The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform
Lizhong Wang - One of the best experts on this subject based on the ideXlab platform.
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Behavior of Installation for Suction Anchor in Soft Clay
29th International Conference on Ocean Offshore and Arctic Engineering: Volume 1, 2010Co-Authors: Heng-jun Dai, Lizhong WangAbstract:Suction anchor foundations are being increasingly used for a variety of Offshore Application. In designing a suction anchor geotechnical engineering must consider the installation process as well as the in-place performance. The main objective of the present study was to investigate the penetration behavior of the suction anchor in normally consolidated and sensitive clay. Numerical analyses are preformed to study the installation by suction in soft clay. The effects of the penetration depth, the shear strength ratio along the interface between the anchor and the clay on the installation process on the failure mechanism and the pattern of soil flow at the anchor tip during installation are discussed in detail. The shear strength reduction factor is the key factor of the installation procedure, and it has a strong effect on the limited installable aspect ratio. The displacement vectors show that the clay beneath the anchor tip will move up inside the anchor when the anchor moves down while soils beneath the tip as well as soils outside the skirt wall also flow inward at the reverse bearing capacity failure. Finally, some conclusions are made, which can be useful in practice.
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behavior of installation for suction anchor in soft clay
ASME 2010 29th International Conference on Ocean Offshore and Arctic Engineering, 2010Co-Authors: Heng-jun Dai, Lizhong WangAbstract:Suction anchor foundations are being increasingly used for a variety of Offshore Application. In designing a suction anchor geotechnical engineering must consider the installation process as well as the in-place performance. The main objective of the present study was to investigate the penetration behavior of the suction anchor in normally consolidated and sensitive clay. Numerical analyses are preformed to study the installation by suction in soft clay. The effects of the penetration depth, the shear strength ratio along the interface between the anchor and the clay on the installation process on the failure mechanism and the pattern of soil flow at the anchor tip during installation are discussed in detail. The shear strength reduction factor is the key factor of the installation procedure, and it has a strong effect on the limited installable aspect ratio. The displacement vectors show that the clay beneath the anchor tip will move up inside the anchor when the anchor moves down while soils beneath the tip as well as soils outside the skirt wall also flow inward at the reverse bearing capacity failure. Finally, some conclusions are made, which can be useful in practice.Copyright © 2010 by ASME
Heng-jun Dai - One of the best experts on this subject based on the ideXlab platform.
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Behavior of Installation for Suction Anchor in Soft Clay
29th International Conference on Ocean Offshore and Arctic Engineering: Volume 1, 2010Co-Authors: Heng-jun Dai, Lizhong WangAbstract:Suction anchor foundations are being increasingly used for a variety of Offshore Application. In designing a suction anchor geotechnical engineering must consider the installation process as well as the in-place performance. The main objective of the present study was to investigate the penetration behavior of the suction anchor in normally consolidated and sensitive clay. Numerical analyses are preformed to study the installation by suction in soft clay. The effects of the penetration depth, the shear strength ratio along the interface between the anchor and the clay on the installation process on the failure mechanism and the pattern of soil flow at the anchor tip during installation are discussed in detail. The shear strength reduction factor is the key factor of the installation procedure, and it has a strong effect on the limited installable aspect ratio. The displacement vectors show that the clay beneath the anchor tip will move up inside the anchor when the anchor moves down while soils beneath the tip as well as soils outside the skirt wall also flow inward at the reverse bearing capacity failure. Finally, some conclusions are made, which can be useful in practice.
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behavior of installation for suction anchor in soft clay
ASME 2010 29th International Conference on Ocean Offshore and Arctic Engineering, 2010Co-Authors: Heng-jun Dai, Lizhong WangAbstract:Suction anchor foundations are being increasingly used for a variety of Offshore Application. In designing a suction anchor geotechnical engineering must consider the installation process as well as the in-place performance. The main objective of the present study was to investigate the penetration behavior of the suction anchor in normally consolidated and sensitive clay. Numerical analyses are preformed to study the installation by suction in soft clay. The effects of the penetration depth, the shear strength ratio along the interface between the anchor and the clay on the installation process on the failure mechanism and the pattern of soil flow at the anchor tip during installation are discussed in detail. The shear strength reduction factor is the key factor of the installation procedure, and it has a strong effect on the limited installable aspect ratio. The displacement vectors show that the clay beneath the anchor tip will move up inside the anchor when the anchor moves down while soils beneath the tip as well as soils outside the skirt wall also flow inward at the reverse bearing capacity failure. Finally, some conclusions are made, which can be useful in practice.Copyright © 2010 by ASME
Pan Sang Kang - One of the best experts on this subject based on the ideXlab platform.
