The Japanese crude oil production has been steadily declining since 1937, the annual production of the fiscal year 1947 ending March 31, 1948 being 196, 000 kilolitres. It is also reported that about 88% of the total reserves of the proved oil fields owned by the Teikoku Oil Company, which is responsible for more than 90% of the domestic crude oil production, has been already depleted at that date. These circumstances are evidently due to the fact that no new oilpools of appreciable magnitude were discover ed in these years. To establish a sound and comprehensive exploration program embracing oil producing and potential oil producing areas, the Petroleum Exploration Advancement Committee was established in the Mining Bureau of the Ministry of Commerce and Industry, at the instigation of the Natural Resources Section, G. H. Q., S. C. A. P. Under the planning of the Committee, extensive exploration works are now being carried on together with the compilation works to review the existing data. Recent discovery of oil pools of fault trap type, such as at the Ishinazaka and Narahashi oil fields in Yamagata Prefecture, and those of stratigraphic trap type such as at the Shibata and Kaji oil fields in Niigata Prefecture, considerably enwidened the possible area of oil production. Also some structures underneath the alluvial plains in the petroliferous Tertiary basins were newly found by geophysical methods and wait further exploration. In Hokkaido large structures of the Tertiary formation are now being explored, to test the oil possibility of the underlying Cretaceous, which abounds in oil seepages in certain areas of the district. In short, the proved oil reserves of Japan is nearly exhausted, but the possibility of gaining new reserves is growing larger.
The progress of hydro-electric industry in Japan is related, considering the post-war power situation in Japan, for the purpose of overall development of rivers, the necessity of development of hydraulic power is stressed. In former days, supply of electricity in dry season, the decrease of hydro-electric power was mainly covered by thermal power to keep the balance. The reasons are : 1. Thermal generating plant was damaged by war amounting to 1, 467, 730 kw (51% of power plant.). 2. Exceedingly high cost of coal. It became unpractical to use power both of hydraulic and thermal. In other words, it became more economical to cover the shortage of power in dry season by the hydro-electricity generated with water in reservoir than thermal power. The reservoir in our country, its capacity to keep water is considerably small in comparison with he size of darn, owing to unfavorable topographic features as shown in table 5-The means to overcome this defect is open for planning reservoirs, considerations should be made by taking in various economic sections, such as electricity, irrigation, water control together. Reservoirs for these three sections if planned, the construction expenses being shared by three parties, will be comparatively lightened. Consequently the quantity of reserve water in need, can be available. Our economic rehabilitation is facing two contradicting phases : need of repressing inflation in reconstruction of industry and rehabilitation of damages caused by disasters, however, necessary to be accomplished vigorously. It is believed that measures of an increase of power sources including augmentation of food production and water control should necessarily be promoted. Construction Bureau of Economic Stabilization Board, for the purpose of developing reservoirs, for common use of irrigation, water control and power generating, is investigating over sixteen rivers since 1947. The outline of this plan is. related hereby.
Natural gas industry in Japan is, at present, in its primitive stage of development. From the standpoint of the fuel problem of the country which lacks in-any dependable petroleum resources, exploration of gas resources, because of its high potentiality in future production, should be intensively carried out. Gas production is increasing very rapidly in these two or three years especially in Niigata district, where gas is found in the Pleistocene and Uppermost Tertiary formations which form a very broad synclinal basin. The gas occurs with saline water and mainly consists of methane without any higher hydrocarbons. Total annual production of natural gas of Japan in 1948 amounts to nearly sixty million cubic metres, about one half of which comes from the gas fields of the foregoing type and another from the oil fields. Natural gas as a motor fuel is far more favourable in efficiency than charcoal or firewood, the Iatters are also widely used in Japan. Geologically, the natural gas o curs, mainly, in the following formations. 1) The Tertiary formations a) The oil fields b) The gas fields (Niigata, Chiba, Shizuoka, etc.) 2) The Quaternary formations (Hokkaido, Yamagata, Niigata, Suwa, and other alluvial plains in basins.)