超深井套管柱力学与控制研究若干进展及展望OA

Casing strings in ultra-deep oil and gas wells operate under extreme conditions,including high temperature and high pressure,high in-situ stress and complex rock formations,and are subjected to multiple loads,such as axial tension/compression/bending,high external and internal pressures,as well as acidic corrosive fluids.All these factors can lead to high failure risk and short service life of the casing strings.In this paper,focusing on the safe and efficient operation of cas-ing strings in ultra-deep wells,the research progresses in casing mechanics and control were reviewed,with particular em-phasis on three key issues:casing running,deformation under external pressure and sealing integrity,in which the recent ad-vancements were analyzed and future research recommendations were proposed.The results indicate that the mechanical anal-ysis of casing running process has been expanded from ideal wellbores to irregular wellbores,and the risk evaluation methods for casing running through to the target depth have evolved from conventional geometric and mechanical approaches to data-mechanism fusion methods considering multiple factors.Casing collapse can be influenced by multiple factors,and the spe-cific cause need to be analyzed based on specific rock formation and well condition.Among those factors,the non-uniformity external pressure and trajectory curvature can significantly affect the degradation of casing collapse resistance.Combining an-nular pressure analysis with wellbore leakage detection can effectively improve the identification accuracy of multiple leakage locations.The conclusions suggest that the research on casing mechanics and control in ultra-deep wells is undergoing an im-portant transition from traditional mechanical analysis to multi-disciplinary integration,and from purely mechanism-driven ap-proaches to data-mechanism fusion methods.Future efforts should be focused on strengthening multi-factor coupling model-ing,multi-disciplinary mechanism analysis,data-mechanism fusion methods,and key downhole measurement and control techniques to advance the innovations in fundamental theories and key technologies of casing strings in ultra-deep wells.