LAUSR

Abstract This paper describes a new analytical model for predicting the buckling behavior of coiled tubing (CT) with initial curvature in an inclined well. In addition, the contact force and the axial force transfer are solved using the new model. The new model is built based on the beam-column method and is solved using the method of weighted residuals. Using the proposed model, the CT's mechanical behaviors are found to be strongly affected by its initial curvature. The critical sinusoidal buckling and critical helical buckling load are both increasing with increasing A0. When CT is undergoing sinusoidal buckling, the contact forces are affected by both axial force and it's initial configuration whereas when CT is in helical buckling, the contact force is primarily affected by the axial force. In general, under the same axial force, the contact force of CT is larger than that of a straight pipe. Compared with A0, OD and u are the primary parameters to affect the axial force transmission. The CT's residual bent appears to have a stronger effect on its buckling load and to be less effective on its axial force transfer based on the new model presented in this paper.