Published on 16 July 2018
Case Study: first patch set in New Zealand
In a 9 year-old well, a communication between the 5-1/2in production casing and the 9-5/8in annulus had to be located then shut off. The objective was to cover and seal off the hole using a Saltel Expandable Casing Patch, allowing the completion to be run through the patch.
The depth of the leak was not known before the job; a 5.5in Reinforced SES Patch was selected in case the damaged zone had been located deep in the well, which would have require a high collapse pressure.A multi finger caliper log allowed to locate the hole in the production casing 25.7m below the Tubing Hanger. The patch and setting BHA were conveyed with 2-7/8in tubing on a service rig and positioned by tubing tally.
The casing patch was rigged up, positioned, installed in 12 expansions, and drifted at 4.331in without issue in less than 3 hours. It was then pressure tested solid at 1,550psi for 10min. Finally the completion was set back into the well.