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Sample records for hanshaho danseiha tansa

  1. Seismic reflection survey of the Uemachi fault in Osaka Prefecture; Osaka Uemachi danso no hanshaho danseiha tansa

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    Sugiyama, Y. [Geological Survey of Japan, Tsukuba (Japan); Yoshizawa, M.; Hirooka, S. [Nikko Exploration and Development Co. Ltd., Tokyo (Japan); Yokota, H.; Ito, S. [Hanshin Consultant Co., Osaka (Japan); Hayashi, K.; Aizawa, H.

    1997-05-27

    Reflection survey is conducted using three traverse lines in Sakai City for confirming the presence of a southward stretch of the Uemachi fault underground along the western periphery of the Uemachi terrace, Osaka, and for elucidating its connection to the Sakamoto fault distributed near Izumi. Another reflection survey is conducted in the bed of Kanzaki river, Osaka, for the confirmation of its connection to the Nembutsuji-zan fault in Senri hillock. It is estimated on the basis of boring data that there exists another flexural structure approximately 3km south of the flexural structure whose presence is confirmed by the Sakai second traverse line. Accordingly, possibilities are high that the southward stretch of the Uemachi fault connects to the Sakamoto fault. The confirmation by the Kanzaki river traverse line of the flexural structure again confirms the continuity between the Uemachi fault and Nembutsuji-zan fault. The above-said findings enable an inference that the three faults of Nembutsuji-zan, Uemachi, and Sakamoto constitute a chain of active faults. Furthermore, there exists an active fault to the south of the Sakamoto fault, which zigzags to the south on the right-hand side as far as the south of the Kumeda pond. Accordingly, the Uemachi fault system as a whole spans approximately 43km from the northern end of the Nembutsuji-zan fault as far as the south of the Kumeda pond. 5 refs., 6 figs.

  2. Near-surface 3D reflections seismic survey; Sanjigen senso hanshaho jishin tansa

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    Nakahigashi, H.; Mitsui, H.; Nakano, O.; Kobayashi, T. [DIA Consultants Co. Ltd., Tokyo (Japan)

    1997-05-27

    Faults are being actively investigated across Japan since the Great Hanshin-Awaji Earthquake. Discussed in this report is the application of the 3D near-surface reflection seismic survey in big cities. Data from trenching and drilling is used for the geological interpretation of the surroundings of a fault, and the reflection seismic survey is used to identify the position, etc., of the fault. In this article, when the results obtained from the experimental field are examined, it is found that the conventional 2D imaging reflection survey betrays the limit of its capability when the geological structure is complicated, that the 3D reflection seismic survey, on the contrary, is capable of high-precision imaging and, when augmented by drilling, etc., becomes capable of a more detailed interpretation, and that it also contributes effectively to the improvement of local disaster prevention in big cities. Using as the model the Tachikawa fault that runs near JR Tachikawa Station, embodiment of the 3D reflection seismic survey is reviewed. For the acquisition of data excellent in quality in a 3D reflection seismic survey conducted utilizing the roads in the sector chosen for experiment in the urban area, the shock generating points and receiving points should be positioned by taking into account the parameters in the bin arranging process so that the mid-points will be regularly distributed on the surface. 3 refs., 11 figs., 1 tab.

  3. Faults survey by 3D reflection seismics; Sanjigen hanshaho jishin tansa ni yoru danso chosa

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    Tsuchiya, T.; Ejiri, T.; Yamada, N.; Narita, N.; Aso, H.; Takano, H.; Matsumura, M. [Dia Consultants Company, Tokyo (Japan)

    1996-10-01

    This paper describes fault survey by 3D seismic reflection exploration. Survey has been conducted mainly at flat land area without pavement not in urban area in Japan. Subsurface structure is complicated with intersecting multiple faults. In this area, a lot of geological investigations have been done prior to the seismic reflection exploration. Fairly certain images of faults have been obtained. However, there were still unknown structures. Survey was conducted at an area of 170m{times}280m in the CDP range. Measurements were carried out by using 100 g of dynamite per seismic generation point combined with 40 Hz velocity geophones. Fixed distribution consisting of lattice points of 12{times}12 was adopted as an observation method. In and around the lattice, a great number of explosions were carried out. The CDP stacking method and the method of migration after stacking were used for the data processing. The 3D structures of six horizons and five faults could be interpreted. Interpreted horizons were well agreed with the logging results. 3 figs.

  4. New seismic source `BLASTER` for seismic survey; Hasaiyaku wo shingen to shite mochiita danseiha tansa

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    Koike, G.; Yoshikuni, Y. [OYO Corp., Tokyo (Japan)

    1996-10-01

    Built-up weight and vacuole have been conceived as seismic sources without using explosive. There have been problems that they have smaller energy to generate elastic wave than explosive, and that they have inferior working performance. Concrete crushing explosive is tried to use as a new seismic source. It is considered to possess rather large seismic generating energy, and it is easy to handle from the viewpoint of safety. Performance as seismic source and applicability to exploration works of this crushing explosive were compared with four kinds of seismic sources using dynamite, dropping weight, shot-pipe utilizing shot vacuole, and impact by wooden maul. When considered by the velocity amplitude, the seismic generating energy of the crushing explosive of 120 g is about one-fifth of dynamite of 100 g. Elastic wave generated includes less high frequency component than that by dynamite, and similar to that using seismic source without explosive, such as the weight dropping. The maximum seismic receiving distance obtained by the seismic generation was about 100 m. This was effective for the slope survey with the exploration depth between 20 m and 30 m. 1 ref., 9 figs., 2 tabs.

  5. Shallow seismic reflection prospecting in Hachiro-kata reclaimed land; Hachirogata kantakuchi ni okeru senbu hanshaho jishin tansa

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    Kitsunezaki, C.; Fukutome, T.; Matsumoto, S.; Noda, K.; Sato, T. [Akita University, Akita (Japan). Mining College; Hayashi, H.; Ishii, E.; Yamanaka, Y.; Matsuno, K.; Mikuni, S. [Suncoh Consultant Co. Ltd., Tokyo (Japan)

    1997-05-27

    Along the Japan Sea coast in Akita Prefecture and in the vicinity, there exist active fault groups, such as the Kitayuri thrust fault group in the south and Noshiro thrust fault group in the north. It is estimated that there is another fault, running from Akita City located between the above-said two thrust fault groups into the Hachiro-kata reclaimed land, roughly connecting the two thrust fault groups. This third fault is supposed to be related to the hypocenter of Tencho Earthquake of 830, but its location and structural configuration are not known, and it is not known whether it is an active fault, either. Investigations are conducted using S- and P-waves. The greatest problem in the use of P-waves is that there exists a layer in which signal attenuation is high and transmission is anomalously slow. This problem is ascribed to the layer pore water rendered unsaturated though slightly by the inclusion of air bubbles, and is explained for the most part by the White model. A survey using S-waves is advantageous in that it does not experience no difficulty of this kind. In the P-wave cross section, a structure supposed to be an inversion layer is observed at a level deeper than 200m. In the case of the S-wave method, more details of the shallow structure will be available when the degree of CMP stacking is augmented as usual. 2 refs., 9 figs., 1 tab.

  6. Seismic reflection survey in Omama fan area, Gunma prefecture; Gunma Omama senjochi ni okeru hanshaho jishin tansa

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    Yamaguchi, K.; Kano, N.; Yokokura, T.; Kiguchi, T.; Yokota, T.; Matsushima, J. [Geological Survey of Japan, Tsukuba (Japan)

    1996-10-01

    Seismic reflection survey was performed for the Medial Tectonic Line, an important geological tectonic line in the Kanto plains, at Kushibiki district, Saitama prefecture in the north-western part of the Kanto plains. It was estimated that movements of the basement were different in the individual sides of the active fault. In this study, the seismic reflection survey was performed at the Omama fan area, Gunma prefecture, which is located at the north-eastern extension of the Kushibiki plateau, to grasp the structure of basement to the depth of about 1.0 s of return travel time, and the upper sediments. Two traverse lines passing Ota city, Kiryu city, and Nitta town were used. Southern part of the traverse line-1 was in the bottom land in the middle of Tone river, and northern part was in the Omama fan area. The ground surface along the traverse line was flat. Hachioji heights are the heights elongating in the NW-SE direction and having relative height of 100 to 200 m against the surrounding plain. Another traverse line-2 was set on the steep slope having relative height more than 100 m. The Brute stack time section of each traverse line was characterized by the gradient reflection surface AA of the traverse line-1. It was suggested that the AA or intermittent parts of reflection surfaces deeper than AA may relate to the tectonic lines in the more ancient geological ages. 2 figs., 1 tab.

  7. Depth imaging system for seismic reflection data. Part 1. Outline of system; Hanshaho jishin tansa data no tame no shindo imaging system. 1. System no gaiyo

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    Shimizu, N. [Japex Jeoscience Institute, Tokyo (Japan); Matsuoka, T. [Japan Petroleum Exploration Corp., Tokyo (Japan); Tsuru, T. [Japan National Oil Corp., Tokyo (Japan)

    1996-10-01

    Structures of oil and gas fields to be recently explored have changed from simple structures represented by anticline into more complicated and more delicate structures in the deeper underground. In order to discover and develop prospective oil and gas fields among such geological structures, it is indispensable to construct a system which can treat seismic exploration date collectively before stacking and can easily perform imaging of underground structures accurately. Based on the advancement of hardware, Japan National Oil Corporation and Japan Petroleum Exploration Co., Ltd. have developed a depth imaging system as an interactive tool for constructing underground structures accurately through a cooperation of highly accurate imaging technology. Using this system, two-dimensional underground structure models can be easily given and modified by interactively referring to results of depth migration velocity analysis and stacking velocity analysis, well data, cross sections after depth transform, etc. 1 fig.

  8. Processing of the reflection seismic data which were acquired in the continental shelf off the north-west Australia; Australia hokusei tairikudana chiiki ni oite shutokusareta hanshaho chishitsu tansa data no shori ni tsuite

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    Amano, H. [Japan National Oil Corp., Tokyo (Japan)

    1996-05-01

    Reflection exploration of earthquakes was conducted in the continental shelf off the north-west Australia, and a report is made concerning the processing of the acquired data. A GI gun was used as the vibration source, and a wave quite similar to a pulse was generated. Hydrophones were arranged with group intervals of 12.5m, and high-resolution field data were acquired. An analog low cut filter was used to suppress the large-amplitude swell noise attributable to sea conditions. A digital filter was designed for the purpose of eliminating coherent noises from other survey ships. At the ultimate stage the f-k filter was applied to each of the shot records, and the effectiveness was verified. The traverse line was as long as 6700km and therefore the design window was set relatively long at 2.0-4.0s in the residual static correction phase. It was found that this setup is effective in improving the continuity of the reflection surface. 5 figs., 1 tab.

  9. FY 1995 report on verification of geothermal exploration technology. Development of fracture reservoir exploration technology (development of seismic exploration); 1995 nendo chinetsu tansa gijutsunado kensho chosa. Danretsugata choryuso tansaho kaihatsu (danseiha riyo tansaho kaihatsu) hokokusho

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    NONE

    1996-03-01

    This report provides the development of new exploration technology using elastic waves, such as reflection seismic survey, VSP, and seismic tomography, for precisely characterizing subsurface fractures in geothermal reservoirs. In order to investigate and improve the effective data acquisition and analysis methods for detecting a fault type of fractures, an experiment of a seismic tomography method was conducted using wells drilled in the Ogiri geothermal field, Aira-gun, Kagoshima Prefecture. An experiment of propagation characteristics of piezo type underground seismic source in the volcanic field was also conducted as a trend survey of underground seismic sources. The fracture type in the model field was systematically analyzed by measuring the core samples obtained in the demonstration test field through remanence measurement, fluid inclusion measurement, and zircon measurement using test equipment, and by analyzing results obtained from cores and results of seismic tomography obtained from the wells. Based on these results, the effectiveness and practical application of exploration methods using elastic waves were investigated. 80 refs., 250 figs., 49 tabs.

  10. Model experiment on detection and monitoring of fractures by using air as a tracer for seismic wave. 2; Kitai wo tracer to shita kiretsu no danseiha tansa no model jikken. 2

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    Watanabe, T.; Takami, Y.; Ishiga, T.; Sassa, K. [Kyoto University, Kyoto (Japan). Faculty of Engineering

    1996-05-01

    Clearance provided between two flat resin blocks (being stacked) used as a model of a crack in rocks was subjected to an experiment to investigate elastic wave propagation characteristics when the crack is filled with water and when injected with air. This paper reports the result of the experiment. The experiment was carried out on a case where a parallel flat layer of water (with a thickness of 2 mm) was used as a crack and a case where crack faces are contacted (small resin pieces are inserted into the crack). The experiment was conducted by injecting air bubbles (air) into the water saturated crack from its side to gradually expand the air bubble existing region. Seven ceramic piezoelectric elements (one is a vibration source) were arranged on top of a resin block and six elements beneath the block to measure a wave reflected from the crack face and a wave permeated through the crack. It was found that as the air bubble existing region is expanded, the amplitude of the permeated wave decreases remarkably (however, only to a certain level when the crack faces are contacted), and the amplitude of the reflected wave increases. 3 refs., 9 figs.

  11. Seismic traveltime tomography by use of gridpoints discritization; Koshitenho ni yoru danseiha tomography kaiseki

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    Hirai, T.; Watanabe, T.; Sassa, K. [Kyoto University, Kyoto (Japan). Faculty of Engineering

    1996-05-01

    Efforts were made to enhance analytical precision and stabilize the results in seismic traveltime tomography by use of a method wherein the velocity distribution is expressed as a continuous function interpolated by parameters respectively assigned to the gridpoints. In this method, the slowness data are regarded as the parameters respectively assigned to the gridpoints, and the slowness value at a given point is determined after interpolation by the gridpoints surrounding the said point. A method based on the variation principle was used for ray tracing. As the result, it was confirmed that this method determines the ray path and traveltime with high precision. A method of least squares using Lagrange`s multiplier was applied for inversion. Comparison was made between the use of cells and the use of gridpoints in the results of inversions performed for an inclined 4-layer structure model, when it was found that the values involving the boundaries between layers, inclinations of the layers, and velocities of seismic waves are ambiguous with the cells while those with the gridpoints are reconstructed roughly correctly. 5 refs., 7 figs., 1 tab.

  12. Chronology of petroleum geophysics; Sekiyu butsuri tansa nenpyo

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    Kametani, T.

    1996-10-01

    A table, chronology of petroleum geophysics in overseas and in Japan, has been prepared for the convenience of checking events, which are thought to be important as notable affairs in application, success, and technical innovation. In overseas, successes in the 1920s were remarkable, when the US modern geophysical exploration made a start. Successes in determining the position of exploratory drilling by means of the gravity torsion balance, fan shooting seismic refraction method, and seismic reflection method occurred one after another. The USA has kept its situation stably as the number one by the seismic reflection method occurred most lately, and its life has been further elongated by adopting digital techniques. The CDP technique which became to be used simultaneously, and the seismic sources without using explosives, such as vibro-seismic source and air gun, extended the success of digital techniques drastically. In the future, the progress of 3-D exploration technology is expected. In Japan, about 18 years lag in the seismic reflection method is observed when compared with the USA. Japan has provided leading techniques in the shallow layer seismic reflection method and S-wave exploration. 40 refs., 1 tab.

