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Zonal Isolation


Zonal isolation

Segmented Flex-Well® design increases options to mitigate reservoir uncertainty and maximizes the economic value of wells.
    High performance, rotatable, zonal isolation.


Geological uncertainty is often a critical risk factor as it defines the outcome and return on a field development over the life of well. Extensive efforts and resource is invested to understand and describe the geology and capture/quantify the uncertainties. As the field matures, increased data captured, improves the models, impacting development decisions. However, the economic value of the project remains dependent on the ability to mitigate the risks associated with remaining uncertainties.

For example, uncertainty associated with the distribution of high permeability streaks in the oil reservoir deliver risk associated with water or gas breakthrough, declining oil production and reduced sweep efficiency impacting total reserves and the project cash flow. 

Integration of key uncertainties in well planning often ensure good prediction of the reserves and the probability of success, however the choice of well technology and completion design will control the method optimize and act to mitigate the risks long-term.

Case highlight

Zonal isolation

Two WABs installed to isolate shallow reservoir for future production. Four WABs installed in lateral for zonal isolation between reservoir zones...

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Extended reach horizontal reservoir

Also to increase net present value of their assets, extended reach horizontal reservoir sections are becoming critical to operators looking to increase well productivity and maximize their ROI. Extended reach lower completion design creates significant concerns over the ability to execute a conventional cement or perforated liner well design due to the high inclination nature of the reservoir section.

To achieve this it is critical to design the well with reliable isolation between lower completion and open hole without the need for cement.

Our ISO 14310 rated, metal expandable WAB® (Welltec® Annular Barrier) for open hole zonal isolation, facilitates the ability to deploy ‘cementless’ extended reach, multi zone, horizontal, lower completions. The WAB provides the on-demand, high pressure zonal isolation across varying borehole geometries unaffected by thermal changes in the wellbore, so often a problem in conventional open hole isolation.  

The WAB for Zonal Isolation between the lower completion and the open hole enables the compartmentalization of the reservoir into many, discrete sections. Whether an injector or producer, this gives the operator the best options to mitigating reservoir uncertainties and maximize the value of the well.

WAB® for zonal isolation


  • Zonal isolation within the reservoir or between adjacent zones
  • Water / gas isolation
  • High pressure open hole isolation for stimulation
  • Can be deployed in open hole, cased hole and hostile environments


  • Rugged, all welded, metallic construction
  • Rotatable during deployment
  • Full bore – as per casing / tubing
  • Burst protection option available


  • Slim OD allows for high rate circulation during deployment
  • High expansion capability
  • Constant, high pressure ∆p over full expansion range
  • Rapid set nature of WAB allows expedites time to production
  • No premature expansion
  • NACE compliant
  • Suitable for sour service

Modelling services

Successful Welltec Annular Barrier sealing across the cap rock can be ensured through 3D geomechanical modelling of the expansion of the Welltec packers into the rock formation.

In specific projects flow modelling is also used in the packer configuration to ensure the zonal isolation benefits and minimize risk of flow through formation behind the packers.

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Contact our technical experts

Petter Lønning

Well Completion Manager, Scandinavia

With 15 years of experience in well construction, multi-zone lower completions and product development, Petter has a broad range of expertise and knowledge. Working from Scandinavia, he will add value to your well planning phase by providing input on smart, flexible and efficient solutions.

+47 94 16 11 84 LinkedIn Profile

Kyle Ivar Jamieson

Well Completions Sales Director, APAC

With around 18 years of upstream experience in both completions and interventions, Kyle supports existing customers’ operational needs, provides technical support, and is proactive in developing new business. Main areas of focus are oil & gas well construction, well completion and geothermal well completions throughout Asia

+60 16 207 3688 LinkedIn Profile

Nick Rakic

Solutions Director, Canada

Nick began with Welltec as a Field Technologist in 2012 and has accomplished continuous growth, progressing though roles in service delivery and commercial. He is experienced globally both onshore and offshore. With a strong foundation of experience in field deployment, operations management, and business development, Nick is our local Canadian expert on Completions and Intervention.

+1 403 404 4575 LinkedIn Profile

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