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ABSTRACT Construction of transmission tower is inevitable but it is hard to select a new construction site due to negative recognition for transmission tower. Construction of transmission tower located at steep slope passing through mountain terrain rather than city center is being increased. Existing foundation type has been faced with difficulties in its application due to large-scaled forest damage and constructability. As an alternative for these problems, a case of applying micro-pile is being increased. So far, there are almost never the studies such as theoretical verification or field-laboratory test for micro piles. In this study, in order to evaluate uplift force of micro-pile for transmission tower, the experimental apparatuses have been made and the model test results have compared with equation.
- North America > United States (0.29)
- Asia > Middle East > Israel > Mediterranean Sea (0.25)
Abstract. The Tarim basin, covering an area of 560000 km2, is the biggest inland basin of China. Exploration in recent years shows that the Tarim basin is a complex intracratonic basin. The geological evolution of this basin is divided into three stages. The geosyncline was formed in the Archaeozoic, followed by the deposition of platform blanket Sediments from the Sinian to Paleozoic. A continental sedimentary basin developed during the Mesozoic to Cenozoic. The tectonically complex basin area is composed of three uplifts and four depressions which are surrounded by youthful, active foldbelts and major basement faults. The sedimentary section in this basin is up to 18000 m thick with four sets of source beds. Multiple types of reservoir have been discovered. Four oil and gas fields have been established in the Kuche and Southwest depressions and the North Tarim uplift. High production of oil and gas was obtained from exploratory wells in the areas of the North Tarim and Central uplifts. The North Tarim uplift and the Central uplift are believed to have the greatest potential for oil and gas. Résumé. Le bassin de Tarim constitue le bassin le plus important de la Chine, et couvre une surface de 560000 km'. L'exploration qui est intervenue au cours des dernières années, a démontré que le bassin de Tarim est un bassin intracratonique complexe. L'évolution géologique de ce bassin est divisée en trois étages. Le géosynclinal s'est formé à PArchéozoïque suivi par le dépôt de sédiments en forme de nappe du Sinien au Paléozoïque. Un bassin sédimentaire continental qui s'est développé au cours de la période du Mésozoïque jusqu'au Cénozoïque. La surface du bassin à caractère complexe d'un point de vue tectonique est composé de trois soulèvements et de quatre affaissements entourés de faisceaux de plis actifs et jeunes et d'imposantes failles verticales de décrochement régionales. La partie sédimentaire de ce bassin est d'une épaisseur allant jusqu'à 18 o00 m et elle est dotée de quatre ensembles de roches mères. Une multitude de types de roches réservoir ont été découvertes. Quatre champs pétrolifères et de gaz naturel ont été découverts dans les affaissements du Sud-Ouest et du ‘Kuche’ et dans le soulèvement du nord du Tarim. Une production élevée de pétrole et de gaz naturel a été obtenue à partir de puits d'exploration dans les régions du soulèvement du nord du Tarim et dans le soulèvement centrai. Le soulèvement du nord du Tarim et le soulèvement central sont supposés posséder les plus importantes ressources pétrolières et gazeuses. INTRO DU CTIO N The Tarim basin is located in the southern part of Xinjiang Uygur Autonomous Region, in northwest China. Figure 1 shows that it
- Phanerozoic > Cenozoic (1.00)
- Phanerozoic > Mesozoic > Triassic (0.48)
- Proterozoic > Neoproterozoic > Sinian (0.34)
- Phanerozoic > Paleozoic > Ordovician (0.30)
- Geology > Structural Geology > Tectonics > Compressional Tectonics > Fold and Thrust Belt (1.00)
- Geology > Sedimentary Geology (1.00)
- Geology > Rock Type > Sedimentary Rock (1.00)
- (2 more...)
