Drill string mechanical analysis of running deepwater oil tree

Key words:  deepwater oil tree  drill string  marine environment load  strength  analytical model

Abstract:

A mechanical analytical model of drill string for running deepwater oil tree was established according to the marine environmental load and material mechanics theory. The drill string parameter, the marine environmental load, drilling ship drift, operating water depth and subsea tree weight were considered in the model. The lateral displacement, angular distortion, bending moment and shear force were analyzed. The results show that wave load has great effect on bending moment of the drill string head, but has little influence on lateral displacement, thus it can 't produce large error without considering deepwater wave load. Drilling ship drift has certain effect on lateral displacement of the drill string, but has little influence on angular distortion, bending moment and shear force of the drill string. The resistance coefficient, current velocity and operating water depth all have great influences on the drill string strength of running deepwater oil tree.