Nonlinear Dynamics Research between Drill Pipe and Coal Hole Wall during Gas Extraction Drilling

Abstract

This paper analyzes the impact of gas drainage borehole drilling rod vibration phenomena stability.Taking 100m hole depth in underground coal mine as an example, the dynamic simulation analysis of the underground gas drainage drilling rod was carried out by using the ANSYS finite element dynamic analysis module LS-DYNA method.According to the collision course between the drill pipe and the coal hole wall, the Lagrange algorithm is introduced to analyze the stress change of drill pipe in the collision course of 98mm, 108mm, 118mm and 128mm. The failure mechanism of drill pipe fatigue fracture and hole wall instability caused by the collision between drill pipe and coal hole is analyzed. The results show that the stress caused by the impact of drilling speed, drilling pressure and coal hole diameter is larger than that caused by the collision between drill pipe and coal wall.