BORING FOR OIL
Closely similar to coal in chemical matter–that is to say, consisting
chiefly of definite chemical compounds, called hydrocarbons, built
up of only two elements, carbon and hydrogen, and of no other–is a
very remarkable class of mineral substances known to the ancients
as "bitumen." In its widest sense, it includes "natural gas," the
variously mixed liquids called "petroleum" and the solid "asphalts."
In ancient times the more fluid kinds of petroleum issuing from the
ground in South Russia and Persia were called "naphtha," and that
name is still applied to the more volatile hydrocarbons obtained by
the distillation of such substances as coal-tar (the residue of the
extraction by heat of commercial gas from coal), bituminous shale,
petroleum, wood and some other bodies which owe their existence to the
activity either of living or of long-extinct and "fossilized" plants
and animals.
The bitumens, together with coal, present in their natural state a
very large variety of inflammable constituents–gaseous, liquid, and
solid hydrocarbons; but, when "distilled" at various temperatures and
under conditions determined by the manufacturing chemist, they yield a
still larger series of pure separable bodies, which have been minutely
studied and classified according to their chemical constitution.
They are produced in great chemical factories in large quantities
for use in the most diverse ways invented by human ingenuity. Thus
natural gas–superseded by distilled coal-gas–has served for fuel and
for illumination: refined petroleum serves not only for those uses
in general, but as the special source of power in the engines of
motor-cars and aeroplanes. A wonderful solid crystalline wax-like
substance, paraffin, as white as snow, is distilled in enormous
quantities (nearly three million tons a year) from "bituminous
shale" or "oil-shale" in this country alone. It can be obtained in
soft (vaseline) and liquid forms, and in fact the "paraffin series"
recognized by chemists starts from the gas "methane," or marsh-gas,
and comprises some thirty kinds, leading from gas to volatile liquids,
thence to viscid liquids, to butter-like solids, and up to hard
crystalline substances which melt only at the temperature of boiling
water. Endless chemical manufacturing industries–_e.g._, those of
dye-stuffs and explosives–depend upon the chemical treatment of these
paraffins and of various bodies obtained as secondary products in their
preparation. Benzine and aniline are chiefly obtained from coal-tar.
The oils and waxes of quasi-mineral origin have a great advantage over
vegetable and animal oils in many uses, since they are not liable to
become "rancid"; that is to say, to decompose owing to the action on
them of bacteria. A marked difference between the paraffins (often
distinguished, together with the "olefines," as "mineral" oils) and the
oils and fats found in living plants and animals is that they do not
"saponify"; that is to say, they do not form those combinations with
alkalis and other bases which are called "soaps," nor can they serve as
food to man or any other animal. They are not acted on by the digestive
juices.
From ancient times natural deposits or outpourings of "bitumens"
have been known and used by mankind. The Assyrians and other early
peoples of the East used "asphalt" (translated by the word "slime"
in the English version of the Bible) in place of calcareous mortar
in building; and to this day it is used largely in this country as a
"damp-course" in walls built of brick. Great deposits of asphalt are
found in Central America and some of the West Indian islands, and
"quarried" for commercial purposes. The great pitch-lake of Trinidad
yields an abundant supply. In the Val de Travers, in the Canton of
Neuchatel (Switzerland), a rich deposit is worked which, mixed with
earthy material, forms a road-making concrete, largely used in London
and other cities, and also for main roads in country districts. The
ancient Egyptians used asphalt for embalming the dead. But the ancients
also knew natural springs of liquid bitumen–that which nowadays we call
petroleum–some of them freely flowing like water, which would take
fire and burn for long periods, and were described as fountains of
"burning water." We find, as we pass from the Middle Ages to the days
of geographical exploration, records of such springs of inflammable
oil and of natural inflammable gas in all parts of the world–Japan,
China, Burma, Persia, Galicia, Italy (Salsomaggiore), Central and North
America, and of not a few in these islands–for instance, in Shropshire,
Derbyshire, Sussex, Kimmeridge and various sites in the southern
counties. The oil was, until the middle of the last century, valued
chiefly as a medicinal application, and "Seneca oil" and "American
medicinal oil" were largely sold and used as an embrocation in the
United States.
