松崎•南阿賀系列における炭化水素の移動と集積
1977 年 42 巻 2 号 p. 129-138
詳細
1977 年 42 巻 2 号 p. 129-138
Isopach map of the stratigraphic interval from the Globorotalia inflata No. 2 zone (top of the lower Nishiyama formation) to the top of the hydrocarbon producing sandstone shows that the definite structural traps were formed after the deposition of the Globorotalia inflata No. 2 zone, and the fault traps were also formed at that time.
Geothermal process in the upper Shiiya formation (main producing zones) yielded hydrocarbon generation at the bottom of the syncline after the time of the deposition of the lower Nishiyama formation.
The hydrocarbon formed thus at the synclinal bottom migrated through the permeable sandstones in various path ways.
The hydrocarbons seemed to migrate along the structurally concave portion of the permeable beds, and finally trapped (Fig. 10).
The sizable hydrocarbon deposits (Id, IIa, IIb in Fig. 7) locate in widespread sandstone layers, whereas rather small deposits are in lenticular sandstones. The sizable deposits are characterized by uniform constituents of the hydrocarbon, and smaller deposits are characterized by the variable contents of the liquid hydrocarbon in gas.
The former hydroarbocns were derived from the synclinal bottoms, and the later hydrocarbons were formed near the present reservoirs.
