Vibration Wave Communication-Realise Remote Control for Zonal Production

摘要

Downhole data transmission is a key technology for oil industry. Traditional methods to realize selective zone production were mainly based on cable or pressure pulse technology and the application scale is limited because of their deficiencies. Downhole vibration wave communication realizes digital signal transmission through tubing or casing, vibration wave is used as carrier wave which is modulated by digital signal before transmission, characterized by low cost, simple operation, it will be used widely in the future. In this paper, the transmission characteristics of tubing and the attenuation rule of tubing are studied by a series of experiment & analysis. According to the findings above, a new digital signal transmission strategy was proposed, that is, three or more carrier waves will be used in series during the vibration wave signal transmission in order to avoid the notch wave band of tubing, at the same time, Manchester coding of digital signals and OOK modulation method of vibration wave were developed. A new vibration signal generator was developed based on magnetostrictive material, a new actuator controlled by vibration sensor was developed based on three degree of freedom sensor together with the tubing or casing, which form a new generation of downhole communication system. A new selective zone production system remotely controlled by vibration wave has been developed based on the above system and is under testing now.