Methods and systems for extracting natural gas are described herein. The source of the natural gas may be a reservoir of natural gas or natural gas and crude oil found on land or in a subterranean or subsea environment. The natural gas also may be that extracted from a subsea reservoir of naturally formed clathrate hydrate. The methods may be performed on land, at the sea surface or at the seafloor. The methods feature providing a suitable promoter to facilitate selective formation of a structure II (sII) methane clathrate hydrate to thereby store natural gas in a readily transportable form. The methods may also feature separating both natural gas and associated water involved in producing it from impurities.