After we publish this article “Hard Shut-In Procedure while Drilling with a Subsea BOP Stack”, there are some people asking us about what about the shut-in procedure while tripping with a subsea stack. So today we will focus on this topic.
For the shutting in procedure with subsea stack, there are 3 steps which are stab valve, space out, and shut in and the details for the procedure are below.
1st step: stab valve
- Stab the full opening safety valve into the string and then make it up to the drillstring. Close the valve.
2nd step: space out
- Space out to ensure that the tool joint will not be located across the BOP. Personnel need to pre calculate where to space out because the position on the rig floor will affect where the tool joint down hole.
3rd step: Shut-in the well
- Shut the well in on the top most BOP as annular preventer first and then open the upper choke valve against a fully closed choke manifold valve.
- Confirm well is properly shut in and double check line up. Check the accumulator unit to ensure that there is no leakage after closure of the BOP.
- Inform rig supervisors.
- Prepare to strip back to the bottom.
Reference books: Well Control Books