The figures shown in the table for oil reserves are of course the roughest approximations, particularly for some of the less explored countries. However, they are compiled from the best available sources and may serve at least to show the apparent relative positions of the different countries at this time. Further exploration is likely to change the percentages and add very greatly to the totals. The significant feature of these figures is the contrast which they indicate between distribution of reserves and distribution of past production. Particularly do they show that the reserves of the United States, which are more closely estimated than those of any other country, are in a far lower ratio to past production than are the reserves in other countries. It was estimated in 1920 that about 40 per cent of the United States reserves are exhausted.[20]
PRESENT AND PAST PRODUCTION AND RESERVES OF OIL, BY COUNTRIES, IN TERMS OF PERCENTAGE OF WORLD'S TOTAL
| Country | Per cent of production, 1918 | Per cent of total production, 1857-1918 | Per cent of total oil resources |
| United States and Alaska | 69.15 | 61.41 | 16.26 |
| Mexico | 12.40 | 3.80 | 10.51 |
| Russia (southeastern Russia, southwestern | 7.86 | 24.96 | 15.69 |
| Siberia, region of the Caucasus, northern | |||
| Russia, and Saghalien | |||
| East Indies | 2.58 | 2.51 | 7.00 |
| Roumania, Galicia, and western Europe | 2.79 | 4.07 | 2.64 |
| India | 1.55 | 1.41 | 2.31 |
| Persia and Mesopotamia | 1.40 | .19 | 13.51 |
| Japan and Formosa | .48 | .51 | 2.87 |
| Egypt and Algeria | .40 | .07 | 2.15 |
| Germany | .14 | .22 | — |
| Canada | .06 | .33 | 2.31 |
| Northern South America, including Peru, | .93 | .43 | 13.31 |
| Trinidad and Venezuela | |||
| China | — | — | 3.19 |
| Italy | } | ||
| Cuba | } | .02 | |
| Other countries | } | ||
| World total | 100.00 | 100.00 | 100.00 |
Looking forward to the future, it is clear that there will be considerable shifts in the centers of principal production of petroleum in the directions indicated by the reserve figures. In particular, conspicuous development of production may be expected in the immediate future in the countries bordering the Caribbean Sea and the Gulf of Mexico. In the eastern hemisphere production is rapidly increasing in Persia and Mesopotamia; and Russia, with the stabilization of political conditions, may become ultimately the world's leading oil producer. At the now indicated rate of production, world reserves now estimated would be exhausted in eighty-six years and the peak of production would be passed earlier. With continuing acceleration of production, total reserves would be exhausted in considerably less time,—providing physical conditions would allow the oil to be pumped from the ground at the necessary speed, which they probably will not. These figures taken at face value are alarming; but the earth offers such huge possibilities for further discoveries that the life of oil reserves above indicated is likely to be considerably extended. At many times in the history of the mineral industry the end has apparently been in sight for certain products; but with the increased demand for these products has come increased activity in exploration, with the result that as yet no definite end has been approached for any one of them. The more immediate problems of the petroleum industry seem to the writer to be of rather different nature: first, whether the discovery and winning of the oil can be made to keep pace with the enormous acceleration of demand; and second, the adjustment of political and financial control of oil resources, the possession of which is becoming so increasingly vital to national prosperity.
In regard to the first question, it is a much more difficult problem today to locate and develop a supply of oil to replace the annual world production (recently half a billion barrels), than it was twenty years ago, when it was necessary for this purpose to find only one-fifth this amount; and if the demand is unchecked, it will be still more difficult to replace the three-quarters of a billion barrels of oil which will doubtless be required in a very few years. Regardless of the amount of oil actually in the ground, it is entirely possible that physical limitations on its rate of discovery and recovery will prevent its being made available as fast as necessary to meet the increasing demand. This fact is likely to make itself felt through increase of price. Other natural results should be the development of substitutes, such as alcohol or benzol for gasoline; the larger recovery of oil from oil shales; and the general speeding up of conservational measures of various kinds. These are all palliatives and not essential remedies. To make enough alcohol to substitute for the gasoline now coming from oil would use a very considerable fraction of the world's food supply. To make enough benzol (a by-product of coke) to replace gasoline would necessitate the manufacture of many times the amount of coke now required by the world's industries. To develop the oil shale industry to a point where it could supply anything like the amount of oil now derived from oil pools would mean the building of great plants, including towns, railroads, and other equipment, equivalent to the plants of the coal mining industry. To apply any one of the various conservational measures discussed on later pages would only temporarily alleviate the situation.
The question of political and financial control of oil supplies may be illustrated by particular reference to the United States. On present figures it appears that within three to five years the peak of production in this country will be passed; and at the present rate of production the life of the reserves may not be over seventeen to twenty years. Of course production could not continue to the end at this rate, and the actual life will necessarily be longer. Again the doubtful factor is the possibility for further discoveries. Many favorable structures have been mapped which have not yet been drilled, and there are considerable unexplored areas where the outcrops are so few that there is no clue at the surface to the location of favorable structures. The future is likely to see a considerable amount of shallow drilling for the sole purpose of geological reconnaissance. For upwards of ten years important parts of the public domain have not been available for exploration, but Congress has now enacted legislation which opens up vast territories for this purpose.
Even with large allowance for these possibilities, it seems unlikely that production in the United States can increase very long at the accelerating rate of the domestic demand, which is already in excess of domestic production. The supplies of Mexico are in a large part controlled by American capital and are thus made available to the United States (subject, of course, to political conditions); but even with these added, the United States is in a somewhat unfavorable situation as compared with certain other countries. This situation is directing attention to the possibility of curtailment of oil exports, and to the possibility of acquiring additional oil supplies in foreign countries. In this quest the United States is peculiarly handicapped in that most foreign countries, in recognition of the vital national importance of the oil resource, have imposed severe restrictions on exploration by outsiders. Nationals of the United States are excluded from acquiring oil concessions, or permitted to do so only under conditions which invalidate control, in the British Empire, France, Japan, Netherlands, and elsewhere, and the current is still moving strong in the direction of further exclusion. As the United States fields are yet open to all comers, it has been suggested that some restriction by the United States might be necessary for purposes of self-protection, or as an aid in securing access to foreign fields. The activity of England during and since the war has increased the amount of oil controlled by that country from an insignificant quantity to potentially over half of the world's oil reserves. The problem of future oil supplies for the United States presents an acute phase of the general question of government coöperation or participation in mineral industries, which is further discussed in Chapter XVIII.
The following table summarizes the distribution of the oil production in the United States, together with the salient features of its geologic distribution and character.
This table, in conjunction with Fig. 8 below, shows clearly that the bulk of the United States production of oil comes from two great sources—the Pennsylvanian sandstones of the Mid-Continent field in Kansas and Oklahoma, and the Cretaceous and Tertiary sediments of the southern half of California. Phenomenal development of the Central and North Texas field in 1919 increased its yield to about one-sixth of the country's total. The older Appalachian oil field, extending from New York to West Virginia and Tennessee, was the earliest area discovered; it is still one of the more productive fields, though it has long since passed its maximum production. The other principal sources of oil are the Gulf Coast field in Louisiana and Texas, the North Louisiana field, the southern Illinois field, and the Rocky Mountain region. This last region, containing large amounts of government land recently opened to exploration, bids fair to produce increasing quantities of oil for some time.
PAST PRODUCTION OF PETROLEUM IN THE UNITED STATES.
(FIGURES FROM U. S. GEOLOGICAL SURVEY)