Downhole Condition Monitoring And Signal Transmission

With the development of the oil industry as well as the growing number of offshore oilfields, the technology of downhole condition monitoring and signal transmission more and more arrests people's attention. The traditional binary parameters (the temperature, the pressure) testing system can no longer meet the users who demanding multi-parameter testing. At present the overseas correlation technique has been already mature, and has many mature products. Due to technical and other reasons, it is slow in this domain's research in our country. Consequently it's meaningful to design and produce the downhole condition monitoring system of independent intellectual property in improving our country's competitiveness in this field.This paper studies the multi-signals'collecting,transmitting and re-processing in allusion to the multi-paramete downhole monitoring system. It also studies the method of time-sharing testing based on the SCM and modulating downhole, demodulating on the ground based on the Power Line Communication(PLC) technology. The signal modulation unit and demodulation unit are designed, which realizes the signal coupling and reverting. A data memory unit based on USB bus with big capacity is designed for data storage. Moreover, the clock unit, the display unit and the alarm unit are designed too.In view of the actual environment of harmonic interference and so on, this paper studies the system's reliability design from the hardware to the software. Many antijamming measures are taken to guarantee the system's normal work under the disturbance environment.The field test indicates that the downhole condition monitoring and signal transmission system based on the method this paper proposed has strong antijamming ability. It can correctly modulate and demodulate the data downhole under the frequency changer continuous and instantaneous disturbance environment. This proves the rationality and feasibility of the method.