基于旋冲螺杆提速器的井下动力特性

随着钻井深度的不断增加,在地层围压作用下岩石的硬度和强度均会明显增加,导致钻头破岩效率不高、寿命降低、钻井速度大幅下降等问题。基于旋冲螺杆原理设计了一种提速器,通过对提速器工作过程的力学分析,并结合钻具设计参数、工况参数以及相关力学计算方法,建立该提速器井下动力学模型,得到不同节点处的振动位移、振动速度以及系统的振动频谱图。通过实验研究,对比分析了冲击频率、冲击力测试结果与相关理论计算结果,验证相关理论计算与模型的正确性;并进行工具下井实验,根据现场实验数据及使用效果分析,验证了该提速器能够有效提高机械钻速。

Downhole dynamic characteristics of an actuator based on rotary screw

With the increase of drilling depth, the hardness and strength of rocks are obviously increased under confining pressure of the formation, thus leading to a series of problems such as low rock-breaking efficiency, low life of bit and a drastic decrease of drilling speed. To solve these problems, a new-type actuator based on rotary screw is proposed in this study. Based on analyzing the mechanical relationship in the working process of new-type actuator as well as the design parameters of drilling tool, the working condition parameters and the related mechanics calculation method, the downhole dynamics analysis model of actuator is established to obtain the vibration displacement, vibration velocity at different nodes and the system vibration spectrum. According to the laboratory study of this tool, a comparative analysis has been conducted on the research results, including the test and theoretical calculation results of vibration frequency and impact, so as to verify the relevant theoretical calculation results and models. Furthermore, this study also carries out field tests of the tool; Using the field data and results, it is confirmed that this tool can improve the drilling efficiency effectively.