The relationship between the vitrinite reflectance and "principal zone of oil formation" in northeastern Japan

Abstract

The relationship between the reflectance value of vitrinite in kerogen and "principal zone of oil formation" in the Neogene Tertiary of northeastern Japan was examined. The reflectance value of about 0.5% was obtained as the value corresponding to the upper limit of principal zone of oil formation. In addition, the vitrinite reflectances of the samples from the marginal regions of sedimentary basin were measured to compare with those of oil producing areas in the central part of the basin. As the results, the reflectance values from the marginal parts were distinctly lower than those of the equivalents in the central part of the basin and did not show any remarkable increase toward the lower formations.