Well control precautions to be used when running casing.
- Change the rams to the casing size (on surface stack) and test the BOP bonnets.
- Prepare a circulating head.
- Ensure a cross-over from casing to drill pipe is available to allow the string to be hung off if needed.
- Take care while filling up the casing. Use clean mud and ensure that junk does not fall into the casing.
- Record the annular volume between the casing and open hole and Outer casing.
- Calculate the running speed to allow an acceptable fluid velocity and a limited surge into the open hole.
- A record of the tank level is necessary and should be compared with the calculated volume increment due to the metal displacement of the casing.
In case of a kick while RIH casing, if the shoe cannot be pulled above the shear/blind rams, the casing rams should be closed.
Prior to doing so, it is recommended that the circulating head should be installed in case of float equipment failure.
Due to the large size of the string, the weight of the casing may not be sufficient to overcome the force pushing the casing out. The circulating head must be chained to the substructure if necessary.