Monitoring System Design Of Dynamic Fluid Level For Oil Well Based On Spread Spectrum Technology

Focusing on the low signal to noise ratio(SNR) and the defect that echo signal is not easy to be identified in dynamic liquid level measurement, spread spectrum technology in the field of dynamic liquid level measurement was researched, and a design method based on spread spectrum technology was provided to realize the dynamic liquid level monitoring system.In this paper, the overseas and domestic research status and development for liquid level measurement field and spread spectrum ranging was summarized systematically, and the relative principles were outlined for dynamic liquid level measurement, spread spectrum ranging and acoustic propagation. The main content of research work was introduced.First of all, for the shortcoming that dynamic level measurement signal is not easy to be recognized under the background of strong noise, spread spectrum ranging technology was applied to the field of dynamic liquid level measurement according to the actual situation. Combining with the basic principle of dynamic liquid level measurement, the overall scheme of system was designed. A development plan was determined that NI sb-RIO 9636 development module was selected as hardware core and LabVIEW as software development tool.Secondly, for signal processing of applying spread spectrum technology in the field of dynamic liquid level measurement, the acoustic transmission performance was studied. The acoustic emission frequency was determined. M-sequence and direct sequence spread spectrum method was to realize the design of the system. Matlab was adopted to realize simulation, which included the transmitter signal, the signal in transmission channels and the receiver signal. The performance of anti white noise and narrowband noise could be validated by adding noise to the system.Thirdly, for the system function realization, according to the design plan and signal processing simulation, the three parts of the whole monitoring system, including the subordinate computer system, the data transmission system and the upper computer system were developed and designed in detail. Among them, the subordinate computer system mainly developed six modules, including the sound source module, the echo signal acquisition module, the data processing module, the battery voltage sampling module and the charge control module. In order to realize the communication between the upper and subordinate computer, the data transmission system mainly developed the data transmission module and the data reception module. The upper computer system mainly developed three function modules, including the data storage module, the historical inquiry module and the oil well management module.Fourthly, aiming at the feasibility and reliability of the system, we carried out the test of the dynamic liquid level monitoring system in the laboratory environment.The dynamic liquid level monitoring system was designed based on spread spectrum technology. The purpose is to apply the spread spectrum technology to the field of dynamic liquid level measurement, and solves the dynamic liquid level measurement problem under the condition of strong noise. The test results show that the system can effectively carry out the measurement, and it conforms to the actual demand.