We owe the introduction of the name "petroleum" to Professor Silliman,
who in 1855 reported upon the "rock oil or petroleum" of Venango
County, Pennsylvania. The first attempt as a commercial enterprise
to obtain rock-oil or petroleum by _boring_ into the strata in which
there was local evidence of its existence in greater or less quantity,
was made in 1854 by the Pennsylvania Rock Oil Company. After some
unsuccessful attempts, when the drilling had been carried to a depth
of 69 ft. the tools suddenly dropped into a subterranean cavity, and
on the following day the well was found to have "struck oil," and
twenty-five barrels a day were yielded by that well for some time. From
here the industry spread over the States and Canada, and in 1908 the
year's yield was 45,000,000 barrels.
Since 1870 the industry has spread all over the globe–Russia, Galicia,
Rumania, Java, Borneo and Burma being prominent sources of the oil
supply of the world. The raw petroleum of different localities differs
in each case in the amount of solid paraffins and olefines dissolved
in the liquid paraffins. Other substances also are dissolved in it in
variable amount–such as benzene, acetylene, camphene and naphthalene.
The fact that the oil, when reached by a boring, is often found to be
under a considerable pressure, so that it rises and flows from the
surface of the well, or even may shoot up as a great fountain, is
an important feature in the oil-seeking industry, though the supply
depends largely on pumping and not necessarily on natural flow. The
borings when made, act like Artesian wells, and sometimes are carried
to a great depth. Those in Pennsylvania vary in depth from 300 ft. to
3700 ft., according to the distance below the surface at which the
oil-bearing strata (usually a sandstone) is situate. As in the case of
an Artesian well, the boring is in the first instance an exploration
subject to uncertainty as to "striking" the desired liquid, but
the uncertainty is greater in the case of the search for oil than
in that for water. The water-well is also far less likely to "give
out" when once flowing than is that bored for oil, which, even if at
first successful, may be soon exhausted owing to the small area of
the oil-bearing strata tapped. A cause of the high pressure in many
oil-wells is the gas which accompanies the oil. The pressure may amount
to as much as 1000 lb. to the square inch. In the Northern Caucasus
spouting wells caused by the high pressure of gas in the boring are
frequent. A famous fountain-well in that region, which began to flow
in August 1895, threw up 4½ million gallons a day, gradually
diminishing during fifteen months until it became exhausted. At first,
when boring was introduced, such outbursts led to an enormous loss of
the oil, for there was not sufficient means of storing or transporting
it. Ordinary cartage in barrels was the earlier method; then followed
tanks on railway trains and canal boats; and this has been supplemented
by the use of pipes along which the oil is pumped from the well to the
refinery. In Pennsylvania there are said to be no less than 25,000
miles of such pipes in use for the distribution of petroleum.
It will be obvious from what is here stated that the attempt to
discover an oil-supply in Derbyshire must not be regarded, at present,
as more than a praiseworthy and interesting enterprise. There is no
room for doubt that the best expert opinion has been brought to bear
on the matter. A small quantity of petroleum has already been raised;
but whether the flow will be sufficient to cover the expenses of the
boring, and how long the flow may last, or how much it may amount
to, are matters quite impossible to foretell. In any case, it is in
the highest degree improbable that such an abundance of oil will
be obtained as to count much, if at all, in the world's production
of petroleum. It must also be remembered that products similar to
those yielded by petroleum are already extracted in quantity as a
remunerative industry by the distillation of oil-shales in various
parts of the United Kingdom; and that there are oil-shales in this
country still unworked. So that we need not be in despair if we do
not tap an oil-spring of any importance close to hand. The world's
supply is still open to British enterprise. Another reflection of some
importance is that these world-wide sources of rock-oil or petroleum
are likely to be exhausted by exploitation much sooner than are the
coal-fields of the world. We cannot rely on their long duration.