  13. Electric and VLF-MT survey of Tegatayama tunnel; Tegatayama tunnel no denki tansa oyobi VLF tansa

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    Nishitani, T. [Akita University, Akita (Japan). Mining College

    1997-05-27

    To survey the structure at the depth between 20 and 30 m, field tests were conducted by means of vertical electric and VFL-MT (magnetotelluric) survey. Tegatayama tunnel has a total length of 276 m, width of 7.5 m, and height of 4.7 m, and the depth from the surface is about 28 m near the top of mountain. Near the tunnel, the thickness of surface soil is about 60 cm, which consists of clay soil including soft mudstone gravel. It was found that terrace deposit is distributed up to the depth of 8 m, and that mudstone is distributed below the depth of 8 m. Weighted four-electrode method was adopted for the vertical electrical survey. Measurements were conducted at the immediately above the tunnel, 10 m apart from the center of tunnel in the right and left, and 20 m apart from the center in the east. For the VLF-MT method, component of frequency 22.2 kHz was used. As a result of the tests, it was difficult to illustrate the existence of tunnel from the vertical electrical survey only at one point. Feature of the tunnel could be well illustrated by means of the VLF-MT method. 3 refs., 9 figs.

  14. Experiment of exploration using the active-faults exploration system; Katsudanso tansa system wo mochiita chika tansa jikken

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    Mikada, H.; Sato, H.; Iwasaki, T.; Hirata, N. [The University of Tokyo, Tokyo (Japan). Earthquake Research Institute; Ikeda, Y. [The University of Tokyo, Tokyo (Japan). Faculty of Science; Ikawa, T.; Kawabe, Y.; Aoki, Y. [JAPEX Geoscience Institute, Tokyo (Japan)

    1996-10-01

    A system for exploration of active-faults by seismic reflection profiling method was introduced at Earthquake Research Institute, University of Tokyo. A test-run was conducted to check the performance of this system at Ranzan, Saitama Prefecture. This paper describes the confirmed performance of mini-VIB as a wide band frequency seismic source, the quality of data obtained using a digital data acquisition system, and problems for data processing of fault exploration in the future. For the test-run at Ranzan, two-dimensional exploration was conducted by the quasi-three-dimensional data acquisition method using three geophones of 8 Hz, 28 Hz, and 40 Hz, simply arranged in parallel on the measurement line. Using an active seismic vibrator, mini-VIB, data acquisition of faults in the wide band frequency was achieved, which would result in the highly accurate imaging. Operation of data acquisition and processing systems is easy, and the system can be also used as a kind of black box. The existing methods are to be used sufficiently as a tool for imaging of faults. Further research for accumulating experience may become necessary toward the extension of the system expected in the future. 5 refs., 6 figs.

  15. Fault analysis in the very shallow seismic reflection method. 2; Gokusenso hanshaho ni okeru danso kaiseki. 2

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    Nagumo, S.; Muraoka, S.; Takahashi, T. [Oyo Corp., Tokyo (Japan)

    1997-05-27

    Fault analysis is required in addition to the ordinary process of structural analysis (CDP stacking) for the examination of discontinuity in the reflection horizon in question. The fault shape restoration principle is that the reflection point of a reflection wave observed at a certain receiving point is on an ellipse with the shock point and receiving point at its focal points and that the sum of the distances between the reflection point and the focal points is equal to the reflection wave propagation time. The DMO velocity is worked out by calculation using the positive travel time and inverse travel time from the common reflection surface. When the reflection surface is inclined by {theta}, the average interval velocity/cos{theta} is called the DMO velocity. When the reflection surface inclination and the average interval velocities are determined separately in this way, the position of the reflection point may be worked out, and this enables the calculation of the amount of migration (lateral movement). The reflection wave lineups carried by the original record are picked up one by one, and the average interval velocities are treated very prudently. After such a basic DMO conversion treatment, the actualities of the fault are described fairly correctly. 3 figs.

  16. Experiment for 3-component S-wave reflection survey. Part 3; Sanseibun S ha hanshaho no kiso jikken. 3

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    Kano, N.; Yamaguchi, K.; Yokota, T.; Kiguchi, T. [Geological Survey of Japan, Tsukuba (Japan)

    1996-10-01

    Anisotropy has been investigated using S-wave as a technique for detecting fractures. In this study, fundamental experiments were carried out with slightly changing the measuring conditions at a place where anisotropy was expected. This paper describes the fundamental data acquisition of anisotropy analysis using S-wave, and a part of the results. The experiments were conducted on the agricultural road in Yamadera district, Matsuyama-machi, Yamagata Prefecture. Two flat unpaved roads meeting at right angles were used as traverse lines. In this place, several reflection surfaces were certainly detected by P-wave, and anisotropy of S-wave was confirmed from the velocity of refracted wave of S-wave. Data were processed for individual traverse lines meeting at right angles. Firstly, signal sweeping, correlation, and vertical superposition were made. Six kinds of data were prepared, i.e., three-component receiving records of data at 0{degree} of generating direction and three-component receiving records of data at 90{degree} of generating direction. Records of T-component at 0{degree} and R-component at 90{degree} were used for processing of the seismic reflection method. These records would be considered to be data of SH-wave and SV-wave, respectively. 4 figs.

  17. Fault analysis in the very shallow seismic reflection method; Gokusenso jishin hanshaho ni okeru danso kaiseki. 1

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    Nagumo, S.; Muraoka, S.; Kaida, Y.; Takahashi, T. [OYO Corp., Tokyo (Japan)

    1996-10-01

    To effectively use the very shallow seismic reflection for active fault survey, a method has been investigated by which fault structures can be appropriately reconstructed from the fault information detected in the original records. The first step of reconstructing the fault system from the travel time reflection curve was to grasp an outline of fault structure from the patterns of travel time curve observed in the original record. For the very shallow seismic reflection method, especially, the low velocity layers in a shallow part succeeding from the ground surface made the issue complicated. Then, the travel time reflection curves were calculated in the case of existing several horizontal reflection surfaces in the surface layer. The constant values, mean velocities to the depth at individual reflection surfaces were used for the approximation of velocities. The outline of fault structure was grasped from the observation of original record. Then, the structure was reconstructed from the travel time curves. When the mean velocity in the medium was known, reconstruction of the feature of reflection surfaces from the travel time curves could be determined by simple mapping. When the mean velocity was unknown, it was calculated using the reciprocal travel time from the common reflection surface for individual reflection surfaces. 7 figs.

  18. Research of the elastic waves generated by a pulse laser. Excitation mechanism of elastic waves and application to nondestructive testing; Pulse laser de reikishita danseiha ni kansuru kenkyu. Danseiha reiki no mechanism to hihakai kensa eno oyo

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    Cho, H.; Takemoto, M. [Aoyama Gakuin University, Tokyo (Japan). College of Science and Engineering

    1994-07-20

    A bulk wave is generated when a pulse laser is irradiated to the material, and the characteristics of a Young`s modulus and Poisson`s ratio can be nondestructively estimated from the bulk wave. The generation mechanism of laser ultrasonic waves must be first clarified for such application. In this paper, fundamental research was conducted to study the generation mechanism of the elastic waves excited by a Q-switched Nd-YAG laser, and the generation method and characteristics of Rayleigh waves. The following result was obtained. A bulk wave is generated by the disk-like adiabatic expansion near the surface if the laser power is small when a spot-shape pulse laser was irradiated. A bulk wave is generated by the thin disk-like adiabatic expansion beneath the surface due to the thermal diffusion in the depth direction of a base material when the laser power becomes large. Moreover, a bulk wave is generated by the impact force due to abrasion and plasma when the power becomes still larger. The information on the bulk wave characteristics and Rayleigh wave was also obtained. 25 refs., 15 figs., 1 tab.

  19. Relation between frequency of seismic wave and resolution of tomography; Danseiha tomography kaiseki ni okeru shuhasu to bunkaino no kankei

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    Fujimoto, M.; Watanabe, T.; Ashida, Y.; Sassa, K. [Kyoto University, Kyoto (Japan). Faculty of Engineering

    1997-05-27

    With regard to the elastic wave exploration, discussions have been given on the relationship between frequency and resolution in P-wave velocity tomography using the initial travel time. The discussions were carried out by using a new analysis method which incorporates the concept of Fresnel volume into tomography analysis. The following two arrangements were used in the calculation: a cross hole arrangement, in which seismic source and vibration receiving points were arranged so as to surround the three directions of a region extending 250 m in the horizontal direction and 500 m in the vertical direction, and observation is performed between two wells, and a permeation VSP arrangement in which the seismic source is installed on the ground surface and receiving points installed in wells. Restructuring was performed on the velocity structure by using a total of 819 observation travel times. This method has derived results of the restructuring according to frequencies of the seismic source used for the exploration. The resolution shown in the result of the restructuring has become higher as elastic waves with higher frequency are used, and the size of the structure identified from the restructuring result has decreased. This fact reveals that sufficient considerations must be given on frequencies of elastic waves used according to size of objects to be explored. 4 refs., 4 figs.

  20. Application of geophysical methods to investigation of old castle, especially of the moat; Joshi no chosa ni okeru butsuri tansa no tekiyo (horiato no tansa)

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    Tanaka, A.; Karube, F.; Kobayashi, M.; Toge, M. [OYO Corp., Tokyo (Japan)

    1996-05-01

    An explanation is made about the application of geophysical methods to the investigation of the ruins of old castles especially of their moats. Techniques currently in use for exploration of the ruins of castles are mainly underground radar exploration and electric exploration. The underground radar method sends electromagnetic waves through the ground and receives the reflection for a high-precision exploration of the layers shallow in the ground. Therefore, this method is suitable for probing the ruins of castles relatively shallow in the flat land, hills, and mountains. The electric method (resistivity image method) do the probing by use of the two-electrode arrangement, performs inverse analysis on the basis of the obtained data for the determination of the underground resistivity distribution, and displays the distribution in an image easy to read. This method, when there is a great separation between the two electrodes, explores relatively deep into the ground. Thanks to this feature, this method is effective in probing relatively wide and deep ruins of moats, that is, the ruins of moats of castles built in later years, especially of those then filled with water. 2 refs., 5 figs.

  1. On the exploration of deep sea mineral resources. Shinkaitei kobutsu shigen no tansa kaihatsu ni tsuite

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    Fujioka, H. (Deep Ocean Resources Development Co. Ltd., Tokyo (Japan))

    1993-10-01

    This paper summarizes exploration and development of deep sea mineral resources. Manganese concretions, cobalt rich crusts, and ocean bottom hydrothermal beds are taken up currently as the objects of discussions. A manganese concretion is a lump of mono-layer metal oxides present on ocean bottoms as deep as 4000 m to 6000 m, composed of Mn at 25% and Fe at 6%. Cobalt rich crust consists of Fe and Mn as the main components, and one that is rich with Co is present in the form of crust and gravel in depths of 800 m to 2400 m. It contains Mn at 23%, Fe at 16%, and Co at 0.7%. Ocean bottom hydrothermal mineral beds consist of sulfide ores and oxide ores produced in relation with hot water eruption, and exist in depths of 1500 m to 2500 m. The main mineral constituents are iron pyrites, marcasites, and chalcopyrites, containing high-grade Cu, Pb, Zn, Au, and Ag. The Deep Ocean Resources Development Company has been established in Japan to carry out mineral resources investigations by executing investigative navigations. Agency of Industrial Science and Technology is discussing development of manganese concretions, and Metal Mining Agency of Japan is discussing recovery of useful metals from deep sea minerals.

  2. Magnetotelluric (MT) surveying in the Kakkonda geothermal area; Kakkonda chinetsu chiiki deno MT ho tansa jikken

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    Ogawa, Y.; Takakura, S. [Geological Survey of Japan, Tsukuba (Japan); Uchida, T. [New Energy and Industrial Technology Development Organization, Tokyo, (Japan)

    1997-05-27

    This paper describes the MT surveying conducted at the vicinity of a deep well (WD-1) in the Kakkonda geothermal area. For the MT surveying, the interval between measuring points was 300 m. Electric field dipole with a length of 300 m was given in the direction of traverse line, and that with a length of 50 m was given in the direction perpendicular to the line. Three components of magnetic field were measured using induction coil. Frequency band of the data was between 0.0005 Hz and 300 Hz. Characteristics of specific resistance model obtained from the MT surveying were illustrated. Low specific resistance zone less than 30 ohm-m was observed in the shallow zone below the altitude 0 m. This zone was comparable to the distribution of montmorillonite. High specific resistance anomaly was analyzed at the western half of the traverse line in the altitude between 0 m and -2000 m, which corresponded to the collective part of focuses. The bottom surface of the anomaly agreed well with the upper surface of neo-granite, i.e., the lower limits of earthquakes. Low specific resistance was observed in the altitude below -2000 m. 17 refs., 5 figs.

  3. Groundwater exploration by self-potential method; Shizen den`iho ni yoru chikasui tansa

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    Onaru, I.; Irie, S.; Mizunaga, H.; Ushijima, K. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

    1997-05-27

    This paper describes results measured from the field experiments and data analysis of the groundwater exploration by self-potential method. The field survey was conducted in the vicinity of spring water source in the suburbs of Fukuoka City. For the field experiments, potential differences from the standard potential electrode set at the distance about 200 m were measured at multi-points, simultaneously. For the laboratory experiments, assuming that the groundwater flows in a permeable layer, streaming potential change was observed against the changes of flow rate and electrical conductivity. Thus, the generation of streaming potential was investigated. For the experiment using specimens obtained at the spring water source, the potential changed to negative and was stabilized in around -80 mV after 15 minutes. Numerical simulation was conducted by means of the three-dimensional finite difference method using parameters obtained from the laboratory experiments. From these results, the groundwater flow image could be obtained. It was also confirmed that the self-potential observed in the spring water source area was caused by the streaming potential. 11 refs., 9 figs.

  4. Refraction experiment in the Kobe-Hanshin area; Kobe Hanshin kan ni okeru kussetsuho tansa

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    Koketsu, K. [The University of Tokyo, Tokyo (Japan). Earthquake Research Institute

    1996-05-01

    The refraction experiments were conducted to investigate the underground structures reaching the basement by analyzing the results of the artificial earthquakes the explosion earthquake research group produced in City of Kobe and the Hanshin District on December 12 to 15, 1995. Considering that noise level can exceed 1 mkine in an urban area even in the mid-night, the courses of traverse were drawn focusing on Points S2 through S4 and U1. The earthquake waves from Points S2 through S4 are generally low in amplitude. However, the major components of the signals have a dominant frequency exceeding 10Hz, which makes them distinguishable from urban noise having a lower frequency, contrary to the previous indication that such a low-amplitude wave might not be distinguishable. On the other hand, the signals from the explosion at Point 4 in Awaji Island cannot be distinguished in the urban area, even on the nearby course of traverse D. At present, the analytical group is organized to read various phases running and analyze the P-velocity structures. 2 refs., 10 figs., 1 tab.

  5. Archaeological prospecting by DEF method; Denkai zansaho ni yoru iseki tansa

    Energy Technology Data Exchange (ETDEWEB)

    Kishikawa, H.; Aono, T.; Tanaka, T.; Mizunaga, H. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

    1996-05-01

    A study is made of a newly-developed differential electric field (DEF) method, wherein potentials between potential electrodes equidistant from a current electrode is measured for directly detecting the secondary potential attributable to an anomalous-resistivity body. In this method, a current is fed into the ground from a point source C1, and four potential electrodes, two each on the X-axis and Y-axis, are provided equidistant from the point source C1 for the measurement of the potentials in the directions of X and Y. Numerical experiments and field experiments in a playground were conducted for this DEF method, and it was found that this method is effective in detecting an anomalous-resistivity bodies (ruins, etc.) situated in a homogeneous medium or in a horizontal multi-layer structure, is capable of displaying anomalous vectors enabling the estimation of the direction from the observation point of the anomalous-resistivity body, improves on work efficiency over the conventional mapping method, enables the estimation of the boundary of the anomalous-resistivity body on the basis of the peak of the anomalous electric field residue on the display, and that the obtained data can be easily processed by use of a personal computer on the site. 3 refs., 9 figs.

