WorldWideScience

Sample records for carbonate platform offshore

  1. Carbonate platform growth and demise offshore Central Vietnam

    DEFF Research Database (Denmark)

    Fyhn, Michael B.W.; Boldreel, Lars Ole; Nielsen, Lars H.;

    2013-01-01

    . East of the fault zone, the Triton Carbonate Platform was also initiated during the Early Miocene. Carbonate growth thrived during Early and part of Middle Miocene time and a thick, clean Lower and Middle Miocene carbonate succession cover the Triton Horst and the Qui Nhon Ridge. During the Middle......Miocene carbonate platforms cover a large part of the Central Vietnamese South China Sea margin. Early carbonate deposition took place on two regional platforms separated by a narrow depression developed along the trace of the East Vietnam Boundary Fault Zone. West of the East Vietnam Boundary...... Fault Zone, the Tuy Hoa Carbonate Platform fringes the continental margin between Da Nang and Nha Trang. Here, platform growth initiated during the Early Miocene and continued until Middle Miocene time when regional uplift led to subaerial exposure, termination of platform growth and karstification...

  2. Radiographic inspection on offshore platforms

    International Nuclear Information System (INIS)

    One of the great challenges for non-destructive inspection is on offshore platforms, where safety is a critical issue. Inspection by gammagraphy is practically forbidden on the platform deck due to problems to personnel safety and radiological protection. Ir-192 sources are used and the risk of an accident with loss of radioisotope must be considered. It is unfeasible to use gammagraphy, because in case of an accident the rapid evacuation from the platform would be impossible. This problem does not occur when X-ray equipment is used as the radiation source. The limited practicality and portability of the X-ray equipment have prevented its use as a replacement for the gammagraphy. This paper presents the preliminary tests to see the viable use of radiographic tests with constant potential on offshore platforms. (author). 2 refs., 1 fig., 2 tabs, 3 photos

  3. New offshore platform in the Mexican Gulf

    Energy Technology Data Exchange (ETDEWEB)

    Beisel, T.

    1982-04-01

    After a construction period of only 10 months, the second steel Offshore platform was recently completed in the Mexican Gulf. The pattern for this structure was the Cognac platform. The erection of the new platform, called the 'Cerveza' platform, is described in the article.

  4. An Experimental Study of an Offshore Platform

    DEFF Research Database (Denmark)

    Brincker, Rune; Asmussen, John Christian; Andersen, Palle; Kirkegaard, Poul Henning

    This report describes the results of an analysis of the ambient response data collected from a Venezuelan near-shore offshore platform constructed in 1992. Recording of the data have been constantly done during the period from May 1993 to July 1994. Using these data the structural integrity of the...... multi-pile offshore platform is investigated by using a vibration based damage detection scheme. Changes in structural integrity are assumed to be reflected in the modal parameters estimated from only output data using an Auto-Regressive Moving Average (ARMA) model. Before the calibration of the ARMA...... model the quality of the measured data have been investigated. The estimated modal parameters and their corresponding variances are used as input to a probability based damage indicator. This indicator indicates, that since the construction of the platform, minor structural changes have taken place....

  5. Analysis of offshore jacket platform

    Digital Repository Service at National Institute of Oceanography (India)

    Harish, N.; Mandal, S.; Shanthala, B.; Rao, S.

    forces. The complex dynamic behavior of the platform to the environmental loads makes in difficult to calculate exactly the dynamic responses. The present need of the industry is to have a time saving and accurate calculation methods, which can be in good...

  6. Offshore Wind Park Connection to an HVDC Platform, without using an AC Collector Platform

    OpenAIRE

    Ahmad, Haseeb

    2012-01-01

    This thesis investigates the comparison between two different alternating current topologies of an offshore wind farms connection to an offshore high voltage direct current (HVDC) converter platform. The offshore high voltage direct current converter platform converts alternating current into direct current. Two different topologies will be investigated. In the first topology, the offshore wind farms are connected to an HVDC converter platform through offshore AC collector platform. An offsho...

  7. Wind tunnel model testing of offshore platforms

    OpenAIRE

    Abrahamsen, Ida Sinnes

    2012-01-01

    The purpose of this thesis is to highlight some of the areas of interest when it comes to wind tunnel experimenting of offshore platforms regarding stability concerns such as critical angles and wind overturning moment. Some important factors include design of tower geometry, the effect of surface roughness on drag, methods of calculating blockage corrections of wall interference and the generation of an atmospheric boundary layer to resemble full-scale conditions. Data obtained from wind tun...

  8. Psychosocial burden among offshore drilling platform employees.

    Science.gov (United States)

    Leszczyńska, Irena; Jeżewska, Maria

    2010-01-01

    Conditions of work on offshore drilling platforms are particularly hard due to extreme environmental situations created both by nature and technological processes. Oil drilling workers employed on the open sea are potentially exposed to permanently high stress. Apart from the obvious objective factors affecting drilling platform employees, a great role in the general work-related stress level is played by the working conditions and work-related psychosocial factors, defined according to Karask's concept as demands, control, and social support. A total of 184 drill platform workers were examined using objective and subjective research methods. The level of subjective stress among drilling platform workers is lower than the level of objective stress and the stress resulting from prognoses related with specificity of work in extremely hard conditions (audit). The examinations of drilling platform workers reveal a positive role of stress in psychological adaptation, being a special case of the "work ethos" and attachment to the firm. In such investigations of work-related stress on drilling platforms, which are very specific workplaces, a multi-aspect character, sociological and economic aspects, organizational culture conditions in the firm, and a tendency to conceal ailments and the stress experienced should be taken into account. It is important to apply measures referring to at least three different types of evidence (objective demands, subjective stress, health problems reported). Otherwise, the result reflecting work-related stress may not be objective and far from the truth. PMID:21154303

  9. AMS-14C measurements for the carbonate platform of the offshore Campos Basin, Rio de Janeiro State, Brazil

    International Nuclear Information System (INIS)

    As part of our accelerator mass spectrometry (AMS) program in Brazil we prepared and measured some red algae carbonate crust samples from Campos Basin, Rio de Janeiro, Brazil. The measurements were performed at Purdue Rare Isotope Measurement Laboratory (PRIME Lab), Purdue University, IN, USA. This carbonate material is interlaminated with foraminiferal lime mud reflecting recurrent intervals of carbonate development, which might be linked to outer-shelf oceanographic circulation

  10. Wireless sensing experiments for structural vibration monitoring of offshore platform

    Institute of Scientific and Technical Information of China (English)

    Yan YU; Jinping OU

    2008-01-01

    In order to validate the feasibility of applying wireless sensing technique to structural monitoring of offshore platform,the experiment of wireless sensor network on offshore platform is presented in this paper.First,wireless sensor network and its topology structure is put forward,and the design of sensor nodes,base station,communication protocol is discussed according to selfdeveloped wireless sensor network.Second,true offshore platform and its experimental model are introduced.Finally,wireless sensing experiment for offshore platform structure is completed and the analysis of the experimental result is given.The research shows that wireless sensor network applied to offshore platform can reflect the vibration of the structure;the sensor nodes are fixed and removed expediently,which saves the cost of signal line as well as installation time.

  11. Waste heat recovery technologies for offshore platforms

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Benato, Alberto; Scolari, E.; Haglind, Fredrik; Stoppato, Anna

    2014-01-01

    to attain optimal designs for each bottoming unit by selecting specific functions tailored to the oil and gas sector, i.e. yearly CO2 emissions, weight and economic revenue. The test case is the gas turbine-based power system serving an offshore platform in the North Sea. Results indicate that the...... expander and of the primary heat exchanger, organic Rankine cycle turbogenerators appear thus to be the preferred solution to abate CO2 emissions and pollutants on oil and gas facilities. As a practical consequence, this paper provides guidelines for the design of high-efficiency, cost-competitive and low...... organic Rankine cycle technology presents larger performances compared to steam Rankine cycle units, whereas the implementation of air bottoming cycle modules is not attractive from an economic and environmental perspective compared to the other two technologies. Despite the relatively high cost of the...

