Offshore Gas Safety
Safety has Top Priority for Offshore Gas Industry
“Nothing to Cry Over”
“If there is a leak in a heat exchanger in a dairy, you get spilled milk — and we all know that’s nothing to cry over”, says Magnus Hoffstein, Alfa Laval’s market unit manager for gas. “But if you have a leak in a gas plant it could lead to deaths, so selecting the right type of equipment cannot be taken lightly. In these cases it’s good to have a strong team including polymer specialists and senior design engineers to discuss the selection with. We obviously want to offer a competitive solution, but we will never compromise on safety.”
Actors in the gas industry have to find a balance between equipment cost and performance, and that balance can depend on the particular application. At a gas–sweetening plant, in one position it is perfectly fine to use a gasketed unit — no hydrogen sulphide, moderate temperatures and reasonable pressures. But in another position in the same plant, the conditions could destroy the polymer gaskets.
“So we make an assessment,” says Hoffstein. “What is the likelihood of a leak and what are the consequences? If the consequences could be fatal, then we only offer our safest solution, the welded Compabloc, even if the customer claims to want a gasketed heat exchanger.”
Safer, but More Expensive
In the vast majority of cases, the customer goes for the safer but more expensive solution. “It’s usually a matter of informing and educating,” says Hoffstein. “The safety awareness throughout the gas business is so high, so it’s fairly easy to get everyone aligned towards reducing risk.” Following its acquisition of Aalborg Industries, Alfa Laval is also a major supplier to the natural gas industry of inert gas systems, which play an important role in safety and are required by law on LNG tankers and elsewhere.
“We rely on inert gas systems a lot,” says Arnold. “We start out with equipment that is full of air and we want it to be full of hydrocarbons. If we replace the air directly with hydrocarbons, there is a risk of explosion. In these big complex facilities almost universally we displace the air with inert gas first, and then displace the inert gas with hydrocarbons, so that we never have a mixture of air and hydrocarbons.” New safety challenges are being thrown up by the fact that gas is being produced in ever-deeper water. “It’s always harder to control something you can’t see,” says Arnold. “Flow assurance and keeping things from plugging or corroding are much more complex in deep water than they were in shallow water. And of course now we are producing from gas wells 120 kilometres from shore and that creates a whole new bunch of problems.”