Real-time Monitoring Of Oil Well Parameters And Development Of Sensors

Accuracy and real-time acquisition of down-hole reservoir parameters are very important to the development of oil production technology.At present,mud pulse,electromagnetic wave,optical fiber and other down-hole parameter transmission methods can not meet the needs of production because of the transmission rate,feasibility,real-time,bit error rate and other problems.With the technology of wireless acoustic communication using the pipe string as the channel and using the acoustic wave as the carrier of the down-hole parameter information,the real-time,accuracy and communication rate of this method can meet the requirements of making the oil production process.Therefore,wireless acoustic communication technology based on tubing channel has become a research hot-spot in the field of down-hole parameter transmission in recent years.Based on the experience and lessons of predecessors,this paper makes a thorough study on the wireless acoustic communication technology of oil well,establishes the mathematical model of acoustic transmission of oil string,and studies the characteristic frequency of oil string,and obtains the general rule of characteristic frequency.On the basis of this theory,a real-time monitoring device for oil extraction parameters based on wireless acoustic communication technology is designed.The hardware circuit design and realization of the device are completed in this paper.Realized the temperature detection,acoustic signal transceiver,codec,computer communication and other functions.The communication protocol is designed for the device,and the communication function is successfully realized.In this paper,the starting point detection of acoustic signal is studied,and two solutions based on flip-flop and narrow time real-time spectrum analysis are given.Besides,this paper presents an effective recognition method—acoustic dynamic model matching method for noise interference and waveform distortion in wireless acoustic communication in oil wells.This method is based on the acoustic model of the tubing column and the principle of signal correlation.The correlation coefficient features of the acoustic signal to be recognized are extracted by correlation processing with the dynamic model,and the meaning of each acoustic signal is identified according to the correlation coefficient.The accuracy of recognition is improved.In order to study the influence of the medium on the acoustic wave transmission and the relationship between the length of the buried sand and the attenuation degree of the acoustic wave,the experiments of water filling and sand burying in the tubing column are designed and carried out.