著者
田口 一雄
出版者
The Japanese Association for Petroleum Technology
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.46, no.1, pp.1-13, 1981
被引用文献数
1

現在における石油の第1次移動に関する論争は,もっぱら石油のケロジェン根源説支持者間での論争である。対立は大きく水媒体移動説と油相移動説の2つに分れている。論争点の第1は,移動に利用し得られる水が存在するかどうかの問題である。圧密水,鉱物層間水の利用は多くの人々から否定される。天水の利用は特殊の場合のみに考慮されることがある。最大の論争は,地下深部の比較的温度の高いところ(〉300°C)での鉱物結晶水の利用の可能性をめぐって行なわれている。しかし全般的傾向としては,油相移動説支持者が圧倒的に多くなりつつある。ある地下深度のケージェンからの石油発生(液状石油の体積増加)と秩序水(structured water)の形成作用が相乗的に働き,孔隙間での飽和率が増加すると,石油は水とは独立的に単一液相として移動しうるとするのが多くの一致した見解である。<br>上記の諸点をふまえて,日本の新第三紀油田の第1次移動機構を考えると2つの可能な場合が存在する。<br>1つは,秩序水の形成がおよそ40%孔隙率程度で油相移動を可能にする場合である。この場合ケージェン起原の石油は対象とならないが,場所により1次ビチューメン中の炭化水素の移動が可能となろう。新潟油田の場合約1,300m,秋田油田の場合約800~900m深度で移動が可能となる。<br>今1つは,石油根源岩としての諸性質を考慮した場合で,女川,船川下部相当層中でのケージェン起原石油の油相移動である。特に女川相当層に存在するケロジェンラミナを通じての油相移動が重要視される。移動通路としては,マイクロフラクチュア,断層を通じての垂直移動,同一層準地層の岩相変化によって生じた層位トラップへの平行移動が考えられる。<br>上記2つの第1次移動は2者択一的なものではなく,地質条件に従って両者の機構による移動が行なわれたものと考えているが,大部分の石油プールは後者によって形成された公算が大である。
著者
西 弘嗣 高嶋 礼詩
出版者
石油技術協会
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.70, no.1, pp.6-14, 2005 (Released:2007-06-01)
参考文献数
55
被引用文献数
1

The Indian subcontinent and Asian continent first contacted in the late Cretaceous (about 65Ma) and strongly collided after 52 Ma that is evidenced by slowed northward motion of the Indian Subcontinent from 18-20cm/yr to 4.5cm/yr. Although the first record of uplift in Himalayan regions has been recorded during the Eocene, major uplifts of the Himalayan Range and Tibetan Plateau and the subsequent sediment supply started from the Oligocene through Miocene. Particularly, the rapid uplift stages of Himalayan-Tibetan regions have been recognized, at least, around 8Ma and the last 1Ma based on sedimentological and paleonbotanical studies of marine and terrestrial sequences. The micropaleontological studies in marine sequences revealed that the increased elevations in the Himalayan-Tibetan regions forced a strong monsoonal circulation about 8 Ma, which produced intense upwelling around the Arabian Sea and more seasonal climate changes of terrestrial sequences around the southern Asia. The hypothesis that uplift of plateaus and mountains caused large-scale climate changes during the Cenozoic is still unknown. However, an enhanced chemical weathering due to tectonic uplift in the Himalayan-Tibetan regions may be explained as the active driving force of the Cenozoic global cooling at the beginning of 50 Ma.
著者
早稲田 周 岩野 裕継
出版者
石油技術協会
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.72, no.6, pp.585-593, 2007 (Released:2008-11-14)
参考文献数
22
被引用文献数
10 9 10

Carbon isotope compositions of methane, ethane and propane, and hydrocarbon ratios in gas samples provide information of their origin (microbial vs. thermogenic), maturity of thermogenic component, compositional change due to migration, and extent of biodegradation. Mixing of gases with different origins or different maturities can also be evaluated using gas isotopic and molecular compositions. While these gas geochemical data have been used mainly for petroleum exploration, their applications for development, production and operation issues are also increasing. Headspace gas analyses can be used to delineate reservoir compartments and pay zones. Carbon isotope compositions in commingled production could be used to allocate contributions form individual production zones if isotopic differences exist between the gases from the contributing reservoirs. Origin of gas seepage in production sites could be investigated by the gas molecular and isotope compositions if enough reference data exist in the area.
著者
市川 真
出版者
石油技術協会
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.74, no.3, pp.234-242, 2009 (Released:2011-02-22)
参考文献数
12

