3rd January 2024

Leading the subsea test tree sector with technical innovations since 1983


HOUSTON – JANUARY 3 2023 – Leading energy services provider Expro (NYSE: XPRO) is celebrating 40 years of successfully leading the way in the subsea sector since the launch of its first subsea test tree system in the North Sea in 1983.


From the creation of its first 10ksi subsea test tree assembly (SSTTA) for an exploration and appraisal well project for Hamilton Brothers in the North Sea in 1983, to the development of its industry-leading high debris 15K shear and seal ball valve technology in 2023, Expro has remained at the forefront of subsea landing string technology.


Several of its SSTTA technologies have been on a first to market basis and instrumental in advancing the sector’s capabilities over the years. Expro has undertaken more than 3,000 subsea deployments in exploration and appraisal, completion, and intervention applications, and remains a global leader in large-bore SSTTA solutions.


Alongside the development of the 3” 10ksi SSTA in 1983, some of the other subsea well access major milestones for Expro in delivering ground-breaking technologies over 40 years include:


  • 1995 – introduction of the first 7 3/8” 10ksi horizontal tree completion landing string system, which supported the growth of the horizontal tree market, in the Norwegian North Sea
  • 1999 - launch of the industry’s first 6 ¾” high debris SSTTA system, in the Norwegian North Sea
  • 2003 – launch of the first large bore 6 ¾” 10 ksi subsea electro hydraulic control system, in the Gulf of Mexico
  • 2005 – first 6 ¾” 10ksi dual bore and mono-bore subsea test tree offshore North Sea and Angola
  • 2007 – first 15ksi 6 1/8” horizontal tree SSTTA and electro-hydraulic control system in the Gulf of Mexico
  • 2017 - development of 7 3/8” 10ksi high debris SSTTA


The evolution of subsea test tree assemblies has allowed Expro to expand into the open water well intervention market through the introduction of both riser-based and riser-less well intervention solutions.


Expro’s dedication to subsea well access application has recently led to the company being named Intervention Champion of the Year at the OWI Global Awards 2023.


Expro’s subsea capabilities have been boosted by the recent acquisition of offshore services provider PRT Offshore, the only company to offer a complete Hook-to-Hanger™ solution enabling comprehensive well completions, interventions, and decommissioning services from surface to subsea. The acquisition enables Expro to expand its portfolio of cost-effective, technology-enabled services in the North and Latin America (NLA) region and accelerate the growth of PRT Offshore’s surface equipment offering into the Europe and Sub-Saharan Africa (ESSA) and Asia Pacific (APAC) regions.


Graham Cheyne, Expro’s Vice President of Subsea Well Access, said:

“At Expro, we’ve been first to the market with many of our subsea test tree assembly products and, as future technical challenges arise, we believe that with our customer-bespoke solution philosophy, we’ll continue to be at the top of the subsea test tree application.


“From starting in 1983 supporting operators in the Norwegian North Sea, we’ve become a global player in all parts of the world, supplying fully integrated technologies and services from surface to seabed – the Hook-to-Hanger concept. The subsea test tree market operates in the full well lifecycle – from exploration and appraisal through to abandonment and decommissioning while continually looking to improve our delivery and operational performance, and service quality to our global client base.  


"Whilst leading in this market for over 40 years with many first to market technologies we are committed to delivering the new technology requirements of tomorrow in order to meet our customer needs whilst maintaining the high level of service quality and customer care”

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