  6. Application of wavelet transform to seismic data; Wavelet henkan no jishin tansa eno tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Nakagami, K.; Murayama, R.; Matsuoka, T. [Japan National Oil Corp., Tokyo (Japan)

    1996-05-01

    Introduced herein is the use of the wavelet transform in the field of seismic exploration. Among applications so far made, there are signal filtering, break point detection, data compression, and the solution of finite differential equations in the wavelet domain. In the field of data compression in particular, some examples of practical application have been introduced already. In seismic exploration, it is expected that the wavelet transform will separate signals and noises in data in a way different from the Fourier transform. The continuous wavelet transform displays time change in frequency easy to read, but is not suitable for the analysis and processing large quantities of data. On the other hand, the discrete wavelet transform, being an orthogonal transform, can handle large quantities of data. As compared with the conventional Fourier transform that handles only the frequency domain, the wavelet transform handles the time domain as well as the frequency domain, and therefore is more convenient in handling unsteady signals. 9 ref., 8 figs.

  7. Development of measurement apparatus for high resolution electrical surveys; Komitsudo denki tansa sokuteiki no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Moriuchi, H.; Matsuda, Y.; Shiokawa, Y. [Sumiko Consultants Co. Ltd., Tokyo (Japan); Uchino, Y. [Cosmic Co. Ltd., Tokyo (Japan)

    1996-05-01

    For the enforcement of the {rho}a-{rho}u survey method which is a type of high-density electrical survey, a multichannel resistivity measuring instrument has been developed. This instrument, in addition to the above, conducts resistivity tomography and various other kinds of high-density electrical survey. A potential produced by a low frequency rectangular current of 1Hz or lower outputted by the transmitter of this instrument is received and measured by the receiver connected to electrodes positioned at 100 or less locations. The receiver comprises a scanner that automatically switches from electrode to electrode, conditioner that processes signals, and controller. A transmitter of the standard design outputs a maximum voltage of 800V and maximum current of 2A, making a device suitable for probing 50 to several 100m-deep levels. The receiver is operated by a personal computer that the controller is provided with. The newly-developed apparatus succeeded in presenting high-precision images of the result of a {rho}a-{rho}u analysis for an apparent resistivity section and of the underground structure, verifying the high quality of the data collected by this apparatus. 10 refs., 5 figs., 1 tab.

  8. Application of the electric discharge logging system; Hodenshiki jiban tansa system no tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, K.; Yasuda, N. [Tokyo Electric Power Co. Inc., Tokyo (Japan); Kuniyasu, T.; Kanda, K.; Naito, Y.; Tanaka, T.

    1997-10-22

    In the process of developing an electric discharge logging system, the advantage over other methods has become clear of P-wave initial amplitude damping coefficient analysis which is accomplished by measuring P-wave velocity in a hard rockbed and examining oscillation receiver bone sensitivity on the spot. In the hope of furthering the advantage, attention is paid to cracks in the rockbed that are deemed to influence damping, and the measurements by the subject system are compared with BSS measurements recorded at a K underground power station. The results of the analysis of P-wave initial amplitude damping coefficients, determined by the electric discharge logging system operated in a measuring hole provided in the cavity accommodating the station main equipment, disclose that there exists a high-coefficient region deeper in the ground where a part of the rockbed is weak. That is, it is inferred that the wide-range variation in damping coefficient detected at levels deeper than the 20.5m-deep hole dug in the arch enlargement corresponds to looseness in the rockbed. Cracks in the BSS records are grouped by aperture width, inclination angle, and strike. The rate of contribution to P-wave initial amplitude damping of each class of cracks is accepted as what shows the geological conditions surrounding the station for the formulation of schematic diagrams exhibiting cracks along the W-E axis and N-S axis. 4 refs., 15 figs.

  9. Development of micro capacitive accelerometer for subsurface microseismic measurement; Micromachining ni yoru chika danseiha kenshutsu no tame no silicon yoryogata kasokudo sensor no seisaku

    Energy Technology Data Exchange (ETDEWEB)

    Nishizawa, M.; Niitsuma, H.; Esashi, M. [Tohoku University, Sendai (Japan). Faculty of Engineering

    1997-05-27

    A silicon capacitive accelerometer was fabricated to detect subsurface elastic waves by using micromachining technology. Characteristics required for it call for capability of detecting acceleration with amplitudes from 0.1 to 1 gal and flat amplitude characteristics in frequency bands of 10 Hz to several kHz. For the purpose of measuring transition phenomena, linear phase characteristics in the required bands must be guaranteed, cross sensitivity must be small, and resistance to water, pressure and heat is demanded. Sensitivity of the sensor is determined finally by noise level in a detection circuit. The sensor`s minimum detection capability was 40 mgal in the case of the distance between a weight and an electrode being 3 {mu}m. This specification value is a value realizable by the current micromachining technology. Dimensions for the weight and other members were decided with the natural frequency to make band width 2 kHz set to 4 kHz. Completion of the product has not been achieved yet, however, because of a problem that the weight gets stuck on the electrode plate in anode bonding in the assembly process. 7 refs., 5 figs., 1 tab.

  10. Detection of travel time delay caused by dilation of an artificial fracture due to pressurization; Jinko chika kiretsu kaatsu ni tomonau toka danseiha denpa jikan henka no kenshutsu

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, K.; Moriya, H.; Asanuma, H.; Niitsuma, H. [Tohoku University, Sendai (Japan). Faculty of Engineering

    1996-10-01

    By revealing the relation between dilation of a subsurface fracture due to pressurization and travel time delay, it may be possible to measure the information as to the subsurface fracture system as a geothermal reservoir. In this study, field experiment was conducted to clarify the relation between the travel time delay of elastic waves and the dilation of fracture, pressure, and incident angles. The travel time delay of P-wave and S-wave tended to increase with the pressurization. When incident angle was about 90{degree} against the fracture, the increase was ranging between 0 and 0.2 ms. The magnitude of this delay could not be explained only by the opening of main fracture. It was considered that there were micro-crack zones around the main fracture. The difference of P-S delay depended on the pressurization and change of the pressure. The delay depended on the incident angle against the fracture. The delay of S-wave showed the polarized wave direction dependency. However, the obtained results might greatly depend on the analytical method and parameters. 4 refs., 10 figs.

  11. Evaluation stationariness of triaxial seismic while drilling and detection of reflected wave; Kosei kussaku ni tomonau danseiha no sanjiku kaiseki ni yoru hiteijo hyoka to hanshaha no kenshutsu

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, T.; Asanuma, H.; Niitsuma, H. [Tohoku University, Sendai (Japan). Faculty of Engineering

    1996-05-01

    This paper reports a method to detect reflected wave components contained in an elastic wave caused in association with well drilling. Measurement was made on an elastic wave caused in association with well drilling in an experimental field by using a triaxial elastic wave detector disposed in a measurement well. Analyzing the particle motion tracks in the derived elastic wave signals (to derive the main axial direction of a three-dimensional hologram) revealed that oscillation direction of the signals changes non-steadily by time centering around the S-wave oscillation direction. In addition, a sound source position was estimated during the drilling. Existence probability of the S-wave signal in the non-steady continuous signals was estimated by handling the particle motion tracks stochastically. In addition, this existence probability was used as a weighting function for a correlative analysis to detect a reflected wave from directly reaching wave components in the non-steady continuous signals. Thus, improvement in reliability of reflected wave detection was attempted. Effectiveness of this method was endorsed by the field data. 3 refs., 7 figs.

  12. Seismic tomography analysis using finite differential calculation of the eikonal equation and reciplocal principle; Eikonal equation no sabunkaiho to sohan genri wo riyoshita danseiha tomography kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, M.; Ashida, Y.; Watanabe, T.; Sassa, K. [Kyoto University, Kyoto (Japan)

    1996-10-01

    This paper describes the seismic tomography analysis of underground structures using finite differential calculation (FDC) and a reciprocal principle which points out that a propagation path is constant even if a source and receiver are exchanged with each other. Tomography analysis generally determines a ray length across each underground cell structure by ray tracing method to modify each cell slowness (inverse of velocity). Travel time field was determined by FDC of eikonal equation among ray tracing methods, and a wave propagation path was determined by reciprocity of elastic wave to carry out inversion. In conventional methods, since a wave length is assumed to be infinitesimal by ray theory, false modified slowness structures frequently appears depending on the density of a ray. Wave propagates in a certain width, and is affected by environment. The slowness was thus modified on the basis of the wave propagation path with a certain width by using not ray-tracing but reciprocity. By this modification, false structures were hardly found under a fine grid, and several propagation paths could be considered. 6 refs., 9 figs.

  13. Optimization of dynamic source depth for seismic surveys. Part 7; Dynamite shingen no hasshin shindo no saitekika ni tsuite (hyoso kozo no suitei (kusssetsuho jishin tansa oyobi denki denjiho tansa)). 7

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, H.; Murayama, R.; Mitsuhata, Y.; Ishikawa, H. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

    1996-05-01

    For the improvement of quality of data collected by reflection aided seismic exploration using dynamite as the seismic source, information has to be collected about the surface layer structure before the charge depth is determined. For this purpose, refraction, electric, and electromagnetic exploration methods were tried. In the refraction method, an impactor was used as the seismic source. In the records, the surface wave prevails because vibration was generated on the surface. Analysis was made by the use of the initial travel time tomography. In the electric exploration, a double pole array was used to measure resistivity. The measured data was subjected to a fully automatic inversion for analysis. As the result, it was disclosed that it was useful to know the deep-level structure directly by use of tomographic methods in refraction seismic exploration so as to find the optimum charge level. Furthermore, about the electric and electromagnetic exploration techniques, it was found that these methods can be applied making use of resistivity to the evaluation of groundwater saturation. 7 refs., 5 figs., 3 tabs.

  14. Fracture mapping in rock slope using geophysical instruments; Butsuri tansa ni yoru ganban shamennai no kiretsu bunpu hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Kurahashi, T.; Inazaki, T. [Public Works Research Institute, Tsukuba (Japan); Watanabe, S. [Geological Survey of Japan, Tsukuba (Japan)

    1997-05-27

    An attempt was made to visualize distribution of cracks in a rock slope by applying geophysical survey onto a rock slope. Geophysical logging and seismic survey using the reflection method were used as the methods for the geophysical survey. The rock slope subjected to the survey is located in a gorge along the Yoshino river in Yamashiro Town, Tokushima Prefecture. The slope has a width of 25 m and a height of 30 m. Its overhang in a nose form may has a possibility of causing collapse due to sliding. Cracks developed by horizontal schistosity were detected by performing geophysical logging on VSP, calipers, natural gamma-ray spectra, temperature and borehole in a borehole drilled vertically from the top of the slope. The seismic survey using the reflection method detected the cracks by emphasizing joints in the perpendicular direction. A possibility was shown to visualize the crack distribution with high resolution by using the above geophysical survey on the rock slope. In order to detect the crack distribution with still higher resolution, development into a three-dimensional exploration in the future is desired, not to speak of improvement in signal receivers, and discussions on geometry. 1 ref., 6 figs.

  15. Fundamental study on airborne electromagnetic survey using grounded source; Chihyo source gata kuchu denji tansa no kisoteki kenkyu. 2

    Energy Technology Data Exchange (ETDEWEB)

    Mogi, T.; Fujimitsu, Y. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Tanaka, Y. [Kyoto University, Kyoto (Japan). Faculty of Science; Jomori, N. [Chiba Electronics Research Institute, Chiba (Japan); Morikawa, T. [Dowa Engineering Co. Ltd., Okayama (Japan); Kusunoki, K. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1997-05-27

    With an objective to develop an airborne electromagnetic survey method for greater depths achievable of exploration, a discussion was given on an exploration method of a type in which a transmitting device is placed on the ground to receive signals in an atmosphere. A prototype exploration apparatus is mounted with a fluxgate magnetometer, an attitude meter, a GPS, and a battery. This exploration apparatus is suspended on a 30 meter long rope from a helicopter to perform the exploration. Two flight tests on this apparatus were carried out in the Unzen area, Nagasaki Prefecture and the Motomiya area, Wakayama Prefecture. The ground source was extended to a distance of 1.5 km, and a current of about 20 A was flown with a quiescent wave having four-second cycles. The helicopter flew nearly horizontally at a ground speed of about 50 km, a flight altitude of 450 m above sea level, and a terrain clearances of 100 to 400 m. The obtained data had variations in correspondence with changes in roll and pitch angles, whereas the variation of about 5000 nT was reduced to about 1000 nT as a result of correction. It was not possible, however, to correct completely the variation with short cycles, requiring further discussions on frequency characteristics of the magnetometer. 6 figs., 1 tab.

  16. 3D seismic experiment in difficult area in Japan; Kokunai nanchiiki ni okeru sanjigen jishin tansa jikken

    Energy Technology Data Exchange (ETDEWEB)

    Minegishi, M.; Nakagami, K.; Tanaka, H. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

    1997-05-27

    Difficult area in this context means an exploration-difficult area supposed to store oil/gas but retarded in exploration for the lack of knowledge about the geological structure due to poor quality of available seismic survey records. Discussed in this paper is a survey conducted into an area covering the southern part of Noshiro-shi, Akita-ken, and Yamamoto-cho, Yamamoto-gun, Akita-ken. An area size suitable for data collection at a target depth of 2500m is determined using an interpretation structure compiled on the basis of available well data and 2D seismic survey data. The plan for siting shock points and receiving points is modified case by case as restrictive factors come to the surface (resulting from the complicated hilly terrain, presence of pipes for agricultural water, etc.). The peculiarities of seismic waves in the terrain are studied through the interpretation of the available well data and 2D seismic survey data for the construction of a 3D velocity model for the confirmation of the appropriateness of the plan for siting shock points and receiving points. Efforts are exerted through enhanced coordination with the contractor to acquire data so that a technologically best design may be won within the limits of the budget. The quality of the data obtained from this experiment is in general better than those obtained from previous experiments, yet many problems remain to be settled in future studies about exploration-difficult areas. 4 refs., 4 figs., 1 tab.

  17. Probe into the slide surface and prediction of landslide; Jisuberi men no tansa to jisuberi no yochi

    Energy Technology Data Exchange (ETDEWEB)

    Tamada, B. [Nishinippon Institute of Technology, Fukuoka (Japan)

    1997-06-01

    While there are various types and occurrence mechanisms for landslide, the landslide in Tertiary deposit has had its occurrence mechanism elucidated to some extent, and the possibility of its prediction is becoming higher if necessary investigations are carried out appropriately. In the case of a large scale landslide, a discontinuous and weak surface called a `latent slide surface` is distributed in a ground bed as a `primary cause`. This primary cause is superimposed with such `inducements` as heavy rains and earthquakes, whereas the weak surface is transformed into a `landslide surface`, resulting in occurrence of a landslide. The creep shear fracture condition has its creep fracture time determined by the ratio between shear stress at the discontinuous portion and upper yield stress limit at the discontinuous portion. The longer the fracture time, such a sign as change on the ground surface appears, which is the only clue to prediction of occurrence of a new landslide under the present state-of-art. It has become possible to explore a landslide surface by mounting a sensor between a rod and a core tube when trial drilling is performed, and by recording rotation torque of the rod. It is thought that time has come to convert the present state-of-art to a direction to preventing a landslide before it occurs. 8 refs., 6 figs.

