Well XX-1 is a newly drilled Oil producer well in offshore east coast of India. Lower completion containing Formation Isolation Valve (FIV), Standalone Screens with integral SSD's & swell packers was run in 6″ Open Hole & set on screen hanger packer. The FIV, packer & Production casing was then pressure tested to 3000 psi, during which pressure drop of ~15 psi/min & continuous return from secondary annulus ~1 litre/min was observed. The above indicated possible communication between 7″ production casing & 9-5/8″ surface casing.

The leak depth was investigated using a drillpipe conveyed single run multiple set mechanical packer & it was established that the bottom connection of Cross over below 7″ casing hanger pup joint was leaking. Leak in production casing was a critical well integrity threat. Further, the well was designed to be operated on gas lift. There was no immediate remedy available to restore the production casing integrity. It was decided to complete the well and produce with adequate controls without gas lift till the casing leak was repaired. Meanwhile, extensive search and literature review was done & various options to repair the casing leak, both mechanical and chemical, were evaluated. Considering the expensive mechanical repair and associated high uncertainty, Pressure Activated Liquid Sealant was proposed as economical alternative.

The sealant works on the principle of polymerization and cross linking when subject to pressure drop. This sealant process has proven to be a successful long-term repair method for completion equipment. Utilizing a combination of fluid density control and packer fluid compressibility, the sealant was injected into the annulus casing valve then spotted & squeezed into the leak at 2500 psi and allowed to cure under pressure for 80 hrs. The production casing was then successfully pressure tested with both liquid and gas and the integrity was confirmed.

It not only prevented expensive work-over saving > 10 MMUSD, but the quick remedy also allowed the well to be brought online at a higher production rate ~ 1000 BOPD incremental. It has proved to be a reliable solution to well integrity problem.

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