Well integrity and decommissioning specialist Unity has completed a technically challenging well intervention project in Central Italy for SMAPE, deploying a bespoke thru-tubing solution to achieve well isolation for a major international oil company.

The project followed unsuccessful conventional cement squeeze operations, which failed to provide the required isolation after a thief zone behind a slotted liner absorbed cement.

The well’s geometry also prevented the use of standard mechanical isolation equipment, requiring a solution capable of passing through a 2.188-inch nipple restriction before expanding and setting inside a 3.958-inch internal diameter above the thief zone.

Unity engineered a custom 2.125-inch inflatable cement retainer, modifying the bottom-hole assembly with a dual check valve system and shear disconnect.

A cement plug was incorporated into the design, enabling the rig team to disconnect immediately after the squeeze without additional ball drops or complications following inflation.

The low fluid level in the well added further operational challenges, requiring careful planning to prevent premature disconnection during cementing or excessive pressure on the treatment packer.

Unity develops its thru-tubing solutions by selecting components from across the OEM market and adapting them to individual well conditions, rather than relying solely on off-the-shelf equipment.

Unity Thru-Tubing Operations Manager Chris Myles said: “This is the first time we have used this configuration, which draws on established principles. This is really the heart of how we work at Unity thru-tubing. We're not tied to one OEM's solution, so we can pull in whatever's most appropriate, adapt it, and build something that fits the exact problem in front of us. That's what sets Unity apart, and it's what clients get in return - a solution built around their well requirements, not the other way round.

“This project marks our second collaboration with SMAPE, and it’s fantastic that the team see the value we bring to complex well integrity challenges. These are often the kinds of jobs where a standard approach isn’t enough, so being able to work closely with the client and develop a solution around the specific requirements of the well is where our expertise really makes a difference.”

The project forms part of Unity’s wider investment in well intervention capabilities. Since early 2025, the company has expanded its intervention tooling portfolio to strengthen its ability to provide integrated well integrity and intervention services through a single supplier.

Unity, part of FrontRow Energy Technology Group, has a 30-year track record supporting operators globally in reducing risk, overcoming technical constraints and extending asset life. SMAPE is an independent engineering company specialising in coiled tubing and well services. -OGN/TradeArabia News Service