  18. Proceedings of the 95th SEGJ Conference; Butsuri tansa gakkai dai 95 kai (1996 nendo shuki) gakujutsu koenkai koen ronbunshu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    This is a proceedings of the 95th SEGJ (The Society of Exploration Geophysicists of Japan) Conference (fall 1996). The number of the papers made public totaled 72: 6 in seismic survey processing; 11 in seismic survey; 7 in ground vibration; 5 in strong magnetic force; 7 in logging/underground measurement; 6 in the IP method and others; 5 in spontaneous potential/streaming potential; 6 in electrical prospecting; 6 in tomography; 5 in electromagnetic method; 8 in time-domain electromagnetic method/radar. As for the seismic survey, reported were the following papers titled An experiment of exploration using the active-faults exploration system; Detection of traveltime delay caused by dilation of an artificial fracture due to pressurization; Faults survey by 3D reflection seismics; etc. As to the ground vibration, Applicability of the spatial autocorrelation method for estimation of basement structure in Kanto Plain-Array measurements of microtremors close to the Iwatsuki and Shimousa Deep Borehole Observatory; Prediction of strong acceleration motion depended on focal mechanism; etc. With relation to the logging/underground measurement, Trial to active seismic while drilling; Estimation of fracture aperture using simulation technique: etc.

  19. Preliminary study of airborne electromagnetic survey using grounded source; Chihyo source gata kuchu denji tansa no kisoteki kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Mogi, T. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Shimoizumi, M. [Kitakyushu Polytechnic College, Kitakyushu (Japan); Kusunoki, K. [Central Research Institute of Electric Power Industry, Tokyo (Japan); Morikawa, T. [Dowa Engineering Co. Ltd., Okayama (Japan); Jomori, N. [Chiba Electronics Research Institute, Chiba (Japan)

    1996-05-01

    For the development of an airborne electromagnetic prospecting method capable of deeper exploration, a basic study was made about a system wherein a transmitter (source) is positioned on the ground and the receiving is done in the sky. Even in case of this airborne electromagnetic method, the TDEM method is supposedly advantageous over others as in case of groundborne exploration. In the study, the transient response of an airborne vertical magnetic field to a horizontal layered structure was calculated. The current source was 2000m long with a capacity of 30A. The one-layer structure was a 10 Ohm m semi-infinite ground, and the two-layer structure had a 100 Ohm m structure just under the one-layer structure. The result of the calculation suggests that, in the absence of a layer of extremely low resistivity, observation of an approximately 1 second long transient response aboard a helicopter flying at approximately 50km/h will enable an approximately 1000m deep exploration. Problems to affect airborne observation, such as swinging, natural magnetic field fluctuation, and artificially produced noises were investigated by use of a magnetometer suspended from a helicopter in flight. 2 refs., 6 figs.

  20. Data processing for the mise-a-la-masse survey; Ryuden den`iho tansa no data shori

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, K.; Mizunaga, H.; Ushijima, K. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Kaieda, H. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1996-10-01

    Data processing method was studied for mise-a-la-masse survey. Mise-a-la-masse method using wells as current sources measures resultant ground surface potential difference, and detects underground local resistivity anomaly. To extract resistivity anomaly largely different from surroundings, the anomaly is extracted as difference between the estimated value of regular resistivity structure (background) and potential difference or apparent resistivity. The following three approximations were attempted to estimate the background: the theoretical equation assuming isotropic homogeneous resistivity structure, that assuming horizontal multi-layered structure and the exponential function of distance from linear electrode for apparent resistivity, and these were compared with each other by numerical model experiment. The data processing method which determines the resistivity structure of the background and the residual of apparent resistivity distribution by inversion analysis using the above second equation, could precisely extract local resistivity anomaly, and estimate the depth distribution of resistivity. 5 refs., 10 figs., 2 tabs.

  1. Study on spontaneous potential exploration considering resistivity structures; Hiteiko kozo wo koryoshita shizen den`iho tansa

    Energy Technology Data Exchange (ETDEWEB)

    Sato, H.; Sakurai, K.; Shimada, H. [OYO Corp., Tokyo (Japan)

    1996-10-01

    Spontaneous potential (SP) was measured on the known traverse line of resistivity structure crossing Hanaori fault in Ohara area, Kyoto city to observe change in SP around the fault and to examine the possibility of fault position exploration. The supposed causes of generation of SP are as follows: the existence of sulfide mineral deposit including polarized minerals, underground fluid flow, and the existence of stratum including chemical compositions from hot springs. The SP method estimates underground structures based on measured surface potential distributions using DC component under anomaly of SP. FEM modeling clarified that a fault fracture zone is one of the causes of generation of SP, by considering SP measurement and resistivity structure strongly affecting observed SP. Consequently, combination of SP measurement with resistivity structure exploration allows a reliable fault estimation method. Under the assumption that anomaly of SP is caused by polarization around fault, the horizontal dipole model based on polarization of current source dipole along fault can well explain the measured data. 2 refs., 6 figs.

  2. Seismic tomography inversion in the case that sources and receivers are distributed out of a 2-D plane; Shingen jushinten ga nijigen heimennai ni nai baai no danseiha tomography kaiseki ni kansuru kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Yokota, T.; Miyazaki, T. [Geological Survey of Japan, Tsukuba (Japan); Rokugawa, S.; Matsushima, J. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering; Ashida, Y. [Kyoto University, Kyoto (Japan). Faculty of Engineering

    1996-10-01

    In the case where sources and receivers are not distributed on a 2-D plane, seismic tomography inversion was studied. In tomography experiments, the existing wells are generally used. In such case, sources and receivers are frequently not distributed on a 2-D plane. The 2.5-D analysis method including 2-D structure and 3-D ray-tracing was thus developed. This method is featured by less memory necessary for ray-tracing calculation, and the same algorithm for velocity determination as 2-D analysis method. In previous methods, since analysis is generally carried out by projecting sources and receivers on a certain assumed 2-D plane, it can derive correct results in the case of constant velocity and straight ray, however, in the other case, it derives incorrect results. Application of 3-D tomography requires a large amount of memory, and falls into poor convergence because of various parameters. The 2.5-D analysis method can avoid these demerits. This analysis method was applied to the data obtained in Ogiri area, Kagoshima prefecture. 5 refs., 3 figs., 2 tabs.

  3. High resolution seismic refraction method with multichannel digital data acquisition system; Digital ta channel sokutei system wo mochiita koseido kussetsuho jishin tansa

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, K. [Oyo Corp., Tokyo (Japan)

    1997-05-27

    This paper introduces a multichannel digital data acquisition system and examples of measurements with the system in seismic exploration using the high resolution seismic refraction method. The high resolution seismic refraction system performs analyses nearly automatically by using a computer after initial travel time has been read. Therefore, the system requires high-accuracy travel time data, for which a multichannel digital measuring instrument developed recently for seismic exploration using the refraction method has been used for the measurement. The specification specifies the number of channels at 144 as a maximum, a sampling time of 62.5 {mu}sec to 4 m sec, the maximum number of sampling of 80,000 samples, and gain accuracy of {plus_minus} 1%. The system was used for surveying a tunnel having a maximum soil cover of about 800 m. The traverse line length is about 6 km, the distance between vibration receiving points is 50 m, and the number of vibration receiving points is 194. Executing measurements of single point system using GPS can derive accurate velocity in the vicinity of the basic face of the tunnel construction. Results were obtained from the investigation, which can serve more for actual construction work. 10 refs., 6 figs., 1 tab.

  4. Efficient calculation of potential distribution in two-layer earth; Niso kozo daichikei ni okeru denki tansa no tame no koritsuteki den`i keisan shuho

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, M.; Okamoto, Y. [Chiba Institute of Technology, Chiba (Japan); Endo, M.; Noguchi, K. [Waseda University, Tokyo (Japan); Teramachi, Y.; Akabane, H. [University of Industrial Technology, Kanagawa (Japan); Agu, M. [Ibaraki University, Ibaraki (Japan)

    1997-05-27

    An efficient calculation method of potential distribution in the presence of an embedded body in multi-layer earth has been proposed by expanding the method of image with a consideration of multiple reflection between the ground surface and each underground boundary. For this method, when solving boundary integral equation with the potential of embedded body surface as only one unknown, i.e., when obtaining discretization equation, ordinary boundary element program developed for analyzing the finite closed region can be used. As an example, numerical calculation was conducted for the two-layer earth. The analysis expression of potential distribution in the case of the certain embedded body in two-layer earth has never published. Accordingly, the calculated results were compared with those by the integral equation method. As a result, it was concluded that the primary potential obtained from the present method agreed well with that obtained from the integral equation method. However, there was a disregarded difference in the secondary potential. For confirming the effectiveness, it was necessary to compare with another numerical calculation method, such as finite element method. 5 refs., 5 figs.

  5. Archaeological prospecting using electrical resistivity method. Case history of Kaibukiyama ancient tomb; Denki tansaho ni yoru iseki tansa. Kaibukiyama kofun no chosarei

    Energy Technology Data Exchange (ETDEWEB)

    Mizunaga, H.; Ushijima, K.; Kishikawa, H. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

    1997-05-27

    To grasp the three-dimensional structure of ancient tomb during the archaeological prospecting of Kaibukiyama ancient tomb, various electrical resistivity methods were tried. For the survey, firstly, in order to clarify the electrical resistivity structure of rear circular part of ancient tomb, roughly, mapping was conducted by means of two-electrode method using a multi-channel measuring system. Then, the vertical prospecting was conducted densely with a mesh form having VES intervals of 2 m as a detailed survey by means of Schlumberger method. For the three-dimensional inverse analysis of apparent electrical resistivity data by the two-electrode method, a program with high calculation speed was developed by using algorithm where Jacobian with a homogeneous model is adopted for the Jacobian calculation. As a result of the analysis, an outline of underground 3-D resistivity structure was determined. The resistivity anomaly with high values obtained from the results of 2-D inverse analysis of VES curve by means of Schlumberger method agreed well with the central part of the ancient tomb, which was confirmed during the archaeological survey. 4 refs., 8 figs.

  6. {Gamma}-ray prospecting of major faults of Miocene basins; Chushinto taisekibon no keisei ni kakawaru danso wo taisho to shita hoshano tansa

    Energy Technology Data Exchange (ETDEWEB)

    Iwata, A. [Shimada Technical Consultants, Ltd., Shimane (Japan); Yamauchi, S.; Adachi, K. [Shimane University, Shimane (Japan); Yoon, S.; Kil, R, [Pusan National University, Pusan (Korea, Republic of)

    1997-05-27

    The Masuda basin in the western edge of Shimane Prefecture and the Pohang basin in the southern part of the east cost of Korea had been formed in the middle of Miocene epoch of Neogene period, and show similarity in their geology and structure. A gamma-ray prospecting was carried out on major faults that have had been involved in forming these basins. A portable gamma-ray analysis device, model 8630 made by Clearpulse Corporation was used for the measurement. Emanation of radon and its migration are known generally, whereas rise in radon is recognized above crevices with deep opening trend. The present faults having been involved in forming the basins are thought to have large falls in positive faults and often accompany crevices with opening trend. This estimation is thought endorsed by the result of the present prospecting. In addition, such faults may often form geological boundaries, and the present survey has had geological division made easily with total gamma-ray. A gamma-ray exploration using both of the spectrum method and the total count method is a process sufficiently utilizable in geological surveys on structures in peripheries of sedimentary basins. 6 refs., 7 figs.

  7. Laboratory study on streaming potential for exploring underground water flow; Shitsunai jikken ni yoru ryudo den`i wo mochiita mizu michi tansa no kanosei no kento

    Energy Technology Data Exchange (ETDEWEB)

    Sato, H.; Shima, H. [Oyo Corp., Tokyo (Japan)

    1997-05-27

    To investigate a possibility of exploration of underground water flow as well as to grasp the underground fluid flow by measuring streaming potential at the ground surface, some experiments were conducted using a model unit by considering the difference of permeability. For this experimental unit, water is driven by adding head difference between the polyethylene vessel filled with water and the experimental water tank. The size of water tank is 350{times}160 mm with a height of 160 mm. Twenty platinum electrodes are set on the cover of water tank. Toyoura standard sand and Kanto loam were used for the experiments. For the experiments, fluid was injected in various combined models by considering the permeability, to measure the streaming potential. As a result, it was explained by the streaming potential that the fluid flows in a form of laminar flow in the experimental water tank, and that the movement of fluid in the Kanto loam is quite slow. It was also confirmed that the streaming potential method is an effective technique for grasping the movement of fluid. 3 refs., 8 figs.

  8. Experiment for buried pipes by stepped FM-CW radar; Step shiki FM-CW radar ni yoru maisetsukan tansa jikken

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K.; Ito, M. [Kawasaki Geological Engineering, Co. Ltd., Tokyo (Japan); Tanabe, K. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1997-05-27

    The underground radar exploration is adopted to surveys of cavity under the road and buried pipes since the result of high resolution is obtained. However, the explorative depth of the radar is shallow, 2-3m in soil basement, and its applicable field has been limited. The continuous wave radar (FM-CW radar) was devised to get deeper explorative depth, but has been used for the geological structure survey such as the fault survey since it is lower in resolution as compared with the pulse radar. Therefore, to make use of characteristics of the continuous wave radar and enhance resolution in the shallow part, an experiment on buried pipes was conducted for the purpose of assessing and improving the FM-CW radar. In this processing, the wave form treatment used in the reflection method seismic survey was adopted for the radar survey. There are some problems, but it is effective to adopt the same algorithm to that used in the seismic survey to the radar exploration. The explorative depth was discussed from the damping rate of electromagnetic waves and dynamic range of facilities of the experimental site, and 7m was obtained. 5 figs., 1 tab.

  9. Airborne gamma-ray survey around the Negoro fault. 1; Negoro danso shuhen chiiki ni okeru kuchu {gamma} sen tansa. 1

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, E.; Kasuya, Y.; Hasegawa, H. [Aero Asahi Corp., Tokyo (Japan); Tsukuda, E. [Geological Survey of Japan, Tsukuba (Japan)

    1997-05-27

    An airborne gamma-ray survey was carried out to investigate the active fault system in the central structure line in the peripheral area of the city of Wakayama. At the same time, with an objective to enhance applicability of the airborne gamma-ray survey to active fault investigation, fundamental data were acquired and discussed. The measurement data were processed according to the standard method specified by IAEA. An ID-FFT filter and a nonlinear filter were employed to extract anomalous gamma-ray intensity values. The gamma-ray intensity distribution chart shows a noticeable positive anomalous area extending from the central part of the western edge to the north-east direction. This area agrees nearly well with the Negoro fault, but its peak portion is positioned slightly more to south than the position of the Negoro fault shown in existing data. The Sakuraike fault and the vicinity of the central structure line also show positive anomaly as a whole, particularly remarkably in the vicinity of their converging portion. However, differing from the vicinity of the Negoro fault, the areas are not extracted as an anomalous area which has directionality and extends in a line form. One of the factors for this would be that it is a fault in unsolidified deposits with low opening trend, differing from the one in solidified rocks. 1 fig., 3 tabs.

  10. Results of geophysical survey on Hanaore-fault in the Kyoto urban area; Butsuri tansa ni yoru Kyoto shigaichi ni okeru Hanaore danso chosa

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, T. [Geological Survey of Japan, Tsukuba (Japan); Echigo, T. [Osaka Soil Test, Osaka (Japan); Toshioka, T.; Matsubara, Y. [Oyo Corp., Tokyo (Japan)

    1997-05-27

    This paper reports results of gravity survey and seismic survey using the shallow bed reflection method to identify distribution of the Hanaore fault in the Kyoto urban area. In the gravity survey, level differential structure caused by the fault was identified as an abrupt change in Bouger anomalous values. The continuity therefrom made the estimation possible on existence and positions of such faults as the Hanaore fault belonging to the Hanaore fault system, the Shishigaya fault, the Kaguraoka fault, and the Okazaki fault. The estimation as a result of the gravity survey include the following findings: the Hanaore fault runs from south of the Yoshidayama in the south-north direction; the distribution of the Okazaki fault has a level differential structure falling on the east side; the structure shows low Bouger anomaly distribution; and this area forms a rift valley belt. In the seismic survey using the shallow bed reflection method, no distinct reflection plane considered as the basement was verified because of influence from urban area noise. However, it was possible to estimate such an underground structure as a monoclinal fold from shapes of the reflection plane and the distribution depths. 7 refs., 5 figs.