  12. Fuzzy Control of Structural Vibration for Offshore Platforms

    Institute of Scientific and Technical Information of China (English)

    ZHOUYa-jun; ZHAODe-you

    2004-01-01

    During the past three decades, fuzzy logic feedback control systems have been utilized for the suppression of structural vibration in numerous studies. With the main advantages of the fuzzy controller, the inherent robustness and ability to handle nonlinearity, uncertainty and imprecision of the structure, active structural control of offshore platforms is accomplished. The robustness of the controller has been demonstrated through the uncertainty in damping ratios of the platforms. The study suggests that the proposed fuzzy control algorithm of structural vibration for offshore platforms is effective and feasible,thus improving both serviceability and survival. This present method undoubtedly provides an efficient way of the active control for offshore platforms.

  13. Load Identification of Offshore Platform for Fatigue Life Estimation

    DEFF Research Database (Denmark)

    Perisic, Nevena; Kirkegaard, Poul Henning; Tygesen, Ulf T.

    -assessment of offshore platforms. Structural monitoring systems (SMSs) on offshore structures typically consist of a set of sensors such as strain gauges, accelerometers, wave radars and GPSs, however direct measuring of the actual loading is usually not feasible. One approach is to measure the loads indirectly...

  14. Methodology for development of risk indicators for offshore platforms

    International Nuclear Information System (INIS)

    This paper presents a generic methodology for development of risk indicators for petroleum installations and a specific set of risk indicators established for one offshore platform. The risk indicators should be used to control the risk during operation of platforms. The methodology is purely risk-based and the basis for development of risk indicators is the platform specific quantitative risk analysis (QRA). In order to identify high risk contributing factors, platform personnel are asked to assess whether and how much the risk influencing factors will change. A brief comparison of probabilistic safety assessment (PSA) for nuclear power plants and quantitative risk analysis (QRA) for petroleum platforms is also given. (au)

  15. Voltage margin control for offshore multi-use platform integration

    OpenAIRE

    Mier, V.; Casielles, P.G.; Koto, J.; Zeni, Lorenzo

    2012-01-01

    This paper discusses a multiterminal direct current (MTDC) connection proposed for integration of offshore multi-use platforms into continental grids. Voltage source converters (VSC) were selected for their suitability for multiterminal dc systems and for their flexibility in control. A five terminal VSC-MTDC which includes offshore generation, storage, loads and ac connection, was modeled and simulated in DigSILENT Power Factory software. Voltage margin method has been used for reliable oper...

  16. Modal Parameter Identification of Offshore Platforms under Ambient Excitation

    Institute of Scientific and Technical Information of China (English)

    Yang Hezhen(杨和振); Li Huajun

    2004-01-01

    This paper intends to identify the modal parameters of an offshore platform under ambient excitation, and to compare the identified results with theoretical solutions. Using ambient sources of excitation to determine the modal characteristics of large civil engineering structures is desirable for several reasons. The forced vibration testing of such structures generally requires a large amount of specialized equipment and makes the tests quite expensive. Also, an automated health monitoring system for a large civil structure will most likely use ambient excitation. The Eigensystem Realization Algorithm (ERA) is applied in conjunctied acceleration information. Finally, offshore platform numerical model gets output response data under ambient excitation. Simulated data from numerical model of an offshore platform under ambient excitation is used for the identification of the system. According to the comparison results, the proposed method is shown to be effective for modal parameter identification under ambient excitation.

  17. Offshore platform supplied by photovoltaic panels: Luna B

    Energy Technology Data Exchange (ETDEWEB)

    Boschi, S.; Vacca, A. (AGIP, Milan (Italy))

    1992-04-01

    AGIP (the Italian General Petroleum Company) currently operates about 60 offshore oil platforms in the Adriatic Sea. For the most part, these platforms, manned and remote controlled, receive their power supplies via cable from from on-shore facilities or by means of gas or diesel generator sets mounted on the rigs themselves. The unmanned platforms require about 400 Watts (continuous) of electrical power which can be supplied through the use of solar panels coupled with an auxiliary storage battery. However, these platforms also require additional power furnished by a gas driven generator set when maintenance crews are on board to perform their tasks. This generator can also be used to supply power in bad weather conditions. To illustrate the feasibility of the use of photovoltaic power supplies, this paper describes the key design, performance and operation features of the Luna B hybrid power supply system installed on an AGIP offshore platform located in the Ionian Sea about 10 km from Crotone.

  18. Modelling, analysis and optimisation of energy systems on offshore platforms

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van

    operating conditions, which results in poorer performance. The present thesis addresses the question of how offshore platforms should be modelled, analysed and optimised from an energy system perspective. The research challenges can be classified into three main areas: (i) the simulation and assessment of......Nowadays, the offshore production of oil and gas requires on-site processing, which includes operations such as separation, compression and purification. The offshore system undergoes variations of the petroleum production rates over the field life – it is therefore operated far from its nominal...... platforms, quantify the potentials for energy savings, and design more efficient conversion units. The findings show that the differences in the field and operating conditions directly impact the energy demand and performance profiles of these facilities. Most inefficiencies are associated with the...

  19. Issues in offshore platform research - Part 1: Semi-submersibles

    Science.gov (United States)

    Sharma, R.; Kim, Tae-Wan; Sha, O. P.; Misra, S. C.

    2010-09-01

    Availability of economic and efficient energy resources is crucial to a nation's development. Because of their low cost and advancement in drilling and exploration technologies, oil and gas based energy systems are the most widely used energy source throughout the world. The inexpensive oil and gas based energy systems are used for everything, i.e., from transportation of goods and people to the harvesting of crops for food. As the energy demand continues to rise, there is strong need for inexpensive energy solutions. An offshore platform is a large structure that is used to house workers and machinery needed to drill wells in the ocean bed, extract oil and/or natural gas, process the produced fluids, and ship or pipe them to shore. Depending on the circumstances, the offshore platform can be fixed (to the ocean floor) or can consist of an artificial island or can float. Semi-submersibles are used for various purposes in offshore and marine engineering, e.g. crane vessels, drilling vessels, tourist vessels, production platforms and accommodation facilities, etc. The challenges of deepwater drilling have further motivated the researchers to design optimum choices for semi-submersibles for a chosen operating depth. In our series of eight papers, we discuss the design and production aspects of all the types of offshore platforms. In the present part I, we present an introduction and critical analysis of semi-submersibles.

