石油技術協会誌
Online ISSN : 1881-4131
Print ISSN : 0370-9868
ISSN-L : 0370-9868
54 巻, 3 号
選択された号の論文の6件中1~6を表示しています
  • 土谷 信之, 大沢 〓, 片平 忠実
    1989 年 54 巻 3 号 p. 179-193
    発行日: 1989年
    公開日: 2008/03/27
    ジャーナル フリー
    秋田県南部由利原油•ガス田付近では, 中新世台島-西黒沢期後期の青沢層が広く伏在し, 主として大量の玄武岩からなる. 一方その東方丘陵地上には同じく台島-西黒沢期の畑村層中に太倉玄武岩部層が狭在する. これら二つの玄武岩は産状や岩石学的特徴が明確に異なる.
    青沢層は厚さ1,500m以上, 主として海底噴出の玄武岩からなり, 漸深海成の泥岩を上部に挟む. 本層玄武岩は, 全FeO/MgO=0.9-1.4程度のかなり未分化なソレアイト玄武岩であり, その産状は山形県庄内地域の青沢層や秋田県の砂子渕層の玄武岩に類似している. また強変質の岩石を除けば, 岩質, 主成分および微量成分の特徴も類似している. この事実は秋田-山形油田地帯に広く分布する台島-西黒沢期玄武岩類の産状や岩石学的特徴が広域的に類似していることを示唆する. 一方, 畑村層中の太倉玄武岩は厚さ300m以下で, 青沢層玄武岩と同時期かその直前に陸域-浅海で噴出したとみられる. この玄武岩は青沢層の玄武岩と比べて, やや分化し, TiO2, K2Oおよび軽希土類に富む. すなわち, 本地域の中新世玄武岩は東北日本弧第四紀火山岩の特徴と異なり, よりアルカリに富む玄武岩が脊梁側に分布している.
    両玄武岩の産状や噴出環境の違いから, 当時の由利原油田地域は, 東側の畑村層および須郷田層の分布域に比べて著しく沈降し, 大規模な塩基性火山活動の場となったことがより明確になった. また, 両玄武岩は変質の影響を受けにくい元素の化学的特徴が海洋底や北米大陸リフト地域の玄武岩の特徴と類似している. これらのことからみて, 両玄武岩は当時の秋田油田地域で, リフト構造運動に伴って噴出したらしい.
  • 田中 弘樹, 今井 朋男, アブデルカリム オマール, 山崎 豊彦
    1989 年 54 巻 3 号 p. 194-201
    発行日: 1989年
    公開日: 2008/03/27
    ジャーナル フリー
    Pore size distribution is one of the most important reservoir rock properties. The purpose of this report is to calculate and evaluate pore size distribution from capillary pressure curves using the centrifuge method.
    The core samples used in this experimental work were Berea Sandstone, Abu-Dhabi Dolomite and Japanese Sandstone. Reservoir rocks were frozen using liquid nitrogen and small core plugs were cut and recovered from them.
    Capillary pressure of small core plugs was measured using the centrifuge method. Pore size distribution was calculated and evaluated from their capillaly pressure curves.
    After analyzing the graphical representation of these data, the following points are reached:
    (1) In Berea Sandstone, the slopes of capillary pressure curves were very steep and most of pore radii distributed 4-5μm.
    (2) In Abu-Dhabi Dolomite, the slopes of capillary pressure curves were relatively steep and pore radii distributed narrowly.
    In addition, irreducible water saturations were low. This is due to the nonwetting characteristic of Dolomite with respect to water.
    (3) In Japanese Sandstone, the slopes of capillary pressure curves were relatively gentle and pore radii distributed widely.
    In addition, irreducible water saturations were high. This is due to the wetting characteristic of Sandstone with respect to water.
    The centrifuge method for the determination of capillary pressure and pore size distribution is proved to be very effective. This is mainly due to the repeatability in conducting capillary pressure experiments and the number of cores that can be tested at the same time using this method.
  • 常山 太, 渡辺 其久男, 島津 光夫
    1989 年 54 巻 3 号 p. 202-218
    発行日: 1989年
    公開日: 2008/03/27
    ジャーナル フリー
    Succession of the Middle Miocene to Pliocene series distributed in this area corresponds to the standard succession of the Niigata sedimentary basin, but is complex because these series include larger amounts of volcanic rocks than that of type area and still remain unknown.
