PETROLEUM, 
41 
practice, from 90 to 30 per cent of the oil is left underground. 1 Then, 
of the quantity produced, an appreciable percentage is lost by fire, 
and a significant portion dissipated by seepage and evaporation due 
to inadequate storage facilities. 2 On the average, therefore, it is safe 
to say that less than 25 per cent of the petroleum underground reaches 
the pipe line. If we subtract from this proportion the losses in- 
volved in improper and wasteful methods of utilization, the recovery 
factor becomes perhaps as low as 10 per cent. 3 
Knowledge of petroleum technology is far in advance of its appli- 
cation to oil production, due to the fact that this country is actively 
engaged in producing such knowledge, but has at the same time 
provided no adequate machinery for putting this knowledge into 
play, once it is produced. 4 Of course part of this advance gets into 
action where the gain from such application accrues to specific inter- 
ests, but by and large there is a marked underconsumption of tech- 
nological science, the discrepancy being often credited, though with 
questionable validity, against the difference between theory and 
practice. We may review some of this technological knowledge 
already in stock, having in mind that the supply is rapidly in- 
creasing. 5 
1 “ Estimates of the total amount extracted range from 10 to 70 per cent, 90 to 30 
per cent being left in the ground.” — Van H. Manning, Yearbook of the Bureau of Mines, 
1917, p. 127. 
“It is universally acknowledged that by the usual production methods much oil is 
left underground, the general opinion being that at least 50 per cent of the oil in a 
field remains unrecovered when the field is abandoned as exhausted. From the writer’s 
own investigations he believes the average recovery is even less * * * ” — J. O. Lewis, 
Methods for increasing the recovery from oil sands, Bulletin 148, Bureau of Mines, 
1917, p. 7. 
2 Evaporation robs petroleum of its lighter components (i. e., gasoline), hence the 
value loss is much greater than is apparent from the bulk removal. 
3 This is not to be taken as an exact figure, but merely as a rough expression of 
magnitude. No one, of course, can estimate such a matter closely. Twenty per cent 
would certainly be too high ; 10 per cent, therefore, is not far from the true proportion 
and is a very salutary figure to accept. 
“ What effort have we made to conserve this supply and to utilize it to its greatest 
advantage? We have made little effort until very recently to do these things. We have 
been wasteful, careless, and recklessly ignorant. We have abandoned oil fields while a 
large part of the oil was still in the ground. We have allowed tremendous quantities 
of gas to waste in the air. We have let water into the oil sands, ruining areas that 
should have produced hundreds of thousands of barrels of oil. We lacked the knowledge 
to properly produce one needed product without overproducing products for which we 
have little need. We have used the most valuable parts of the oil for purposes to which 
the cheapest should have been devoted. For many years the gasoline fractions were 
practically a waste product during our quest for kerosene ; with the development of the 
internal-combustion engine the kerosene is now almost a waste product in our strenuous 
efforts to increase the yield of lighter distillates.” (Yearbook of the Bureau of Mines, 
1916, Washington, 1917, p. 117.) If we add to this quotation the statement that gaso- 
line is now almost a waste product in our efforts to make fuel oil help out a bad coal 
situation, the picture will be true down to April, 1918. 
4 An analogous situation would obtain if laws were made with no provision for putting 
them ipto execution. 
5 The treatment here, of necessity, merely touches on the more significant features. 
For details the reader is referred to the numerous publications of the United States 
Bureau of Mines concerning this matter. 
