Strohm, Petrobras and Shell have completed a joint industry programme (JIP) qualifying a 6-in. carbon fibre-PA12 Thermoplastic Composite Pipe (TCP) flowline for ultra-deepwater service, clearing the final technical hurdles before Petrobras installs and operates a pilot flowline in a Brazilian pre-salt field in early 2027.

The qualification, carried out by DNV in accordance with DNV-ST-F119, covers alternating water and gas (WAG) injection service for enhanced oil recovery under the most onerous conditions of the Brazilian pre-salt, including high CO2 content, with a 30-year design life.

The programme logged more than 50,000 testing hours — the equivalent of six calendar years — spanning materials, sealing testing and full-scale validation. The full-scale campaign alone comprised more than 40 individual tests conducted across seven laboratories and certified testing houses in Europe and Brazil. The work complements earlier material testing performed by Strohm's supplier Evonik.

System-representative testing validated the interaction between the pipe, end-fittings and sealing interfaces under realistic operating conditions, according to the company, with the aim of ensuring predictable performance across the system lifecycle.

The corrosion problem

Brazil's pre-salt provinces host some of the most productive wells in the world, but the high CO2 concentrations in these fields have been reported to cause premature failure of conventional flexible pipes. The failure mechanism is stress corrosion cracking, an aggressive form of corrosion driven by CO2. Avoiding it has forced operators to replace conventional flexible flowlines at regular intervals, deferring production in the process.

TCP removes the issue by removing the metal. Martin van Onna, Strohm's CEO, said: "The project has great strategic relevance for the subsea sector in Brazil and beyond, as it decisively solves one of the major pipeline integrity challenges identified in recent years: the risk of stress corrosion cracking in environments with a high CO2 concentration. By using non-metallic TCP, corrosion is simply eliminated, strengthening system integrity and operational reliability in challenging subsea environments."

Installation logistics were a central design consideration. "Strohm's TCP flowline is designed to be installed by today's installation vessels without the need to change anything," van Onna said. "The installation procedures do not require material changes and the pipeline's behaviour both on the vessel and subsea during installation is fully predictable and in line with industry practice. Strohm's TCP can be considered as a suitable replacement for flexible lines currently vulnerable to corrosion and we are ramping up production capacity to meet the expected demand."

The pipe's fatigue performance exceeds that of steel, and its lighter weight allows installation from vessels of convenience rather than dedicated pipelay spreads.

Integrated methodology

Ramón Rojas, JIP programme manager at Strohm, described the development approach: "The development is based on a fully integrated methodology that combines engineering design, material selection, structural analysis and full scale validation. This approach ensures that predicted and actual performance are aligned, providing a high level of confidence in the system's behaviour under demanding operational conditions and guaranteeing reliability throughout its 30 year service life."

Philippe Noury, technical lead for the DNV verification, said the qualification "provides the independent technical basis for moving into the planned pilot" and gives the industry "a practical example of how non-metallic flowlines can be assessed under DNV-ST-F119 for demanding, high-CO2 deepwater service."

Offshore trials completed

Following the DNV qualification, offshore field trials with a TCP flowline concluded successfully in July 2026. The trials included deep immersion performance (DIP) tests and subsea vertical connection tests, designed to validate the pipe's robustness and confirm reliable performance during offshore handling, installation and subsea system connection.

The full-scale qualification and offshore field trial marked the final steps before Petrobras proceeds to install and operate the pilot flowline in a Brazilian pre-salt field, planned for early 2027.

The watch item: whether that pilot converts into commercial deployment across the pre-salt, where operators face recurring replacement costs on CO2-susceptible flexible lines — and whether Strohm's ramped-up production capacity meets the demand that follows.