Graphene Added to Protect Subsea Oil, Gas Pipes

Researchers are incorporating graphene into the polymer liner used in subsea pipes transporting oil and gas. Image courtesy of The University of Manchester.

Researchers at The University of Manchester (Manchester, United Kingdom) and The Welding Institute (TWI) (Cambridge, United Kingdom) have found that laminating subsea oil and gas pipes with graphene can help reduce the permeation of corrosive substances.

In their research, the team has incorporated graphene into a polymer liner often used in pipes transporting crude oil and gas from the subsea floor. These pipes are generally made of internal layers of polymer or composite and external strengthening steel, they explain. Within these pipes, fluids are often found at very high pressures and elevated temperatures.

When carbon dioxide (CO2), hydrogen sulfide (H2S), and water permeate through the pipe’s protective barrier layer, the steel has the potential to corrode. This causes the pipe to lose strength over time, leading traditionally to a risk of failure.

In their study, the researchers found that if the graphene was mechanically mixed with the plastic—or if a single layer of graphene were applied—gases could still pass through.

However, by laminating a thin layer of graphene nanoplatelets to polyamide 11 (PA11)—a plastic often used in these liners—the researchers produced structures that performed as exceptionally good barriers.

The multi-layered laminate structures were tested at 60 °C (140 °F) and at pressures of up to 400 times atmospheric pressure, with CO2 permeation reduced by over 90% compared to PA11 alone. Meanwhile, the permeation of H2S was reduced to undetectable levels.

“Our work represents an important step in taking graphene out of the laboratory and into the real world,” says Peter Budd, a professor of polymer chemistry who led the Manchester team.

Source: The University of Manchester,