Mechanics Analysis And Fatigue Life Prediction Of Casing Drilling Connection Thread Joint

Casing drilling technology had the significant advantages of reducing operation period and cost investment in oil and gas industry.In recent years,the interest in the deep study of casing drilling technology is still prevalent and meaningful.The integrity of casing connection thread joint structure is usually the key to the success of casing drilling.The simulation based on finite element analysis becomed stable and reliable.Based on finite elements analysis method,this paper analyzes the stress distribution of the casing in different sections and try to determine the stress state of each thread clearly.In addiction,the prediction of the fatigue life is taken for the part with most stress concentration and the maximum equivalen stress.The purpose of this paper is to propose a formula to give a method for measuring the integrity of thread joints under different conditions.The fatigue life which means the maximum allowable number of cycles is also drawed as a formula related to the loads.This method can be applied to the test well and get the results successsfully.