Technical Challenge:
Retrieval of sub-surface safety valve (SSSV) with damaged fish neck.
Well Type:
Oil producer (maximum 35 degree deviation).
Peak Solution:
7-in IN FRC heavy-duty pulling tool and the 5 1/2-in heavy-duty releasable spear.
Customer:
UK-based operator, North Sea
The Challenge:
An SSSV was changed out in 2007 and 2010 – taking three attempts to set on each occasion due to scale. In 2014, the well was shut in due to a failed SSSV test arising after an unsuccessful attempt to pull the SSSV to surface with the standard GS pulling tool. Damage to the fish neck was suspected to be the cause.
Considerations:
The following key requirements and concerns were identified:
Summary:
Peak’s 7” IN-FRC heavy-duty pulling tool has full radial contact allowing 30 percent more contact with the fish neck than a standard GS pulling tool. Fitted with serrated dogs for additional internal grip it was able to latch but pulled free from the fish neck on every attempt - this confirmed that damage to the fish neck was extensive.
It was therefore decided with the customer to use Peak’s 5 1/2-in heavy-duty releasable spear fitted with the long adjustment sleeve to ensure shear off capabilities should this be required. The viability of this option was proven following trials on a similar lock onshore to ensure latching was the best fit possible.
After a few attempts to latch it was found to be free to take a large overpull. With this confirming that the fish neck of the SSSV had successfully been latched, jarring commenced - the SSSV was successfully pulled to surface where severe damage to the fish neck was observed by the operators.
Value to Customer:
All operations were carried out safely and efficiently:
Produce Code: 204, 210