Analysis on Modulation Principle of Mechanical Spring Valve Block-Type Pulse Jet

To take full advantage of the bottom-hole hydraulic energy to improve the drilling rate, it is proposed the technique assumption that using mechanical spring valve periodically is to block the fluid pathway, and modulating pulse jet is to increase the drilling rat. The internal flow field of mechanical spring valve block-type(MSVBT) device is anslyzed with the numerical simulation method, and confirmed the feasibility of modulating the hydraulic pulse. Based on simulation results, the principle prototype of MSVBT pulse jet was developed. The results of jet rock breaking were shown that as the pump pressure increased, the pressure fluctuation was increasing, and effects of the jet rock breaking was gradually improved, significantly better than continuous jet, which was proved the modulation principle feasibility of MSVBT pulse jet. The reaults are provided the basis for the drilling tool and related technologies development.