A float collar is placed at the top of the float joint and a float shoe placed at the bottom to prevent reverse flow of cement back into the casing after placement.
浮箍是放置于浮动接头之上的，而浮鞋则是放置于浮动接头之下，以防止水泥浆回流到套管内。
2
Fit the rig tongs with the correct jaws for the drill pipe tool joint or the drill collar. Re-install the safety lock springs.
给大钳装上与钻杆接头或钻铤相匹配的钳头，再装上安全锁簧。
3
A short pup joint that registers clearly in a collar locator log is a common flag joint.