Aberdeen-based Plexus has teamed up with UK manufacturer BEL Valves to offer a surface wellhead and tree production package that builds on the metal-to-metal seal technology that Plexus says reduces the need for repair and maintenance and lowers the risk of methane emissions.

The joint venture indicates a new business strategy for the 20-year-old Plexus, which made its name selling wellhead systems incorporating the friction-grip technology, dubbed POS-GRIP, for jack-up exploration drilling.

The company sold that business line to TechnipFMC early last year and has since turned its attention to what Plexus Holdings technical director Craig Hendrie calls the “core business of production wellheads and christmas trees based on POS-GRIP technology”.

The move, part of what Plexus founder and chief executive Ben van Bilderbeek has called a “reconstruction” of the business, was brought on by the oil price crash.

With the jack-up services business divested — and a steady revenue stream coming in from the technology licence — the company set out to apply the friction-grip method to the “much-larger prize” of production wellheads and trees, Hendrie says.

The technology involves a metal-to-metal sealing which is externally activated to squeeze the outer wellhead housing so that it grips the hangers and tools and holds the seal rigid.

The seal has been used in oil and gas assemblies since 1999, Plexus says, and is proven to maintain its integrity in the harsh offshore environment.

The company had determined that the technology was suitable for production wells and experience had shown it to be “highly efficient, cost-effective, easy to work with and much more reliable than conventional wellhead technology, eliminating any leaks”, Hendrie says.

“But we didn’t have access to valve and christmas tree technology in our arsenal, so we set about finding the right partner for that,” he says.

“We were very proud to find another UK-based partner to help us on the next leg of our journey.”

Newcastle-based BEL Valves has been designing and manufacturing high-pressure, high-temperature valves for oil and gas applications since the mid-1960s.

“It is one of the most longest-standing valve companies in the world, certainly in the upstream oil and gas sector, although they’ve never been specifically in the christmas tree market because they didn’t have access to wellheads,” Hendrie says.

“They didn’t have wellheads and we didn’t have trees, so joining forces made an enormous amount of sense for both parties, as well as the fact that we both have the kind of technology and service set-up which is much more technically and scientifically based, to provide equipment that can far outperform current standards.”

Step-change

Qualification standards for the many components in a production system are relatively low, he says.

“Which means typical API wellheads and valves leak over time. They are designed to be maintained on an annual basis," Hendrie says.

"Annular seals and valves regularly leak, which is part of the methane emissions crisis — as well as causing wells to be shut in, with the resulting loss of production and repair costs.

“We are now demonstrating that we can create a real step-change by providing a package of equipment which is innovative both in reducing the number of leak paths and in making the installation steps quicker and simpler, as well as technology which can be qualified to performance standards much greater than the status quo.”

Plexus is a majority shareholder in the joint venture, Plexus Pressure Control (PPC), and will control the design and manufacture of the trees and wellhead annulus valve systems. PPC will be based in Plexus’ existing Aberdeen facility.

Hendrie says the dry-tree production systems will be applicable in many regions but the company’s initial focus will be “on the North Sea, 15 to 20-year field life type of applications, where the cost of maintenance over that period is extremely high, as are the risks of leaking and incidents”.

Plexus says the PPC offering can reduce operating expenses for wellheads and trees by as much as 70%, more than offsetting the higher up-front cost. “We are not a high-volume manufacturer, so the equipment will typically cost more, and the right environment can justify that,” Hendrie says.

PPC will target offshore surface platforms and reservoirs ranging from conventional hydrocarbons to high-pressure gas, as well as inland drilling in Europe — “high-pressure gas particularly”, Hendrie says — where aggressive measures to eliminate greenhouse gas emissions will be vital for the continent to meet its stated zero-carbon goals.

He adds: “We can offer technology which is guaranteed to be leak-free and maintenance-free for field life.”

Focus

Plexus and BEL seal the deal