The theoretical model and sinusoidal optimization strategy for oscillating shear valve type continuous waves generator.

Continuous-wave mud generator is widely adopted for real-time downhole data transmission of deep wells in the oil industry. There have been many studies on rotor structure optimization of continuous rotary valve tools but few studies on the different optimization mechanisms of oscillating shear valve tools. In this paper, a theoretical model of pressure wave generation for oscillating shear valve tools was presented, and the reason for the non-sinusoidal waveform was analyzed theoretically for the first time. A series of rotor rotation strategies were proposed to improve the sinusoidal properties of pressure waves without changing the mechanical structure of the rotor. Finally, CFD with different parameters was conducted to verify the feasibility of the optimization scheme. The numerical results give the recommended range of parameters under different control schemes. In addition, the relationship between throttle pressure drop and pressure wave waveform is found through comparison with previous research of the team, which provides a new research idea for the optimization of the pressure wave in the future.