A North Sea operator approached Oilenco to provide assistance with a tubing retrievable subsurface safety valve (TRSSSV) that failed integrity tests.

When the operator experienced low flow rates, they suspected the TRSSSV was stuck in a partially open/closed position. Upon investigation, the client identified significant scale build-up within the well.

The client required a solution to not only remediate the scale issue within the wellbore, but also reinstate the functionality and integrity of the TRSSSV. As this was one of the largest producing wells for the asset, they required a timely resolution.


Oilenco deployed a scale remedial package. This consisted of a scraper tool, soak sleeve and syringe, and wire roller brush.

The Oilenco scraper tool was run to remove the scale from surface to the TRSSSV. 3 runs of the scraper tool were completed, adjusting the teeth to increase the diameter of the tool with each pass.

This cleared a pathway to allow the Oilenco soak sleeve and syringe to be set across the TRSSSV. The syringe was filled with formic/Cal acid at surface then run in to the soak sleeve where the chemical was dispersed to treat scale within the TRSSSV.


After an initial 3-hour soak, the TRSSSV flow tube was functioned with the soak sleeve in-situ to determine movement and measure flow returns.

The first tests indicated a small increase in returns showing progress. A further 9-hour soak was completed before a final test recorded the correct volume of returns.

The final phase was to run the Oilenco wire roller brush to clear scale around the flow tube recess and brush the safety valve to remove any remaining debris. With all scale remedial work complete, final testing confirmed full reinstatement of the TRSSSV allowing operations to continue.


With a range of tooling for different tubing sizes in our rental fleet, Oilenco were able to tailor a package and rapidly mobilise tooling to meet the client's requirements. An Oilenco offshore technician was also mobilised to work alongside the client and service management teams to ensure smooth operation of the tools.

Our rapid response to solve our client's challenges was crucial to help minimise downtime and reinstate the TRSSSV as efficiently as possible.


To speak to one of our engineers about your application or to discuss our scale remedial solutions, call +44 (0)1224 548700 or email


Trsssv Scale Remedial Case Study Tools

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