【摘要】 建立螺杆钻具本体的有限元模型,采用有限元法模拟计算声纵波在螺杆钻具中的传输特性,同时在实际钻具上对模拟结果进行试验验证,并选择4kHz频率的声波在螺杆钻具上进行通信试验。结果表明:螺杆钻具及其上部钻具具有较宽的通信频带,类似于一个低通滤波器,可以利用声波实现近钻头信息的短距离传输,并可能获得较高的数据传输速率;80bits/s的数据传输速率可实现稳定通信;钻具接头处的尺寸和介质变化所引起的衰减和反射不可忽视,须通过增加隔声或消声结构减少干扰。更多还原

【Abstract】 Based on a finite element analysis model of a screw drill tool,the transmission properties of acoustic longitudinal wave in the body of the screw drill tool were analyzed using ANSYS software.Meanwhile an experiment on a real screw drill tool was done to verify the calculated results.A communication test was executed by using 4 kHz acoustic wave.The results show that the screw drill tool and its upper tools have a wide pass band like a low pass filter,which can be used as the channel of near-bit acoustic communication.A high data transmission rate is obtained.The communication is performed steadily in 80 bits/s data rate.The difference in size or medium at joints of drill tools will cause reflection and attenuation.In some cases,the reflections may bring serious interference to communication.So some structures are needed to insulate and eliminate the reflections.更多还原