Research On Wireless Seismic Data Transmission Technology Based On Load Balancing

Real-time seismic data transmission is a major technology for micro-seismic fracturing monitoring.Recently,the technology has also received constant attention from the researchers in seismic exploration with the country's attention to deep-seated exploration.The seismic data transmission technology transmits the seismic waves collected by the seismograph nodes to the mobile control center in real time through the wireless network for on-site processing,and uses the processing results to track and locate the development direction and size of the cracks in the fracturing process in real time so as to objectively evaluate the effects of fracturing engineering,providing guidance for on-site production.Although the technology has achieved leaps and bounds in recent years,the existing technology still has the shortcomings of narrow wireless bandwidth,short transmission distance,large delay,etc.But these deficiencies resulting in poor real-time performance of seismic data transmission technology are the important reasons.Therefore,continued in-depth research on the problem of poor real-time performance of the technology is still the focus of research in the field of future seismic exploration.This dissertation aims at the above problems and proposed wireless seismic data transmission technology based on load balancing.The main contents of this paper are as follows:Firstly,the paper designed wireless communication modules and real-time protocols for data transmission.The network units and real-time protocols for the data transmission of the seismograph nodes were designed based on the overall design of the seismograph node.The network units included an Ethernet network module and a wireless communication module.The experimental tests showed that the uplink throughput of the wireless communication module is stable at about 44.3 Mbps,and the actual communication distance is 800 m when the transmission power is 26 dBm,which satisfied the maximum demand of the seismograph node at a sampling rate of 4 kHz.The real-time protocols included real-time status monitoring protocol and real-time data transmission protocol.The real-time status monitoring protocol is used to assist real-time data transmission protocol for unified management of seismograph nodes.The real-time data transmission protocol uses the RTMP protocol to transmit data streams.Secondly,the paper established a wireless relay network structure suitable for seismic data transmission.This paper first established the channel model of multi-relay direct transmission network,and used this model to deeply analyze the outage probability of wireless relay network,and deduced the general outage formula of its link when the spectrum efficiency is R bit/s/Hz.Eventually,the outage formula in combination with the actual demand rate of seismic data transmission performed a numerical simulation on the link outage probability formula,and determining a wireless relay direct transmission network suitable for seismic data transmission is constructed with the number of relays as two.Thirdly,the paper researched the load balancing policy of the relay node and the channel equalization strategy when the multiple seismograph nodes access their MAC layer simultaneously.The paper proposed to solve the load balancing problem of the relay node by adjusting the power of the relay node,and implementing the load balancing of the relay node is to reduce the congestion of the branch network,thereby improving the overall performance of the seismic data transmission system.For the problem of fierce competition when multiple seismograph nodes access the MAC layer of the relay node at the same time,this paper adopted Asynchronous Time Division Multiplexing Technology to virtual segment the MAC layer channel of the relay node.The main purpose of this strategy is to make each seismograph Nodes can simultaneously transmit real-time seismic data to improve the real-time performance of each data stream.This paper has performed an actual fracturing test on a well in Langfang City,Hebei Province based on the above research.The test results showed that the subject achieved data transmission of a total of 96 seismograph nodes within a 1.5km fracturing range.The average transmission rate of the seismograph nodes was 1.6Mbps,and the throughput of the entire seismic data transmission system was 7.53MB/s,which has reached the expected targets and meet the data transmission needs of the microseismic fracturing monitoring.