  11. Case study of geostructural prospect of a tunnel by using geophysical methods; Butsuri tansa ni yoru tunnel chisan yosoku to jissai

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, H. [Japan Railway Construction Public Corp., Tokyo (Japan); Kawakami, J. [Taisei Construction Corp., Tokyo (Japan); Nagasue, I.; Hiwatashi, S.; Wakuno, M. [Oyo Corp., Tokyo (Japan)

    1997-05-27

    A preliminary survey was carried out by combining elastic wave exploration (using a refraction method) and electrical exploration (using a resistivity imaging method) on a long tunnel planned in a granite distributed area. This paper describes a case of verifying geological condition in the area by using a trial survey well and horizontal boring. This tunnel goes through the Seburi mountainous area on the border of Fukuoka Prefecture and Saga Prefecture for a total distance of 12 km. The refraction method and the resistivity imaging method were selected from the necessity of identifying the weathering condition in natural ground, and distributions of fault crush zones and underground water in a section extending 560 m from the well entrance. As a result of comparing the natural ground condition interpreted from the geophysical survey results with the construction records, the fault was detected as a cracked or deformed section in the part where the resistivity value changes abruptly or where the resistivity is low. The tunnel natural ground classification showed a good correspondence with the elastic wave velocities. The largest flooding section showed a good agreement with the section where the resistivity changes suddenly to a lateral direction. Thus, the geological information interpreted from both surveys presented a good correspondence with the construction records, leading to a judgment that the prediction is possible. 3 refs., 4 figs., 5 tabs.

  12. Proceeding of the 96th (spring, fiscal 1997) SEGJ Conference; Butsuri tansa gakkai dai 96 kai (1997 nendo shunki) gakujutsu koenkai koen ronbunshu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-27

    This is a proceedings of the 96th SEGJ (The Society of Exploration Geophysicists of Japan). As for the well measurement, described were seismic survey and logging of geothermal wells and hot dry rock artificial reservoirs. As to the reflection method, analyzed were characteristics of seismic propagation and stratum structures. In the data processing, topics were on the neural network, stacking process and resolution, migration, etc. Concerning the electromagnetic method, research results were reported of TEM, CSAMT, EM tomography, MT method, etc. About the electrical exploration, introduced were resistivity structures by the electrical log, and exploration by the streaming potential or self-potential methods. Relating to the gravity/magnetic force exploration, reported were continuous gravity monitoring of geothermal activity, magnetic structures of rock, data on magnetic susceptibility, aeromagnetic survey, and remote sensing. As to the underground radar method, described were the survey of buried pipes and the inspection of fracture zones using the borehole radar, etc. With respect to the global system, the global structure was discussed from a global point of view. Additionally, reports were made on radioactive prospecting, seismometer observation, and ground motion.

  13. Proceedings of the 94th SEGJ (The Society of Exploration Geophysicists of Japan) Conference; Butsuri tansa gakkai dai 94 kai (1996 nendo shunki) gakujutsu koenkai koen ronbunshu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    The fiscal 1996 SEGJ Conference was held in Tokyo during May 15-17, and 101 papers were reported. As for disaster prevention, the following were reported: Questionnaire investigation for the earthquake, Localization of b-values and maximum earthquakes, Cooperative measurements of microtremors in the north-eastern region of Nishinomiya City, Hyogo Pref., etc. As to elastic wave data recording and modeling data processing, Optimization of dynamite source depth for seismic surveys, Simulation of breakage of heterogeneous materials caused by detonative loading, etc. With relation to archeology, radar, and refraction method, Reexamining results of Iwatoyama tumulus by means of directive antenna, Application of geophysical method to investigation of old castle, etc. Concerning microtremors and surface waves, Estimation of shallow ground structure using short-period microtremors array observation, etc. Besides, papers were reported on electromagnetism, tomography, gravity/magnetism/numerical calculation, measurement while drilling, etc. Moreover, a symposium on underground structures in the Hanshin/Awaji area as viewed from geophysical exploration was held presenting nine papers.

  14. Evaluation for characteristics of around the Nojima fault; Butsuri tansa ni yoru `Nojima jishin danso` shuhen no jiban bussei ni kansuru ichihyoka

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, K.; Tsuji, T. [Newjec Inc., Osaka (Japan); Tsuji, M. [OYO Corp., Tokyo (Japan)

    1996-05-01

    Various surveys were conducted for the area around the Nojima fault, including ground surface, two-dimensional electrical and boring surveys and elastic wave tomography, in order to grasp properties of the ground around the `Nojima earthquake fault.` The resistivity image method as one of the two-dimensional electrical methods was used to grasp fault shapes over a wide range of the 1.6km long section extending between Esaki and Hirabayashi. The courses of traverse were set in the direction almost perpendicular to the fault. Boreholes were excavated and elastic wave tomography was conducted between the boreholes on the 9th and 17th courses of traverse, to confirm ground/mountain conditions and to compare the results with observed elastic wave velocities. Very low resistivities are observed at places where granite is distributed, suggesting that the fault-induced changes are not limited to the area around the fault. The zone in which elastic wave velocity decreases is narrow, 10m at the longest, at a velocity of 2.4km/s or lower, which is a low velocity for that propagating in granite. 5 refs., 4 figs.

  15. Interpretation of seismic section by acoustic modeling. Study of large amplitude events; Hadoba modeling ni yoru jishin tansa danmen no kaishaku. Kyoshinhaba event ni taisuru kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Tamagawa, T.; Matsuoka, T.; Sato, T. [Japan Petroleum Exploration Corp., Tokyo (Japan); Minegishi, M.; Tsuru, T. [Japan National Oil Corp., Tokyo (Japan)

    1996-05-01

    A large amplitude event difficult to interpret was discovered in the overlap section in offset data beyond 10km targeting at deep structures, and the event was examined. A wave field modeling was carried out by use of a simplified synclinal structure model because it had been estimated that the large amplitude event had something to do with a synclinal structure. A pseudospectral program was used for modeling the wave field on the assumption that the synclinal structure model would be an acoustic body and that the surface would contain free boundaries and multiple reflection. It was found as the result that a discontinuous large amplitude event is mapped out in the synclinal part of the overlap section when a far trace is applied beyond the structure during a CMP overlap process. This can be attributed to the concentration of energy produced by multiple reflection in the synclinal part and by the reflection waves beyond the critical angle. Accordingly, it is possible that phenomena similar to those encountered in the modeling process are emerging during actual observation. 2 refs., 8 figs.

  16. Forward prediction of tunnel face by use of equi-traveltime planes; Tosojimen no riyo ni yoru tunnel kiriha zenpo tansa

    Energy Technology Data Exchange (ETDEWEB)

    Ashida, Y. [Kyoto University, Kyoto (Japan). Faculty of Engineering; Hirano, T. [Nishimatsu Construction Co. Ltd., Tokyo (Japan)

    1996-05-01

    The result is reported herein of a depth transform algorithm application utilizing equi-traveltime planes in reflection seismic exploration for the purpose of knowing the structure configuration in front of the tunnel face in a tunnel excavation process. A vibration producing hole was provided 0.5m above the ground surface while a vibration receiving hole was provided at 1.5m above the ground surface, and the excavated lengths were 1.5m and 0.5m, respectively. There were 24 recording channels, from which inline offset records were taken. The on-site records were subjected to 100-1000Hz band pass filtering. The elastic wave propagation rate in the rock used for depth conversion was set at 400m/s in consideration of the distance and direct wave travel time from the vibration source to the vibration receiving point. As the result of study, weak layers were found in the neighborhood of 230-240m, 260-270m, and 280-290m. This method requires less core memory for calculation and completes calculation in a shorter period of time, which enables a conclusion that it will be effective in grasping the 3-dimensional structure in front of the tunnel face in the working scene. 4 refs., 7 figs.

  17. Pseudo-random data acquisition geometry in 3D seismic survey; Sanjigen jishin tansa ni okeru giji random data shutoku reiauto ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Minegishi, M.; Tsuburaya, Y. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

    1996-10-01

    Influence of pseudo-random geometry on the imaging for 3D seismic exploration data acquisition has been investigate using a simple model by comparing with the regular geometry. When constituting wave front by the interference of elemental waves, pseudo-random geometry data did not always provide good results. In the case of a point diffractor, the imaging operation, where the constituted wave front was returned to the point diffractor by the interference of elemental waves for the spatial alias records, did not always give clear images. In the case of multi point diffractor, good images were obtained with less noise generation in spite of alias records. There are a lot of diffractors in the actual geological structures, which corresponds to the case of multi point diffractors. Finally, better images could be obtained by inputting records acquired using the pseudo-random geometry rather than by inputting spatial alias records acquired using the regular geometry. 7 refs., 6 figs.

  18. Three-dimensional seismic survey planning based on the newest data acquisition design technique; Saishin no data shutoku design ni motozuku sanjigen jishin tansa keikaku

    Energy Technology Data Exchange (ETDEWEB)

    Minehara, M.; Nakagami, K.; Tanaka, H. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

    1996-10-01

    Theory of parameter setting for data acquisition is arranged, mainly as to the seismic generating and receiving geometry. This paper also introduces an example of survey planning for three-dimensional land seismic exploration in progress. For the design of data acquisition, fundamental parameters are firstly determined on the basis of the characteristics of reflection records at a given district, and then, the layout of survey is determined. In this study, information through modeling based on the existing interpretation of geologic structures is also utilized, to reflect them for survey specifications. Land three-dimensional seismic survey was designed. Ground surface of the surveyed area consists of rice fields and hilly regions. The target was a nose-shaped structure in the depth about 2,500 m underground. A survey area of 4km{times}5km was set. Records in the shallow layers could not obtained when near offset was not ensured. Quality control of this distribution was important for grasping the shallow structure required. In this survey, the seismic generating point could be ensured more certainly than initially expected, which resulted in the sufficient security of near offset. 2 refs., 2 figs.

  19. Annual view (1999) - aeronautic relation/space relation. Space relation - space science/lunar excursion; Nenkan tenbo (1999) koku kankei uchu kankei. Uchu kagaku, tsuki tansa kanren

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-05

    For the purpose of learning the technology required for a mission to sample rocks, soil, etc. from small planets or satellites and bring them back to the earth, the Institute of the Space and Astronautical Science has been proceeding with the development of No. 20 scientific satellite (MUSES-C) and conducted the technical development of the electric propulsion system, interplanetary self-contained navigation, sampling, reentry into the earth, recovery, etc. With the aim of acquiring data for survey of usability of the moon and developing science to study the origin and evolution of the moon, the Institute of the Space and Astronautical Science and National Space Development Agency of Japan are jointly carrying out the R and D of a selenological and engineering explorer (SELENE). The explorer is planned to be launched with H-II A rocket in 2004. No. 17 scientific satellite is now under development with the aim of elucidating the crustal structure and thermal structure inside the moon, but the plan for launching in summer 1999 was postponed because it takes time to develop the penetrator. The 5th X-ray astronomical satellite (ASTRO-E) of Japan is now in final inspection and service toward the launch in February 8, 2000. (NEDO)

  20. Seismic refraction analysis with high accuracy based on traveltime modeling; Basu keisan wo base to shita kussekiho jishin tansa kaiseki no koseidoka

    Energy Technology Data Exchange (ETDEWEB)

    Saito, H.; Hayashi, K. [OYO Corp., Tokyo (Japan)

    1996-05-01

    For the purpose of enhancing the efficiency of analytical processes so that those not equipped with high skill may perform a certain level of analysis and that analysis precision may be improved, some analytical techniques based on path calculation were examined. As the result, a flow of work has become feasible, wherein an early model is constructed by use of a tomography-assisted analysis to be accomplished automatedly and the result is then converted into a layer system with the velocity and thickness to be automatically corrected for the determination of the ultimate velocity layer section. Following this flow of work, almost all the parts of the work may be accomplished automatically once the travel time curve is completed. Furthermore, the calculated travel time obtained by this method can be easily compared with the observed travel time creating an opportunity to show the high reliability of this method, for this to be accepted as a standard for evaluating the accuracy of exploration. It has also been found that this method may be applied to more complicated structures which fail to satisfy the conditions for a structure to be treated by other methods such as `Hagiwara`s method.` 3 refs., 5 figs.

  1. 2D resistivity survey in complex geological structure area. Application to the volcanic area; Fukuzatsuna chishitsu kozo chiiki ni okeru hiteiko nijigen tansa. Kazangan chiiki deno tekiorei

    Energy Technology Data Exchange (ETDEWEB)

    Asakawa, S.; Ikuma, T.; Tanifuji, R. [DIA Consultants Co. Ltd., Tokyo (Japan)

    1996-05-01

    Introduced herein is an application of 2D resistivity survey to a volcanic rock area where the survey result is difficult to interpret because of its complex geological structure. In a dam site survey, main problems involve the permeability of water through faults and weathered, altered zones. At this site, a 2D resistivity survey was conducted, a 2D geological structure was deduced from the resistivity section, and the result was examined. It was found that resistivity distribution was closely related to hydrographic factors, but no obvious correlation was detected between rock classes and R, Q, and D. In conducting investigations into a section planned for a highway tunnel, it was learned that the problem was a volcanic ash layer to collapse instantly upon absorbing water, and the distribution of the ash layer, not to be disclosed by boring, was subjected to a 2D resistivity survey. The survey was conducted into the structure above where the tunnel would run, and further into the face, and studies were made about what layer was reflected by the resistivity distribution obtained by analysis. The result of the analysis agreed with the details of the layer that was disclosed afterward. 4 figs., 1 tab.

  2. Fiscal 1995 verification survey of geothermal exploration technology. Report on a deep geothermal resource survey; 1995 nendo chinetsu tansa gijutsu nado kensho chosa. Shinbu chinetsu shigen hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-06-01

    For the purpose of reducing the risk of deep geothermal resource development, the paper investigated three factors for the formation of geothermal resource in the deep underground, that is, heat supply from heat source, supply of geothermal fluids, and the developmental status of fracture systems forming reservoir structures. The survey further clarified the status of existence of deep geothermal resource and the whole image of the geothermal system including shallow geothermal energy in order to research/study usability of deep geothermal resource. In the deep geothermal resource survey, drilling/examination were made of a deep geothermal exploration well (`WD-1,` target depth: approximately 3,000-4,000m) in the already developed area, with the aim of making rationalized promotion of the geothermal development. And the status of existence of deep geothermal resource and the whole image of the geothermal system were clarified to investigate/study usability of the geothermal system. In fiscal 1995, `WD-1` in the Kakkonda area reached a depth of 3,729m. By this, surveys were made to grasp the whole image of the shallow-deep geothermal system and to obtain basic data for researching usability of deep geothermal resource. 22 refs., 531 figs., 136 tabs.

