Vår Energi - Balder - P&A application

Challenge:

Vår Energi urgently required a solution for retrieving an old vertical Tubing Hanger (TH) during P&A of a subsea well.

It was important that the solution had a high pulling capacity to release the TH, and that it was possible to lift the TH with a closed BOP ram to safely circulate out potential gas. In addition, a mechanical barrier that was installed during pre-P&A had to be cycled open prior to releasing the TH.

Solution:

Simple Tools proposed a solution using the ADAPT and BakerHughes THRT. The ADAPT operates the THRT without an umbilical, and the functional design allows for stripping through a closed BOP.

The THRT interface to TH gives pressure integrity and additional pulling strength by latching to TH body.  A System Integration Test (SIT) was performed successfully proving all functions of the THRT.

Results

Time from kick-off to delivery was just 45 days. The THRT and ADAPT was prepared onshore ready to be picked up offshore. Together with handling pup in top the assembly was below 8 meters.

The TH was tagged, land-out verified and THRT latched to TH before unlocking. Using the ADAPT and THRT to retrieve the TH allowed the operator to circulate the entire well free from gas prior to POOH.

Simple Tools and BakerHughes field engineers ensured a safe and efficient retrieval of the TH according to procedure and ahead of time estimates.

Conclusion

ADAPT enabled an improved and time saving method for retrieving subsea TH by incorporating all the benefits of a THRT and removing the umbilical. This removed HSE risks, improved well control and simplified the operation.