    From detail field and biostratigraphical study, and fission track dating, the succession and age of the Nanatani, Teradomari and Shiiya formations of the Miocene and the Nishiyama Formation of the Pliocene were clarified.
    Biotite-hornblende dacite and hornblende andesite (9.0Ma) of the Teradomari Formation are interbedded with siltstones deposited in sedimentary environment of upper to middle bathyal zone and pyroxene andesite of the Shiiya Formation are interbedded with siltstones and sandstones deposited in the same environment as the Teradomari Formation. The Teradomari Formation is considered to has deposited on the Nanatani Formation which has occured as topographical high, resulting in clinounconformity between the two formations. The Nokogiriyama fault, which is main geological structure and is related to the Nigoro anticline, may has began to occur in the Shiiya stage as shown in defferences of lithofacies between both flanks of the Nigoro anticline.
  • 初期の水飽和率, 絶対浸透率, 孔隙率並びに油層厚さの影響について
    榎本 兵治, 洪 承燮, 田中 正三, 千田 佶
    1989 年 54 巻 3 号 p. 219-230
    発行日: 1989年
    公開日: 2008/03/27
    ジャーナル フリー
    Simulation study was carried out to investigate the behavior of fireflooding and to obtain basic information for designing and/or screening fireflood projects. The simulator used has been reported elsewhere (JJAPT 52, 5, 1987). Parameters investigated were
    (1) initial water saturation, (2) absolute permeability, (3) porosity, and (4) thickness of reservoir (as a parameter representing heat loss to the upper and lower strata).
    Results are summerized as follows:
    (1) The course of oil production may be very much affected by the initial oil saturation.
    (2) Absolute permeability of a reservoir may not be sensitive to the total performance but the injection pressure of air.
    (3) Porosity is one of the critical parameter of screening.
    (4) A thin reservoir may lose heat to the surrounding strata resulting in cease of the combustion reaction.
  • その2 擬似関数自動生成手法の詳細および離散化誤差と擬似関数に関する一般的議論
    登坂 博行
    1989 年 54 巻 3 号 p. 231-239
    発行日: 1989年
    公開日: 2008/03/27
    ジャーナル フリー
    In the preceding paper21), the author presented a new method of generariog directional pseudofunctions automatically by the simulator itself. The method combines the vertical equilibrium concept with the Buckley-Levrett's Fronal Advance Theory. In this paper, additional details of the method which generates the FAP (Frontal Advance Profile) pseudofunctions are described in conjunction with B-L theory. Results of 1-D and 2-D test runs are presented to show that the water-cut performances and profiles of water front obtained by coares-grid models using FAP pseudofunctions are almost identical with those obtained by fine-grid models using rock saturation functions. General discussion on numerical dispersion and pseudo-generation methods are also made focused on field-scale reservoir simulation using a coarse-grid system.
  • 佐藤 光夫, 田中 彰一
    1989 年 54 巻 3 号 p. 240-253
    発行日: 1989年
    公開日: 2008/03/27
    ジャーナル フリー
    New type of polycrystalline-diamond-compact (PDC) bits are tested for drilling hard rocks in laboratory conditions. Slender cylindrical inserts are used as cutters, so the bits are called as polycrystalline-diamond-insert (PDI) bits in this study. The inserts are 3-3.5mm in diameter, and 5mm in length in the test bit of 6cm in diameter. The inserts are composed of PDC and tungsten carbide (WC). Four types of inserts are tested: PDC sheathed by WC coaxially, PDC coverd by WC eccentrically, semicircular PDC welded with semicircular WC, and circular PDC.
    Drilling rate and bit life are measured of nine test bits with different profiles. The bit profile is designed considering inserts distribution pattern, cuttings removal, stable motion of bit, breakage of a center plug of bottom-hole rock and so on. No. 8 bit drilled about 30m of granite, of which compressive strength ranges from 130MPa to 160MPa, with drilling rate of about 2.2m/h at bit weight of 25-15kN and rotating speed of 99rpm. No. 9bit shows high drilling ability of 4m/h in granite, of which compressive strength is about 130MPa, at bit weight of 12kN and rotating speed of 99rpm. The bit has stable drilling rate and torque during long periods, when an adequate combination of bit weight and rotating speed is applied. Low bit weight is apt to wear off inserts faster than matrix, and high bit weight is apt to wear off matrix. At optimum conditions, inserts and matrix seem to wear off slowly keeping the relative height of inserts from the matrix.
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