  20. The macrofouling on offshore platforms at Ravenna

    Energy Technology Data Exchange (ETDEWEB)

    Relini, G.; Tixi, F.; Relini, M.; Torchia, G. [Universita degli Studi di Genova-Istituto di Zoologia (Italy). Lab. di Biologia Marina e Ecologia Animale

    1998-12-31

    The fouling which settles on gas platform piles was studied using samples taken in 1993 from the PCWA and ANTARES platforms positioned, at 7 and 10.5 km from the shore respectively and on bottoms at 12 m and 14 m in the Adriatic Sea. For each platform a pile was chosen as representative of the macrofouling found on the whole platform. In March and September 1993 samples were obtained by scraping an area of 600 cm{sup 2} from three or four different aspects (North, East, South, West), at the same depth. Samples were taken at depths of 0.5, 5.5 and 12 m on PCWA and 0.5, 7 and 12 m on ANTARES. Photographs and video recordings taken over the whole length of the chosen pile were used for an additional description of the settlement. On both platforms the macrofouling was characterized by a dominance of mussels from sea surface to a depth of about 10m. Near the bottom of the bivalve Crassostrea gigas, barnacles, hydroids and serpulids were more important. The presence of the bryozoan Schizoporella errata (present only at ANTARES) and the zoanthid Epizoanthus arenaceus (present only at PCWA) were the main differences at this depth. The fouling, or mussel weights, of the two platforms were similar for the two seasons, even though the highest values were registered in September on PCWA (1m) with 1561.3 g/dm{sup 2}, of which 1553 g/dm{sup 2} comprised mussels. A comparison is drawn with a previous fouling experiment (which used one-year panels) carried out in 1975-76. (Author)

  1. Hybrid Analysis Approach for Stochastic Response of Offshore Jacket Platforms

    Institute of Scientific and Technical Information of China (English)

    金伟良; 郑忠双; 李海波; 张立

    2000-01-01

    The dynamic response of offshore platforms is more serious in hostile sea environment than in shallow sea. In this paper, a hybrid solution combined with analytical and numerical method is proposed to compute the stochastic response of fixed offshore platforms to random waves, considering wave-structure interaction and non-linear drag force. The simulation program includes two steps: the first step is the eigenanalysis aspects associated the structure and the second step is response estimation based on spectral equations. The eigenanalysis could be done through conventional finite element method conveniently and its natural frequency and mode shapes obtained. In the second part of the process, the solution of the offshore structural response is obtained by iteration of a series of coupled spectral equations. Considering the third-order term in the drag force, the evaluation of the three-fold convolution should be demanded for nonlinear stochastic response analysis. To demonstrate this method, a numerical analysis is carried out for both linear and non-linear platform motions. The final response spectra have the typical two peaks in agreement with reality, indicating that the hybrid method is effective and can be applied to offshore engineering.

  2. Offshore Minerals Management Platforms for the Gulf of Mexico (GOM), Geographic NAD83, MMS (2006) [platforms_mms_2006

    Data.gov (United States)

    Louisiana Geographic Information Center — Offshore Minerals Management Platforms for the Gulf of Mexico (GOM). Identifies the location of platforms in GOM. All platforms existing in the database are included.

  3. Voltage margin control for offshore multi-use platform integration

    DEFF Research Database (Denmark)

    Mier, V.; Casielles, P.G.; Koto, J.;

    This paper discusses a multiterminal direct current (MTDC) connection proposed for integration of offshore multi-use platforms into continental grids. Voltage source converters (VSC) were selected for their suitability for multiterminal dc systems and for their flexibility in control. A five...... terminal VSC-MTDC which includes offshore generation, storage, loads and ac connection, was modeled and simulated in DigSILENT Power Factory software. Voltage margin method has been used for reliable operation of the MTDC system without the need of fast communication. Simulation results show that the......, sell or store energy attending to the price in the electricity market....

  4. An Improved CHC Algorithm for Damage Diagnosis of Offshore Platforms

    Institute of Scientific and Technical Information of China (English)

    HUANG Weiping; WANG Xiaoyan

    2007-01-01

    An improved CHC algorithm is proposed in the paper and it could be used for the damage diagnosis of structures. It breaks the bottle neck of genetic algorithm in the damage diagnosis of large structures and takes a shorter time than the SGA (Standard Genetic Algorithm) in diagnosing structural damage with the same level of error. The case studies show that the algorithm is rapid in convergence and produces satisfactory results in diagnosing both fixed-end beams and jacket offshore platforms.

  5. Torsional Response of the Offshore Platform with TMD

    Institute of Scientific and Technical Information of China (English)

    江宜城; 唐家祥

    2001-01-01

    It is pointed out in this paper that the offshore platform could be controlled by means of the Tuned Mass Damper(TMD) if there is torsional vibration in the system. The effectiveness of the location of TMD is quantified with the helpof the response ratio between the peak responses of the system in the presence and in the absence of TMD. In addition,the parameters of frequency and damping ratio of TMD are optimized.

  6. Access Platforms for Offshore Wind Turbines Using Gratings

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Rasmussen, Michael R.

    2008-01-01

    The paper deals with forces generated by a stationary jet on different types of gratings and a solid plate. The force reduction factors for the different gratings compared to the solid plate mainly depend on the porosity of the gratings, but the geometry of the grating is also of some importance....... The derived reduction factors are expected to be applicable to design of offshore wind turbine access platforms with gratings where slamming also is an important factor....

  7. Damage Localization of Offshore Platforms Under Ambient Excitation

    Institute of Scientific and Technical Information of China (English)

    杨和振; 李华军; 王树青

    2003-01-01

    In this paper Nondestructive Damage Detection (NDD) for offshore platforms is investigated under operational conditions. As is known, there is no easy way to measure ambient excitation, so damage detection methods based on ambient excitation have become very vital for the Structural Health Monitoring (SHM) of offshore platforms. The modal parameters (natural frequencies, damping ratios and mode shapes) are identified from structural response data with the Natural Excitation Technique (NExT) in conjunction with the Eigensystem Realization Algorithm (ERA). A new method of damage detection is presented, which utilizes the invariance property of element modal strain energy. This method is to assign element modal strain energy to two parts, and defines two damage detection indicators. One is compression modal strain energy change ratio (CMSECR); the other is flexural modal strain energy change ratio (FMSECR). The present modal strain energy is obtained by incomplete modal shape and structural stiffness matrix. Structural health monitoring is thus accomplished via monitoring the elemental CMSECR and FMSECR. Several damage cases are simulated by an offshore platform numerical model, and presented to illustrate the utility of the proposed method. According to the damage localization results, the proposed method is shown to be effective and precise for complex structural damage detection.

  8. Dynamic behavior of offshore spar platforms under regular sea waves

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, A.K.; Jain, A.K. [Indian Inst. of Technology, Dept. of Civil Engineering, New Delhi (India)

    2003-03-01

    Many innovative floating offshore structures have been proposed for cost effectiveness of oil and gas exploration and production in water depths exceeding one thousand meters in recent years. One such type of platform is the offshore floating Spar platform. The Spar platform is modelled as a rigid body with six degrees-of-freedom, connected to the sea floor by multi-component catenary mooring lines, which are attached to the Spar platform at the fairleads. The response dependent stiffness matrix consists of two parts (a) the hydrostatics provide restoring force in heave, roll and pitch, (b) the mooring lines provide the restoring force which are represented here by nonlinear horizontal springs. A unidirectional regular wave model is used for computing the incident wave kinematics by Airy's wave theory and force by Morison's equation. The response analysis is performed in time domain to solve the dynamic behavior of the moored Spar platform as an integrated system using the iterative incremental Newmark's Beta approach. Numerical studies are conducted for sea state conditions with and without coupling of degrees-of-freedom. (Author)

  9. Evaluation of Global Positioning System Data for Offshore Platform Deformation

    Directory of Open Access Journals (Sweden)

    Abdul N. Matori

    2011-01-01

    Full Text Available Problem statement: Reservoir compaction and shallow gas migration phenomena may cause offshore platform to experience deformation which if happens excessively will affect their structural integrity. Approach: Hence it is crucial to monitor and quantify the magnitude of the deformation especially if they are not uniform throughout the platform structure. However since mostly the offshore platforms are few hundreds kilometers away from shore, the precise monitoring of their deformation is limited to very few sophisticated instruments, in which GPS technology is one of them albeit using very special GPS data processing technique such as Long Baseline Relative Positioning. Results: Using this technique and employing GPS data observed on one of PETRONAS own platform, Pulai, its deformation magnitude will be determined with various options such as number of reference stations used, configuration and their geographic location. This study presents initial deformation processing result using scientific software GAMIT/GLOBK and their analysis utilizing postfit nrms and chi-squared statistics. The result indicated that for the period of two months there was displacement as big as 0.0094 m with standard deviation of 0.0106 m. However following congruency statistical test using t-student distribution with 95% confidence level, indicated that this displacement is insignificance. Analysis of the output result with postfit nrms also indicated that the data were of good quality, the processing procedure was correct and the output for each processing epoch is internally and externally consistent. Conclusion/Recommendations: It could be concluded with correct data processing strategy GPS data could be used to determine deformation magnitude which consequently could be utilized as input to assess structural integrity of an offshore platform.

