Research On The Bottom Hole Flow Field Of Jet PDC Bit

Flow field is the space to discovery hydraulic problem of bits directly. We can find the hydraulic problem of bits, improve nozzle combination and design junk slot by means of analyzing flowing phenomenon of flow field. A three-dimension model PDC bit was constructed in ANSYS software in order to obtain the physical model of the PDC bit's flow field on bottom hole. Triaxial geometric model of PDC bit was created by ANSYS and meshed by GAMBIT, analyzed by FLUENT by setting boundary condition of velocity inlet and outflow. Finally, we get the flow field figure while the velocity is 232m/s. The district where fluid speed is slow and there is reverse flow is small between borehole wall and the nozzle which is far from the center of bit. The district where fluid speed is slow and there is reverse flow is small between axes of bit and the nozzle which is close to the center of bit. If the nozzle velocity is different, the effect to clear and carry over cuttings will be more obvious. The speed of the nozzle which is close to the center of bit should be highest. The two nozzles adjacent to this nozzle should have higher speed. The studies have great engineering signification in guidance of configuration optimization of PDC bit.