The natural gas is held in a reservoir rock named the Collyhurst Sandstone which can be seen in parts of Northwest England. It is a Lower Permian sandstone rock deposited by desert sands and rivers. It is referred to as a “conventional reservoir” which means it is a sandstone that holds the natural gas within the pore spaces between the sand grains. The Skeddan Collyhurst sandstone conventional reservoir is the Irish Sea equivalent of one of the Southern North Sea sandstone reservoir rocks, which has been producing natural gas for the UK since the 1960s.