HU Jinshuai， ZHANG Guangwei， CHEN Yu， LI Junling， YAN Fengping

（College of Mechanical Engineering， Xi’an Shiyou University， Xi’an 710065， China）

Abstract: In order to investigate the kinematic characteristics of the rock chip particles in the bottom of the well during the guided drilling process of rotary-guided drilling tools, a complex two-phase flow model describing the drilling fluid and rock chip particles in the bottom of the well was developed by using a coupled algorithm of computational fluid dynamics and discrete element method，and the kinematic characteristics of rock chip particles in the bottom of the well of rotary-guided drilling tools were analyzed by using software of FLUENT and EDEM. The effects of offset angle of rotary-guided drill bit, drilling fluid flow rate, drill bit speed and particle size on the kinematic characteristics of rock chip particles in the wellbore were investigated. The results show that increasing the rotational speed and drilling fluid flow rate increase the transport speed of rock chip particles, which has a positive feedback effect on the transport of rock chip particles and improve the cleanliness of the well bottom. Increasing the particle size of rock chip particles reduces the transport speed of rock chip particles, and when the diameter of rock chip particles is larger than 3 mm, the reduction of rock chip transport speed is more obvious.The offset of the drill bit of the rotary-guided drilling tool causes the change of the spatial structure of the well bottom and the change of rock chip particles. The change of spatial structure, the collision between rock chip particles lead to kinetic energy loss, and the hydraulic energy is also weakened by the change of spatial structure, which makes the rock chip particle transportation efficiency decrease, and eventually will aggravate the bit wear and produce the mud packing.

Keywords: computational fluid dynamics； discrete element method； coupling algorithm; bottom hole flow field; rotary-guided drilling tool; cutting particles

中图分类号： TE928                          文献标志码：A

收稿日期： 2022-04-09， 修回日期：2022-05-10，在线出版时间：2022-11-01。

基金项目：国家自然科学基金项目，编号：51174164；陕西省自然科学基金项目，编号：2018JM5015。

第一作者简介：胡金帅（1996—），男，硕士研究生，研究方向为旋转导向钻井工具及井下岩屑运移。E-mail: 1014030562@qq.com。

通信作者简介：张光伟（1961—），男，教授，硕士，硕士生导师，研究方向为井下旋转导向钻井工具。E-mail： zhangguangwei@163.com。

文章编号：1008-5548（2022）06-0037-12

DOI:10.13732/j.issn.1008-5548.2022.06.005