  10. Application of Risk Probability Evaluation Method to Offshore Platform Construction

    Institute of Scientific and Technical Information of China (English)

    YU Jianxing; TAN Zhendong

    2005-01-01

    Offshore project risk concerns many influence factors with complex relationship, and traditional methods cannot be used for the evaluation on risk probability. To deal with this problem, a new method was developed by the combination of improved technique for order preference by similarity ideal solution method, analytical hierarchy process method and the network response surface method. The risk probability was calculated by adopting network response surface analysis based on the state variable of a known event and its degree of membership.This quantification method was applied to an offshore platform project, Bonan oil and gas field project in Bohai Bay in June 2004.There were 7 sub-projects and each includes 4 risk factors.The values of 28 risk factors, ranging from 10-6 to 10-4, were achieved. This precision conforms to the international principle of as low as reasonably practically.The evaluation indicates that the values of comprehensive level of construction group and ability of technical personnel on the spot are relatively high among all risk factors, so these two factors should be paid more attention to in offshore platform construction.

  11. Orbital welding technology speeds riser construction of offshore platforms

    Energy Technology Data Exchange (ETDEWEB)

    Henon, B.K. (Arc Machines, Inc., Pacoima, CA (United States))

    1994-05-01

    Strategically situated adjacent to the North Sea oil fields, Haugesund Mekaniske Versted (HMV) has become one of Norway's leading construction yards for the oil and gas-related industry. In keeping with its leadership role in offshore construction, HMV has just completed its first project using advanced orbital GTA welding technology. The project, which was begun in August 1992 and completed in January 1993, was the construction of risers for the Draugen platform, owned by Shell Oil, and the Statfjord platform, owned by Statoil. The risers are the piping that extends from the well head on the seabed up to the platform hull. This hull is supported above the water level by concrete towers. This paper discusses the welding equipment used and the weld procedure qualifications.

  12. Damage Localization of an Offshore Platform considering Temperature Variations

    Directory of Open Access Journals (Sweden)

    Shuqing Wang

    2015-01-01

    Full Text Available Modal parameters are sensitive indicators of structural damages. However, these modal parameters are sensitive not only to damage, but also to the environmental variations. Development of vibration based damage detection methodology which is robust to environmental variation is essentially important for the structural safety. The present paper utilizes a recently developed modal strain energy decomposition (MSED method to localize the damage of an offshore structure. A progress of the present paper is to take the temperature variation into consideration and Monte Carlo simulation is introduced to investigate the effect of temperature variation on the robustness of damage localization. Numerical study is conducted on an offshore platform structure considering the temperature variation. Several damage cases, including single and double damage scenarios, are included to investigate the damage localization algorithm. Results indicate that the MSED algorithm is able to detect the damage despite the temperature variations.

  13. Neural Network-Based Active Control for Offshore Platforms

    Institute of Scientific and Technical Information of China (English)

    周亚军; 赵德有

    2003-01-01

    A new active control scheme, based on neural network, for the suppression of oscillation in multiple-degree-of-freedom (MDOF) offshore platforms, is studied in this paper. With the main advantages of neural network, i.e. the inherent robustness, fault tolerance, and generalized capability of its parallel massive interconnection structure, the active structural control of offshore platforms under random waves is accomplished by use of the BP neural network model. The neural network is trained offline with the data generated from numerical analysis, and it simulates the process of Classical Linear Quadratic Regular Control for the platform under random waves. After the learning phase, the trained network has learned about the nonlinear dynamic behavior of the active control system, and is capable of predicting the active control forces of the next time steps. The results obtained show that the active control is feasible and effective, and it finally overcomes time delay owing to the robustness, fault tolerance, and generalized capability of artificial neural network.

  14. Offshore Platform Hydrocarbon Risk Assessment – OPHRA: Feasibility

    DEFF Research Database (Denmark)

    Duijm, Nijs Jan; Kozine, Igor; Markert, Frank

    and data needed for the risk assessment framework, and provides specific suggestions for some of those models. Some preliminary calculations with the DES model have been performed to illustrate type of results that can be obtained and to provide some insight in the accuracy and computational efforts......This report describes the feasibility demonstration of a new method to perform risk assessments for offshore platforms. This method simulates the following phenomena as concurrent sequences of events using the Arena® Discrete Event Simulation (DES) software (version 14.50.00): • Release, ignition....... Finally, further work is identified in order to develop an operational risk assessment tool....

  15. Minimising life cycle costs of automated valves in offshore platforms

    Energy Technology Data Exchange (ETDEWEB)

    Yli-Petays, Juha [Metso Automation do Brasil Ltda., Rio de Janeiro, RJ (Brazil); Niemela, Ismo [Metso Automation, Imatra (Finland)

    2012-07-01

    Automated process valves play an essential role in offshore platforms operation. If you are able to optimize their operation and maintenance activities you can receive extensive operational savings with minimal investment. Valves used in offshore platforms doesn't differentiate that much from the valves used in downstream but there are certain specialties, which makes the operations more challenging in offshore: Process valves are more difficult to access and maintain because of space limitations. Also spare part inventories and deliveries are challenging because of offshore platform's remote location. To overcome these challenges usage of digital positioners with diagnostic features has become more common because predictive maintenance capabilities enable possibilities to plan the maintenance activities and this way optimise the spare part orders regarding to valves. There are intelligent controllers available for control valves, automated on/off valves as well as ESD-valves and whole network of automated valves on platforms can be controlled by intelligent valve controllers. This creates many new opportunities in regards of optimized process performance or predictive maintenance point-of-view. By means of intelligent valve controllers and predictive diagnostics, condition monitoring and maintenance planning can also be performed remotely from an onshore location. Thus, intelligent valve controllers provide good way to minimize spending related to total cost of ownership of automated process valves. When purchase value of control valve represent 20% of TCO, intelligent positioner and predictive maintenance methods can enable as high as 30% savings over the life cycle of asset so basically it benefit savings higher than whole investment of monitored asset over its life cycle. This is mainly achieved through the optimized maintenance activities since real life examples has shown that with time based maintenance (preventive maintenance) approach 70% of

  16. Using decommissioned offshore oil/gas platforms for nuclear/RO desalination: the ONDP (Offshore Nuclear Desalination Platform)

    International Nuclear Information System (INIS)

    Oil platforms are manmade concrete and steel giant structures standing high on ocean floor weighing anywhere between 10,000 tonnes and 150,000 tonnes or more and designed to withstand cruel forces of nature, having an average life of 70 years. With the declining petrol reserves within next 30 years, hundreds of platforms will be scheduled for decommissioning. This issue is a hot topic as oil companies tussle with environmentalists and state lawmakers over the future. The cash strapped oil companies have a legal obligation to remove each rig entirely, returning the ocean floor to its original condition. Lean times in oil industry mean a tight cash flow. Safely removing massive structures from deep waters and shipping the pile to the shores for reuse and recycling presents a technological challenge for operators. Some conceptual applications investigated to reuse them are the conversion of offshore structures into fish farms, prisons, military outposts, hotels, for Search and Rescue operations or Centers for Waste Processing and Disposal. Decommissioning oil and gas installation is exorbitantly expensive. On an average, removing a complete platform with or without pipeline in sea waters with 'clean sea approach' costs $15 million to $ 6 billion depending on location. Global warming has adversely affected world climate. Water levels in ground and reservoirs have shown drastic decrement. In future there will be need for more and more water all over the world. Fossil fuel energy based desalination is expensive and not eco-friendly so is dismantling of oil platform with its pipeline. The oil platforms are far located from population, have sufficient tank capacity and pipeline structure to store and pump water to shore. When found economically unviable these mammoth structures with modifications can be installed with 02 or more small or medium sized nuclear reactors such as KLT 40S with required module to desalinate water and co generate electricity which can be sent to