While conventional oil and gas production is expected to hit a peak in dozens of years, the world still requires hydrocarbons as the main source of energy. The need to fill the gap between supply and demand, and the recent high oil price, have aroused enthusiasm for unconventional oil and gas. But, the development of them is, full of ups and downs.The extra heavy oil boom began in early 2000's, when large projects started in Canada and Venezuela. But, rising plant cost, shortage of skilled workers, and environmental concerns have increased uncertainty of those projects, and finally this year global economic crunch and oil price plunge ended the boom. In those circumstances, technologies to reduce production cost are keenly craved and several are on trial in actual projects.In 2005, U.S. Congress directed the Bureau of Land Management to manage oil shale development on public lands. By 2008, the bureau issued six research development and demonstration leases that will allow oil shale development to resume on a 160-acre tract of public land. Currently, in-situ conversion process is arguably the most cost effective recovery method.The U.S. has led the world in coalbed methane (CBM) development, and the production reached 1.8 tcf by 2006. While some countries are after the footsteps of the U.S. in CBM development, the U.S. is now considering giving a higher priority to shale gas instead as the results of efforts to develop economical production methods for years.Japan has studied gas hydrate development since 1990's. In 2008, the Japan Oil, Gas and Metals National Corporation carried out a successful gas hydrate production test in Canada. The next step of their pursuit will include practical application of the production method, nationwide potential evaluation, and development of environmental assessment technique.
著者
能村 幸輝
出版者
石油技術協会
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.79, no.2, pp.105-108, 2014 (Released:2016-07-15)

In the wake of the Great East Japan Earthquake in 2011, the thermal power ration has increased to 90% of total electric power due to the long-term shutdown of nuclear plants. Currently LNG thermal power alone accounts for nearly 50% of domestic power generation. Accordingly Japan's LNG demand increased by 30% after 2011, and in addition, Japan's LNG import price, linked to crude oil import price, has soared because of the increase in oil prices. As a result, the overall fuel cost in Japan has increased. Lowering fuel import costs is an urgent mission for the Japanese Government. We briefly introduce Japan's strategy for securing natural resources with competitive prices through diversification in this paper.
著者
加藤 進
出版者
石油技術協会
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.53, no.2, pp.131-143, 1988 (Released:2008-03-27)
参考文献数
36
被引用文献数
1 2

Several hydrocarbon deposits have been found in volcanic rocks of the Nanatani stage (so-called Green Tuff) in the Niigata basin, Japan.Their characteristics are summarized as follows.1) Hydrocarbon deposits are formed in anticlinal structures and are mostly located close to depressions.2) Oil accumulations have been found in anticlinal structures which are formed in the early stage.3) All hydrocarbon deposits except for the Shiunji gas field are located in the Chuetsu sub-basin.4) Larger oil and gas fields are located in or close to the kitchen areas of oil and gas. This suggests the short lateral migration of hydrocarbons together with the distribution of oil and gas in neighboring areas of the Mitsuke oil field.5) In larger gas fields, the Teradomari formation shows a typical abnormally high pressur e, whereas the Geen Tuff is hydrostatical or slightly highly-pressured. On the other hand, formation pressure in the Mitsuke oil field increases toward lower straigraphic horizons that is similar to the pressure distribution in the Shiiya and Nishiyama reservoirs. These pressure patters are closely related to the manner of accumulation of oil and gas.6) The migration of oil and gas in larger oil and gas fields is thought to have occurred during and after the Nishiyama stage.7) The distributions of oil and gas in the Green Tuff depend rather on the kinetics of hydrocarbon expulsion from source rocks than on the type of organic matter. The kinetics of expulsion is controlled by the relative positions of the hydrocarbon generation zone and the overpressured zone.The Niigata basin can be sub-divided into three parts according to their geologic conditions: Kaetsu sub-basin, Kakuta-Sanjo uplift and Chuetsu sub-basin. Considering the combination of trap, source rock, reservoir and migration mechanism, it is concluded that the Chuetsu sub-basin is the most prospective for future exploration.
著者
藤井 晴一
出版者
石油技術協会
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.47, no.6, pp.380-388, 1982 (Released:2008-03-27)
参考文献数
7
著者
佐々木 久郎 菅井 裕一 河野 洋之 高橋 孝志 伊藤 大輔 岡部 孝
出版者
石油技術協会
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.76, no.6, pp.522-529, 2011 (Released:2014-01-18)
参考文献数
8
被引用文献数
2 2

