PETROLEUM, OR ROCK OIL. 



GG7 



Evidently, the prospector will be aided by a 

 knowledge of the geology of, and the history 

 of explorations in, the various oil regions, as 

 well as by experience. Almost any of the signs 

 already named may be considered as affording, 

 where met with, a presumption, more or less 

 strong, of the existence of oil deposits ; and the 

 supposition thence arising requires then to be 

 tested by examination with reference to the 

 other indications. 



The Sinking of Oil Wells. The processes 

 involved in the sinking of wells for oil, and 

 which, with the exception usually of some feet 

 depth of superficial alluvium, must penetrate 

 mainly or altogether in the way of drilling 

 through rock, are substantially those .resorted 

 to in the case of artesian wells generally. The 

 place for a well having been fixed upon, a der- 

 rick of some thirty to sixty feet height its 

 frame being chiefly four strong upright posts, 

 standing some ten feet apart below and about 

 five feet above is erected over the spot. The 

 distance from the surface to the rock is at the 

 present time usually traversed by driving down 

 into the earth a strong cast-iron pipe, of an in- 

 ternal diameter of about five to seven inches. 

 This is forced down in' the manner of pile-driv- 

 ing. The power for this purpose, and for the 

 subsequent operations, including those of drill- 

 ing and pumping, is now commonly that fur- 

 nished by a steam-engine of some eight to 

 twelve horse-power. The cast-iron pipe is in 

 sections of a few feet length, which are succes- 

 sively jointed on above as required, till the rock 

 is reached. Drilling tools may be used to loosen 

 up the earth within the pipe; and the water 

 entering it from above converts this mass, as it 

 penetrates it, into a paste or mud: a "sand- 

 pump" a three to five-inch copper tube, six 

 feet long, with a simple valve in the lower end, 

 opening upward is then let down into the 

 muddy water, agitated until it fills, and raised ; 

 and these operations are repeated until the 

 whole depth is cleared. 



Of the complete drilling apparatus, consist- 

 ing essentially of the rope socket, of two heavy 

 intermediate links, or "jars, " the purpose of 

 which is to jar the tools loose when they might 

 otherwise stick fast in the rock, and of a " sinker 

 bar " and " auger stem," to the lower end of 

 which last is finally attached the " centre bit." 

 for cutting, or the slightly larger "reamer," 

 which is blunt and used for rounding and 

 finishing the opening made by the former, the 

 total weight is commonly not less than from 

 seven hundred to nine hundred pounds. By 

 the socket above the apparatus is attached to 

 the rope, which again is now commonly made 

 to receive its motion from that of one end of a 

 Avorking-beam suitably erected near the spot, 

 having a stroke of thirty to thirty-six inches, 

 and actuated by the steam engine. The centre- 

 bit has an edge of about three to three and a 

 half inches, and the reamer somewhat larger, 

 brings the boring to near the calibre of the pipe 

 above ; the drilling is with both performed sim- 



ply by the force with which *he tools are let 

 fall. As often as the boring has been carried 

 down a few inches, so that the cWirii would 

 clog the tools, these are withdrawn, and a some- 

 what smaller sand-pump is used to clear out the 

 comminuted rock by aid of the water which is 

 always present in the boring. It is said that 

 in gravelly or shaly formations a progress of 

 from three to ten feet a day is made ; in rock, 

 of from one to three feet. Judicious operators 

 commonly keep a record of the strata passed 

 through, their thickness, the place of veins of 

 water or oil, etc. Among the difficulties in the 

 way of sinking the iron pipe, are the meeting 

 of boulders, which then usually have to be drill- 

 ed through, the fracturing of the pipe, etc. ; and 

 in the way of drilling, the breaking of the bits, 

 or rarely, their sticking so that they cannot bo 

 removed, etc. ; and from causes of this sort the 

 borings, even when far advanced, must some- 

 times be abandoned altogether. And apain, 

 wells which have consumed months of labor, 

 may in the end prove unsuccessful. 



In ordinary wells, as soon as the boring has 

 struck oil, and in flowing wells, so soon as the 

 flow so far remits as to allow of the process, 

 the tubing of the well is to be performed. Sec- 

 tions of a copper or iron tube, two to three in- 

 ches in diameter, are screwed together to the 

 required length, a pump-barrel containing two 

 valves always forming the lowermost joint ; and 

 the tube so formed is lowered within the larger 

 pipe and boring, so as to enter the liquid in 

 the subterranean cavity. Along jointed pump- 

 rod is inserted within the tube, having at 

 its lower end a metallic valve-box, with its 

 valve opening upward. The pumping of the 

 oil or water from the well is effected, subject 

 to the control of the operator, by connecting 

 the rod with the working-beam or other de- 

 vice for imparting motion to it. In order to 

 arrest the downward flow around the tubing, 

 and into the oil cavity, of water from vcius 

 pierced in boring the well, a sort of packing is 

 made use of, in form of what is known as 

 a " seed-bag." This, a leathern tube some 

 eighteen inches long, partly filled with flax- 

 seed, and closed at the ends, is, before sinking 

 the tubing, bound about it near the lower end : 

 once in place, the water soon swells the flax- 

 seed so as to close the space about the tube, 

 and thus the further access of water from above 

 is prevented. The upper end of the coiled seed- 

 bag being more slightly tied, this readily rup- 

 tures whenever an effort is made, from any 

 cause requiring it, to raise the tubing. "\Yhen 

 two or more wells belonging to different owners 

 enter the same oil cavity, or are in any way 

 connected below, the drawing of the tubing of 

 one of the wells, allowing as it does the water 

 to flow freely down into the oil reservoirs, floods 

 the connected wells also, usually rendering 

 them quite worthless for the time. In this 

 way the proprietors of one well have, in some 

 instances, compelled those of others near, and 

 more profitably yielding, to come to their terras. 



