充填滑套安装在上延伸筒及底部延伸筒中间，它有两个主要作用，一是在充填过 程中提供砾石充填的通道，二是充填结束后，通过关闭充填滑套来隔离地层。

主要特性

◎ 台阶的管柱通过充填滑套时不会误打开滑套；

◎ 开关工具安全装置可保证工具顺利起出井筒。

SLIDING SLEEVE

INTRODUCTION

It is installed between the upper extension and lower extension, and mainly having two  functions. The first is to provide channel for gravel pack during pack, the other is to isolate  the formation after pack.

FEATURES

Stepper string not opening the sliding sleeve mistakenly when through pack sliding sleeve. Tool safety device ensuring the tool smooth tripping out of the bore.

Note: Other specification products are available.