Contingency Hanger for Mud Line Suspension
05 July 2018
As in Surface Wellhead, if casing stuck happen we have contingency hanger (slip hanger). We can just cut the casing, install the slip hanger and packoff. Operation go as normal.
For Mud Line Suspension (MLS), do we have similar slip hanger as contingency if the casing goes stuck? From several discussion that we have, the only option is only 2 : cut the casing, hang with slip hanger in surface wellhead and sacrifice the MLS function; or abandon the well.
Kindly share your thought and experience.
Thank you for your reply. It really answer our question.
Looking at the documents from online, it seems logic. However, do you have any experience and succes story in running the method and equipments?
You don't need to sacrifice your ML hanger.
You can cut your casing, dress it off and run a casing patch (Bowen style 'underwater casing patch' - available from NOV) and Dril-Quip 'Adjustment Sub'.
After engaging the casing patch, you tension your casing, function the adjustment sub the correct distance and then land out your mud line hanger.
The casing patch may have a lower pressure capability than you casing.
You should be able to find PDFs of these tools online. Your fishing company and MLS supplier should also be able to help.
You would need to calculate how much tension to pull with the casing patch, how much travel was required for the adjustment sub and how much tension you would have below your ML hanger at the end.