超声波高频旋冲钻井技术破岩效果试验研究

为了研究超声波高频旋冲钻井技术相较于常规旋转钻井技术的提速效果，以及钻进条件和参数对超声波高频旋冲破岩效率的影响规律，设计了超声波振动发生短节，搭建了超声波破岩模拟试验台，采用控制变量法和正交试验法，开展了超声波破岩提速试验及影响超声波破岩效率的试验，得到了钻压、超声波振幅、转速和钻头直径对超声波高频旋冲破岩效率的影响规律。结果表明:在实验室常规温度和压力条件下，与常规旋转破岩技术相比，超声波高频旋冲钻井技术的破岩效率更高，平均提高幅度达77.65%；影响超声波高频旋冲破岩效率的因素从大到小依次是钻压、振幅、钻头直径和转速；钻压和振幅对超声波高频旋冲破岩效率的影响显著，且振幅越大，超声波高频旋冲破岩的效率越高。研究结果表明，超声波高频旋冲钻井技术可为提高深部硬地层机械钻速提供一种新的破岩方法。 

An Experimental Study on Rock Breaking Efficiency with Ultrasonic High-Frequency Rotary-Percussive Drilling Technology

In order to investigate the penetration rate improvement by implementing ultrasonic high-frequency rotary-percussive (UHFRP) drilling compared to conventional rotary drilling, as well as determining the influence of different drilling conditions and parameters on UHFRP rock breaking, we designed an ultrasonic vibration pup joint and built a test bench for ultrasonic rock breaking simulation. By using control variable method and orthogonal experiment method, we carried out a penetration rate enhancement test of ultrasonic rock breaking and the corresponding influencing-factor analysis tests. Thereby we obtained the influence law of weight on bit, ultrasonic amplitude, penetration rate, and bit diameter on the UHFRP rock breaking. The test results show that compared with conventional rotary rock breaking, the UHFRP drilling has higher efficiency of rock breaking at normal temperatures and pressures in the laboratory, with an average penetration rate increase of 77.65%. In addition, weight on bit, ultrasonic amplitude, bit diameter and penetration rate have a declining impact on the rock breaking efficiency of UHFRP drilling. Furthermore, weight on bit and ultrasonic amplitude have a highly significant effect on the efficiency of UHFRP rock breaking, and a larger amplitude results in a higher efficiency of rock breaking. The results show that the UHFRP drilling technology could provide a new rock breaking method in penetration rate enhancement of deep hard formations.