液压压胀式尾管顶部封隔器研制与试验

Design and Experimental Study on Liner Top Packer Driven by Hydraulic Cylinder

机械式尾管顶部封隔器在小尺寸井、浅井和水平井中进行压裂作业时,由于机械下压力不足,容易出现封隔器坐封困难的问题。研制了一种基于液压坐封方式的封隔器,即液压式尾管顶部封隔器。在封隔器坐封原理的基础上设计了多级液缸串联工作方式的坐封结构,解决了机械式封隔器坐封力不足的问题;同时设计了锚定结构,增大了封隔器坐封的可靠性。地面性能试验表明,该封隔器可在25 MPa内压力条件下实现坐封、30 MPa内压力条件下完成坐挂功能,坐封后密封压力达到70 MPa。该封隔器可实现对尾管重叠段环空的有效封隔。

The mechanical packer usually can't be completely set when using in fracturing operation in the small size well or shallow well and horizontal well due to the insufficient mechanical pressure.Therefore,this paper developed the liner top packer that driven by hydraulic pressure.According to research the mechanism of packer,the multi-stage cylinder setting mechanism has been designed to improving setting force,which can solve the insufficient mechanical pressure question of mechanical packer.Furthermore,in order to enhance the reliability of sealing packer,the anchoring mechanism was developed.The experiment data suggest that the packer can set completely under lower tube pressure,which less than 25 MPa,and anchor within 30 MPa pressure.After setting,the sealing pressure can up to 70 MPa.Thus,the annular space of the overlapping section of liner can be effectively sealed by the liner top packer.