition requirements.Because the power supply battery used by the wireless collection node has limited energy,in order to extend the field work time of the wireless acquisition node,the STM32L1 and STM32L4 series ultra-low power MCUs are selected as the microcontroller.In order to solve the problem of data loss caused by unexpected transmission network failure,power failure,etc.,the developed AD conversion and data storage system has a local storage function.By transplanting the FatFs file system,the AD converted seismic data is written into the large-capacity memory TF card in chronological order.so that the corresponding collected data can be read at any time according to the time of the vibration source.For the time synchronization requirements of the seismic acquisition data wireless acquisition system,the system adopts GPS timing and single-chip timer timing to make the time synchronization accuracy reach microsecond level,and can regularly synchronize the seismic data sampling time,which can basically meet the requirements for time synchronization.In order to achieve the timely transmission of the collected data in the seismic acquisition wireless acquisition system,a wireless network transmission scheme based on WiFi and ZigBee is adopted,and the collected data stored in the AD conversion and data storage system is collected to the collection center wirelessly.The low-speed,low-power ZigBee protocol is used for command transmission between the host computer and the acquisition node,and the system is always in working state after the system is online;However,the high-speed,high-power WiFi is only used to transmit a large amount of seismic data,only works when data needs to be transmitted.The multi-component seismic exploration data acquisition technology has become the mainstream seismic exploration technology.The AD conversion and data storage system of the wireless acquisition node of the three-component seismic exploration data is designed in the thesis,and the X component,Y component and Z component data of the seismic wave can be received at the same time,and relevant processing is performed.