Reliability Analysis Of Deepwater Drilling Riser

Deepwater drilling is one of the key links in the development of deepwater oil and gas resources.Deepwater drilling is facing a series of complex marine environment,in order to ensure that the deepwater drilling riser system in the field work has a long service life,prevent the occurrence of fatigue failure and wear failure,the reliability analysis of it has become particularly important.The paper summarizes and analyzes the factors of deepwater drilling riser reliability of the main factors,can be divided into environmental factors and job factors,effects of environmental factors on reliability is more significant,including water depth,wave and current;operation factors mainly include drilling fluid density,vibration and suspension mode VIV suppression device of water pipe system.With the increase of seawater depth and ocean current velocity,vortex induced vibration is more likely to occur in deepwater drilling riser.Optimization of deepwater drilling riser based on wave induced fatigue cumulative damage model of reliability analysis model and analysis model of vortex induced fatigue life based on the model,and analyses the wave induced fatigue reliability and reliability calculation of deepwater drilling riser.The results show that the deep water drilling riser under wave load of wave induced fatigue wave induced fatigue damage smaller,higher reliability,wave in the design life of the fatigue reliability can meet the requirements of reliability design.Deepwater drilling riser wear form according to the different wear mechanism can be divided into bottom wear and dogleg wear,riser flexible joint angle is crucial for the bottom wear,the wear is mainly composed of a dogleg drill string and riser wall contact friction.The residual strength model based on the riser wear evaluation results show that the wear life of the riser and increased with the decrease of the bottom of the flexible joint angle,in order to ensure the riser with sufficient reliability and wear life,should try to control the angle in a reasonable range.Through the systematic analysis and summary,the reliability of deepwater drilling riser analysis method was studied,the reliability design of riser system is of great significance and role for deepwater drilling.