Journal of the Japanese Association for Petroleum Technology
Online ISSN : 1881-4131
Print ISSN : 0370-9868
ISSN-L : 0370-9868
Volume 51, Issue 3
Displaying 1-7 of 7 articles from this issue
  • Atsushi YAMAJI
    1986 Volume 51 Issue 3 Pages 197-204
    Published: 1986
    Released on J-STAGE: March 27, 2008
    JOURNAL FREE ACCESS
    Kinetic equation of organic maturation is integrated to simulate vitrinite reflectance-burial depth relations for essential geological settings. The integration of the equation shows that the linear relation between vitrinite reflectance and burial depth does not hold in active sedimentary basins any longer. The integration gives analytic solutions*1 for the kinetic equation for such sedimentary basins which undergoes dynamic tectonics. And the integration gives a good perspective for theoretical consideratins on vitrinite reflectance-depth relations.
    It is possible to determine the coefficients in the kinetic equation by comparing predicted vitrinite reflectance-depth relations with measured ones. The direct integration of the kinetic equation easily predicts the relation using the observed burial history and the geothermal gradient in active basins.
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  • [in Japanese]
    1986 Volume 51 Issue 3 Pages 205-208
    Published: 1986
    Released on J-STAGE: March 27, 2008
    JOURNAL FREE ACCESS
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  • Heiji ENOMOTO, Cheng-Xie HONG, Shozo TANAKA, Hiroshi KIYOHASHI
    1986 Volume 51 Issue 3 Pages 209-217
    Published: 1986
    Released on J-STAGE: March 27, 2008
    JOURNAL FREE ACCESS
    Because of the high interfacial tension between water and oil, the injection pressure of water in water flooding is fairly high and the subsequent oil displacement efficiency is rather low. Then the improvement was aimed for the reduction of injection pressure and the efficient displacement by adding a small amount of surfactant into the injection water. Surfactants used were Polyoxyethylenenonylphenylether HLB=17.1 and 12.6 as nonionic, and SDBS as anionic. These were separately used as water solutions of 300ppm in concentration without any additives like alcohols as co-surfactants.
    Results are summarized as follows.
    (1) Adding a surfactant into the injection water can reduce the injection pressure surprisingly even if the concentration of the surfactant is as low as 300ppm, which is 1/50 to 1/100 of that in the low concentration surfactant flooding. Results were correlated with the capillary number as shown in Fig. 10.
    (2) 300ppm surfactant-water solution was able to increase the oil recovery. This may be caused by the snap-off mechanism proposed by ARRIOLA et al.
    (3) krw/kro decreases with decreasing the interfacial tension, that is to say, the oil gets to flow easily compared to the water as the interfacial tension decreases. This effect was related to the shift of residual oil saturation with the interfacial tension.
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  • Akio SASAKI
    1986 Volume 51 Issue 3 Pages 218-227
    Published: 1986
    Released on J-STAGE: March 27, 2008
    JOURNAL FREE ACCESS
    In this paper, the distribution of carbon dioxide in natural gases recovered from the Platong gas field and its origin are discussed on the basis of geological evidences.
    Carbon dioxide content in gases of this field is average 15% and partly more than 40%.
    Gas bearing Tertiary sediments are dominated by gas-prone woody-coaly organic matters. Main east-dipping faults in the western flank of this structure cut basement complex. Gas reservoirs containing rich carbon dioxide, more than 40%, are locally distributed in the northwestern part of this field. The spatial spread is clearly oblique to stratigraphic markers and is like “conical mass”. This mass is characterized by high density shale more than 2.70gm/cc and very low Cl- content in formation water.
    The above marked features suggest that carbon dioxide has been generated from woody-coaly kerogen in sediments during thermal diagenesis, and also has been supplied from “magmatic origin” through the faults, and/or formed by oxidation of hydrocarbons through contact with mineralized waters, which have ascended into Tertiary sediments along fractures and fault zones.
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  • Susumu SAKATA, Makoto TAKAHASHI, Kazuo HOSHINO
    1986 Volume 51 Issue 3 Pages 228-237
    Published: 1986
    Released on J-STAGE: March 27, 2008
    JOURNAL FREE ACCESS
    Chemical and isotopic analyses were applied to characterize genesis of natural gases commercially produced in north-east Japan, so called “Green Tuff” region. Concentrations of He and N2, isotopic ratios of 3He/4He and 4He/20Ne, δ13C values of CH4 showed positive correlations with stratigraphy of gas reservoirs. Especially isotopic values of He included in the deepest gases from volcaniclastic rocks in Nanatani and Nishikurosawa Formations were almost equivalent to those of volcanic fumaroles in the Japanese Islands, suggesting high contribution of mantle materials.
    On the other hand the genetic diagram of hydrocarbon compositions versus δ13C values of methane attributed hydrocarbon compounds exactly to pyrolysis products of organic matters in sedimentary rocks regardless of their reservoir rock types.
    No more than 1% of methane seems to be derived from upper mantle, whose contribution may be estimated by comparing CH4/3He values of Green Tuff gases with those of hydrothermal fluids according to studies of EPR.
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  • Satoshi AKIBAYASHI, Koichi KARUBE, Junji HARA
    1986 Volume 51 Issue 3 Pages 238-244
    Published: 1986
    Released on J-STAGE: March 27, 2008
    JOURNAL FREE ACCESS
    The spatial distribution of transmissivity in the water-dissolved gas field (G6 formation) in the Nishikanbara district, Niigata prefecture, was estimated using time histories of the groundwater heads which were calculated from the production data such as flow rate, gas-water ratio and wellhead pressure etc. at a number of wells. A quasi-linear approach was used to estimate the transmissivity.
    The estimated values of transmissivity were in the region of 2.0×10-4-7.8×10-2m2/s, and in the same accuracy as the values of transmissivity which were estimated using time histries of the groundwater heads including the errors which were expressed by random numbers of normal distribution N (0, 4.92).
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  • [in Japanese]
    1986 Volume 51 Issue 3 Pages 245-255
    Published: 1986
    Released on J-STAGE: March 27, 2008
    JOURNAL FREE ACCESS
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