水平井斜井段井眼与套管相容性分析

Analysis of the Compatibility between Casing and Inclined Section in Horizontal Well

分析了斜井段套管下入的难点;通过对长庆油田水平井斜井段常用套管可通过的最大井眼允许曲率及特定井眼曲率下套管可通过的最大不可弯曲长度的计算,表明斜井段下套管保证套管能通过的最大井眼曲率要大于实钻井眼的曲率,同时在斜井段下套管前有必要针对实际通井钻具组合进行更为合理的力学模型简化;采用加权平均法计算了多种通井钻具组合的等效惯性矩,得到了不同通井钻具组合与套管的刚度匹配系数,为水平井斜井段套管顺利下到预定位置提供理论支撑。

The compatibility difficulty of inclined section casing is analyzed. The maximum borehole permissible curvature of common casing in horizontal well section of horizontal well and the maximum flexural length of a casing that can be passed under a specific borehole curvature are calculated in Changqing oil field. It is showed that the max curvature of casing is larger than actual train curvature before running casing inclined section. The more appro- priate simplification of mechanical model for the drilling assembly has been proposed. The equivalent rigidity of the drilling assembly has been calculated with method of weighted mean to obtain the stiffness matching coefficient of different well drilling assembly and casing, which provides theoretical support for inclined section casing of the hori- zontal well going down to the predetermined position smoothly.