Vibration characteristics study of drill string based on rotary-impact drilling tool in horizontal well

Document Type : Research Paper


1 Southwest Petroleum University, No.8 xindu District, Chengdu, Sichuan, China

2 Southwest Petroleum University, No.8 xindu District, Chengdu, China


To address the problems of large drilling friction and low rate of penetration(ROP) in the drilling process of horizontal well, the vibration characteristics research of drill string is conducted on the basis of rotary-impact. The force analysis model of horizontal drill string is determined and the dynamics differential equations are established to analyze the influence of key parameters. The vibration characteristics of different drill string nodes are studied and then the performance parameters of rotary-impact tool are obtained by experimental test with the combination of a new rotary-impact drilling tool. The research results show that with the increase of stroke, weight on bit(WOB), impact deformation coefficient and effective contact area, the impact force can increase gradually. And vibration displacement, velocity and frequency are maximum in the installation position of rotary-impact tool. The research conclusions can provide a theoretical reference for the structure optimization design and field application of the rotary-impact tool and can also provide guidance for the dynamics study of horizontal drill string.