Influence of internal stresses in steel as a factor of corrosion cracking and destruction of drill pipes during their operation

Abstract

Drill pipes in the oil-gas industry play a major role in the extraction of petroleum products. These pipes are the main link in the drilling rig, these pipes create the necessary rotation and transfer the load to the cutting element (chisels), and they also serve to lift working tools from the bottom of the well to the surface. The main goal of the drill pipe is to supply the drilling fluid, which performs the function of cooling the bit. The destruction of such pipes leads to large economic losses, therefore, these pipes must have high quality primarily in terms of mechanical properties. Based on the foregoing, this work is aimed at studying the causes of accidental destruction of steel drill pipes during their operation in the presence of an increased level of internal stresses in them. As the main method for assessing the level of residual internal stresses, a method is proposed for measuring the groove width during the longitudinal opening of ring samples cut from the body wall of drill pipes. This method is distinguished by its clarity and high speed of obtaining the result. The increased level of internal residual stresses, combined with external working loads during operation, leads to a significant reduction in the service life of drill pipes under the influence of corrosion cracking mechanism.