北海道地域における石油の生成と移動の時期の推定
1980 年 45 巻 6 号 p. 393-404
詳細
1980 年 45 巻 6 号 p. 393-404
Conditions of the oil zone for wells in Hokkaido were estimated in this study. The results indicate that the primary migration of petroleum is prosperous in the early mature stage as widely accepted by many authors at the present time. Wells used here are classified into following three groups because of the areal differences of conditions;
(1) Tempoku well group: burial depth of 2400-3600m, paleotemperature of 100-130°C and vitrinate reflectance of 0.47-0.56% are recognizable as the upper limit of the oil generation zone. Corresponding formations range from the middle part of the Masporo Formation to the upper part of the Cretaceous system. In other words, formations younger than the middle part of the Masporo Formation are immature.
(2) Hidaka well group: burial depth of 2400-2900m, paleotemperature of 70-95°C and vitrinate reflectance of 0.50-0.54% are recognizable as the upper limit of the oil generation zone. Corresponding formations range from the middle part to the base of the Fureoi Formation.
(3) ‘ Green Tuff Region’ well group: burial depth of 1600-2500m, paleotemperature of 60?-100°C and vitrinate reflectance of 0.50-0.57% are recognizable as the upper limit of the oil generation zone. Corresponding formations range from the Nina Formation to the upper part of the Fureoi Formation (the upper part of the Atsuta Formation).
