中文摘要：

井下液压脉冲发生器是一种可调制脉冲射流的井下提速工具,该装置的工作原理是利用井底钻柱振动能量,采用活塞激励的方式调制脉冲射流,基于该装置工作原理,利用Matlab环境下的Simulink系统建立装置工作状态下的仿真模型,对装置的工作特性进行仿真分析。结果表明：装置调制脉冲射流的压力变化值与装置内柱塞运动规律密切相关,装置产生的脉冲压力幅值随钻头压降的增大而增大,但增长幅度逐渐变缓,随钻井液流量的增加呈线性减小趋势,随钻压的增大而增大,随转速的升高而增大,合理选取钻进参数有助于装置工作性能的进一步提升。

英文摘要：

The downhole hydraulically pulsed jet generator is a downhole tool that can transform the vibration of drill string into modulated pulse jet to improve the rate of penetration（ ROP） in oil and gas well drilling. A simulation model of the device was established using the Simulink system of the Matlab software. The simulation results show that the pressure of the pulsed jet generated by the device is closely related to the motion of the piston in the jet generator. The amplitude of the jet pressure increases with the pressure drop over the drilling bit increasing,but decreases linearly with flow rate of the drilling fluid increasing. The jet pressure also increases with the increase of the weight on bit and the rotating speed of drilling string.Therefore,the efficiency of the pulsed jet generator can be improved by adjusting the parameters of drilling operation.