  17. Evaluating alternatives for decommissioning California's offshore oil and gas platforms.

    Science.gov (United States)

    Bernstein, Brock B

    2015-10-01

    This paper introduces a series of 6 additional papers in this issue that describe an in-depth analysis of options for decommissioning oil and gas platforms offshore southern California. Although current leases require lessees in both state and federal waters to completely remove all production facilities and restore the seafloor to its pre-platform condition, other options have emerged since these leases were signed. Laws and regulations in other jurisdictions (particularly in federal waters) have evolved to allow a number of other uses such as aquaculture, alternative energy production, and artificial reefing. In response, the California Natural Resources Agency initiated an effort to investigate the issues associated with these and other decommissioning alternatives. The papers in this series are the result of the second phase in this process, a broad investigation of the engineering, economic, and environmental costs and benefits of the most feasible and likely options. In addition to the project's final report, the authors produced an interactive mathematical decision model, PLATFORM, that enables users to explore the implications of different decommissioning projects and options, as well as the effects of different approaches to valuing the associated costs and benefits. PMID:25914401

  18. PRA-1 offshore platform start-up within seven days; Operacionalizacao da plataforma offshore PRA-1 em sete dias

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Fernando; Mitidieri, Jorge; Faria, Jose Luis Coutinho de; Ribeiro, Juan Carlos; Moura, Mario Arthur [Construtora Norberto Oderbrecht S.A., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The technologic innovations are very hard features with regards to Offshore Engineering and Construction over the worldwide. The innovations only make sense since they are focus on the high productivity, safe job and cost reduction compared with the current technologies. Inside the scenario mentioned above is Construtora Norberto Odebrecht S.A. concept for the PRA-1 platform Engineering and Construction. Through a very advanced and innovation concept, it was defined as the Main Strategic Planning of the undertaking not use a temporary platform support (named in Brazil as 'Flotel') during the 'Hook-up', commissioning and star-up offshore phase. The success of the strategic made possible through the implementation of new engineering tools, and, besides this, through a very careful offshore planning focused on minimizing and make easier as much as possible the offshore activities. The planning can be basically spitted on the following parts: A- Onshore preparations (Assembly, Integration and Commissioning of the Utilities and Accommodation Modules) B- Offshore detailed planning of the critical activities concerning the start-up of the systems responsible for leaving the platform ready for 'live'. This operation was defined as 'seven days of platform live support' (main target of this paper). (author)

  19. Modeling and Simulation of Offshore Wind Power Platform for 5 MW Baseline NREL Turbine

    Directory of Open Access Journals (Sweden)

    Taufik Roni Sahroni

    2015-01-01

    Full Text Available This paper presents the modeling and simulation of offshore wind power platform for oil and gas companies. Wind energy has become the fastest growing renewable energy in the world and major gains in terms of energy generation are achievable when turbines are moved offshore. The objective of this project is to propose new design of an offshore wind power platform. Offshore wind turbine (OWT is composed of three main structures comprising the rotor/blades, the tower nacelle, and the supporting structure. The modeling analysis was focused on the nacelle and supporting structure. The completed final design was analyzed using finite element modeling tool ANSYS to obtain the structure’s response towards loading conditions and to ensure it complies with guidelines laid out by classification authority Det Norske Veritas. As a result, a new model of the offshore wind power platform for 5 MW Baseline NREL turbine was proposed.

  20. Evaluation of stress resultant of offshore jacket platform using neural network

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.; Hegde, G.; Gupta, K.G.

    . This paper deals with the prediction of stress resultant deflections of fixed offshore platform to the varying environmental loading conditions using neural networks. The manual estimation of stress resultant to the varying loading conditions involves tedious...

  1. Calibration of LRFD Format for Steel Jacket Offshore Platform in China Offshore Area (2): Load, Resistance and Load Combination Factors

    Institute of Scientific and Technical Information of China (English)

    ZHOU Dao-cheng; DUAN Zhong-dong; OU Jin-ping

    2006-01-01

    Adopting the load and resistance factor design format, the design method for steel jacket platform structures is developed. Firstly, the limit state equations and design format for steel jacket platform structures are introduced. Then, the ratio of live load effect to dead load effect is estimated. The target reliabilities for design of offshore structures in China offshore area are calibrated by past practice in API RP2A-WSD code. The load and resistance factors are optimized by minimizing the difference within the target reliability and the resulting reliability over the range of load effect ratios. Considering the concurrence of different loads, load combination factors are obtained through an optimization process, and the relation between the load combination factor and load correlation coefficient is established. Finally, the design formulae for steel jacket structures in China offshore area are recommended.

  2. Seismic Response Control of Offshore Platform Structures with Shape Memory Alloy Dampers

    Institute of Scientific and Technical Information of China (English)

    LI Hong-nan; HE Xiao-yu; HUO Lin-sheng

    2005-01-01

    In this study, the seismic response control of offshore platform structures with Shape Memory Alloy (SMA) dampers is investigated. A new SMA damper and its restoring force model are introduced for the calculation of seismic response reduction. Based on an actual platform structure and its mechanical model, the parameters which may affect the rate of shock absorption are analyzed, such as the number, position and characteristics of the SMA dampers andthe condition of the site where the platform is located. The results show that the SMA damper is an effective control device for offshore platforms and satisfactory control can be achieved by proper selection of the parameters.

  3. Air emissions associated with decommissioning California's offshore oil and gas platforms.

    Science.gov (United States)

    Cantle, Peter; Bernstein, Brock

    2015-10-01

    The 27 oil and gas platforms offshore southern California are nearing the end of their productive lives and will be decommissioned in the near future. Many are in deep water and are correspondingly large, with the largest, Harmony, in 1200 feet of water and weighing approximately 43,000 tons. Nearly 30% of California's platforms are in water depths that exceed those of any previous decommissioning project anywhere in the world. Decommissioning will involve the operation of diesel-powered heavy equipment for long periods in virtually all phases of the operation (e.g, at the platform, in transit to and from the platform, in port, at offloading, salvage, and recycling facilities) in a region where air quality is a crucial concern for state, federal, and local regulatory agencies, as well as the public. To support future decision making about the choice between decommissioning options, we consider potential air emissions generated under complete and partial (removal to 85 feet below water line) removal options. We describe major emissions categories, and the environmental and human health issues associated with each, and examine how the regulatory system would operate in specific projects. We then describe methods to estimate emissions for a worst-case example involving the largest platform, Harmony. We estimate that complete versus partial removal of Harmony would result, respectively, in 600 or 89 tons of NOx, 50 or 7 tons of carbon monoxide, 29,400 or 4400 tons of CO2 , 21 or 3 tons of PM10, and 20 or 3 tons of PM2.5. Complete removal of Harmony's jacket and topsides creates approximately 6.75 times more air pollution than partial removal down to 85 feet below the sea surface. We discuss how the Harmony estimate can be used as a baseline to roughly estimate emissions from decommissioning other platforms, using expected time on station for the major categories of decommissioning equipment. PMID:25914363

  4. Environmental load factors and system strength evaluation of offshore jacket platforms

    CERN Document Server

    Nizamani, Zafarullah

    2015-01-01

    This book presents a study for the determination of environmental load factors for Jacket Platforms in Malaysia and a methodology to determine the life extension of aging platforms. The simplified methods described here could be used for determining not only structural reliability but also safety factors. Its content is particularly interesting to design and maintenance engineers who are working in offshore or onshore industry.

