Abstract:In the later stages of the development of extended-reach long horizontal wells, there is a problem of large friction, which severely restricts the rapid drilling of the drill tool to a farther target, and has attracted widespread attention worldwide. Hydraulic oscillator is an important tool for friction reduction in the later stage of oil well development. To solve this problem, a turbine-type hydraulic oscillator is proposed. The hydraulic oscillator converts the kinetic energy of the drilling fluid into periodic pulse pressure through the phase change between the static valve and the flow passage of the rotary valve, which effectively solves the problems of back pressure and self-locking during the drilling process. Optimized the design of the circular runner mouth, the fan-shaped runner mouth and the square runner mouth respectively, and found that the square runner mouth has the best friction and drag reduction effect. Using theoretical calculations and FLUENT fluid simulation analysis to study the motion law of static valves and rotary valves, and the influence of the size and length of the flow path on the pressure drop of the valve group, a set of optimal valve group sizes are obtained: the radius of the middle flow path is 14.2 mm, the side length of the square outer runner mouth is 27mm, and the runner length is 30mm. The research results show that the structure can provide a stable pulse pressure of 0.096~2.96MPa.