超高压PDC钻头超高压喷嘴布置实验研究

Experimental study of ultra-high pressure nozzle collocation of ultra-high pressure PDC bit

通过实验研究与理论分析相结合,提出了超高压喷嘴布置方案。实验结果表明,在射流压力低于150MPa时,随着射流压力升高,单位功率下的岩石冲蚀体积迅速增大,但当射流压力达到150MPa并进一步升高时,单位功率下的岩石冲蚀体积略有下降,150MPa时破岩效率最高;超高压喷嘴按前进的方式移动,破岩效果最佳;喷嘴移动速度小于2.9mm/s时对岩石的冲蚀效果影响不大,超过此值后,冲蚀效果明显降低。从实验结果可以看出,喷嘴在钻头上的布置直接影响破岩效果。

The ultra-high pressure nozzle collocation scheme is put forward through the experimental study and theoretical analysis. The experimental results show that the jet pressure rises and the rock erosion volume at unit horsepower increases rapidly when the jet pressure is lower than 150 MPa; but when the jet pressure reaches 150 MPa, it continues to rise and the rock erosion volume at unit horsepower decreases slightly. The rock-breaking efficiency is the highest at 150 MPa. If the ultra-high pressure nozzle moves forwardly, the rock-breaking effect is the best. The influence of nozzle moving speed on the rock erosion effect is slight when the speed is less than 2.9 mm/s; but when it exceeds the value, the erosion effect decreases significantly. It can be seen from the experimental results that the collocation of nozzle on the drill bit directly affects the rock-breaking effect.