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Collaborating Authors
Production and Well Operations
ABSTRACT JAMSTEC has developed the 7,000m class expendable fiber optics ROV," UROV7K". The purposes of UROV7K are to watch mooring systems installed in deep sea and exploration deep seabed. UROV7K equips a lithium-ion rechargeable battery for the power source without providing the power from the mother ship. And only one fiber optics cable with a diameter of I mm interconnects onboard system and UROV7K. All data between the mother ship and UROV7K communicate through one fiber optics cable. Therefore, the optical communication system is most important equipment for UROV7K. This paper describes the communication system of UROV7K. I. INTRODUCTION In recent years, the mooring systems installed in deep sea are increasing and the ROVto watch themis required. The conventional ROVs have the thick and long tether cable for sending the electric power, and it is dangerous that the tether cable of ROV may get entangled mooring line. AUVs without tether cable communicate with acoustic communication, so it is impossible to get real-time and clear picture. UROV system developed by JAMSTEC is suitable for above purpose. In UROV system, power source is mounted on the vehicle and only one fiber optics cable, which is l mm in diameter, connects the vehicle and onboard unit. In addition, when the vehicle finishes investigation or emergency occurs, the vehicle cuts off the fiber optics cable and surfaces. Therefore, even if the fiber optics cable gets entangled in something like mooring line, the vehicle can recover. In UROV system, the optical communication system is very, important since all data between the vehicle and onboard system communicate through only one fiber optics cable. Experimental model " UROV 2000 " and practical model " GENTATSU 500 ", which was made by cooperative development with Fukui Prefecture, with UROV system was developed in JAMSTEC.
- Production and Well Operations > Well & Reservoir Surveillance and Monitoring > Production logging (1.00)
- Data Science & Engineering Analytics > Information Management and Systems (1.00)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems > Mooring systems (0.95)
ABSTRACT The Hydro Bottom Station (HBS) was specially designed for the sampling and measuring of hydrothermal fluids. It can be positioned directly above a plume site via video-control with the research vessel. Twelve water samples can be taken in variable distances (0–1 m) from the emanation centre at the bottom. The objectives of this interdisciplinary cruise were the investigations of the hydrothermal activity in areas of the Central Fiji Ridge. We detected geochemical anomalies (Mn and other metals, Cr speciation, H2S, CH4 and physico-chemical parameters) in the near-bottom-water layer and also below the surface resulting from the outflow of diffuse low-temperature hydrothermal fluids. INTRODUCTION AND GEOLOGICAL BACKGROUND The investigations presented here are part of the co-operative project HYFIFLUX II which is a German research project carried out with international partners. The objectives of this interdisciplinary project are the investigations of the hydrothermal activity in areas of the Central Fiji Ridge (CFR) and the related geochemical fluxes, mineral precipitations and biological characteristics. Geological and geochemical-mineralogical studies are carried out on mineral precipitates, basaltic rocks (including alterites), sediments and hydrothermal fluids. The investigations of material transport, mineral precipitation (ore formation and zonation) and special biological activity started during the SO 99-cruise (HYFIFLUX I; Halbach et al., 1995) in the North Fiji Basin (a mature intra-oceanic backarc-basin) are continued and intensified, especially by well-aimed sampling of different fluids. The micro- and macrofauna of the hydrothermally very active region is studied regarding their correlation with local bottomwater chemistry. Since the geochemical and microbiological studies are carried out on the same fluid samples, these investigations allow the identification of geo-bio-interfaces of the hydrothermal system; one specific aspect is the quantification of the different dissolved sulphurspecies in relation to primary bioproductivity.
- Europe (0.93)
- Oceania > Fiji > South Pacific Ocean (0.57)
- Geology > Geological Subdiscipline > Volcanology (1.00)
- Geology > Geological Subdiscipline > Geochemistry (0.95)
- Reservoir Description and Dynamics (0.88)
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (0.34)
- Health, Safety, Environment & Sustainability > Health > Noise, chemicals, and other workplace hazards (0.34)
ABSTRACT In the present paper a series of experiments devoted to analyse the shedding vortex system, arising from an unappended bare hull in large steady drift conditions, are presented. A Series 60 ship model (C8=0.6, length∼1.219 m) which conforms to the standard offset has been selected to be investigated in the doublemodel configuration, for the sake of free surface effect exclusion. Mean velocity measurements of the cross-flow in two transverse sections are performed by using LDV technique for Fn=0.2 and for a large yaw angle (35°) at Rn = 0.8 10. INTRODUCTION Ship-flow patterns depend on hull geometry and operating conditions such as speed, manoeuvring and sea-state conditions. Ships running in the straight-ahead condition in calm water generate symmetric flow patterns with respect to the hull centreplane (the so called «design condition>). But when the ship undergoes a rudder action, the hull is settled at incidence, the flow generated around the body drastically changes and an off-design condition does occur. In such case a typical strong vortex flow is generated and the shedding vorticity features are strictly related to the side force experienced by the manoeuvring hull. For low Froude numbers (Fn<0.2) the force system related to the generated wave pattern can be neglected and a double model configuration, deeply submersed, can be adopted to investigate the flow field behaviour. The aim of this paper is to present results concerned with the cross flow measurements of a Series 60 double model in large steady drift condition at 35° angle of attack at Rn = 0.8 10 6. The chosen incidence angle represent a typical large yaw angle in the so called «steady turning» phase of a turning circle manoeuvre and has been selected to highlight the turbulent strong crossflow characteristics that are present when the hull is settled at incidence.
