Shell says it is continuing to evaluate possible gas-to-liquid (GTL) production in the US to add to its huge Pearl project already established near Doha in Qatar.

The oil producer operates the first commercial GTL plant in Bintulu, Malaysia as well as the world's largest such site, Pearl GTL and is mulling production on the US Gulf coast as technology makes new supplies potentially available.

"Shell is considering construction of a very big GTL plant in the US," Shell fuels strategy adviser, Jean Cadu, told this week's Shell Energy and Technology Forum near Paris. "We have got two already, one on a massive scale in Qatar and one in Malaysia.

"The question is now, should we start one in the US? An investment like this one is enormous - we are talking more than US$10bn.

"Before you plough a sum of money like that, you need to try and understand what the impact might have on the overall oil balance."

Shell has previously estimated the US could be self-sufficient in energy within the next 20 years as it starts to reap the benefits of a huge increase in gas production.

However, any investment would have to be on a vast scale and with the oil producer's colossal Pearl GTL project costing US$20bn for example, any US decision is being mulled at board level.

"It is being considered at the moment," Shell general manager technology commercial and industry sales and lubricants, Richard Tucker, told just-auto on the sidelines of the Paris conference.

"It is obviously something where you need to make very careful consideration [of] the financial situation.

"That will be signed off at a board level - it is certainly under consideration. A whole bunch of other people are considering GTL in the US [at] the same time."