An Aerial view taken on August 18, 2011

As US natural gas production swelled in recent years – largely a result of shale gas development – and prices fell amid burgeoning supply, producers moved rigs to economically greener pastures. In a world of comparatively high oil prices, this meant more liquids rich natural gas resources that produced ethane, butane, propane and pentanes, known as natural gas liquids, which fetched higher prices than dry natural gas. NGLs are used to produce plastics and petrochemicals.

“The dirty little secret is that most gas wells are really ethane wells with a little natural gas byproduct,” Albert Passy, Principal Analyst at Norwegian oil company Statoil said at the recent USAEE/IAEE North American Conference.