  3. Application of vertical electrical sounding combined with induced polarization method in ground water exploration; IP koka wo koryoshita hiteikoho suichoku tansa no chikasui chosa eno tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Kondo, M.; Sakurada, H. [Sumiko Consultants Co. Ltd., Tokyo (Japan); Suzuki, T. [Hokkaido Development Bureau, Hokkaido Development Agency, Sapporo (Japan)

    1996-10-01

    For ground water exploration using vertical Schlumberger exploration method, measurement and analysis combined with induced polarization (IP) effect were conducted as trial. For the Schlumberger method, potential is measured at the center between potential electrodes during flow of dc current between current electrodes. In the case of vertical exploration, measurements are repeated with fixed potential electrodes by extending the distance between current electrodes. Ground water exploration was conducted using this method at Otaki village, Hokkaido. Geology of surveyed plateau consists of a basement of Pliocene tuffs and Quaternary Pleistocene sediments covering on the surface. For the results of analysis, four to seven beds were detected from the resistivity. The depth up to the lowest bed was between 25 and 85 m, the resistivity of each bed was between 9 and 8,000 ohm{times}m, and the polarizability was between 1 and 15 mV/V. Among these resistivity zones, it was judged that zones satisfying following three conditions correspond to coarse grain sediments saturated with ground water, and can be expected as aquifers; having resistivity ranging between 100 and 1,000 ohm{times}m, polarizability higher than 10 mV/V, and relatively large thickness. 11 refs., 6 figs.

  4. Comparison of {gamma}-ray profile across active normal and reverse faults; Seidansogata to gyakudansogata katsudanso ni okeru hoshano tansa kekka no hikaku

    Energy Technology Data Exchange (ETDEWEB)

    Iwata, A.; Wada, N.; Sumi, H. [Shimada Technical Consultants, Ltd., Shimane (Japan); Yamauchi, S.; Iga, T. [Shimane Univ., Shimane (Japan)

    1996-10-01

    Active faults confirmed at trench and outcrop were surveyed by the {gamma}-ray spectrometry. The active fault found at trench is a normal fault, and that found at outcrop is a reverse fault. The {gamma}-ray spectral characteristics of these two types of faults were compared to each other. The normal fault is named as Asagane fault located in Aimi-machi, Saihaku-gun, Tottori prefecture. The reverse fault is named as Yokota reverse fault located in Yokota-cho, Nita-gun, Shimane prefecture. Rises of radon gas indicating the existence of opening cracks were confirmed above the fault for the normal fault, and at the side of thrust block for the reverse fault. It was considered that such characteristics were caused by the difference of fault formation in the tensile stress field and in the compressive stress field. It was also reconfirmed that much more information as to faults can be obtained by the combined exploration method using the total counting method and the spectral method. 14 refs., 7 figs.

  5. High-resolution aeromagnetic survey in the area of Arima-Takatsuki-Rokko active fault system; Arima Takatsuki Rokko katsudanso chiiki ni okeru komitsudo kuchu jiki tansa

    Energy Technology Data Exchange (ETDEWEB)

    Nakatsuka, T.; Okuma, S.; Morijiri, R.; Makino, M. [Geological Survey of Japan, Tsukuba (Japan)

    1996-10-01

    High-resolution aeromagnetic survey was conducted in December, 1995, over the area of Arima-Takatsuki-Rokko active fault system, where the 1995 Hyogo-South (Kobe) earthquake took place. Based on the surveyed data, the magnetic anomaly distribution in the Kei-Hanshin district was illustrated. Features of magnetic anomaly observed in it were discussed. Influence of artificial structures in the coastal zone of Kobe City was tried to be removed. Distinct magnetic anomaly observed in the center of Kyoto City was located at the southern part near Shijo-Karasuma. This was mainly affected by the artificial structure. A high magnetic anomaly with a long wave length was observed in the southern part of Kyoto. There was a high magnetic anomaly in an area surrounded by central cities of Nishinomiya-Toyonaka district. At the location where positive and negative magnetic anomalies were illustrated in NEDO`s map in the coastal zone of Kobe City, the anomaly pattern was clarified. The influence of artificial structure was approximated using a point dipole. The dipole was placed in each block having a magnetic anomaly. The parameter was determined by the inverse analysis, to remove the influence. Consequently, most of magnetic anomalies due to artificial structures could be removed. 6 figs.

  6. FY 1998 report on the verification survey of geothermal exploration technology, etc. 1/2. Survey of deep geothermal resource; 1998 nendo chinetsu tansa gijutsu nado kensho chosa hokokusho. 1/2. Shinbu chinetsu shigen chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-12-01

    For the purpose of commercializing deep geothermal resource, a deep exploration well of 4000m class was drilled in the existing geothermal development area to survey the situation of deep geothermal resource existence and the availability. Concretely, the deep geothermal exploration well was drilled for study in the Kakkonda area, Shizukuishi town, Iwate prefecture, to clarify the situation of deep geothermal resource existence and the whole image of geothermal system. Consideration was made of the deep geothermal exploration method, systematization of deep high temperature drilling technology, and availability of deep geothermal resource. The results of the survey were summed up as follows: 1) general remarks; 2) deep exploration well drilling work; 3) details of the study. 1) and 2) were included in this report, and 3) in the next report. In 1), the items were as follows: the study plan/gist of study execution, the details and results of the deep geothermal resource survey, the outline of the deep exploration well drilling work, and the outline of the results of the FY 1998 study. In 2), the drilling work plan/the actual results of the drilling work were summed up. As to the results of the study, summarized were the acquisition of survey data on deep exploration well, heightening of accuracy of the deep geothermal resource exploration method, etc. (NEDO)

  7. Report on fiscal 2000 survey for geothermal exploration technology verification. Survey of deep-seated geothermal resources; 2000 nendo chinetsu tansa gijutsu nado kensho chosa hokokusho. Shinbu chinetsu shigen chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    To promote the development of deep-seated geothermal resources in a rationalized way, studies are conducted about deep-seated geothermal resource assessment techniques, development guidelines, and the like. Data were collected at the Sumikawa-Onuma district, Ogiri district, Mori district, Yanaizu-Nishiyama district, and the Onikobe district, and compiled into a database to be open to the public. Studies were made about methods for estimating parameters for deep-seated geothermal reservoirs. The resultant findings indicate that, in the Uenotai and Sumikawa-Onuma districts where geothermal reservoirs are governed mainly by a fracture network, the relaxation method and extrapolation will be effective for deep-seated reservoir temperature estimation, and the ascending current analysis method and extrapolation for permeability estimation. The findings also indicate that the expanse of deep-seated reservoirs will be suitably estimated using a method similar to that applied to shallow-seated reservoirs. In the study of the estimation of the amount of deep-seated geothermal resources, it is concluded that the simplified model A will be effective in dealing with a geothermal district where there is a well-developed fracture network and the simplified model B in dealing with a geothermal district where supply of deep-seated fluid governed by an extensive fault prevails. (NEDO)

  8. Generation of seismic base map using satellite images in the southern deltaic area, People`s Republic of Bangladesh; Eisei data ni motozuku jishin tansa base map no sakusei (Bangladesh nanbu delta no rei)

    Energy Technology Data Exchange (ETDEWEB)

    Kotera, Y. [Japan Energy Corp., Tokyo (Japan); Ochi, M. [Nikko Exploration and Development Co. Ltd., Tokyo (Japan); Hato, M. [Earth Remote Sensing Data Analysis Center, Tokyo (Japan)

    1997-05-27

    Assuming a two-dimensional seismic survey in a mangrove jungle in the southeast part of People`s Republic of Bangladesh and trially making a basemap for the survey plan from images of satellites such as LANDSAT, the paper considered the use and marginal use in the case of using satellite remote sensing for such a use field. When utilizing water channels in the mangrove jungle in the southwest of Bangladesh and using the seismic survey method for shallow sea, it is important to grasp the distribution of channels in the planning stage of the survey. Satellite remote sensing data are extremely important for knowing the wide-regional information including factors of hourly variations. In the area for this survey, for directly recognizing the channel, it is good only if the difference in reflectance between water and substances except water is indicated in the image because of flatness of the topography. There was seen few difference in accuracy between the passive multispectral image and the active SAR image which is sensitive to topographical changes. 2 figs.

  9. Reduction of artificial source effect in the high-resolution aeromagnetic survey in the Hanshin region; Hanshin chiiki no komitsudo kuchu jiki tansa ni okeru jinko noise source no eikyo no jokyo

    Energy Technology Data Exchange (ETDEWEB)

    Nakatsuka, T.; Makino, M.; Morijiri, R.; Okuma, S. [Geological Survey of Japan, Tsukuba (Japan)

    1997-05-27

    A high-resolution aeromagnetic survey was carried out in December 1995 on areas from Kobe City to Kyoto City in relation to the Hyogoken-nanbu Earthquake in 1995. It was found in the survey that effects of electric trains driven by direct current and man-made structures cannot be avoided, working as a large noise factor in extraction and analysis of geological information. This paper describes a quantitative analysis on magnetic anomaly suspected to have been caused from artificial sources seen in the magnetic map of the Hanshin area obtained from the above exploration data. The paper also gives considerations on methods to remove the effects therefrom. It then describes a quantitative analysis and the result of attempts on removal of the anomaly, taking up the following factors: (1) distribution of specific and remarkable magnetic anomalies which correspond to railroad positions of the Hanshin Railways running through the Nishinomiya-Toyonaka area, (2) the magnetic anomaly trend in positive and negative pair seen in the seafront area of Kobe City, and (3) typical bipolar isolated type magnetic anomaly in the north-west part of Kobe City. The cause for (1) was loop current flown for the railway operation, that for (2) was man-made structures in the improved seafront area, and that for (3) was a provisionally built metal waste storage yard. 9 figs.

  10. Estimation of subsurface structures in a Minami Noshiro 3D seismic survey region by seismic-array observations of microtremors; Minami Noshiro sanjigen jishin tansa kuikinai no hyoso kozo ni tsuite. Bido no array kansoku ni yoru suitei

    Energy Technology Data Exchange (ETDEWEB)

    Okada, H.; Ling, S.; Ishikawa, K. [Hokkaido University, Sapporo (Japan); Tsuburaya, Y.; Minegishi, M. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

    1997-05-27

    Japan National Oil Corporation Technology Research Center has carried out experiments on the three-dimensional seismic survey method which is regarded as an effective means for petroleum exploration. The experiments were conducted at the Minami Noshiro area in Akita Prefecture. Seismometer arrays were developed in radii of 30 to 300 m at seven points in the three-dimensional seismic exploration region to observe microtremors. The purpose is to estimate S-wave velocities from the ground surface to the foundation by using surface waves included in microtremors. Estimation of the surface bed structure is also included in the purpose since this is indispensable in seismic exploration using the reflection method. This paper reports results of the microtremor observations and the estimation on S-wave velocities (microtremor exploration). One or two kinds of arrays with different sizes composed of seven observation points per area were developed to observe microtremors independently. The important point in the result obtained in the present experiments is that a low velocity bed suggesting existence of faults was estimated. It will be necessary to repeat experiments and observations in the future to verify whether this microtremor exploration method has that much of exploration capability. For the time being, however, interest is addressed to considerations on comparison with the result of 3D experiments using the reflection method. 4 refs., 7 figs.

  11. Fiscal 1996 verification and survey of geothermal prospecting technology etc. 1/2. Survey report on deep-seated geothermal resources; 1996 nendo chinetsu tansa gijutsu nado kensho chosa hokokusho. 1/2. Shinbu chinetsu shigen chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    For the purpose of reducing the risk to accompany the exploitation of deep-seated geothermal resources, investigations are conducted into the three factors that govern the formation of geothermal resources at deep levels, that is, the supply of heat from heat sources, the supply of geothermal fluids, and the development of fracture systems contributing to the constitution of reservoir structures. In fiscal 1996, the deep-seated exploration well WD-1a is sidetracked for penetration for a target newly assigned at the 3,000m-deep level. Carried out in a survey of well geology are the naked-eye and microscopic observation of core cuttings, X-ray powder method, examination of inclusions in fluids, chemical analysis of whole rocks, analysis of isotopes in minerals, analysis of core fracturing, etc. Also, data are collected from a survey of mud log, survey of water in the well before digging, and from well logging. Furthermore, pressure monitoring etc. are conducted in order to determine the interference in pressure between the deep-seated and shallow-seated wells that accompanies multiple outbursts from the Kakkonda No. 2 machine, to know the water permeability between the shallow-seated and deep-seated parts, and to grasp the anisotropy in permeability in shallow-seated reservoirs. (NEDO)

  12. 3D seismic survey in Honjo, Akita. Problems and struggles in acquisition and processing; Akitaken Honjo koku ni okeru sanjigen jishin tansa. Genba sagyo to data shori ni okeru mondaiten

    Energy Technology Data Exchange (ETDEWEB)

    Imahori, S.; Kotera, Y.; Nakanishi, T. [Japan Energy Development Co. Ltd., Tokyo (Japan)

    1997-05-27

    Honjo mining area where investigations are conducted is hilly and has a complicated terrain with gas pipes buried in the ground just under the access road disabling the proper positioning of shock-generating large excavators or vibrators. Auger`s shallow hole shooting method is used in this survey to execute blastings at 639 points. In this method using charge depths of 4m, different from the conventional method using deeper charge depths (20-25m), surface waves prevail in the shot records giving rise to a new problem of removing them in the stage of data processing. The 2D filter that is a powerful tool in 2D data processing is not available in a 3D-survey where the tracing intervals are irregular in the shot records. In the effort of this time, a window length as a parameter in the direction of time is specified, and the F-X dip filtering method is employed in which any event that linearly continues beyond a certain number of traces in the said window is eliminated as a linear noise. It is recommended that the weighting function be changed in the direction of space since surface wave velocities are different at different locations. 1 fig., 1 tab.

  13. Fault-related-folding structures and reflection seismic sections. Study by seismic modeling and balanced cross section; Danso ga kaizaisuru shukyoku kozo no keitai to jishin tansa danmen. 2. Seismic modeling oyobi balanced cross section ni yoru study

    Energy Technology Data Exchange (ETDEWEB)

    Tamagawa, T.; Matsuoka, T. [Japan Petroleum Exploration Corp., Tokyo (Japan); Tsukui, R. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

    1997-05-27

    It occasionally happens that there exists a part where reflection near the thrust is not clearly observed in a thrust zone seismic survey cross section. For the effective interpretation of such an occurrence, the use of geological structures as well as the reflected pattern is effective. When the velocity structures for a fold structure having a listric fault caused anticline (unidirectionally inclined with a backlimb, without a forelimb) and for a fault propagation fold are involved, a wrong interpretation may be made since they look alike in reflection wave pattern despite their difference in geological structure. In the concept of balanced cross section, a check is performed, when the stratum after deformation is recovered to the time of deposition, as to whether the geologic stratum area is conserved without excess or shortage. An excess or shortage occurs if there is an error in the model, and this shows that the fault surface or fold structure is not correctly reflected. Positive application of geological knowledge is required in the processing and interpreting of data from a seismic survey. 6 refs., 6 figs.

  14. Fault-related-folding structure and reflection seismic sections. Construction of earth model using balanced cross section; Danso ga kaizaisuru shukyoku kozo no keitai to jishin tansa danmen. 1. Balanced cross section wo mochiita chika model no kochiku

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, T.; Tamagawa, T. [Japan Petroleum Exploration Corp., Tokyo (Japan); Tsukui, R. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

    1997-05-27

    Pre-stacking depth migration treatment is studied for the estimation of the fold configuration from seismic survey cross sections. The estimation of a velocity structure is necessary for the execution of such treatment, and the utilization of structural-geological knowledge is required for its interpretation. The concept of balanced cross section in relation to the fault-bend fold constructs a stratum structure model under conditions that the deformation during fold and fault formation is a planar strain, that there is no change in volume due to deformation, and that a fold is a parallel fold. In addition to the above geometric and kinetic approach, there is another fold formation process simulation model using a Newtonian fluid for study from the viewpoint of dynamics. This simulation stands on the presumption that the boundary contains a ramp that had been in presence before fold formation and that an incompressible viscous matter is mounted on the top surface. The viscous matter flows and deforms for the formation of an anticline on the ramp. Such enables the reproduction of a fault-bend fold formation process, and helpful discussion may be furthered on the dynamic aspect of this simulation. 5 refs., 4 figs.