- Asia > China > Xinjiang Uyghur Autonomous Region > Tarim Basin > Lunnan Field (0.99)
- Asia > China > Xinjiang Uyghur Autonomous Region > Tarim Basin > Kuche Basin > Yakela Field (0.99)
- Asia > China > Xinjiang Uyghur Autonomous Region > Kekeya Field (0.99)
- Oceania > Australia > Victoria > Bass Strait > Gippsland Basin (0.89)
- Reservoir Description and Dynamics > Reservoir Characterization > Seismic processing and interpretation (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Exploration, development, structural geology (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Geologic modeling (0.88)
Seismic Velocity Imaging of the Steen River Crater: Technique Development for Exploring Crater Reservoirs
Hildebrande, A.R. (University of Calgary) | Mazur, M.J. (University of Calgary) | Stewart, R.R. (University of Calgary) | Schafer, A. (Gulf Canada Resources) | Hladiuk, D.W. (Gulf Canada Resources) | Scheonthaler, L. (Gulf Canada Resources) | Pilkington, M. (Geological Survey of Canada)
Introduction The ∼25 km-diameter Steen River impact structure, (59 ° 30' N, 117 ° 38' W) is the remnant of the largest known impact crater in the Western Canadian Sedimentary Basin (WCSB). The eroded crater lies buried under ∼200 m of cover with no surface expression necessitating geophysical and drilling projects for its exploration. In this area, the WCSB is composed of ∼1 km-thick gently SW-dipping strata. The terrain is predominantly poorly drained taiga, necessitating winter operation for most exploration and production activities. As of this writing, the crater rim hosts gas production of 30 Mmcf/d from the Slave Point Formation, but a second gas plant is expected to begin production during 2000. Seasonal petroleum production of ∼1000 BOPD occurs from the Keg River Formation. Approximately one dozen Slave Point gas wells have been drilled with sandface AOF potential up to 95 Mmcf/d, and exploration is continuing around the crater rim. Initial gas production was on the regionally high side, the northeastern rim of the crater. Reserves of ∼70 bcf have been established. IMPACT ORIGIN Although Steen River was discovered more than thirty years ago with documented evidence of shock metamorphism , little has been published about it in the open literature, and its classification as an impact structure has been challenged from time to time. Shock metamorphism was first reported from well 12-19-121-21W5M. An examination of chips recovered from the 3–12 well located ∼3 km SSW of the 12–19 well also reveals abundant evidence of shock metamorphism, and altered and recrystallized melts in a unit once logged as volcanics that immediately underlies the Cretaceous cover. Well 12–19 penetrated impact lithologies immediately below the Cretaceous cover at a depth of 184 m. An ∼120 m thick unit of clay-altered, vesicular rock was recorded on top of the unequivocal crystalline basement rocks , establishing a minimum structural uplift of 1000 to 1100 m relative to the surrounding basement surface. The upper unit could be a remnant of crater floor breccias like that found in the 3–12 well rather than representing a dyke contained within the central uplift. GEOPHYSICAL DATA SETS, WELL CONTROL, AND POTENTIAL FIELD MODELLING Hydrocarbon exploration companies have acquired more than one hundred and seventy 2-D seismic reflection profiles over the impact structure, and one 3-D seismic survey has been executed over the northwest corner of the crater rim. Approximately sixty wells have been drilled in and near the crater, providing generally good control for the coherent seismic data. All known hydrocarbon reservoirs occur in structural closures formed by the rim deformation. Reflection seismic data outline parts of the rim uplift in some detail, but most profiles record only chaotic reflectors interior to this. Mapping the impact structure's interior structures has been attempted with magnetic- and gravity-field surveys. In 1995 an aeromagnetic survey with a maximum of 0.5 km line spacing was flown across the entire structure, revealing large-amplitude central and concentric anomalies.
- North America > Canada > Alberta (1.00)
- North America > Canada > Saskatchewan (0.75)
- North America > Canada > Northwest Territories (0.75)
- (2 more...)
