Analysis on the pull strength´s calculation method during the construction of oil pipeline directional drilling crossing the yellow river and improvement

This paper reviewed the methods, which calculate the pull strength during directional drilling crossing construction of oil pipeline, both at home and aboard. And based on the analysis of these methods, the detailed research was given. At the same time, considering the peculiarity of this channel geologic structure and the technological requirements, the method, averaged standard method and unloading arch method, was given to calculate the maximal pull strength. It is practiced that, this method is instructive and meaningful to the directional drilling crossing construction.