连续油管注入器结构设计及载荷分析

连续油管注入器是连续油管作业装置的关键设备，根据其工作原理，将油管夹紧机构及张紧机构采用单缸杠杆方式，链条驱动机构采用油马达加减速机构方式，可以在保证性能的条件下，降低注入器制造成本。对于油管在高压井作业时的失稳问题，只要注入器的夹紧压块以下到油管导口问距离小于３８０ｍｍ，常用油管就可用于７０ＭＰａ的高压井内作业而不会失稳。根据对连续油管注入器载荷的分析，得出注入器链条载荷与井口压力和油管下入井深间的关系及夹紧油缸和张紧油缸负载计算方法，对于３８．１油管，在井口压力大于或等于２５ＭＰａ的情况下，链条的牵引载荷始终与链条牵引力的方向相反，油马达不会受到扭矩；井口压力小于２５ＭＰａ，油管下入一定深度后，链条的牵引载荷会与链条牵引力的方向相同，但这时载荷的绝对值较小，对系统影响不大。若欲减小注入器张紧油缸的载荷，设计时应尽可能减小驱动链轮的轴线与张紧链轮的轴线间的水平距离。

Structural Design of Coiled Tubing Injector and Its Load Analysis

Coiled tubing injector is a key equipment. According to its operation principle, some modificationshave been made on condition that performance is guaranteed, for example, tubing clamp mechanism and tightenermechanism change to adopt one -- vat lever method, and chain driving mechanism adopts oil motor accelerationand deceleration mechanism, in this way its manufacture cost will be decreased. The paper discusses tubing instability problem in high pressure well operations. It concludes as long as the distance between clamp bar of injectorand tubing conductor is less than 380mm, conventional coiled tubing can be used in wells pressured up to 70MPawithout instability problem. On the basis of load analysis of coiled tubing injector, the relationships of chain loadwith wellhead pressure and deepth of tubing are got. Meanwhile methods of computing the load on clamp oilcylinder and tightener oil cylinder are also obtained.