Optimization of hydraulic parameters and structure parameters of rotary jetting tools

The jet tool with rotary nozzles can generate a high-speed jet flow, and under the action of the recoil force from the jet flow, the nozzles will be driven to rotate to form a complex rotating jet flow, which can achieve efficient cleaning of oil pipes and casings. Taking the Ø73 mm oil tubing under the condition of 7 000 m well depth as an example, a Ø54 mm series jet tool with rotary nozzles matched with Ø44.5 mm coiled tubing was designed. Then, the hydraulic parameters of the jet tool with rotary nozzles were optimized, and the structural parameters of the tool were also optimized by using computational fluid dynamics method. The research shows that: when the displacement is 270 L/min, the jet flow velocity of the jet tool with rotary nozzles is about 170 m/s and the total pressure consumption of the system is about 42 MPa, which can meet the cleaning requirements; as the offset radius of the lateral nozzles increases, the back impact moment generated by the lateral nozzles increases approximately linearly, and the impact pressure on the wall decreases first and then increases; with the increase of the inclination angle, the impact pressure of the inclined nozzles on the inner wall of the oil tubing increases; when the rotation speed is within the range of 60-360 r/min, the impact pressure of the inclined nozzles on the wall surface does not change much; the optimal combination of structural parameters is the lateral nozzle offset radius of 12 mm, the inclined nozzle inclination angle of 75°, and the forward inclined nozzle angle of 15°. This research can provide a guidance for on-site construction and parameter optimization of the jet tools with rotary nozzles.