  15. Borehole geophysics for delineating the geological structure in the Sakonishi prospect, the Hida area, Japan; Hida chiiki Sako nishi chiku ni okeru boring ko riyo butsuri tansa ni yoru chishitsu kozo kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Katayama, H.; Hishida, H.; Yoshioka, K. [Metal Mining Agency of Japan, Tokyo (Japan)

    1997-05-27

    In order to discuss effectiveness of physical exploration in the Sakonishi prospect in the Hida area, physical exploration was carried out by utilizing bored wells. This area contains the Kamioka mine, one of the major base metal mines in Japan, where electrical exploration has been attempted several times in the past. No effective results have been obtained, however, because specific resistance contrast between mine beds and base rocks is too small, and the topography is too steep making site workability inferior. As part of the investigations on geological structures over wide areas, electrical logging (specific resistance and natural potential) was performed in fiscal 1995 and 1996 by utilizing the boreholes. Induced polarization logging was also conducted on the same boreholes. A traverse line on the ground with a length of 600 m and boreholes were used to execute specific resistance tomography. Clear extraction was possible on a fault structure which is thought related with limestone distribution and mine bed creation. However, it was not possible to identify upward continuity of zinc ores expected in the exploration. Because of not large a specific resistance contrast between zinc ores and base rocks, it is difficult to find mine bed locations only from the information on the specific resistance. 5 refs., 5 figs., 1 tab.

  16. Fiscal 1997 verification and survey of geothermal prospecting technology etc. 2/2. Survey report on deep-seated geothermal resources; 1997 nendo chinetsu tansa gijutsu nado kensho chosa hokokusho. 2/2. Shinbu chinetsu shigen chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    For the purpose of reducing the risk to accompany the exploitation of deep-seated geothermal resources, investigations are conducted into the three factors that govern the formation of geothermal resources at deep levels, that is, the supply of heat from heat sources, the supply of geothermal fluids, and the development of fracture systems contributing to the constitution of reservoir structures. In the evaluation and study of reservoirs and the amount of resources, a reservoir simulation is conducted to grasp the characteristics of reservoirs and the amount of resources. For this purpose, the origin and history of the Kakkonda geothermal field are studied, with special attention paid to the origin of the difference in temperature between the shallow-seated and deep-seated reservoirs, the geometry of granite at Kakkonda, the region of recharge of meteoric water, the distribution of saline concentration in the natural state and the cause of the occurrence, the amount of supply of fluids and heat from the depth to the reservoirs, etc. In the evaluation and study of the economic effectiveness of the exploitation of deep-seated geothermal resources, it is learned that, if a 50MW geothermal power station is to be built at a deep level (drilled depth of 3000m on the average) with a rate of 50% attained in drilling, the steam amount required at such a deep level (presumed to be 75t/h) will be more than twice that required at a shallow level (presumed to be 35/h). (NEDO)

  17. Report on the results of the Sunshine Project - Verification survey for geothermal exploration technology, etc. Summary. Survey of deep geothermal resource; Chinetsu tansa gijutsu tou kensho chosa. Shinbu chinetsu shigen chosa sokatsu seika hokokusho (Yoyaku)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-03-01

    As to the development of deep geothermal resource which is expected to contribute to increasing the capacity of future power generation in Japan, investigational study was made from FY 1992 to FY 2000, and the results were summed up. The investigational study was conducted for the hydrothermal convection type deep geothermal resource with a thermal conducting heating mechanism, of which Kakkonda is typical, including the drilling of deep exploration well using the existing technology. As a result, new information/knowledge were acquired about the thermal structure, reservoir structure and hydrothermal supply structure of the depths, and a deep geothermal model was made. Based on the model, a detailed simulation was made possible, and a whole image of the hydrothermal convection type deep geothermal resource with the thermal conducting heating mechanism was made clear. In the surface survey, observation of microearthquakes, high-accuracy MT method, etc. were carried out, and a grasp of the shape of a new granite body from the surface was made possible. Concerning the drilling technology, the geologic stratum with a temperature over 500 degrees C was successfully drilled down to a depth of 3,729m by prolonging the life of bit at the time of drilling by introducing the top drive system, the closed mud cooling device, etc. (NEDO)

  18. Investigation of data acquisition parameters for Minami Noshiro 3D experiment using 3D seismic modeling; Sanjigen hado denpa modeling wo riyoshita Minami Noshiro sanjigen jishin tansa data shutoku parameter no kento

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, H.; Nakagami, K.; Minegishi, M. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center; Kano, R. [Teikoku Oil Co. Ltd., Tokyo (Japan)

    1996-10-01

    This paper describes how to grasp the characteristics of reflected waves which means how the reflected wave can be received in its magnitude depending on the complicated subsurface structure. Data acquisition parameters were also investigated, as to offset distance distribution and mute setting during the HMO correction. A velocity structure model was prepared for an area of 9km{times}8km including the given 3D seismic exploration area at Minami Noshiro, Akita Prefecture. For the geological sequence used for the velocity structure model, three formations, i.e., Katsurane Formation, Funakawa Formation, and Onagawa Formation, were inputted in an order from the shallower depth on the basis of the depth structure profile obtained from the previous data. Ray tracing was calculated by means of the two-dot dashed line tracing method. For this method, amplitude as well as travel time of waves can be calculated at the same time. This was effective for grasping the magnitude of reflected wave on simulating the traced data. For the velocity structure model used in this study, existing data inputted were old, which limited the quantity of information. However, this model would sufficiently contribute to the verification of survey design and the determination of optimal layout. 1 ref., 3 figs.

  19. Fiscal 1997 report on the survey of overseas geological structures, `the Tanjungenim Coal Exploration Project between Japan and Indonesia`; 1997 nendo kaigai chishitsu kozonado chosa `Nippon Indonesia sekitan kyodo tansa Tanjungenim project`

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The basic survey for coal mine development was conducted in the Banjarsari area of Tanjungenim, Sumatra, Indonesia. In the survey, Japan deals with ground surface exploration, borehole physical survey, VSP survey and seismic survey, and Indonesia exploratory drilling, topographical mapping, measurement, hydrologic/hydraulic survey, access road formation, etc. The boreholes drilled are 35 in number and 4004m in total drilling length. The borehole physical survey was conducted in all 35 holes. The seismic survey was conducted on 5 traverse lines and in a total length of 10.19km, and the VSP survey in two boreholes. As a result of the survey, it was found out that there existed a large amount of coal reserve in a comparatively shallow area in the south-central part of the Banjarsari area. There exist faults, which has no great effects on the open pit mining. There is a high possibility of developing large-scale coal mines of open pit mining type with a comparatively low soil removing ratio. Concerning the coal quality, the heating value is comparatively low, the latter half of a 4000 kcal/kg level. It can be expected to realize a pit-mouth power plant which is low in coal carrying cost. 129 figs., 28 tabs.

  20. Joint analysis of refraction seismic survey with multilevel hydrophone measurement (application for detecting the high velocity thin lid); Kussekiho jishin tansa data to kochu hydrophone data no fukugo kaiseki no rei

    Energy Technology Data Exchange (ETDEWEB)

    Mori, S.; Harada, T.; Hayashi, K. [OYO Corp., Tokyo (Japan)

    1996-05-01

    During a refraction seismic survey conducted at a spot where a high-speed lava layer is supposedly concealed, the distribution of lava layer was estimated, and a composite analysis involving the vibration data received via hydrophones arranged in a bore hole was accomplished using a high-speed model based on an assumed geological section. The refraction survey centered on the bore hole and was accomplished using 250m-long traverse lines extending therefrom, one to the upstream and the other to the downstream of a river, producing a total length of 500m. The hydrophones were installed in the bore hole, and the measurement was carried out in an offset VSP-like observation pattern. In the analysis, the velocities obtained by the refraction survey and velocity logging were assigned to each layer on the basis of the assumed geological section for the construction of a velocity distribution model, which served as the early model for the repetition of calculation. Calculation was repeated with help of the said model, and a geological structure, capable of explaining the travel time data collected during the refraction survey and velocity logging, was successfully estimated. 1 ref., 5 figs.

  1. Time domain electromagnetic method for petroleum exploration. Part 3. Case study in Yoneyama area; Sekiyu tansa ni okeru TDEM ho data shutoku to kaiseki ni tsuite. 3. Niigataken Yoneyama chiiki deno tekiyorei

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, H.; Mitsuhata, Y. [Japan National Oil Corp., Tokyo (Japan); Shiga, N. [Mitsui Mineral Development Engineering Co. Ltd., Tokyo (Japan)

    1996-05-01

    The result is reported of a TDEM method-based survey for oil exploration conducted in the Yoneyama district, Niigata Prefecture. The survey covered the southern part of the sedimentary basin in the prefecture, known for the poor quality of the seismic prospecting data that had been recorded. The purpose of the TDEM method-assisted survey was to probe the high-resistivity volcanic rock structure and low-resistivity sedimentary layer, and to know their details. The obtained data were subjected to interpretation by use of the 1D inversion method. A 4000m-deep level was subjected to interpretation, 34 data were inputted, and the early model consisted of 20 layers. As the result, it was found that there was a high-resistivity layer ranging from the ground surface down to a depth of approximately 500m, that a low-resistivity layer 2500-3000m in thickness lay thereunder, and that the lowest layer had a high resistivity of approximately 100 Ohm m. By comparing these data with the geological structure, structures were disclosed corresponding to the rock bed depth, Ukawa syncline, Ishiguro anticline, and Yoneyama mountain mass. 3 refs., 10 figs., 1 tab.

  2. Fiscal 2000 survey report on overseas geological structure, etc. Project for exchanging experts - Exploration technology (Indonesia); 2000 nendo kaigai chishitsu kozo to chosa hokokusho. Gijutsusha koryu jigyo - Tansa gijutsu bunya (Indonesia)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    For the stabilization of coal supply/demand in the APEC (Asia-Pacific Economic Cooperation Conference) region and for the stable supply of coal to Japan, Japanese engineers and experts were dispatched to Indonesia, where coal production was remarkably increasing and efforts were being actively exerted to develop new coal mining fields, for training Indonesian specialists there, and Indonesian specialists were invited to Japan for training here. Japanese instructors on dispatch delivered lectures on coal geology, exploration, and exploitation at the human resource development center of Bandung City during the period July 20 through August 4, 2000, which was followed by a coal outcrop survey training session in the field. The trainees were from Kalimantan, Sumatra, Java, etc., and numbered 30. The trainees invited to Japan received lectures and training related to coal geology, exploration, and mining programs during the period October 19 through November 18, 2000, at the Geological Survey of Japan, Agency of Industrial Science and Technology, Ministry of International Trade and Industry; Matsushima Coal Mining Co., Ltd.; Enzan Plant, Tone Corporation; DIA Consultants Co., Ltd.; and Mitsubishi Materials Corporation. (NEDO)

  3. Fiscal 1997 verification and survey of geothermal prospecting technology etc. 1/2. Survey report on deep-seated geothermal resources; 1997 nendo chinetsu tansa gijutsu nado kensho chosa hokokusho. 1/2. Shinbu chinetsu shigen chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    For the purpose of reducing the risk to accompany the exploitation of deep-seated geothermal resources, investigations are conducted into the three factors that govern the formation of geothermal resources at deep levels, that is, the supply of heat from heat sources, the supply of geothermal fluids, and the development of fracture systems contributing to the constitution of reservoir structures. In fiscal 1997, a fumarolic gas test is conducted at the deep-seated geothermal well WD-1b which was drilled in the preceding fiscal year. In the test, chemical and isotopic characteristics are compared between the fluids of the WD-1b and the other existing deep-seated wells, and it is found that the fluids from the WD1b originates in surface water just like the fluids from the others and that the constitution of its gas is not greatly affected by magmatic fluids. A PTS (Pressure, Temperature, Spinner flowmeter) logging is performed to observe conditions in the well with the fluids being discharged and to know the inflow point and rate the fumarolic fluids, and the result is utilized to presume the 3-dimensional stress in the vicinity of the WD-1. An isotopic measurement of water included in the fluids is conducted to examine the origin of the geothermal fluids, constant observation and analysis of micro-earthquakes are carried out, and the fluid flow and fluid hydraulic characteristics are also studied. (NEDO)

  4. Confirmation study of the effectiveness of prospect techniques for geothermal resources. Deep-seated geothermal resources survey report (Fiscal year 1994); 1994 nendo chinetsu tansa gijutsu nado kensho chosa. Shinbu chinetsu shigen chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Drilling and survey of deep geothermal exploration wells were conducted to grasp the existing situation of deep geothermal resource and the whole image of geothermal systems in the area where geothermal resource was already developed. In the drilling work in fiscal 1994, 4000m-class rigs and the top drive system were planned to be used for drilling of 12-1/4 inch wells, but 9-5/8 inch liners were used for drilling down to depths of 2550m or deeper since the amount of lost circulation is large and the withdrawal of devices may be very difficult. And in 8-1/2 inch wells, the well was drilled down to a depth of 2950m. As to the deep resistivity exploration technology using electromagnetic method, studies were made of a multiple-frequency array induction logging (MAIL) method, a vertical electromagnetic profiling (VEMP) method, a joint analysis method, etc. Concerning the synthetic fluid inclusion logging technology, containers were lowered into the well and a comparison was made between data of the homogenization temperature analysis of the formed fluid inclusion and those of the temperature log analysis. With relation to the making of deep geothermal structural models, revision was made according to the determination of depths of Miocene formations, Pre-tertiary formations, and the Kakkonda granite. 65 refs., 268 figs., 79 tabs.

  5. Utilization of two-way multicore cables and comparison of various electrode configurations in electrical prospecting; Denki tansa ni okeru sohokogata tashin cable no riyo to kakushu dekyoku haichi no hikaku

    Energy Technology Data Exchange (ETDEWEB)

    Takakura, S. [Geological Survey of Japan, Tsukuba (Japan); Matsushima, J. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering

    1996-10-01

    For more precise electrical prospecting, the new multicore cable was developed to allow high-density measurement by conventional equipment. Since conventional multicore cables are inferior in cost, length and weight, the new cable is composed of an n-conductor cable, two n-conductor male connectors and n lead wires. For connection of the multi-conductor cable and lead wires, cable sheath is peeled at n points at specific intervals. Sheath of the k-th conductor is peeled at k-th point from the terminal, and restored for insulation after connection of the conductor and lead wire. The male connectors are attached to the both ends of the multi-conductor cable. Since this two-way type cable can be used at every end, the measuring equipment can measure at one divisional point after another of a long measuring line while shifting the equipment from one point to another. All measurements are perfected only with two short cables. Resistivities were successfully measured along the long measuring line of 480m long with 97 electrodes arranged at intervals of 5m. Various electrode configurations were also compared. 1 ref., 4 figs., 2 tabs.

