SEARCH FOR OIL

Wairarapa Times-Age, 27 October 1939, Page 6

SEARCH FOR OIL

SOME WONDERFUL DEVICES ADOPTED EXTRAORDINARY INSTRUMENTS CONTRIBUTION OF SCIENCE. Science has brought some wonderful devices into operation in helping man in the search for oil. The old idea of making a hole in the ground, here and there, on the chance of finding oil has been forgotten. The modern oil prospector uses a number of extraordinary instruments which help him first of all to locate oil and then to extract it from the ground. The most difficult part is finding the oil. In this search science comes to our aid, even to making artificial earthquakes and taking tiny underground photographs. . In Taranaki, where a party of American experts is searching foi’ oil, the making of artificial earthquakes will be an important phase of the work. This will be done by setting off small charges of dynamite at various depths. The vibrations set up by the explosions are carefully recorded on delicate instruments on the surface. From the results of tests over a wide area, the experts are able to tell what the geological structure of the country is like, and they may then decide on the best points for oil boring. Once having chosen the most likely looking areas, the boring experts take over from the geological team, and they, too,, have in their control some wonderful machinery. At Totangi, near Gisborne, where a party is drilling for oil, this equipment is in operation. It is one of the finest plants in the world, and is capable of drilling down to 12,000 feet. Over the actual bore is a huge ring, 155 feet high, and the drill i^'directed down the centre of it. The drill itself is forced down through the earth by a rotary or revolving action. The giant bit—an I ugly looking thing, made of tough steel with sharp cutting edges and weighing several tons —bites into the ground and makes a hole which varies in diameter. The width of the bore varies according to the depth. For the first 180 feet a 25-inch hole is driven, and from there to 2500 feet the diameter is reduced to 17 inches. After that the bore goes down at a diameter of 12 7 1 inches, and beyond that again it will be 7"; inches. For the first 170 feet the hole is concreted. to stand the tremendous strain that may be exei'ted upon it. The drilling bit is attached to a driving unit under the derrick by hollow steel points 90 feet in length, 6 5-8 inches in diameter, and consisting of three sections. These joints are added as the head of the drill grinds deeper.

At every 100 feet a check is taken to see that the' hole is straight. The drill is affected by the varying kinds of strata, and there are cases on record in other countries where a drill has struck off at an angle of from 50 to 20 degrees. In extreme cases it has been, known to turn as much as 45 degrees. With big deviations like these, the man in charge of the job has to do some more calculating and considerable adjustment to bring the straying drill back to normal. When a check is made, the hollow steel joints are unscrewed one by one and stacked aside as the bit is brought to the surface. These have to be screwed on again when the drilling is resumed. The bit keeps on screwing into the earth until it reaches the precious liquid or until the prospectors are satisfied there is no oil there. If oil should be struck, special tools will be used to carry on the work. They are made of bronze, because bronze does not make sparks—the sparks are dangerous when petroleum is anywhere near.