Analysis And Research On High Speed Signal Carrier Frequency Modulation In Drilling Fluid Pressure Continuous Wave

Currently,measurement while drilling(MWD)technology is widely used in drilling complex wells.Wherein,transferring downhole signal with drilling mud pressure wave is one of the economical and reliable way.Moreover,internationally the mud pulse signal generator was generally used.However,as more and more parameters is required to be transmitted,the mud pulse generator is no longer able to meet the requirements of data transmission while drilling process.The sinusoidal pressure pulse generator is the most advanced technology for measurement while drilling.Based on previous studies on Sinusoidal pressure pulse generator,this paper has analyzed the validity and reliability of different modulation signal,according to the principle of communication & technology,and selected the suitable modulating system after comparison.By analyzing the equation of mechanical properties and the principle of the motor speed regulation,a method to generate PSK and FSK signal under the control of motor was obtained.Through the short wind tunnel experiments,the influence of different orifice parameters on the hydraulic torque is obtained.The signal was collected and stored by LabVIEW,and verified the coincidence between the pressure wave and sinusoidal wave.The effects of the flow rate of drilling fluid and the gap between stator and rotor on the shape of the pressure wave were studied.On the foundations of theoretical research,the experiment of studying the shape of PSK and FSK signal under the control of motor was designed,the theoretical foundation is provided in order to speed up the downhole signal transmission rate.