STUDY ON THE PLACEMENT OF CENTRALIZERS ON PIPE STRING IN STRAIGHT WELL

Pipe string buckling causes many troubles during production, and it’s necessary to evaluate pipe stability in the well. This paper tries to analyze the stability of vertical pipe string affected by axial load, by means of energy method in the elastic stability theory. An equation is established based on the result, which incorporates axial load, bottom axial load and geometric parameters, and an analytical solution is obtained. Different limiting factors are required from different end boundary conditions, and two examples are given for illustration. This equation and its solution are beneficial for the placement optimization of centralizer on pipe string in vertical well.