Britain Has Its Own Small Oilfields

Press, Volume XCIV, Issue 28159, 24 December 1956, Page 17

Britain Has Its Own Small Oilfields

(By

HENRY NICHOLLS)

Do you ever look at a gallon of petrol—if you can find one these days —and think of its romantic story? Do you think, perhaps, of its being born as a thick, black liquid, among Arabian sands, refined in plant languishing beneath a tropical sun, and brought by tanker to a British port across the storm-ridden seas?

The pictures you have imagined may be accurate. But be careful. That gallon of petrol may have come from a well in some corner of an English field.

Admittedly the chances are remote. But there is some oil beneath the hills and plains of Britain. About 60,000 tons a year is the present rate of production—out of a total British consumption of 25,000,000 tons a year. All right then, you may say, what are we waiting for? If the oil is there, why don’t we speed up wellboring and pumping until native production is enough to supply all our needs?

Unfortunately, that is impossible. There isn’t that much oil underneath Britain. In the great oil producing areas of the Middle East and America, the precious commodity is contained in vast underground “lakes” of oil-soaked rock. Some of them may be 50 miles across. The largest underground oil “lake” in Britain is probably not more than a mile or so across. In fact, the oilmen tell us, the best we can hope for is to push up production to the wartime rate of about 100.000 tons a year. And we shall do well to maintain the current rate of output. “Inverted Saucers” The existence of oil in Britain has been known for hundreds of years. Serious commercial exploitation began only 20 years ago. after a long period of exploration, which was sometimes zealous, and sometimes half-hearted, according to the economic climate at the time.

It is not easy to find the British oilfields, because the oil ir contained in such small reservoirs. Sometimes surface seepages give a clue to the presence of underground supplies. Sometimes only a trained geologist can recognise that the types of rock, and their formation, offer possibilities. Oil collects in "inverted saucers” in the upper parts of folds in porous rock, provided that there is a layer of non-porous rock above, to prevent the oil seeping upwards. But even if the geologist recognises that conditions are right for oil, he cannot say that the oil will be there. It has to be looked for, either by boring test wells, or by exploding charges and listening to the echoes. The best British oil wells found so far are in Nottinghamshire, about half-way between Nottingham and Newark. Production has been going on there since just before the war. The largest field discovered so far is there, beneath the village of Eakring. It is about two miles long. But many of the wells in Nottinghamshire have shown signs of drying up. This does not mean that all their oil is exhausted. It is a common feature of very small oilfields—the amount of oil in the "inverted saucer” is so small that not much has to be drawn off before the pressure falls too low for it to be worth pumping out. This is overcome by pumping water back into the ground round the edges of the "saucer.” The water gets

under the oil, and builds up its pressure again.

In this way, the Nottingham oilfields are being given a new lease of life. Even so, they will not last for ever. That is the main reason why an exploratory subsidiary company of one of the major oil firms is intensifying its search for oil. “Excellent Quality” The experts are pretty certain that there are many more pockets of oil under Britain. As they continue their search, they probably wish that the pockets were a bit bigger. But unfortunately, because the layers of rock in this country are usually very much folded, large pockets of oil cannot exist. Once you have found your oil, you can be fairly certain that it is of excellent quality. It is all refined at Pumpherston, in Scotland, the main products being motor spirit, diesel oil, wax and naphthas. Indeed, there is so much wax in British oil that it is a nuisance when the oil is being pumped out of the well. It isn’t a nuisance at the refinery, of course—it is a very valuable product there.

But the wax in crude oil starts to solidify if the temperature falls much below 80 degrees fahrenheit. And the temperature in Britain isn’t often that high. This drawback is overcome by heating the well linings electrically, and by pumping steel stoppers with leather ends through the surface pipes from time to time. There are other sources of oil in Britain. Nearly 100,000 tons a year is distilled from some of the shales found among the Scottish coal measures. Indeed, Britain is usually regarded as the world’s leading nation in shale oil production. Unfortunately, shale oil production is declining, partly because of the shortage of miners, and partly because, at the present rate of duty preference, it is hardly economic. Another 400,000 tons or so of oil a year is produced from coal and coal tar. So that gallon of petrol need not be quite so exotic as you thought. But even if it turns out to be “made in Britain’’ its story is still romantic.— Central Press.