石油技術協会誌
Online ISSN : 1881-4131
Print ISSN : 0370-9868
ISSN-L : 0370-9868
73 巻, 3 号
選択された号の論文の4件中1~4を表示しています
論説
  • 川辺 能成, 西脇 淳子, 坂本 靖英, 原 淳子, 駒井 武
    2008 年 73 巻 3 号 p. 225-231
    発行日: 2008年
    公開日: 2008/11/14
    ジャーナル フリー
    The authors have developed the original risk assessment model for soil contamination caused by mineral oils. The exposure rates, the distribution of exposure paths and the risk level of gasoline, kerosene and diesel oil have been evaluated by using Geo-environmental Risk Assessment System (GERAS-1). The major exposure pathways to the human of gasoline and kerosene are the air inhalation, whereas they are mainly exposed to diesel oil from air inhalation, groundwater intake and crops intake. The major components of total petroleum hydrocarbon (TPH) involved in the exposure were aliphatic TPH (C5-C8) for gasoline, aliphatic TPH (C7-C12) for kerosene, and aliphatic TPH (C7-C16) and aromatic TPH (C7-12) for diesel oil. The soil contents of total TPH for exposure limits are estimated at following levels, 14 (sandy soil)-38 (loamy soil) mg/kg for gasoline, and 1400 (sandy soil)-3400 (loamy soil) mg/kg for kerosene, and 540 (sandy soil)-1300 (loamy soil) mg/kg for diesel oil.
  • 関口 林彦, 森田 信男
    2008 年 73 巻 3 号 p. 232-243
    発行日: 2008年
    公開日: 2008/11/14
    ジャーナル フリー
    More than 15 sand control methods are available to oil industries, including down hole sand exclusion methods and surface sand management methods. Several selection guidelines have been proposed by industries comparing expected productivity, failure risks, installation complexity, and cost. However, all of them are ambiguous since the comparisons are based on these specific features.
    When oil industries decide whether to develop oil and gas fields, one of the most frequently used economic analysis is to calculate NPV, the net present value of the field. This index is used in this paper since we believe it is the best index available for oil industries to judge whether certain sand control methods are more effective than others. In this paper, NPV is calculated for the seven most frequently used sand control methods for three typical gas and oil reservoirs in the North Sea. The selected typical North Sea reservoirs (Depth = 7,500 ft TVDSS) are
    (A) A medium gas reservoir which has 30 wells with an initial flow rate of 30 MMscfD/well.
    (B) A large gas reservoir which has 30 wells with an initial flow rate of 150 MMscfD/well.
    (C) A medium oil reservoir which has 30 wells with 8,000 STB/D/well with 35° API.
    The NPV is calculated based on CAPEX, OPEX, productivity, sand management cost and risk of failure. A comparison of seven methods adapted by several companies experienced with various sand problems in the North Sea shows that the sand rate control method is one of the most effective methods to manage sand problems if formation is strong enough not to induce catastrophic failure. However, this method requires careful sand management based on long experience. Cased Hole Frac & Pack method also generates a high NPV for weak formations because of the small failure rate and low skin after several years of production.
  • ―その概要と有用微生物について―
    藤原 和弘, 菅井 裕一, 榎本 兵治
    2008 年 73 巻 3 号 p. 244-253
    発行日: 2008年
    公開日: 2008/11/14
    ジャーナル フリー
    Recently, a sharp skyrocket in crude oil has become a destabilizing factor to the world economy. For instance, all over the world including China and India have been competing against one another for maintaining the petroleum resources. Hence, the position of Enhanced Oil Recovery (EOR) techniques in the petroleum development technology has become more important. On the other hand, various environmental problems caused by global warming also have become serious issues since 1990, so that consideration to environmental problems will be also required for oil industry. On this background, expectations are rising for the practical use of Microbial Enhanced Oil Recovery (MEOR) technique which is one of the techniques expected to be both economically feasible and environmentally friendly.
    This paper elaborates the present state of MEOR regarding the acquisition methods and preceding results relevant to high performance microbes for MEOR process, in addition to introducing the outline of MEOR technique and the current state of MEOR research. Culture conditions of microbes for achieving even greater functionality are also described as a critical technology for MEOR process.
解説
  • 淺川 栄一, 大西 正純
    2008 年 73 巻 3 号 p. 254-259
    発行日: 2008年
    公開日: 2008/11/14
    ジャーナル フリー
    Seismic imaging is generally a technique to figure out the subsurface structure or physical properties of subsurface media. It is often considered the same as seismic migration in reflection seismic. Migration has been the means of collapsing diffraction events to points, moving (“migrating”) reflection events to the proper locations to obtain a true image of subsurface structures.
    Over the years, the technique of migration has evolved. It started from NMO (normal move out) for the horizontally layered structure, and then DMO (dip move out) for dipping layer has been developed. For more general velocity structure, a variety of migration techniques has been applied in time and depth domain. In case of small variation of the subsurface velocity, time migration is enough to gain true image, whereas depth migration is required for abrupt lateral change of the velocity. As the computer technology is developed, CPU intensive pre-stack migration methods become into practice use. Pre-stack depth migration (PSDM) is one the final steps of the seismic imaging with proper velocity estimation.
    In this paper, we introduce the general ideas of migration as well as some of the issues related to it, such as computation efficiency and velocity estimation, without describing the details of the migration algorithms themselves. This short paper is intended to provide the overview of migration methods for non-geophysicists.
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