- Production and Well Operations > Well & Reservoir Surveillance and Monitoring > Production logging (0.36)
- Reservoir Description and Dynamics (0.35)
ABSTRACT The development of an oilfield involves several aspects of engineering. These aspects are related with the field data and the operational environment such as drilling program, the sizing of the system that will support production and definition of oil and gas lift methods. Generally, design and planning of an oilfield development are based on maximization of oil recovery with operational and capital costs minimized. In the present paper, a systematic design and planning procedure to develop an offshore oilfield and to evaluate attractiveness of an oilfield is described. The present method considers the concept of design spiral to coordinate the several aspects of the development and hierarchical decision method to make necessary decisions. The design spiral method is largely applied in the literature for ship design purpose and the hierarchical decision was originally used in the field of economic planning. Finally, comparative study is made in order to evaluate the present method with those available in the literature. The main conclusion is that the offshore oilfield development needs a rational design and planning, and the present method is very suitable for this purpose. INTRODUCTION Recent technology developments for improving efficiency of offshore oilfield exploration and production should be one of reasons for the growth of worldwide hydrocarbon reserves. These oilfields are placed in very diversified environments and geographic locations in the world. They are affected by a large variety of environmental conditions, spreading from frozen regions as in the Arctic and severe seas as in the North Sea to ultra deep water in tropical seas as in Brazil and Gulf of Mexico. Then, a rational project development which maximizes oil and gas recovery of the oilfield at a minimum cost, in a systematic approach, appears as a key of success for hydrocarbon production business.
- South America > Brazil (0.89)
- Europe > United Kingdom > North Sea (0.24)
- Europe > Norway > North Sea (0.24)
- (2 more...)
- South America > Brazil > Rio de Janeiro > South Atlantic Ocean > Campos Basin > Marlim Field > Macae Formation (0.99)
- South America > Brazil > Rio de Janeiro > South Atlantic Ocean > Campos Basin > Marlim Field > Lago Feia Formation (0.99)
- South America > Brazil > Campos Basin (0.99)
- Well Drilling (1.00)
- Well Completion (1.00)
- Reservoir Description and Dynamics > Reserves Evaluation (1.00)
- (7 more...)
ABSTRACT Thermodynamically and mechanically ideal Stirling machines offer the greatest potential of any heat engine in terms of performance quality. This great potential has not been fully realised in practical designs but high performing Stifling machines have found a market in cryogenic and underwater power generation applications. In the latter case, over the last two decades, Stirling systems have been used, in a small 500 ton civilian manned research submarine and in medium-sized operational N~icken and Gotland class naval submarines of the Royal Swedish Navy, as auxiliary power units called Air Independent Propulsion systems (AIPs). Stirling systems have also been investigated for use as the main power units in smaller manned and unmanned autonomous underwater vehicles (AUVs) as well as diver propulsion devices/vehicles (DPD/Vs) and swimmer delivery vehicles (SDVs). In the post-Cold War environment the latter types of underwater vehicles are attracting increasing interest, particularly in the United States, as navies strive to develop the brown-water or littoral warfare capabilities necessary to prosecute operations in hostile coastal waters. Moreover, with offshore commercial oil and gas production moving into increasing deeper waters and other commercial and scientific ventures requiring AUVs of increasing endurance and under-ice capabilities there is a global interest in developing improved power systems for the new generation of underwater vehicles. The Stirling machine, with its proven record in the underwater environment, is an obvious candidate for such applications When their cycle of operations is reversed Stirling machines can be used not only to produce power but also to provide cooling, i.e. they can be refrigeration machines and excellent cryocoolers. Many of the emerging underwater technologies such as magnetohydrodynamics and superconducting machinery require cryogenic cooling facilities to operate effectively - as do many sensor systems and the Stirling cooling machines may have a role to play in such systems.
