Prediction of serious abrasion position and mechanism of uneven abrasion between sucker rod string and tubing

Based on the practical situation of oilfield, the medium type and mechanism of abrasion between sucker rod string and tubing were analyzed. A 3D mechanics calculation model for analyzing sucker rod string was established. The relative software was programmed with VB 6.0 and Matlab 6.0 language. The influence of 3D wellbore trajectory on the stress and deformation of sucker rod string was studied with this software. The serious abrasion position can also be predicted with this software. By using new anti-abrasion joint in the serious abrasive position, the degree of uneven abrasion between sucker rod string and tubing can be largely decreased. The new anti-abrasion joint can prolong the production life of oil well and save the time of well workover.