In this lecture, a cold drainage mechanism of heavy oil from sandstone cores has been presented by using immiscible CO2 gas dissolution into the oil. Dissolution curves of CO2 and CH4 gases for Japanese heavy oil were measured using with a PVT apparatus to decide the pressures of bubble point for the gases. CO2 swelling factors of the heavy oil and Oman intermediate oil were measured from surface movements of oil columns placed in a high-pressure cell which was controlled less than 10 MPa for the oil reservoir temperature 50°C. Two oil swelling factors increased with increasing gas pressure, and swelling coefficients were evaluated for CO2 and CH4 gases. The swelling-time curves for an oil column were fitted with the analytical solution of one dimensional gas diffusion derivative equation, and CO2 gas diffusion coefficients in the oils, D(m2/s), were evaluated. The values of D in the heavy oil were presented as 1.1 to 1.6 % of that of the intermediate oil, and the empirical equation for values of D has been presented with function of exponential to API gravity. Based on the observation tests on oil drainage from the sandstone cores saturated with the heavy oil, gas dissolution in the heavy oil does not make any oil drainage, however foamy heavy oil including huge number of micron CO2 gas bubbles, that were generated in depressurization process, effectively contributed to oil drainage out from the cores.
著者
合田 隆 佐藤 光三
出版者
石油技術協会
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.76, no.3, pp.233-243, 2011 (Released:2014-01-18)
参考文献数
21
被引用文献数
3

This study aims at developing a new population-based global optimization algorithm, called iterative Latin hypercube samplings (ILHS), and applying the ILHS to a global optimization of well placement for geological storage of CO2. The ILHS utilizes a space-filling property specific to the Latin hypercube sampling (LHS) : each independent variable xj(j=1, …, d) is divided into n strata of equal marginal probability and sampled once from each stratum. In the ILHS, the LHS is generated iteratively while a cumulative distribution function for each variable at the current step is updated from the fitnesses evaluated at the previous step. This iterative process enables us to search a global optimum in a derivativefree way. Considering a global minimization of an objective function involving only continuous independent variables, the mathematical formulation of the basic algorithm is described first.In general, in order to carry out a numerical simulation of CO2 migration in the subsurface, the target domain is divided into multiple grids and the well placement is indicated by the grid index. Therefore, we need to consider a global optimization of an objective function involving discrete independent variables. Here, a brief handling method toward the application of the ILHS involving discrete independent variables is introduced and we attempt to find an optimal well placement using the ILHS so as to minimize the amount of mobile CO2. The results for example problems confirm that our proposed algorithm can search an optimal solution effectively within a practical number of simulation runs.
著者
加藤 進 西田 英毅 岩野 裕継
出版者
石油技術協会
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.79, no.3, pp.171-179, 2014 (Released:2016-07-15)
参考文献数
29

Three oil samples, eight gas samples, and three rock samples, collected mainly from surface seepages in the northern Fossa Magna region, Nagano Prefecture, Japan, were subjected to geochemical analysis, yielding the following results.1) The oils are heavy and biodegraded, and are classified as Kubiki-type (Hirai et al., 1995). Geochemical characteristics of the oils indicate an origin from type II-III organic matter, and their maturity is estimated to be ∼ 0.7% Ro equivalent.2) The gases are mainly methane (C1); only three samples from Tenjinzawa and Nakatsuka contain heavier hydrocarbons, up to C6, and these samples have with high wetness over 10%. The chemical and isotopic compositions of the gases indicate that they are partly biodegraded and mostly thermogenic in origin, with a maturity of 0.7%-0.9% Ro equivalent.3) Mudstones in the Bessho Formation and the lower part of the Aoki Formation are probably the source rocks that generated the oil and gas in the areas of the Takafu and Komeji synclines as indicated by source rock analysis and by surface oil and gas seepages. Although subsurface geologic structures remain unclear, there is hydrocarbon potential in the zone between the areas of oil and gas seepages and the synclines.
著者
平林 憲次
出版者
石油技術協会
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.75, no.4, pp.296-305, 2010 (Released:2012-03-01)
参考文献数
20

In the Sakhalin Island, the oil show was discovered near Okha city in 1880. Hokushinkai (Japanese company) developed this oil and imported it into Japan in 1924. Japanese North Sakhalin Oil Co., Ltd. succeeded the business of Hokushinkai and continued until 1943.56 Japanese died during 1923-1943 years and were buried in Okha. After 1943, none of the Japanese visited the Japanese grave of Okha.In 1975, Sakhalin Oil Development Cooperation Co., Ltd (old SODECO) made the agreement (G/A) with the USSR to explore the shelf of the Sakhalin Island.In the north-east shelf area, the Odoptu and Chayvo oil/gas fields were discovered. These oil/gas fields and the Arkutun/Dagi oil/gas field developed as Sakhalin-1 project. And the Luni structure and the Piltun/Astokh structure developed as Sakhalin-2 project.The author worked in Sakhalin in times of the Japan and Soviet co-operational exploration based on G/A. But the foreigners who worked in Sakhalin were not able to be accompanied by a family in the Sakhalin.In 2009, he guided his wife and visited Sakhalin, and she enjoyed sight seeing of the place that he worked in old days. And he recognized the present circumstances of the Sakhalin and difference with that of the USSR era.Another purpose of his visit to the Sakhalin was to burn incense for the 56 Japanese deceased in Okha. But the graveyard was removed, and he recited the sutra from the hill which overlooked the lost grave.
著者
瀬能 修
出版者
石油技術協会
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.83, no.2, pp.138-142, 2018-04-23 (Released:2021-01-09)
参考文献数
13

