Why Use The DPC™?
To circulate, fill-up, or take flow back without the DPC:
Rotary Rigs: Use a circulating sub made up to the upper joint and connected to the rig mud system using a 1502 union on each circulating sub. 1. A complete stand of drill pipe can be raised or lowered while circulating. 2. Circulating sub must be made up to every stand if taking flow back.
- Derrick man must make up a 1502 connection in the rig, which is very dangerous.
- Rig crew must break every 1502 connection and remove the circulating sub on every stand, which is dangerous.
- Circulating sub must be broken out to run the drill pipe.
3. Circulating sub must be made up to every stand if expanding or pumping out of the hole.
- Rig crew must make up the 1502 connection on every stand using a hammer, which is dangerous.
- Derrick man must disconnect a 1502 connection in the rig on every stand, which is very dangerous.
- Rig crew must break out ever circulating sub when running back in hole. Pick up the Kelly and make a connection to the drill pipe.
4. Drill pipe can be raised and lowered about 2 joints while circulating.