The Study of Maximum Hole Curvature based on Casing Tripability

Abstract

The axial force of the bending section is the key point to select the curvature of the wellbore for the stress analysis of the bending section casing and the design of directional well track. Its size is subject to a variety of conditions. The derivation of the maximum borehole curvature traditional formula is based on the API.The scope and deficiencies of its application are clarified. It makes a comment on the optimization of the calculation model of other scholars. In order to improve the applicability and accuracy, the calculation model is derived based on the effective stress of the bending segment casing and effective stress. All kinds of working conditions are analyzed in the process of casing running. The analysis results show that the top casing is the most dangerous condition. Under this condition, the maximum wellbore curvature is a certain curved section to ensure the maximum wellbore curvature under the safety of the casing. A new model of maximum borehole curvature applicable to any tension condition is obtained.