HAYES AND 
KENNEDY. 
UTILIZATION OF THE OIL. 
157 
oil, and hence yields only water which may or may not flow at the 
surface. 
These simple theoretical conditions are, however, seldom, if ever, 
realized in nature. It is evident that the oil and gas in the Texas- 
Louisiana pools are not sharply separated by a plane surface. Some 
of the wells on Spindletop, it is true, have yielded only gas, and cer- 
tain portions of the reservoir must therefore contain only that form 
of hydrocarbon, as shown on the diagram; but these gas wells are not 
all shallower than some which have yielded oil, and hence the two 
substances are not separated by a horizontal plane. It is probable 
that under the pressure existing in the oil reservoir the liquid hydro- 
carbons absorb a very large volume of the gaseous compounds, and 
Land surface 
Fig. 9.— Theoretical relations of gas, oil, and water in the reservoir rock. 
it may be that the expansion of this absorbed gas is the principal 
agent in causing the oil to gush. 
UTILIZATION OF THE GULF COAST PETROLEUM. 
ILLUMINATING OIL. 
The three chief purposes for which petroleum is used are, in the 
order of profit to the producer, for illuminants, for lubricants, and for 
fuel. Concerning the adaptability of the Gulf Coast oil for the first 
two purposes, there is much diversity of opinion, and sufficient inves- 
tigation has not yet been given to the subject to yield definite conclu- 
sions. The general consensus of opinion appears to be, however, 
that the petroleum is not adapted to the production of illuminating 
oil by any refining process at present known. This is not due chiefly 
to the presence of sulphur compounds, for methods have been devised 
for removing the sulphur economically, but to the chemical constitu- 
tion of the distillates themselves. Being what are known as unsatu- 
rated hydrocarbons, they have a high specific gravity and burn with 
a smoky flame. This difficulty can not at present be overcome except 
by very expensive processes of refining, which are not practicable in 
competition with the cheap illuminating oils from other petroleums. 