  5. Load out and offshore lifting of the PRA-1 platform modules; Embarque e icamento offshore dos modulos de PRA-1

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Fernando; Raigorodsky, Jacques; Mitidieri, Jorge L.U.; Ricardi, Paulo S. [Construtora Norberto Odebrecht S.A., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The technology innovations are characteristics of offshore Engineering around the world. These technologies just make sense when they aim the productivity, security and costs gains compared to ordinary methods. It is in this context that the proposal of the Consorcio PRA-1 (Odebrecht e UTC) team makes sense, in the definition of basic methodology for the PRA-1 platform construction and installation. Through the innovative concept, It was defined (still in the proposal phase) the basic premise that the modules construction and assembly were onshore ending up that just few hours after the offshore installation the modules should be operational in minimal habitability conditions. This innovative method allowed the lack of Flotel, that is a platform which provide support to the offshore construction and assembly (Flotel represents a high costs to the project) and, as consequence, the contract signature by CONSORCIO PRA-1. This work aims to describe the method used for the LOUD-OUT of the PRA-1 modules and the installation of them on the jacket through a vessel provide with cranes the has performed the lifting. Theses operations became unique in Brazil due its challengers characteristics: Module 12 weight = 7203 tf and Module 35 = 5725 tf. For the accomplishment of the Load-out and offshore lifting, was performed a detailed planning and a high level of subcontract interface management. The operations mentioned above were filmed/photographed and published in the specialized media. (author)

  6. Nonlinear Behavior of Single Piles in Jacket Type Offshore Platforms Using Incremental Dynamic Analysis

    Directory of Open Access Journals (Sweden)

    Mohammad A. Assareh

    2008-01-01

    Full Text Available The operation for offshore oil has become an important issue in the recent years. Offshore platforms are some of those structures which are built to withstand environmental and accidental loads during oil exploitation operation. One of the most usual types of these platforms is the Jacket Type Offshore Platform (JTOP which can be divided into three important parts, which are Deck, Jacket and piles. In order to increase the safety, particular attention should be paid to earthquake excitations which are directly applied to the piles of these structures. Nonlinearity in piles and buckling of the struts are important issues which have to be considered by the designers of offshore platforms. The case of nonlinearity in piles and failure capture in these members has not effectively been covered by researchers. Incremental Dynamic Analysis (IDA is a powerful tool to assess the capacity of a structure upon seismic loads. In this paper incremental dynamic analysis has been implemented on single piles considering soil-pile interactions and free field site response. The use of nonlinear materials and lateral load resisting elements in the incremental dynamic analysis done in this paper has made it possible to get promising insights for incorporation of appropriate limit states and applications of performance based engineering. Special Engineering Demand Parameters (EDP and Intensity Measures (IM have been introduced for the single pile dynamic analysis in jacket type offshore platforms.

  7. Variable Torque Control of Offshore Wind Turbine on Spar Floating Platform Using Advanced RBF Neural Network

    OpenAIRE

    Lei Wang; Shan Zuo; Song, Y. D.; Zheng Zhou

    2014-01-01

    Offshore floating wind turbine (OFWT) has been a challenging research spot because of the high-quality wind power and complex load environment. This paper focuses on the research of variable torque control of offshore wind turbine on Spar floating platform. The control objective in below-rated wind speed region is to optimize the output power by tracking the optimal tip-speed ratio and ideal power curve. Aiming at the external disturbances and nonlinear uncertain dynamic systems of OFWT becau...

  8. Offshore energy structures for wind power, wave energy and hybrid marine platforms

    CERN Document Server

    Karimirad, Madjid

    2014-01-01

    This book provides all the key information needed to design offshore structures for renewable energy applications successfully. Suitable for practicing engineers and students, the author conveys design principles and best practices in a clear, concise manner, focusing on underlying physics while eschewing complicated mathematical detail. The text connects underlying scientific theory with industry standards and practical implementation issues for offshore wind turbines, wave energy converters and current turbines. Combined concepts such as wave-wind energy platforms are discussed, as well. Cov

  9. Job Satisfaction, Organizational Commitment and Stress among Offshore Oil and Gas Platform Employees

    OpenAIRE

    Haryanni Harun; Rohani Salleh; Mumtaz Ali Memon; M Noor Rosli Baharom; Azrai Abdullah

    2014-01-01

    Working offshore on an oil rig is perceived as a challenge to many people. Having to live and work at the same site, shift-work schedule with long working hours, high risks and remote work environment; are some common features of an offshore job. High job satisfaction (JS), strong organizational commitment (OC) and minimal stress (St) are key factors to retain the offshore oil and gas platform employees. This is critical to oil and gas companies as skilled and experienced employees are highly...

  10. Multi-Objective Fuzzy Optimum Design Based on Reliability for Offshore Jacket Platforms

    Institute of Scientific and Technical Information of China (English)

    康海贵; 刘未; 翟钢军; 徐发淙; 封盛

    2001-01-01

    In consideration of the fuzzy constraint boundary and through analysis of structural reliability, a model of structural fuzzy optimum design is established based on reliability for offshore jacket platforms. According to the characteristics of offshore jacket platforms, the tolerance coefficient of the constraint boundary is determined with the fuzzy optimization method. The optimum level cut set λ *, which is the intersection of the fuzzy constraint set and fuzzy objective set, is determined with the bound search method, and then the fuzzy optimum solution to the fuzzy optimization problem is obtained. The central offshore platform SZ36-1 is designed with the fuzzy optimum model based on reliability; the results are compared with those from deterministic optimum design and fuzzy optimum design. The tendency of design variables in the above three methods and its reasons are analyzed. The results of an example show that the fuzzy optimum design based on reliability is stable and reliable.

  11. P-D Effects on the Reliability of Oil Offshore Jacket Platforms in Mexico

    Directory of Open Access Journals (Sweden)

    De León-Escobedo D.

    2012-07-01

    Full Text Available Given the important economic consequences of an oil platform failure, all the aspects of its structural behavior and safety issues need to be carefully considered. In particular, P-Δ effects on the deck legs of marine offshore jacket platforms may be relevant when the deck height and the vertical load are significant. In this paper, the impact of the moment amplification, due to slenderness of the deck legs, on the platform safety is examined and appraised from the viewpoint of the structural reliability. The formulation is applied to a typical tall deck marine platform under the environmental loading at the Bay of Campeche, Mexico, and its reliability index is calculated with and without the P-Δeffect. The results presented herein may be used to improve the current practice in the design and assessment of offshore marine platforms in Mexico and to update the current version of the code.

  12. Coniacian-Turonian Carbonates of the Miskar Field, offshore Tunisia

    Energy Technology Data Exchange (ETDEWEB)

    Knott, I. [Gas Exploration & Prod. Ltd., Reading Berkshire (United Kingdom); Moody, R. [Kingston Univ., Surrey (United Kingdom); Sandman, R. [Hedge End, Hampshire (United Kingdom)

    1995-08-01

    The R1 and R1 Superior Carbonates of the Miskar Field, offshore Tunisia are of Coniacian-Turonian age. These ages are constrained by several biostratigraphic events including a rapid increase in ostracod diversity at the base of the overlying Aleg Formation and the occurrence of several diagnostic benthonic foraminifera including Rotalia algeriana. The indication is that the R1 and R1 Superior Carbonates are the lateral equivalents, in part, of the Douleb Formation which is a known reservoir, onshore Tunisia. During the Coniacian-Turonian the area of the Miskar Field was subject to regional extension with the opening of several major North-South trending fractures. These culminate in the contemporaneous outpouring of submarine serpentinized volcanics during deposition of the R1 Superior/Aleg Formation. The R1 lithologies are deposited in a shallow water regime and consist of rudist buildup and debraic carbonates overlain by lagoonal facies in the North with an increase in beach/sabkha facies to the South. The indication is for a shallowing upward sequence and a general progradation of lithofacies northwards across a tilted block. In contrast the R1 Superior is indicative of a flooding event with relative sea-level changes reflected in variations of both lithofacies and biofacies. Overall the lithofacies are dominated by calcispheric/bioclastic wackestone-packstones probably deposited in a mid-platform setting. The diagenetic history of the R1 is the more complex of the two carbonate sequences reflecting several phases of fluid movement through the constituent lithologies. Original depositional characteristics and subsequent diagenetic meditation result in the development of highly variable reservoir properties.

