Engineering Wonders of the World
Volume I

326 ENGINEERING WONDERS OF THE WORLD. DIGGING A SHAFT ON THE BINAGADI OIL FIELDS, NEAR BAKU. The sail-cloth supported by the three poles acts as a wind sail for conveying fresh air to the bottom of the shaft for ventilation purposes. evolved district of the known. adhered to. The miners, specially skilled by years of experience and practice, are able to excavate shafts one metre square to a depth of 300 to 500 feet as cheaply as a well can be drilled. The process, however, is slow, and is attended by considerable risk, as the strata are so impregnated with gas that the miners are protected from asphyxiation only by the pumping of copious supplies of air down the well. The development of the drilled oil well is largely bound up with the story of the brine wells of certain parts of the United States. As early as 1797 the brine wells of Kanawha Valley, West Virginia, produced, along with the salt-impregnated water, amount of oil, which was The story of Drake’s dis- covery has been told too often to need repetition here. Since his time the practice of drilling has been gradually in each oil as the peculiarities strata have become At first the imperfect tools permitted only shallow wells to be sunk; but by degrees the depth has been increased as the result of improve- ments in machinery and tools, till it is not unusual now to drill to depths of 2,500 and 3,000 feet. in use are almost legion in Systems of sinking Wells. Brine Wells and Petroleum. quite a large used for lubricating machinery and burning in lamps. By 1830 these wells had been driven to a depth of 1,500 feet. Later on the natural gas issuing from the wells was em- ployed for lighting the salt works and evap- orating the brine. But it was not until Drake demonstrated, in 1859, the full value of the “ impurity ” that the first oil “ boom ” began, and people forgot the brine in their frantic search for rock oil. The systems number. They can, however, be divided into two large classes—(1) percussion, and (2) rotary. The first have for object the pulverization of the strata into small fragments, which can be raised in the form of mud ; the second either aim at tho extraction of a core, or are used for washing away soft formations by means of a con- tinuous flush of water. The percussion system may itself be sub- divided into—(a) cable drilling, as generally used in the United States ; (6) pole drilling, which is the common practice in Russia, Canada, and Roumania. Water-flush systems are used to some extent in Roumania and Austria, and especially in the Texas and Louisiana oil fields of America, where quick- sands are prevalent. Unfortunately, space permits of the first only of these systems being described. Con- sidering, however, that the tools and under- lying principles of both the cable and rod systems have much in common, a general idea of the modus operandi of both will be gained by following out the practice adopted in tho American fields.