- North America > United States (1.00)
- Europe (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Government > Military > Navy (0.94)
- Government > Regional Government > North America Government > United States Government (0.68)
- North America > Canada > Alberta > Royal Field > Allied Et Al Royal Park 11-10-52-16 Well (0.89)
- Europe > Netherlands > German Basin (0.89)
- Europe > Germany > German Basin (0.89)
- Europe > Denmark > German Basin (0.89)
- Production and Well Operations (0.88)
- Reservoir Description and Dynamics > Non-Traditional Resources > Geothermal resources (0.49)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems > Remotely operated vehicles (0.34)
ABSTRACT An assessment program for simulating the tidal flow and ecosystem in the sea around a very large floating structure or a Mega- Float, developed in the first phase of the Mega-Float project in Japan is presented. The model consists of two parts, a hydrodynamic model and a marine ecosystem. Tidal currents, water temperature, salinity and water density are calculated in a bay with/without a Mega-Float in the hydrodynamic model. A marine ecosystem model including nutrients, phytoplankton, zooplankton and organic matters has developed in detail. Simulation results with/without a Mega-Float of 4.75 km length, 1.5 km breadth and 1.2 m draft are presented in Tokyo Bay. Changes of marine environmental factors by the installation of the Mega- Float are studied for some configurations of a Mega-Float and breakwater. Lastly, some potential technologies for the environmental preservation and restoration are studied. 1 INTRODUCTION Predicting the marine environment changes caused by installation of a Very Large Floating Structure or a Meg.-Float is one of the technical challenges in introducing a Mega-Float into practical use. It has been known that the marine environment such as flow and ecosystem shows complicated changes due to a various natural conditions. So that on prediction of the environmental changes caused by installation of Mega-Float with precision, it is well recognized that the prediction of ecosystem changes including low-level planktons, organic matters and nutrients must be done after the prediction of 3-dimentioanl flow changes including wind driven current and density current due to thermal and salinity concentrations changes. In "An experimental Research of Very Large Floating Structure" by Technological Research Association of Mega-Float launched in 1995, researchers have been conducted studies taking these matters into account. It has been revealed through numeral calculations that the Mega-Float is expected to affect on the flow slightly 1)2).
- Reservoir Description and Dynamics (1.00)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems (1.00)
- Production and Well Operations > Well & Reservoir Surveillance and Monitoring > Production logging (0.47)
ABSTRACT A unique temporary foundation system, which combined skirted mudmats with an air lift system, was used during the installation of two fixed offshore platforms. The skirts on the mudmats allowed the use of active suction to penetrate the mats. To optimize simplicity, reliability, and cost, water removal from inside the mudmats was achieved through the careful design of an air lift system using oil well gas lift technology. This skirted mudmat system has numerous advantages: it improves on-bottom stability of the structure, allows for a controlled initial penetration of the mudmats and provides a means to quickly and accurately level jackets. INTRODUCTION The Amoco Trinidad Mahogany "A" and "B" platforms are conventional 4 leg jacket structures with 4 skirt piles and are currently in place in the Atlantic Ocean approximately 50 miles (31 km) off the East coast of the island of Trinidad in approximately 285 ft (86 m) of water (Fig. 1). A unique temporary foundation system was utilized during the installation of these structures. This system provided a relatively high level of jacket on-bottom stability and permitted jacket leveling operations to take place at any time between jacket set down and the start of pile to sleeve grouting operations. Jacket leveling operations were accomplished with minimal installation vessel critical time and without hook assistance from the installation vessel. This system and its performance are discussed below. Platform Description Figure 2 shows two elevation views of the Mahogany "B" platform. The lift-installed jacket has mudline plan dimensions of approximately 100 x 100 ft (30 m x 30 m) while the top of the jacket is 50 x 100 ft (15 m x 30 m). The four main jacket legs are approximately 60 in. (1.52 m) in diameter. The topsides lift weight was approximately 3000 short tons (2700 tonnes).
- North America > United States (0.29)
- North America > Trinidad and Tobago > Trinidad (0.24)
ABSTRACT The fundamental concept behind the constant rate of strain consolidation (CRS) test is the application of strain at a constant velocity on clayey soil specimen to the consolidation process. A moving finite difference (MFD) solution of a generalized finite theory has been derived for analyzing the results of CRS tests. Then the equation is applied to the test results of isotropic consolidation and CRS tests to obtain specific time factor, and also the coefficients of consolidation are calculated. It is concluded that the selected rate of strain 0.04 % per minute is suitable for the tested clayey soil specimen which are suggested by ASTM- D4186–82 (1983). INTRODUCTION For design of a slurred mineral waste retention is located near seashore, west of kaohusing fish harbor, kaohusing city, Taiwan. The one-dimensional consolidation theories developed by Gibson, et al., (1967 and 1981) have been verified to predict the consolidation behavior of soft or very soft clays more accurately than Terzaghi consolidation theory (1943). A generalized finite consolidation theory is first investigated in this study. Conventional one-dimensional and isotropic consolidation tests are widely used so-called standard methods for measuing coefficients of consolidation. But, these two types of tests on too time-consuming and test procedures may induce enormous errors (Znidarcic, et al 1986). The constant rate of strain (CRS) test (Crawford, 1988 and Smith, RE. et al 1969) was modified for improving these drawbacks. The generalized finite consolidation theory is now applied the results of CRS tests and how to select a suitable strain rate from CRS tests was also involved in this study. GENERALIZED FINITE CONSOLIDATION THEORY Lagrangian Point of View For incorporating the finite strain condition, the undefomed specimen is described by the Lagrangian coordinate; while the deformed specimen is described by the connective coordinate.