- Geology > Rock Type (1.00)
- Geology > Geological Subdiscipline > Stratigraphy (0.30)
Offshore pipelines are often placed in the seabed by the process called jetting, which has implications for the resistance of the soil to upward pipeline movements. A series of centrifuge model tests has been conducted to investigate the uplift capacity and the load-displacement behaviour of pipelines buried in recently liquefied clay. Undrained uplift capacities were seen to be lower than the drained capacities. Recently liquefied clay may still be consolidating when pipelines are commissioned; the effective stresses in the soil (and thus the shear strengths) at the expected switch-on time have to be calculated in order to calculate the uplift capacity of the pipeline. A simple method is presented which predicts uplift capacity from the average degree of consolidation of the backfill. INTRODUCTION As the North Sea has matured as a producing region, pipeline activity has moved from large-diameter trunk pipelines to smaller in-field flowlines. These are often buried in the seabed, which provides protection from fishing activity and additional thermal insulation. The move to small-diameter pipelines has prompted the use of reel-lay techniques, requiring thicker-walled pipe to prevent buckling during the bending and straightening process. As a consequence of this new approach, upheaval buckling is promoted by the elevated temperatures (which lead to thermal expansion) and the high degree of lateral and axial soil restraint. The resulting compressive forces can result in the pipeline being forced upwards out of the trench—a phenomenon known as upheaval buckling. The backfill soil in the trench and the pipe weight contribute to prevent the upheaval buckling load imposed by the pipeline. However, the resistance to the upheaval load provided by the soil is difficult to calculate. Pipelines are often placed in the seabed by jetting. A remotely operated vehicle (a trencher) with tracks is driven over the seabed.
- North America > United States > California (0.46)
- Europe > United Kingdom > Scotland (0.28)
ABSTRACT This investigation is concerned with the prediction of wave uplift forces on horizontal decks under the action of periodic non-breaking waves and waves breaking on 1:3 and 1:5 beach slopes. The variables encountered are the wave height, the wave length, the water depth, the length of the deck, and the clearance between the bottom of the deck and the still water level. Theoretical solutions to this problem were given by Stoker (1957), Ijima (1970), and Wang (1970) for the case of no beaches under certain assumptions of wave conditions. Laboratory experiments were carried out, and time histories of uplift forces and pressures were recorded simultaneously. Deviations from the available theories are discussed, and a modified theory is presented which agrees with the experimental results for the case of waves in constant water depth. Pressure and uplift forces recorded in the case of-waves breaking on 1:3 and 1:5 beach slopes showed that peak uplift pressures and forces are of random nature. The probability distribution of peak pressures within a cycle was found to be Gaussian with a standard deviation approximately equal to one-half of the mean. The peak uplift forces on the deck had a Rayleigh distribution. Correlations of mean peak pressures and mean peak forces with wave characteristics and deck geometry are introduced. INTRODUCTION The problem of wave uplift forces on horizontal decks is of considerable importance to engineers engaged in the design of offshore platforms, breakwaters, and docks. Decks may be constructed in relatively deep water, shallow water, or in the surf zone. In the first two cases, they are attacked by non-breaking waves while in the latter case they are subject to waves breaking on the beach slope. Permeable breakwaters consisting of three or four layers of horizontal slabs supported by vertical piles were constructed in Japan. Laboratory studies showed that the transmitted wave on the leeward side of the deck is of different nature as compared to the incident wave. Although a considerable amount of laboratory and field observations are available on the wave pressures and forces on vertical barriers l, 2,3,5, very little is known about the uplift wave pressures and forces induced on a deck. Two different approaches were followed to describe the wave uplift forces and pressures, namely deterministic and probabilistic. Stoker introduced a closed form theoretical solution for the case of shallow water-long small amplitude waves. Ijima6 introduced another type of solution based upon a series expansion of the velocity potential. assuming only small amplitude waves. These two methods do not consider any energy transmission from one frequency (incident wave frequency) to another. Wang8 studied the wave induced pressures on the underside of a horizontal flat plate mounted on a pier deck under a dispersive wave system.