ADN has excellent reporting on the subject:
Repair divers inspecting a natural gas leak at a Hilcorp Alaska pipeline in Cook Inlet have found a gash that appears…www.adn.com
It’s hard to tell from the TP article what the pipeline is carrying:
In early February, officials with pipeline company Hilcorp Alaska reported that natural gas was leaking into Cook Inlet from an eight-inch pipeline used to transport gas to offshore oil drilling platforms.
If this is gas going TO the drilling platform it could be well gas with a whole host of other things besides methane (i.e. ethane through pentanes, aromatics like benzene and volatile metals) to be run through gas processing OR it could just be mostly methane (after processing) and reinjected back into wells to maintain reservoir pressure.