  6. FY 1998 report on the basic survey for coal resource development (Summary). New exploration technology survey and development (land area shallow seam exploration); 1998 nendo sekitan shigen kaihatsu kiso chosa hokokusho. Shintansa gijutsu chosa kaihatsu (rikuiki senso tansa)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The paper described the FY 1998 results of the development of new exploration technology of coal resource. The detailed design was made based on the conceptual design of a high accuracy 3D geological modeling system in the FY 1997 equipment development. The expression of the reverse fault, excess folding, etc., which has been difficult, became possible, and high-level visualization of the geological model made became possible. The prototype model in Caroona district as survey field is easy of expression of fault, folding, etc. By the increase of data on test boring, made clear were geological characteristics of this area, especially the complicated geological state of Black Jack Formation groups of the coal-bearing formation. In explaining the reflection section, after roughly identifying 5 horizons from features of the total reflection patterns, reflection waves were explained from specified reflected waves, that is, the base of the Quaternary, the top of the Doona coal seam group, the base of the Clift coal seam group, and the top of the Hoskissons coal seam. By adopting the S-wave reflection method which is effective in converting in-situ numerical values such as the rock-mass related elastic modulus, compressive strength and rigidity ratio, an outlook for getting data of good quality was obtained in VSP survey. (NEDO)

  7. FY 2000 report on the survey of geological structures overseas, etc. Volume 1. 'Tanjung Enim IV Coal Exploration Project between Japan and Indonesia'; 2000 nendo kaigai chishitsu kozo nado chosa hokokusho. 1. Nippon Indonesia sekitan kyodo tansa Tanjung Enim project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    The paper summarized the results of the surveys in the final fiscal year (FY 2000) and in the past five years of the Tanjung Enim IV Coal Exploration Project between Japan and Indonesia. In FY 2000, conducted in the South Arahan area were the surface reconnaissance (50km+ACI-2), boring survey (11 holes, 1,847m), borehole physical logging (11 holes), reflection method seismic survey (3 traverse lines), pumping test, coal analysis (112 specimens), etc. As a result of the exploration/study made during 5 years, coal reserves in the South Arahan area were 223 million tons in north block (proved coal reserves: 213 million tons) and 332 million tons (proved coal reserves: 303 million tons) in south block. The coal in the area is in the depth of {+-}0m from surface, and the coal reserve is enough for large scale open pit mining. Further, coal reserves in the Banjarsari area were 442 million tons (proved coal reserves: 330 million tons) in the whole area and 223 million tons (proved coal reserves: 214 million tons) in the syncline part. About the syncline part promising as that for open pit mining, the overburden ratio was divided into three for calculation: 2:1, 3:1 and 4:1 or below. (NEDO)

  8. Exploration of underground basement structures in Kanto plain using the spatial autocorrelation method. 1. S-wave velocity structure along the line from Hatoyama, Saitama to Noda, Chiba; Kukan jiko sokanho ni yoru Kanto heiya no kiban kozo tansa. 1. Saitamaken Hatoyama machi - Chibaken Nodashi kan no S ha sokudo kozo

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, T.; Umezawa, N.; Shiraishi, H. [Saitama Institute of Environmental Pollution, Saitama (Japan)

    1997-05-27

    The Saitama prefectural government has been conducting basement structure exploration using the spatial autocorrelation method by dividing the entire plain area into meshes, for the purpose of improving the accuracy of estimating large-scale seismic damages. This paper reports the result of explorations on meshes in the east-west direction in the central part of Saitama Prefecture. The present exploration was intended on ten meshes in the east-west direction along the north latitude 36-degree line. The number of exploration points is 13 comprising three points on the hilly area bordering on the eastern edge of the Kanto mountainous area and ten points on the plain area. The arrangement constitutes a traverse line with a total distance of about 33 km from the west edge (Hatoyama-machi in Saitama Prefecture) to the east edge (Noda City in Chiba Prefecture). The phase velocities were estimated from the result of the array microtremor observations using the spatial autocorrelation method applied with the FET. The phase velocities were used to estimate underground structures by using an inverse analysis. As a result, detailed two-dimensional S-wave velocity structures were revealed on the traverse line. The velocity cross section expresses change in the basement structures with sufficient resolution, and at the same time the information is judged highly harmonious with existing deep boring data and the result of artificial earthquake exploration. 15 refs., 6 figs.

  9. An application of SP-method utilizing streaming potential to investigation of underground water-flow at a landslide; Ryudo den'i wo riyo shita shizen den'iho tansa no jisuberi chiiki ni okeru chikasui chosa jikken

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Hiroshi; Toshioka, Tetsuma; Haryu, Shinya [Oyo Corp., Tokyo (Japan)

    1999-02-01

    SP-method utilizing streaming potential was applied to the investigation at a landslide to estimate the flowing direction of underground water-flow at a landslide. As a result, the flowing direction of underground water estimated by the potential gradient method are substantially confirmable with the flow distribution of the underground water estimated from the flow rate in a catchment well. Further, the specific resistivity image method was executed within the same investigation region to estimate the underground specific resistivity structure. It is estimated from the comparison between the results of the specific resistivity imaging method and the results of the potential gradient method that underground water flows from a recess of a contour line of a specific resistivity of 100{omega}m to the catchment well. At the same time, an indoor experiment was carried out for revealing the effectiveness of the potential gradient method in the investigation of underground water. A water channel was formed in an experiment tank, a fluid is flowed into the tank, and a spontaneous potential at the top face in the tank was measured. As a result of the experiment, a phenomenon that the potential decreases right above the water channel was determined. Consequently, the investigation by the SP method utilizing streaming potential is considered to be effective in a landslide region. (translated by NEDO)

  10. 3D electrical method and step continuous wave radar method for Nojima site. Results of measurement of resistivity at trench site; Nojima danso ni okeru sanjigenhi teikoho to step shiki renzokuha chika radar ho tansa. Trench chosa chiten deno hiteiko sokutei kekka

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K.; Oda, Y.; Tank, K. [Central Research Institute of Electric Power Industry, Tokyo (Japan); Hayashi, H. [Kawasaki Geological Engineering Co. Ltd., Tokyo (Japan); Jomori, A. [Japan Crust Research, Tokyo (Japan)

    1996-05-01

    Several surveys were carried out near the Nojima fault, including three-dimensional resistivity measurement and underground radar survey at the Ogura area, underground radar survey at the Hirabayashi area, and resistivity measurement in the vicinity of the trench at the Nashinomoto area, in order to investigate in detail the underground structures at a depth up to several tens meters from the ground surface. Resistivity was measured by an automatic analyzer capable of simultaneously measuring potential levels at 14 channels which can cover 112 measuring points at the largest. At the Ogura area, the boundary planes of the resistivity structures are continuously detected in the direction of the fault moving during the earthquake period. The underground radar measurement results suggest accumulated displacement of strata at a depth of around 25m in the Osaka Strata and flexible structures. At the Hirabayashi area, the underground radar analysis detects discrete sections in the reflection planes at the fault position, but no reflection planes of high continuity. At the Nashinomoto area, the clay stratum detected in the fault by excavating the trenches are found to be low in resistivity by the resistivity measurement. 4 refs., 11 figs., 2 tabs.

  11. Fiscal 1997 report on the verification survey of geothermal exploration technology. 2. Development of the reservoir variation survey method (development of the gravity survey method); 1997 nendo chinetsu tansa gijutsu nado kensho chosa. Choryuso hendo tansaho kaihatsu (juryoku tansaho kaihatsu) hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    Among technology developments such as the reservoir evaluation at initial developmental stage and stabilization/maintenance of power after the start of operation, the fiscal 1997 result was described of the development of the gravity survey method. The paper conducted the installation of gravity measuring points outside the existing monitoring range, introduction of CG-3M gravimeter/GPS measuring system, drilling of ground water level monitoring well, etc. for the setup of a system for new gravity monitoring. Moreover, regular measurement of gravity was made for the first fiscal year, and at the same time the continued observation of ground water level, precipitation, atmospheric pressure, and temperature was started. It is necessary to study the effects on gravity variation such as gravity gradient and tidal correction. Conducted were collection/arrangement of the existing data and database construction for history matching/variation prediction in the Yanaizu Nishiyama area. The paper made surveys of the trends/literature. In the future, needed are the computation using density models of geothermal reservoirs and test use of EDCON`s downhole gravimeter. 44 refs., 30 figs., 17 tabs.

  12. Field experiment in jointed rock mass with electro-magnetic tomography. Challenge for 50m energy penetration and an interpretation with additional geological data; Denjiha tomography ni yoru setsurisei ganban no tansa. Kokan kyori 50m no sokutei to chishitsu kaishaku no kokoromi

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K.; Koga, K.; Nishiyama, E.; Yamamoto, T. [Kawasaki Geological Engineering, Co. Ltd., Tokyo (Japan)

    1996-05-01

    With the purpose of extending an exploring distance in electromagnetic tomography, a prototype was made as a device to receive and transmit continuous waves in a borehole, so that a tomographic observation was carried out on a jointed rock mass that had a conventionally short exploring distance. The device consisted of a transmitter, receiver, antenna, cable and surface controller, with a personal computer used for displaying and storing data. The prototype antenna was provided with a size insertable into a VP50 vinyl chloride tube. In order to determine a relative permittivity of a rock, a boring core was shaped and an impedance was measured. The measurement of tomography was carried out at 1m spaces apart in the bore holes with a distance of 50m in between. The received waveforms were stored in a floppy disk built in the personal computer. As a result of the analysis, a tomographic cross-section of the electromagnetic wave velocity was obtained, showing the distribution of sandstone with a high electromagnetic wave velocity and little joints, shale with a low electromagnetic wave velocity, chart with a high electromagnetic wave velocity, etc. 2 refs., 4 figs., 1 tab.

  13. Fiscal 1997 report of the verification research on geothermal prospecting technology. Theme 5-2. Development of a reservoir change prospecting method (reservoir change prediction technique (modeling support technique)); 1997 nendo chinetsu tansa gijutsu nado kensho chosa. 5-2. Choryuso hendo tansaho kaihatsu (choryuso hendo yosoku gijutsu (modeling shien gijutsu)) hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    To evaluate geothermal reservoirs in the initial stage of development, to keep stable output in service operation, and to develop a technology effective for extraction from peripheral reservoirs, study was made on a reservoir variation prediction technique, in particular, a modeling support technique. This paper describes the result in fiscal 1997. Underground temperature estimation technique using homogenization temperatures of fluid inclusions among core fault system measurement systems was applied to Wasabizawa field. The effect of stretching is important to estimate reservoir temperatures, and use of a minimum homogenization temperature of fluid inclusions in quartz was suitable. Even in the case of no quartz in hydrothermal veins, measured data of quartz (secondary fluid inclusion) in parent rocks adjacent to hydrothermal veins well agreed with measured temperature data. The developmental possibility of a new modeling support technique was confirmed enough through collection of documents and information. Based on the result, measurement equipment suitable for R and D was selected, and a measurement system was established through preliminary experiments. 39 refs., 35 figs., 6 tabs.

  14. Fiscal 1997 report on the survey of verification of geothermal exploration technology, etc. 1. Development of the reservoir variation exploration method (development of the fracture hydraulic exploration method); 1997 nendo chinetsu tansa gijutsu nado kensho chosa. Choryuso hendo tansaho kaihatsu (danretsu suiri tansaho kaihatsu) hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The paper described the fiscal 1997 result of the fracture hydraulic exploration method as the variation exploration method of geothermal reservoirs. By elucidating hydraulic characteristics of the fracture system forming reservoir, technologies are established which are effective for the reservoir evaluation in early stages of development, maintenance of stable power after operational start-up, and extraction of peripheral reservoirs. As for the pressure transient test method, a test supporting system was basically designed to obtain high accuracy hydraulic parameters. As to the tiltmeter fracture monitoring method, a simulation was made for distribution of active fractures and evaluation of hydraulic constants without drilling wells. In relation to the two-phase flow measuring method, for stable steam production, the use of the orifice plate, the existing flow measuring method, etc. was forecast as a simple measuring method of the two-phase state of reservoir. Concerning the hydrophone VSP method, a feasibility study was made of the practical VSP for high temperature which can analyze hydraulic characteristics and geological structures around the well at the same time which the existing methods were unable to grasp, and brought the results. Moreover, to make high accuracy reservoir modeling possible, Doppler borehole televiewer was made in each reservoir. 80 refs., 147 figs., 22 tabs.

  15. Fiscal 1997 basic research on coal resource development (equipment development). Report on R and D of new exploration technology (exploration of medium-depth coal deposits in water areas); 1997 nendo sekitan shigen kaihatsu kiso chosa (kiki kaihatsu hen) hokokusho. Shintansa gijutsu chosa kaihatsu (suiiki chushindoso tansa)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This report summarizes the research result on development of new coal exploration technology. For a high-precision and high-resolution reflective seismic exploration system, R and D was made on the exploration technology of several meter in resolution for medium-depth (800m) coal deposits under a lake of 2m deep. As a result, the high-frequency and high-power source (150-200Hz in dominant frequency, 700-800m in penetrability) and the high-frequency and high sensitivity receiver (10-1000Hz in frequency band, 35V/PA in sensitivity) were developed successfully, and the positioning system was improved. The final evaluation of these elementary technologies was carried out through demonstration tests, resulting in satisfactory results. For a high-efficiency trial drilling system, the in-bore trouble prevention system for measurement, processing and analysis of drilling data (drilling length, drilling rate, revolution, bit load, torque) and drilling mud data (charge water pressure, charge/discharge water, density, pH, viscosity) was constructed. The outlook for low-cost measurement and a safety during drilling was thus obtained. (NEDO)

  16. Fiscal 1997 report on the verification survey of geothermal exploration technology. 5-1. Development of the reservoir variation survey method (technology of prediction of reservoir variation); 1997 nendo chinetsu tansa gijutsu nado kensho chosa. Choryuso hendo tansaho kaihatsu (choryuso hendo yosoku gijutsu) hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    For the reservoir evaluation at an initial developmental stage and stabilization/maintenance of power after the start of operation, the fiscal 1997 result was described of the study of technology of prediction of reservoir variation. Using the conventional post processor, feasibilities were computed of reservoir models and behavior after the development, and gravity/self potential/resistivity variation. Variation in the seismic wave speed structure was large in travel time change distribution. The measuring accuracy of 1m sec is required to get enough detection resolving power. A conceptual design of the post processor development was conducted to study a system operated on Windows. Based on the reservoir numerical simulation technology, by taking in variation parameters such as gravity and self potentials as new model constraint conditions, the reservoir modeling technology which increased in accuracy by history matching was trially developed. Using the conventional reservoir model in the Oguni area, predictably computed were reservoir behaviors during 50 years which simulated a 20 MW development. Effectiveness of the post processor were able to be shown though influenced by characteristics such as permeability and resistivity. 74 refs., 95 refs., 12 tabs.

  17. Report on the achievements in fiscal 1999. Technology to use gas hydrate as a resource (Research and development for exploration, research and development on drilling technologies, investigative research on an environment influence evaluation method, and investigative research on a utilization system); 1999 nendo gas hydrate shigenka gijutsu sendo kenkyu kaihatsu seika hokokusho. Tansa nado ni kansuru kenkyu kaihatsu, kussaku gijutsu nado ni kansuru kenkyu kaihatsu, kankyo eikyo hyokaho no chosa kenkyu, riyo system ni kansuru chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    The contents of the research and development performed in the current fiscal year are as follows: (1) research and development for exploration, (2) research and development on drilling technologies, (3) investigative research on an environment influence evaluation method, and (4) investigative research on a utilization system. In Item (1), element analysis data are used to study a method to estimate production environment of hydrate ore beds by using an inorganic ion analyzer and a trace amount element analyzer, the crust thermal flow measuring method is used to discuss a method to analyze the hydrate stability zones together with the data of sea area exploration records, and conceptual design is made on a resource potential evaluation system. In Item (2), experiments and analytical discussions are performed on decomposition control of the gas hydrate solid-liquid interface according to such conditions for the drilling fluid as temperatures and flow rates. Elucidation is given on the initial process of bubble generation for behavior of decomposed gas bubbles. Observation and elucidation are made on two-phase flow behavior of non-Newtonian fluid. In Item (3), conceptual design is carried out on a system to detect elements of shape change in each bed due to fluid movement in a gas hydrate bed and an upper bed. In Item (4), discussions are given on the optimizing conditions for generation and dissociation of gas hydrates. Investigation is made also on a possibility of the transportation and storage system. (NEDO)