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Introducing Complete Seal - zonal isolation, the CannSeal & Interwell way

3 May 2022

Over the past few decades, aging oil and gas fields have slowly become more complex as operators try to extend the lifespan of their fields. Spurred by technological advances in drilling technology and well completion, the sector has witnessed huge technological change. With the rising complexity of these fields, the need for zonal isolation has become more important than ever.

As the different zones in a production field produce at different rates, situations may arise where certain zones start to produce undesired fluids - like water - while other zones still have a lot of production potential, although less potent. Establishing zonal isolation is often the only way forward to keep these producing zones in operation. This avoids an entire recompletion of the well, which is often an extremely costly endeavour.

Zonal isolation of lower zones is typically relatively straightforward. A plug is placed in the wellbore of the lower completion, and production of the upper zones can continue as usual. However, traditionally, full isolation of zones further up the well always remained a very costly and time-consuming challenge - until now.

Combining our Strengths for Increased Optimization

At CannSeal, we are in a unique position that allows us to combine our expertise in annular isolation with the industry-leading plugging solutions of our parent company Interwell. By combining our knowledge, we are able to offer a seal that both plugs the annulus and the wellbore - our unique 'Complete Seal'.

Our innovative epoxy solutions form a sealing doughnut in the annulus, while the Interwell designed straddlers plug the internal piping. Together, this allows us to create a complete seal that can isolate a zone, while simultaneously allowing production from other zones in the same well.

Besides increasing production from the well, our Complete Seal can also be applied to block off water producing zones. This significantly reduces costs for dealing with unwanted water production and can have a positive impact on the operators ESG metrics.

The Complete Seal in action

As with all of our projects, a Complete Seal application starts with meticulous planning. In our line of work, there is no room for second chances, so everything needs to be right the first time around. Together with reservoir engineers, we aim to find the optimal location for a successful seal, taking into account annular conditions, depth, pressure and temperature.

We precisely inject our custom epoxy sealant into the annulus using our Downhole Delivery Tool, creating a doughnut-shaped external seal. Depending on the well configuration, additional doughnuts may be required. After the epoxy has cured, the Interwell straddles or tubular plugs are put in place, creating a complete seal.

Working together with Interwell not only allows us to place a better performing seal, but it also brings clear benefits with regards to improving efficiency and reducing operational risks. As the same crew installs the annular epoxy seal and the internal wellbore plug, POB is significantly reduced, the time used onboard the rig is used more efficiently, and HSE is increased.

Building on Success

To date, CannSeal has completed 5 successful Complete Seal installations around the world. One notable success story is a gas well in the North Sea region, which suffered from zones that were completely watered out. After installing our Complete Seal, we were able to bring the well back to life, up to a production of 400,000 m3 gas a day.

Complete Seal offers an excellent solution to a problem that faces operators all around the world: maturing production fields that suffer from increasing water breakthroughs. These issues not only hinder production, but also increase costs with regards to dealing with undesired fluids. Strategically placed Complete Seal installations offer a very cost-effective solution for guarding well integrity, increasing the useful life of your well while decreasing undesired fluids.

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