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Screening Criteria and Considerations of Offshore Enhanced Oil Recovery
Energies, 2016Co-Authors: Pan Sang KangAbstract:The Application of enhanced oil recovery (EOR) in Offshore oil fields has received significant attention due to the potentially enormous amount of recoverable oil. However, EOR Application Offshore is in its very early stage due to conditions that are more complex than onshore oil fields, owing to the unique parameters present Offshore. Therefore, successful EOR Applications in Offshore oil fields require different screening criteria than those for conventional onshore Applications. A comprehensive database for onshore Applications of EOR processes together with a limited Offshore EOR Application database are analyzed in this paper, and the important parameters for successful Offshore Application are incorporated into the new EOR screening criteria. In this paper, screening criteria to determine acceptable EOR processes for Offshore fields, including hydrocarbon gas miscible, CO 2 miscible, and polymer processes, are presented. Suggested screening criteria for these EOR processes comprise quantitative boundaries and qualitative considerations. Quantitative screening criteria are predominantly based on quantifiable data, such as oil and reservoir properties. Qualitative screening considerations mainly focus on the operational issues present Offshore, including platform space constraints, limited disposal options, injectant availability, and flow assurance matters (including hydrate formation and difficulties in emulsion separation).
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Integrated Screening Criteria for Offshore Application of Enhanced Oil Recovery
All Days, 2014Co-Authors: Pan Sang Kang, Jong-se Lim, Chun HuhAbstract:Abstract Recently, Enhanced Oil Recovery (EOR) Application in Offshore oil fields is receiving significant attention. The size of targeted Offshore oil fields is generally large, because their Original-Oil-In-Place (OOIP) should be sufficiently large to overcome the high cost of Offshore oil field development. Therefore, the amount of recoverable oil using EOR may be enormous. The risks of applying EOR are lower than the exploration for deep-water oil, because EOR except for thermal EOR is usually applied to the already producing oil fields. Because of the above reasons, Offshore EOR Application has been considered as a highly acceptable option. However, Application conditions for Offshore oil fields are more complex than onshore oil fields due to the unique parameters present in Offshore fields. Therefore, successful EOR Application in an Offshore oil field requires screening criteria that are different from the conventional onshore screening criteria. A comprehensive database for onshore Applications of EOR processes, together with a limited Offshore EOR Application database, are analyzed in this paper; and the important parameters for successful Offshore Application are incorporated into the new EOR screening criteria. In this paper, screening criteria for highly acceptable EOR processes in Offshore fields including hydrocarbon (HC) gas miscible, CO2 miscible and polymer are presented. Gas EOR using produced hydrocarbon gas has high potential for light oil recovery in Offshore fields because of high availability of injectant and its reduced handling cost. For medium oil and even heavier oil recovery, polymer process is highly acceptable because it is a well proven technology by the earlier onshore and even Offshore Applications. CO2 miscible process has been proven as a successful technology worldwide, mainly in onshore fields. In many cases, minimum miscibility pressure of CO2 is lower than hydrocarbon gas; hence, the CO2 miscible process has a wider range of field candidates. In view of the current active interests in seeking synergy between CO2 storage and the high efficiency of the CO2-based oil recovery, this process has high potential for Offshore EOR Application if CO2 can be available economically. Suggested screening criteria for these EOR processes comprise quantitative boundary and qualitative considerations. Quantitative screening criteria are mostly based on quantifiable data including oil and reservoir properties. Most screening criteria suggested in this paper are generally similar to those previously suggested. Due to the recent significant polymer development efforts and their active Applications, however, the difference for oil viscosity criteria in the polymer process is relatively large. There is a high potential for further criteria extension in the polymer process. Qualitative screening considerations mainly focuses on operational issues present in Offshore including limited space on the platform, limited disposal option, injectant availability and flow assurance matters (mainly hydrate formation and difficulty in emulsion separation). These considerations are very hard to be quantified and highly depend on operational limitation of each EOR process in specific fields. However, it is found that economical availability of injectant is most critical parameter in early stage of EOR screening.
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Screening criteria for Application of EOR processes in Offshore fields
2014Co-Authors: Pan Sang Kang, Jong-se Lim, Chun HuhAbstract:Comprehensive onshore and limited Offshore Application databases of EOR (Enhanced Oil Recovery) processes were analyzed; and successful Offshore Applications were incorporated into the new EOR screening criteria. Water-Alternating-Gas (WAG), hydrocarbon miscible, polymer, immiscible gas, and carbon dioxide (CO2) miscible processes can be successfully implemented in Offshore fields and the screening criteria for each of these processes are discussed in this paper. With the rapidly increasing, current interests in applying EOR to huge remaining reserves in Offshore fields, the refined screening criteria should be useful for the initial EOR feasibility studies.
Helen C.m. Smith - One of the best experts on this subject based on the ideXlab platform.