  13. A Global Refiability Assessment Method on Aging Offshore Platforms with Corrosion and Cracks

    Institute of Scientific and Technical Information of China (English)

    JI Chun-yan; LI Shan-shan; CHEN Ming-lu

    2009-01-01

    Corrosion and fatigue cracks are major threats to the structural integrity of aging offshore platforms.For the rational estimation of the safety levels of aging platforms,a global reliability assessment approach for aging offshore platforms with corrosion and fatigue cracks is presented in this paper.The base shear capacity is taken as the global ultimate strength of the offshore plaffoms,it is modeled as a random process that decreases with time in the presence of corrosion and fatigue crack propagation.And the corrosion and fatigue crack growth rates in the main members and key joints are modeled as random variables.A simulation method of the extreme wave loads which are applied to the structures of offshore platforms is proposed too.Furthermore,the statistics of global base shear capacity and extreme wave loads are obtained by Monte Carlo simulation method.On the basis of the limit state equation of global failure mode,the instantaneous reliability and time dependent reliability assessment methods are both presented in this paper.Finally the instantaueous reliability index and time dependent failure probability of a jacket platform are estimated with different ages in the demonstration example.

  14. Investigation of the effects of platform motion on the aerodynamics of a floating offshore wind turbine

    Institute of Scientific and Technical Information of China (English)

    万德成

    2016-01-01

    Along with the flourishing of the wind energy industry, floating offshore wind turbines have aroused much interest among the academia as well as enterprises. In this paper, the effects of the supporting platform motion on the aerodynamics of a floating wind turbine are studied using the open source CFD framework OpenFOAM. The platform motion responses, including surge, heave and pitch, are superimposed onto the rotation of the wind turbine. Thrust and torque on the wind turbine are compared and analysed for the cases of different platform motion patterns together with the flow field. It is shown that the movement of the supporting platform can have large influences on a floating offshore wind turbine and thus needs to be considered carefully during the design process.

  15. Case Study of Integrating an Offshore Wind Farm with Offshore Oil and Gas Platforms and with an Onshore Electrical Grid

    Directory of Open Access Journals (Sweden)

    Wei He

    2013-01-01

    Full Text Available This research project explored the technical feasibility of utilizing an offshore wind farm as a supplementary power source to several electrical grids of offshore oil and gas platforms and providing surplus power to an onshore grid. Three case studies comprising wind farms rated at 20 MW, 100 MW, and 1000 MW have been studied with the focus on (i the operation benefits of CO2/NOx emission reduction, (ii the electrical grid stability, and (iii the technical implementation feasibility. The proposed 20 MW, 100 MW, and 1000 MW wind farm cases are theoretically feasible in terms of the selected technical criteria, although further detailed design operational studies, and economical analysis are required.

  16. Investigation on the Cause of Excessive Vibration of an Offshore Platform

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    An offshore platform of jacket type in Bohai Bay vibrated excessively under design environmental conditions, which had affected the normal operation of the platform. In order to mitigate the vibration of the platform, it is essentially important to explore the cause of the vibration. So the objective of this study is to investigate the cause of the excessive vibration. In this paper, dynamic characteristics of the offshore platform is analyzed by numerical simulation using finite element (FE) modeling. For further verifying the numerical results, model experiment is conducted. Numerical and experimental results demonstrate that there is relative movement and impact between the piles and the jacket, i.e. the piles and the jacket didnt connect well to an entity. It is this cause that the stiffness of the platform decreases and the impact between piles and the jacket legs induces excessive vibration. And also the grouting measure is advised to reduce the vibration of the offshore platform according to the analysis results.

  17. Location and sizing of off-shore platforms for oil exploration

    International Nuclear Information System (INIS)

    The problem of optimal location and sizing of off-shore platforms can be expressed as a multicapacitated plant Location Problem (MCPLP). A solution to MCPLP can be defined through a tabu search heuristic algorithm with partial neighborhood search and variable size extended lists of forbidden moves

  18. Effect of Joint Flexibility on Overall Behavior of Jacket Type Offshore Platforms

    Directory of Open Access Journals (Sweden)

    Masoud Mirtaheri

    2009-01-01

    Full Text Available Problem Statement: Nonlinear behavior of offshore structure is attracting tremendous amount of attention in recent years. Response of these structures is strictly dependent upon behavior of their joints. Because of the lack of information about this part of a structure, most of the recent analysis and designs do not contain appropriate material in the case of joints. In most cases, joints are assumed to be fully clamped and their deformability is not accounted for in assessment of Jacket Type Offshore Platforms (JTOP whereas, in reality there is always deformation in joints particularly when members undergo beyond elastic region. Approach: In this study, finite element modeling of tubular connections is carried out in order to assess their nonlinear behavior. As a result in a separate study, two FE models of a platform are made and effect of joint flexibility on these models is investigated analytically. Nonlinear static and dynamic analyses are performed considering joint deformation and compared to platform with clamped connections. Furthermore, some important parametric studies are carried out such as effect of joint flexibility on natural frequency of vibration of the structure and the process of plastic hinge formation in platform. Results: Results prove considerable effect of local joint deformation on nonlinear static and dynamic behavior of offshore structures. Conclusions/Recommendations: Taking into account the calculated results in this paper, it is highly recommended to consider the effect of joints in the design and analysis of offshore structures based on the importance of the project.

  19. Modal Analysis of an Offshore Platform Using Two Different ARMA Approaches

    DEFF Research Database (Denmark)

    Brincker, Rune; Andersen, P.; Martinez, M. E.;

    In the present investigation, multi-channel response measurements on an offshore platform subjected to wave loads is analysed using Auto regressive Moving Average(ARMA) models. two different estimation schemes are used and the results are compared. In the first approach, a scalar ARMA model is us...

  20. Energy efficiency measures for offshore oil and gas platforms

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van; Voldsund, Mari; Breuhaus, Peter;

    2016-01-01

    Oil and gas platforms are energy-intensive systems { each facility uses from a few to several hundredsMW of energy, depending on the petroleum properties, export specifcations and feld lifetime. Several technologies for increasing the energy effciency of these plants are investigated in this work...

  1. Hibernia's tow-out triumph : platform successfully installed offshore

    International Nuclear Information System (INIS)

    The 75 storey Hibernia platform is now in position off the Grand Banks of Newfoundland, after a 500-kilometer tow-out, through 100-metre deep water, that lasted 14 days. Unfavourable weather conditions held up the tow for a week. When the weather cleared, the crew completed the final 10 kilometres through very shallow water. Remarkably, the platform was installed within 1.5 metres of the target contact point on the ocean bottom. The grouting of the platform to the ocean floor was completed in just a few days. The permanent solid ballasting operation will take about 35 days to complete. Magnetite was transported by carriers to the site where it was mixed with seawater and pumped into the cells just inside the structure's jagged ice wall. Specialized equipment is used to pump 400,000 tonnes of crushed ore into the platform. When the correct amount of ballast is in, the holes will be permanently sealed. Prospects look good for production to begin on the December 15 target date. 2 figs

  2. Development of jacket platform tsunami risk rating system in waters offshore North Borneo

    Science.gov (United States)

    Lee, H. E.; Liew, M. S.; Mardi, N. H.; Na, K. L.; Toloue, Iraj; Wong, S. K.

