| 摘要 |
A stage tool for wellbore annular cementing includes: a main body including a tubular wall with an outer surface and a longitudinal bore extending from a top end to a bottom end; a fluid port through the tubular wall providing fluidic access between the longitudinal bore and the outer surface; a valve for controlling flow through the fluid port between the outer surface and the inner bore; a backup sleeve to act as a secondary closure for the fluid port; and an automatic mechanism for automatically closing the backup sleeve without running in a string to move the backup sleeve. |
