震击型中空螺杆取心钻具钻进效率分析

Analysis of drilling efficiency of shock hollow screw coring tool

摘要:

针对深海硬岩取心钻进过程中钻进效率低、取心率低、扰动大、事故率高等问题，本文以深海硬岩为研究对象，通过有限元数值分析软件，探究深海硬岩在回转、冲击复合工况下的破碎机理。研究结果表明：旋转冲击的破岩方式可有效的提高深海硬岩钻进效率；钻进取心过程中可优选15~25 kN钻压，凸台高度可优选4~6 mm，此时钻进速度较快、获取岩心质量较高、能量利用率高；在震击部件强度允许的条件下，冲击频率越接近最优频率，钻进效率越高。

关键词:深海硬岩取心;震击型螺杆;钻进效率;冲击力;冲击频率

Abstract:

This paper aims at the problems of low drilling efficiency， low core recovery， large disturbance and high accident rate during the coring process of deep-sea hard rock， discusses the fracture mechanism of deep-sea hard rock under the combined conditions of rotary and impact taking the deep-sea hard rock as the research object and using the finite element numerical analysis software. The results show that the rotary rock breaking method can effectively improve the drilling efficiency. In the drilling process，15~25kN WOB and 4~6 mm boss height can be optimized. Under this condition， the ROP is faster， the core quality is higher， and the energy utilization rate is also higher. The closer the working frequency is to the optimal frequency ，the more efficient the drilling will be as long as the strength of the jarring component allows.

Key words:deep-sea hard rock coring;shock-type screw;drilling efficiency;impact force;impact frequency