连续油管在水平井中的稳定性分析

ANALYSIS OF STABILITY OF COILED TUBING IN HORIZONTAL WELL/

考虑端部约束条件，建立了连续油管在水平井中的稳定性方程。用差分法求解这个方程，得到了连续油管的临界失稳载荷。讨论了井斜角、环空间隙、管柱长度和摩擦系数对连续油管在水平井中稳定性的影响。在水平井眼中，随着连续油管长度的增加，其临界失稳载荷趋于一个常数。井斜角越大或环空间隙越小，管柱越不易失稳。

The formula for analyzing the stability of coiled tubing in horizontal well is deduced with consideration of boundary conditions. The buckling critical load is calculated with finite difference method. The effects of deviation angle, annular tolerance, tubing length and friction factors on the stability of tubing in horizontal well are discussed. In such wells, the buckling critical load tends to be a constant with the increase of tubing length. When the deviation angle tends to be bigger, or the annular tolerance weaker, the tubing becomes more stable. The friction factor has a little effect on bucking critical load.