Gas From Coast To Customer
Barry Wilkinson, making a very welcome return visit, spoke of the complex system and many challenges of getting North Sea gas into our homes. UK is the largest user of gas in Europe.
Starting at the giant drilling platforms, some of which tower over 250 feet above sea-level, many miles from our coast, which are the home of up to 150 mainly young, fit men and women responsible for carrying out the arduous task of drilling for and then supplying gas to us from the inhospitable North Sea. The men work 12-hour shifts, two weeks on – two weeks off.
Each rig has to be self-contained with accommodation, medical staff, cooking facilities, rest rooms and cinema. All supplies have to be brought in by supply ships and helicopter. A safety boat is on station at all times.
When subterranean gas is discovered it can sometimes be at pressures above 3,000 PSI (pounds per square inch). It is then left to blow off for two days during which time various measurements are taken. The pressure of the gas is then reduced to 2000 PSI, filtered and odorised ( natural gas which is 91.8% methane is odourless, non-toxic and has twice the calorific value of coal gas.) before being piped ashore in a pipeline buried in the seabed. Once ashore the gas pressure is again reduced, to 1,000 PSI before being piped to regional centres in the UK. Pipelines run mainly North/South with interconnections East/West for maintenance and safety purposes.
In urban areas the gas pressure is then reduced to 100PSI and finally to almost 1 PSI for supply into domestic homes.
Gas can be stored underground in specially treated salt caverns and even in exhausted gas fields under the sea. Liquid gas has to be stored at very low temperature in large insulated tanks.
Barry finished his talk by listing some common-sense safety precautions when using domestic gas.
When asked about remaining gas supplies, he said that he was confident that the North Sea could supply us with natural gas for the foreseeable future.