Influence of tangential residual stresses on the fatigue resistance of drill pipes

Abstract

The causes of steel drill pipes destruction in rotary drilling are presented in the article. It is proved that except
for external stresses and various factors residual stress affects the life time of drill pipes. Residual stress set in the
metal of pipes during their manufacturing in tube work stations as a result of plastic deformation at high
temperature and strong applied efforts. Depending on a size and character of distribution of remaining tensions
they can be useful or harmful during work of different wares. For the exposure of influence of tangential remaining
tensions on tireless durability of drill pipes of 114x10E, that worked the more than nine thousand hours of the
mechanical drilling. The results of experiments showed that remaining tensions had an influence on tireless
durability of drill pipes. It is shown that after of long duration exploitation of drill pipes. It is necessary to conduct
high vacation for the removal of harmful influence of remaining tensions that are additional reserve of increase of
longevity of the steel drill pipes.