718 PETROLEUM j DERRICK FLOOR DERRICK SILL ^s^S-Q^m E=i< (O DR/V/E PiPE=O , ft . SfttttfNMr?- S and which is held down by 2000 feet of motionless air, must be followed by an expansion into the porous rock that drives both oil and gas before it, until a point of maximum tension is reached. The resistance then becomes greatest within the rock, and, reaction following, oil and gas are driven out of the rock and out of the well until the expansive force is expended. Figs. 2 and 3 show the general arrangement ot pumping and flowing wells. After the well is torpedoed it is prepared for flowing. A section of 2 -inch pipe, per forated with holes, which serves as a strainer, is low ered into the well and other sections coupled to it, until a sufficient length is intro duced to reach from the bot tom to a point above the oil- sand. An indiarubber packer is then attached in such a manner that within it the pipe that is above it slides in that which is below it, and the rubber is forced yz~ against the sides of the drill- 5g hole with the weight of 1200 Iff to 1800 feet of 2-inch pipe, "-. thus making a gas-tight _ joint. The pressure of the gas within the oil-sand and ^ below the packer forces the = oil to the surface. As the ? flow diminishes, a pump- barrel is introduced to the bottom of the well and the oil is lifted to the surface. Gas -pumps are also used to remove the pressure of the atmosphere from the well | and rock. In some of the =Jjsf older districts from twelve to forty wells are attached to one engine, and pumped by what is called a "sucker-rod" connexion. - In West Vir ginia five different horizons of sandstone have yielded oil. A well w^is put down there in 1865 to the "first white oak sand," 255 feet in depth, and pumped at inter vals for fifteen years ; it was then reamed out to 8 inches in diameter, and from the bottom of the old well was carried down 4 inches in diameter to the third sand. A tube was inserted with a packer at the bottom of the 8-inch hole to stop off the heavy oil of the first sand. Through this oil of a speci- } fie gravity 79 (45 B.) was - pumped from the third sand, | and through a second tube, ^ introduced beside the first to E the bottom of the old well, - oil of a specific gravity 88 (27 B.) was pumped from the - first sand, both pumps being ^ simultaneously worked by 1 the same walking- beam. The first-sand oil was worth seven dollars a barrel, while the third-sand oil was worth only one dollar a barrel. The average duration of the profitable production of an oil-well is estimated at F,g. 3.-Flowmg Well, five years. This period is subject to great fluctuations, as there are wells in the Cole Creek district of the Bradford field that were abandoned in two years, while wells on Triumph Hill, Venango county, where the sand is 125 feet thick, have been pumped fifteen years. The yield of some single wells has been enormous. A well in Donegal township, Butler county, Pennsylvania, produced more BpTTOM _O =- SfZ HOLE SSS&& -c>~o~^ 0-0 Cr -f}<3-o-*l< q^^ja . --* =>,.-> : ,- PERFORATED PlPEfSZ?*? than 110,000 barrels in ten years, and twelve wells, of which this was one, on the same farm produced over 750,000 barrels. In Burmah and other Eastern countries petroleum was stored and transported in flasks and jars. In the United States it was for many years transported in barrels made tight for oil by being coated on the inside with a stiff solution of glue. Later, it was transported on the rivers in bulk barges, and on the railroads in tanks upon cars. These tanks were at first made of wood, but they have lately been made of iron. The usual form is a plain cylinder, 24 feet 6 inches long and 66 inches in diameter, having a capacity of from 4000 to 5000 gallons. These cars are also used in the Caucasus. At the present time, in all the regions pro ducing petroleum in commercial quantities, the bulk of the crude oil is transported through pipe-lines, which consist of lines of pipe carried across the country, often for hundreds of miles, through which the oil is forced by powerful pumps under a pressure of from 1000 to 1600 lt> to the square inch. Eacli well h:is a tank into which the oil flows from the well, and from which it is carried in a 2-inch pipe by gravity to a pumping station, where it is pumped into the "main line." Main lines run out of the oil -regions of Pennsylvania to Cleveland (Ohio), Pittsburgh (Pennsylvania), Buffalo (New York), and New York, Philadelphia, and Baltimore on the Atlantic coast. They are constructed of 6-inch pipe, the joints of which are screwed into couplings like sections of gas-pipe. During recent years the production of petroleum in excess of anv demand for it has led to the storage of vast quantities (30,000,000 barrels in 1882) in iron tanks of enormous size. Many of these tanks are owned by private individuals, but the majority belong to the pipe-lines. There are 1375 iron tanks connected with the united pipe-lines, ranging in capacity from 1000 to 38,000 barrels, and representing a total storage capacity of 38,000,000 barrels. These tanks are frequently tired by lightning or other accidents, and when burning present a spectacle of unsurpassed grandeur. The bulk of the trade in crude petroleum in the United States is conducted through the pipe-lines and their certificates. When oil is received into the line from a well, the amount is ascertained and passed to the credit of the well-owner on the books of the company, less 3 per cent, to cover loss in handling. This oil is held like a bank-deposit, subject to transfer on a written order. When such an order has been "accepted" by an officer of the company it becomes an "acceptance" or "certificate," and is then negotiable like a certified cheque. As the exchanges deal only in certificates of 1000 barrels they are made of that amount so far as is possible. When oil is delivered by the pipe-lines a pipage charge of 20 cents per barrel is paid and a storage fee of 12 50 per 1000 barrels per month must be paid at least once in six months. The issuing of certificates by the pipe-lines has made speculation in oil, brokerage, and exchanges possible to an extent vastly beyond the requirements of any actual trade in the oil itself. About 250,000,000 barrels of petroleum have been produced in the United States and Canada from 1859 to 1884. No reliable statistics are to be had of the production in other regions, but of late years the Caucasian fields have yielded about 5,000,000 barrels per annum. The total annual production for 1883 cannot be far from 35,000,000 barrels. Technology. The technology of petroleum is quite simple. In the crude state it enters largely into mixtures with other oils, tallow, lead, soap, graphite, &c., that are chiefly used for lubrica tion. Crude petroleum is also filtered through charcoal. Crude oils that are too fluid for lubrication are reduced to the required consistence by partial evaporation, both by exposure to the sun in shallow tanks and also by distillation of the more volatile portion in stills. Such oils are called "reduced oils." In the technology of petroleum by distillation a great variety of details are employed by different manufacturers, but in general they may be treated under the three heads of destructive distillation or "cracking," distilla tion with superheated steam, and distillation in vacuo. The stills used vary greatly in respect of form and capacity. Formerly stills holding 80,000 gallons were used, but recently they have been constructed of a capacity of from 40,000 to 48,000 gallons. They are ordinarily made either in the form of plain cylinders 30 feet in length and 12 feet 6 inches in diameter, and set horizontally in banks of three or more, or there may be an upright cylinder 30 feet in diameter and 9 feet in height, set vertically with numerous fire boxes arranged around the circumference. Another form of still is an upright cylinder holding about 1000 gallons, heated from beneath and furnished with a steam-coil immersed in the body of the oil. In this coil the steam is superheated to the tempera ture of the oil, and is then allowed to escape into it, by which means the overheating of the oil is prevented and the distillation assisted by the mechanical action of the steam in lifting the oil- vapour out of the still. Another form of still is a vacuum still, in which a partial vacuum is maintained by a pump. The top of the still is usually constructed with a high dome, into which the vapours rise and from which they escape into the condensers. The condensers usually consist of a large number of 2-inch pipes immersed in water contained in a long trough. The distillation