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novel Offshore Application of photovoltaics in comparison to conventional marine renewable energy technologies
Renewable Energy, 2013Co-Authors: Kim Trapani, Dean L Millar, Helen C.m. SmithAbstract:An original proposal for the deployment of photovoltaic (PV) systems in Offshore environments is presented in this paper. Crystalline PV panels are considered where they are deployed on pontoon type structures and there are six case study examples precedent practise of such deployments in lakes and reservoirs (but not seas). The authors put forward an alternative based on flexible thin film PV that floats directly on the waterline. The paper then concentrates on the techno-economic appraisal of Offshore PV systems in comparison to conventional marine renewable energy technologies. The difficulties of comparing Offshore technology projects developed in various countries, using different currencies and in different years are overcome so that such comparisons are made on an equitable basis. The discounted cost of electricity generated by each scheme is determined, including capital expenditure (CAPEX) and yearly operation and maintenance (O&M) costs.
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novel Offshore Application of photovoltaics in comparison to conventional marine renewable energy technologies
Renewable Energy, 2013Co-Authors: Kim Trapani, Dean L Millar, Helen C.m. SmithAbstract:Abstract An original proposal for the deployment of photovoltaic (PV) systems in Offshore environments is presented in this paper. Crystalline PV panels are considered where they are deployed on pontoon type structures and there are six case study examples precedent practise of such deployments in lakes and reservoirs (but not seas). The authors put forward an alternative based on flexible thin film PV that floats directly on the waterline. The paper then concentrates on the techno-economic appraisal of Offshore PV systems in comparison to conventional marine renewable energy technologies. The difficulties of comparing Offshore technology projects developed in various countries, using different currencies and in different years are overcome so that such comparisons are made on an equitable basis. The discounted cost of electricity generated by each scheme is determined, including capital expenditure (CAPEX) and yearly operation and maintenance (O&M) costs. Actual wind, tidal (current turbines and barrages) and wave projects were considered in the analysis alongside crystalline and thin film PV. Thin film PV was found to be economically competitive with Offshore wind energy projects for latitudes ranging from 45°N to 45°S. The specific yield, assessed in terms of GWh/km 2 was higher for thin film PV than for wind, wave and tidal barrage systems. In addition the specific installed capacity, expressed in MW/km 2 was also higher than the other conventional technologies considered (excluding tidal current turbines).
Kim Trapani - One of the best experts on this subject based on the ideXlab platform.
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novel Offshore Application of photovoltaics in comparison to conventional marine renewable energy technologies
Renewable Energy, 2013Co-Authors: Kim Trapani, Dean L Millar, Helen C.m. SmithAbstract:An original proposal for the deployment of photovoltaic (PV) systems in Offshore environments is presented in this paper. Crystalline PV panels are considered where they are deployed on pontoon type structures and there are six case study examples precedent practise of such deployments in lakes and reservoirs (but not seas). The authors put forward an alternative based on flexible thin film PV that floats directly on the waterline. The paper then concentrates on the techno-economic appraisal of Offshore PV systems in comparison to conventional marine renewable energy technologies. The difficulties of comparing Offshore technology projects developed in various countries, using different currencies and in different years are overcome so that such comparisons are made on an equitable basis. The discounted cost of electricity generated by each scheme is determined, including capital expenditure (CAPEX) and yearly operation and maintenance (O&M) costs.
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novel Offshore Application of photovoltaics in comparison to conventional marine renewable energy technologies
Renewable Energy, 2013Co-Authors: Kim Trapani, Dean L Millar, Helen C.m. SmithAbstract:Abstract An original proposal for the deployment of photovoltaic (PV) systems in Offshore environments is presented in this paper. Crystalline PV panels are considered where they are deployed on pontoon type structures and there are six case study examples precedent practise of such deployments in lakes and reservoirs (but not seas). The authors put forward an alternative based on flexible thin film PV that floats directly on the waterline. The paper then concentrates on the techno-economic appraisal of Offshore PV systems in comparison to conventional marine renewable energy technologies. The difficulties of comparing Offshore technology projects developed in various countries, using different currencies and in different years are overcome so that such comparisons are made on an equitable basis. The discounted cost of electricity generated by each scheme is determined, including capital expenditure (CAPEX) and yearly operation and maintenance (O&M) costs. Actual wind, tidal (current turbines and barrages) and wave projects were considered in the analysis alongside crystalline and thin film PV. Thin film PV was found to be economically competitive with Offshore wind energy projects for latitudes ranging from 45°N to 45°S. The specific yield, assessed in terms of GWh/km 2 was higher for thin film PV than for wind, wave and tidal barrage systems. In addition the specific installed capacity, expressed in MW/km 2 was also higher than the other conventional technologies considered (excluding tidal current turbines).
