地向斜堆積物における石油貯溜の条件
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概要
- 論文の詳細を見る
(1) Essential conditions that are required for accumulation of oil are as follows: (a) source rocks and reservoir rocks occur inter-relatedly; (b) sediments of the source rocks are thicker than those of there servoir rocks (with variations in the thickness); (c) sedimentary environments are so deep under the sea that they are beyond the action of the wave; (d) cap rocks exist over reservoir rocks, (2) The geosynclinal sediments, whether in the stable zone, substable zone or unstable zone, include a cycle to satisfy the conditions referred to in (1) above. In other words, there were two major periods in each geosynclinal sedimentary cycle during which source rocks accumulated accompanied with reservoir rocks, one being a period of sinking from general uplifting and the other a period of uplifting from generalsinking. (3) Final factors for oil accumulation are governed by such structural conditions as anticlines, faults and unconformities. (4) Sediments are metamorphosed by diagenesis. Beyond a certain depth under the ground, petroleum is gasified to be turned into condensate. At a further depth, petroleum is changed into graphite. (5) Further stronger metamorphisms are due to orogenic movements with in the geosyncline and such movements result in the destruction of oil accumulation, even if there exists any such accumulation. (6) There is a very close interrelation between geosynclinal structures and sediments as well as between sediments and oil accumulation. In areas where the geosynclinal structures extend under sea, as they do in Japan, the state of the geosynclinal structures and the sediments can be clarified only by combining seismic exploration and structural geology. The results obtained from such researches can greatly contribute toward development of offshore oil fields.
- 日本地質学会の論文
- 1968-07-31