- North America > United States (0.28)
- Asia > Taiwan (0.25)
- Production and Well Operations > Well & Reservoir Surveillance and Monitoring (0.91)
- Reservoir Description and Dynamics > Reservoir Fluid Dynamics > Flow in porous media (0.47)
ABSTRACT The production of gas pipelines with high strength and toughness level for offshore application, with or without resistance against sour gas, demands sophisticated product oriented facilities not only for the plate and pipe manufacturer but also for the installation companies. The equipment and the processing know-how have to be exploited to achieve the complete property profile specified for the linepipe. Based on intensive development work for each processing step, the plate mill is using optimized variants of the Thermo-Mechanical Control Process (TMCP) to achieve the appropriate microstructure and properties without costintensive alloying to assure good weldability. In addition the pipemill requires stringent plate tolerances to match its advanced forming methods and sophisticated welding techniques to complete the product. The decisive elements of the metallurgical approach are low carbon chemistry with well defined usage of microalloying elements, good reproducibility of a high level of cleanliness and homogeneity of microstructure. Some significant sweet and sour gas pipeline projects within a range of wall-thickness from 14.2 to 36.5 mm from the recent years are presented. Statistical Results are reported from the projects Interconnector, Norfra, Eldfisk, Asgard, BP-Etap, and South-Arne- Hydro. THE PIPELINE PROJECTS AND THE MANUFACTURING CHALLENGES During the recent years many new oil- and gasfields have been developed. The customers want a pipeline on the seabed operating up to 3 5 years. Three major challenges have to be met:"High pressure", internal from the gas or external from the water pressure, depending of the depth. This leads to a requirement for a steel with high strength and high toughness. "The gas- or oil-composition" leads to a requirement for a sweet or sour service steel. Duplex or Inconel have not been considered due to the very high tonnages required in long pipelines, which makes these materials less economic.
- Production and Well Operations > Production Chemistry, Metallurgy and Biology > Corrosion inhibition and management (including H2S and CO2) (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers (1.00)
- Health, Safety, Environment & Sustainability > Health > Noise, chemicals, and other workplace hazards (0.92)
INTRODUCTION According to petroleum scientists, the Caspian Sea region contains the third largest reserve of oil and natural gas in the world, behind the Gulf region and Siberia. Drilling for oil in the region is not recent. Oil derricks dotted the landscape during the latter decades of the nineteenth central. Oil was a major source of hard currency for the former Soviet Union, but the drilling methods were technologically less efficient compared with western finns when it came to large-scale oil exploration. This restricted Soviet exploration in the Caspian region. When the Soviet Union implemented perestroika and glastnost in the mid 1980s, its oil exploration sector was ready to implement the benefits from the west. The breakup of the Soviet Union, however, put a hold on these plans, as several nations emerged in the former Soviet lands around the Caspian Sea. The major issue regarding oil exploration in the region is a question of how best to deliver the oil to world markets. The Caspian sea area is landlocked, thus pipelines are required. The exact routes of such pipelines are as of yet undecided, and may prove to be a very important factor in determining the ultimate success of oil exploration in the region. AZERBAIJANIAN OIL The necessity of increasing oil and gas extraction to overcome the economic difficulties appeared after gaining independence. The government of the republic then concluded that it is necessary to attract foreign companies to invest in this branch [2]. The recoverable reserves of the Chirag, Azeri and deep water Gunahsli oil fields amount to approximately 4 billion barrels. The fields are located 90 kilometers offshore, south-east of Baku in water depths of 120 to 400 meters, the potential field sizes are large by international standards.
- Asia > Azerbaijan > Caspian Sea > Apsheron-Pribalkhan Ridge > South Caspian Basin > Azeri-Chirag-Guneshli Field > Chirag Field (0.99)
- Asia > Kazakhstan (0.96)
- Production and Well Operations (1.00)
- Facilities Design, Construction and Operation > Pipelines, Flowlines and Risers (1.00)
- Facilities Design, Construction and Operation > Offshore Facilities and Subsea Systems > Mooring systems (0.46)