Why the UKCS must make the most of HPHT development

Morten Kelstrup, Managing Director, Maersk Oil UK

December 1, 2015

Anyone who doubts high-pressure, high-temperature (HPHT) developments are a different ball game to normal-pressure, normal-temperature (NPNT) offshore projects should look at a simple example of a 12in ball valve. For a conventional development, one of these valves would sit on top of an average office desk and still leave room for your PC. A 12in ball valve for HPHT conditions would fill up the office itself.

The Culzean development. Image from Maersk Oil UK.

Maersk Oil, together with our co-venturers BP and JX Nippon, is developing the HPHT Culzean field. It’s a hugely exciting project, and as the example illustrates, one with considerable engineering complexity. Culzean shows that large discoveries remain possible in the UK North Sea. The rub comes in the fact that, in a mature basin, where many of the large NPNT discoveries have already been made, finding significant new volumes means you have to be prepared for a range of technical challenges – in Culzean’s case, the challenges of HPHT. It therefore stands to reason that such technically complex projects will increasingly drive change and innovation.

Handling the extreme pressures and temperatures in HPHT development safely calls for highly specialized equipment. That means a far greater cost than for a NPNT field. Our knowledge of the conditions and their effects on drilling and production has greatly increased. Developing the skills needed to make these fields a success is not only important for Maersk Oil, but also for the future of the North Sea. Together with West of Shetland and heavy oil, HPHT is believed to be one of the main areas of “running room” in terms of future UK North Sea development potential.

Developing an HPHT reservoir brings unique challenges. There are probably fewer than 100 HPHT wells currently producing around the world. It is, relatively speaking, a niche market. This makes the equipment necessary to complete these complex wells scarce, along with raising the costs, as equipment needs to be engineered to order; there are few “off the shelf” solutions. Upfront costs are also increased by the need to drill HPHT wells prior to the installation of the topsides in order to minimize depletion drilling. If we want to prolong the life of the UKCS we therefore have to be innovative to make more of these fields economic.


Strengthening the UK’s HPHT skill set is essential. That isn’t simply a message for operators. It also applies to partners in the supply chain who can export what they learn and develop far beyond the waves of the North Sea. What has been clear during the development of Culzean to date is that HPHT has a very distinct engineering community, defined by a willingness to share expertise and lessons learned. In an era when greater collaboration is so important, our experience has been tremendously positive, demonstrated by the willingness of other operators and experts to provide insight which has undoubtedly contributed to not only reducing the risk but also enhancing the engineering solutions of Culzean.

What we are doing with Culzean is working to build a truly 21st century installation, which keeps the safety of our people at its core. This has defined every part of the development plan, from detailed engineering, to drilling, to the layout of the topsides. We hope to deliver first production in 2019, and Maersk Oil and partners are committed to ensuring the wider engineering community shares in the lessons and learnings from the development of this project.