Show rotary Is common type of drill used on plateau when a guilt lui lt glances nut out of his indo ns ix lie drives alone along any any one of tile highways on the colorado flattau IlUf Ilat tau flu he may see on oil oil well drilling outfit it hard ard at voik in of black cold id ordinarily ordinal lly the lie tot longist f ahei ii fo little A after thought lo 10 the file me hanks of oil well ell drilling drill ing for it N 1 something about uhichi he knows very little drilling alf powered by steam gatig 9 IS or caoline ga oline ale ate of two to renie rene it 1 kinds cable tool and rotary elji cable tool pounds its way ay down town through eaith and lock much as punching a hole in the ground with an iron bar the rotary drills its vay ay down as one might drill a hole by rotating file point of 0 a screwdriver against a p piece jece of soft wood rotary rigs account for or most of the drilling footage today the rotary Is complicated in detail but dahly simple in principle A cable from a huge drum or winch runs to the lop top of the deri derbick ick passes through a heavy heavy pulley called a crown block then down to a sort of block and tackle arrangement c called a I 1 I 1 e d a traveling block to he the bottom of the traveling block is attached a hook book with alth a swivel joint which supports the kelly the kelly helly is a 40 foot hollow steel forging either square or hexagonal in cross section it passes down through a similarly shaped opening in the rotary table which is 3 a flat horizontal steel casting resting on bearings in the derrick floor the rotary table Is connected to th the power ower source by a chain drive crivea and evas as it rotates it causes the kelly to rotate too to get the picture force a hexagonal pen cil through a piece of carbonard car board if it the cardboard is rotated the pencil turns yet the pencil rencil can be moved up and down through th the e bo hole 1 e below the kelly comes the drill pipe and drill collar and below them the drill bit host alost drill pipe is made in 30 foot sections with threaded ends roughly the same as water pipe As the bit drills down the kelly slowly sinks through the opening in the rotary table when it can sink no farther it is lifted out uncoupled and a new section of drill pipe is a added d ded eventually the string 0 of f pipe may be two or three miles mile s long ai 1114 vicar out odd and have to he b replied acil bcd tile whole shing mi ink hn hit tn to lip he taken out of iho the hole this Is done hv dionn eting the kelly and it to one kllc kide then raking ilic pipe and I 1 biva king or list monn eting ting it at evry lard third or I 1 it il III joint ain in tile he I 1 gi it of alic ile |