Biogenic methane gas is generated by methanogen in sediments. The generated gas can be concentrated as water dissolved gas and accumulated as methane hydrate or free gas. The sea areas around Japan have optimal conditions for biogenic gas generation comparable with other biogenic gas generating basins in the world. Gas bubbles generated from oversaturated dissolved gas cause free gas accumulation effectively, and the mechanism to produce oversaturation differs by basin. The main mechanism for oversaturation is the continuation of gas generation and decompression caused by vertical crustal movement or upward migration of formation water.Biogenic free gas accumulation often occurs at shallow depths, and direct hydrocarbon indicators( DHIs) on the seismic section provide a strong clue of their existence. The combined implementation of marine electro-magnetic survey with seismic survey is however recommended to reduce exploration risk, as low saturation gas also causes DHIs.In near feature, it is expected that the understanding of the underground carbon cycle and gas accumulation mechanism will advance, and biogenic gas exploration in the seas around Japan will become more common.
著者
秋葉 文雄 谷村 好洋 大井 剛志 石浜 佐栄子 松本 良
出版者
石油技術協会
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.79, no.2, pp.130-139, 2014 (Released:2016-07-15)
参考文献数
31
被引用文献数
5 3

Eight diatom zones are recognized for the uppermost Quaternary piston cores from the Joetsu Basin of the eastern margin of the Japan Sea recovered by a methane hydrate cruise, MD179. They are primarily based on the occurrences of a warm-water marker diatom Fragilariopsis doliolus and a cold-water one Thalassiosira hyperborea and secondarily on that of a new cold-water one Thalassionema umitakae n. sp., and represent major changes of surface water of the Japan Sea. In addition, very fluctuating occurrences of diatom-derived black grains, which might be a proxy of stagnant condition of the sea bottom, first observed in horizons mostly where dark thinly laminated layers are recognized. Because both the diatom zonal subdivision and the occurrence of black grains correlate very well to those of the marine isotope stages, MIS1 through MIS5e recognized by Ishihama et al. (2014) in the same cores examined, it is obvious that they reflect major paleoceanographic changes of the Japan Sea induced by global glacial and interglacial cycles over the last 130 ka. Thalassionema umitakae n. sp. is described in Appendix.
著者
鶴 哲郎 溝部 晃 田中 暁 田中 誠 佐藤 隆一
出版者
石油技術協会
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.81, no.1, pp.56-65, 2016 (Released:2018-05-09)
参考文献数
41

An extremely low velocity layer was detected in a deep water area, whose velocity was estimated to be 1500 m/s by velocity analysis of the seismic data. Its thickness is approximately 500 m in average and exceeds 700 m in maximum. Although obtained data are limited to reveal its origin, the layer was interpreted to be a mass transport deposit based on the observations: a distribution feature spreading toward the deep water, a chaotic-to-transparent reflection pattern, basal erosions of the underlying sediments and a pressure ridge developed at the tip region. However, mass transport deposit is normally characterized by high seismic velocity according to previous studies, whereas such a mass transport deposit with low velocity is seldom reported. From detailed seismic interpretation, active normal faults cutting the seafloor were recognized in overlying sediments. The faults appear also to cut the uppermost part of the mass transport deposit. Moreover, pore pressure gradient within the deposit was estimated to be from 12.0 to 14.4 MPa/km, being comparable with the fracture gradient from previous study. As a result, the presently-detected low velocity layer can be concluded most likely as a slow-moving earthflow type of mass transport deposit in deep water.
著者
若林 尚幸
出版者
石油技術協会
雑誌
石油技術協会誌 (ISSN:03709868)
巻号頁・発行日
vol.69, no.3, pp.255-260, 2004

Testing and gathering data from a well to evaluate the potential of a new field is a common practice in the oil and gas industry. However, performing this task in ultra deep water presents significantly greater challenges to the operator and service providers, since testing in the depths required for the subject well had not previously been attempted, there were concerns of problems that might occur in maintaining response times and control of the test equipment. <br>This paper will present the innovative solution that was devised to perform the testing in the deep water well. The equipment, the well, location condition, and procedures were used to safely and efficiently perform the evaluation testing will be discussed.