自锁式封隔管柱的设计与应用

Y221封隔器广泛地应用在隔抽管柱上,但常规Y221封隔器坐封后,在压重作用下,封隔器以上的油管、泵筒会在轴向上弯曲变形,加剧管杆偏磨,增加抽油机负荷,针对此现象,研制了一种自锁式Y221封隔器。阐述了该种封隔器的工作原理,并且针对封隔器胶筒的合理压重,对封隔器卡瓦的锚定力进行了校验,对解封负荷进行了计算。此外,还设计了配套的自锁式Y221封隔器的坐封工具,使得卸载压重后,封隔器既不解封,油管挂还能顺利坐入井口,实现管柱的入井回接。由于在封隔器内部增加了自锁机构及双级解封机构,封隔器坐封后,当释放掉压重时,封隔器依然能够保持坐封状态,封隔器上部管柱处于自由状态,从而减少了抽油杆的上下行摩阻及抽油机负荷。但该管柱在自锁方面有其局限性,即虽然可多次坐封,但只能第1次坐封后可以自锁,再次坐封后不能自锁。

Design and application of self-locking packer string

Y221 packer is extensively used in packer string, but when conventional Y221 packer is set, the tubing and pump cylinder above the packer shall bend and deform axially under the action of weight, which exacerbates eccentric wear on tubing and rod and increases the load on pumping unit. In view of this problem, a self-locking Y221 packer has been developed. This paper sets forth the working principle of this packer and verifies the anchoring force of the packer slips in line with the proper weight of packer rubber tube and calculates the unlocking load. In addition, a setting tool for this self-locking Y221 packer has been designed, which ensures that the packer is not unlocked while the tubing hanger can successfully sit in the wellhead when the weight is removed, so the string is tied back in hole. A self-locking mechanism and duel-stage unlocking mechanism are added inside the packer, so after the packer is set and the weight is released, the packer can still stay set while the string above the packer is in a free state, hence reducing the up and down friction of the sucker rod and the load on pumping unit. However, this string has some limitation in its self-locking performance, that is, the packer can be set many times, but it can realize self-locking after it is first set and cannot self-lock after being set twice.