| 摘要 |
A circulating sub apparatus including a substantially tubular outer body member having a throughbore formed therein and a substantially tubular inner body member. The outer body member having at least one hole formed therein and a displacement mechanism for producing movement of the inner body member relative to the outer body member such that the inner body member is moveable between an open configuration and an obturated configuration. The inner body member includes a seat member adapted to catch a dropped object, the seat member is located upstream of the hole(s) of the outer body member in both the open and obturated configurations, and wherein the seat member is adapted to permit at least a proportion of fluid to flow past the dropped object when it is seated thereon. |