    2016-07-01

    This work details the simulation of tsunami waves generated by seaquakes in the Manila Trench and their effect on fixed oil and gas jacket platforms in waters offshore North Borneo. For this study, a four-leg living quarter jacket platform located in a water depth of 63m is modelled in SACS v5.3. Malaysia has traditionally been perceived to be safe from the hazards of earthquakes and tsunamis. Local design practices tend to neglect tsunami waves and include no such provisions. In 2004, a 9.3M w seaquake occurred off the northwest coast of Aceh, which generated tsunami waves that caused destruction in Malaysia totalling US 25 million and 68 deaths. This event prompted an awareness of the need to study the reliability of fixed offshore platforms scattered throughout Malaysian waters. In this paper, we present a review of research on the seismicity of the Manila Trench, which is perceived to be high risk for Southeast Asia. From the tsunami numerical model TUNA-M2, we extract computer-simulated tsunami waves at prescribed grid points in the vicinity of the platforms in the region. Using wave heights as input, we simulate the tsunami using SACS v5.3 structural analysis software of offshore platforms, which is widely accepted by the industry. We employ the nonlinear solitary wave theory in our tsunami loading calculations for the platforms, and formulate a platform-specific risk quantification system. We then perform an intensive structural sensitivity analysis and derive a corresponding platform-specific risk rating model.

  3. Impact of offshore gas platforms on the structural and functional biodiversity of nematodes.

    Science.gov (United States)

    Fraschetti, S; Guarnieri, G; Gambi, C; Bevilacqua, S; Terlizzi, A; Danovaro, R

    2016-04-01

    The Mediterranean Sea hosts hundreds of offshore gas platforms, whose activity represents a potential threat to marine ecosystems. Evidence from several studies indicates that nematodes can be highly sensitive to changes in the environmental quality. Here, we investigated the response of nematode assemblages to the presence of offshore gas platforms (located in the central Mediterranean Sea) in terms of spatial heterogeneity, structural and functional diversity. Since the effect of the investigated offshore platforms on macrofaunal assemblages were previously assessed by Terlizzi et al. (2008), the study provided also the opportunity to compare the response of different benthic compartments to the same impact related to fossil fuel extraction on marine environments. The platforms had a significant impact on nematode assemblages up to 1000 m distance from the structure. The effects were evident in term of: a) more homogeneous spatial distribution of nematode assemblages, b) increased trophic diversity of deposit feeders and c) changes in life strategies with an increase of opportunistic species in sediments closer to the platforms. Such effects seemed to be related to the dimension of the platform structures, rather than to chemical pollution or changes in food availability. These findings suggest that the platforms exert a physical alteration of the surrounding environment that is reflected by altered structural and functional traits of nematode biodiversity. The use of nematodes for monitoring the effects of the platforms only partially matched with the results obtained using macrofauna, providing further insights on potential outcomes on the functional response of marine assemblages to fossil fuel extraction. PMID:26878347

  4. Loads on Entrance Platforms for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Frigaard, Peter; Andersen, Thomas Lykke; Ramirez, Jorge Robert Rodriguez;

    2010-01-01

    The present paper gives an overview of the performed large scale tests in GWK, Hannover for studying wave run-up generated forces on wind turbine entrance platforms. The run-up height and velocity was measured by use of high speed video recordings supplemented by some wave gauges mounted at the p....... The purpose of all the tests was to study scale effects related to the above items by comparison with small scale tests and also to present new guidelines for design.......The present paper gives an overview of the performed large scale tests in GWK, Hannover for studying wave run-up generated forces on wind turbine entrance platforms. The run-up height and velocity was measured by use of high speed video recordings supplemented by some wave gauges mounted at the...

  5. Cetacean occurrence near an offshore oil platform in southern Brazil

    Directory of Open Access Journals (Sweden)

    Marta Jussara Cremer

    2009-09-01

    Full Text Available Information about cetaceans in offshore Brazilian waters is scarce, and oil-rigs could provide an important opportunity to obtain new data. The present work was conducted on the P-XIV oil-rig (Petrobrás (26o46’02.2”S; 46o47’02.15”W, located on the border of the continental slope, in an area of 200m depth. In the period between July 2000 and August 2002, 75 sightings of cetaceans were recorded during 38 days of effort. Among the species identified, Tursiops truncatus was the most common, corresponding to 53.3% of the records. Among the misticets, only Balaenoptera acutorostrata was identified with accuracy, with 4 records (5.3%. These were the only species that approached and stayed close to the oil-rig. Many records were made at night, when the gas burner illuminated the area around the oil-rig. We recorded an aggressive interaction involving T. truncatus and B. acutorostrata.

  6. Dynamic performance of power generation systems for off-shore oil and gas platforms

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Breuhaus, Peter; Haglind, Fredrik;

    2014-01-01

    On off-shore oil and gas platforms two or more gas turbines typically support the electrical demand on site by operating as a stand-alone (island) power system. As reliability and availability are major concerns during operation, the dynamic performance of the power generation system becomes a...... crucial aspect for stable operation and prevention of unwanted shut down in case of disturbances in the local grid. This paper aims at developing and validating a dynamic model of the gas turbine-based power generation system installed on the Draugen off-shore oil and gas platform (located in the North...... Sea, Norway). The dynamic model of the SGT-500 gas turbine includes dynamic equations for the combustion chamber and for the high pressure, low pressure and turbine shafts. The low and high pressure compressors are modeled by using quasi steady-state conditions by scaling the maps of axial compressors...

  7. Grid Simulator for Testing a Wind Turbine on Offshore Floating Platform

    Energy Technology Data Exchange (ETDEWEB)

    Gevorgian, V.

    2012-02-01

    An important aspect of such offshore testing of a wind turbine floating platform is electrical loading of the wind turbine generator. An option of interconnecting the floating wind turbine with the onshore grid via submarine power cable is limited by many factors such as costs and associated environmental aspects (i.e., an expensive and lengthy sea floor study is needed for cable routing, burial, etc). It appears to be a more cost effective solution to implement a standalone grid simulator on a floating platform itself for electrical loading of the test wind turbine. Such a grid simulator must create a stable fault-resilient voltage and frequency bus (a micro grid) for continuous operation of the test wind turbine. In this report, several electrical topologies for an offshore grid simulator were analyzed and modeled.

  8. An improved modal strain energy method for damage detection in offshore platform structures

    Science.gov (United States)

    Li, Yingchao; Wang, Shuqing; Zhang, Min; Zheng, Chunmei

    2016-06-01

    The development of robust damage detection methods for offshore structures is crucial to prevent catastrophes caused by structural failures. In this research, we developed an Improved Modal Strain Energy (IMSE) method for detecting damage in offshore platform structures based on a traditional modal strain energy method (the Stubbs index method). The most significant difference from the Stubbs index method was the application of modal frequencies. The goal was to improve the robustness of the traditional method. To demonstrate the effectiveness and practicality of the proposed IMSE method, both numerical and experimental studies were conducted for different damage scenarios using a jacket platform structure. The results demonstrated the effectiveness of the IMSE method in damage location when only limited, spatially incomplete, and noise-polluted modal data is available. Comparative studies showed that the IMSE index outperformed the Stubbs index and exhibited stronger robustness, confirming the superiority of the proposed approach.

  9. An improved modal strain energy method for damage detection in offshore platform structures

    Science.gov (United States)

    Li, Yingchao; Wang, Shuqing; Zhang, Min; Zheng, Chunmei

    2016-04-01

    The development of robust damage detection methods for offshore structures is crucial to prevent catastrophes caused by structural failures. In this research, we developed an Improved Modal Strain Energy (IMSE) method for detecting damage in offshore platform structures based on a traditional modal strain energy method (the Stubbs index method). The most significant difference from the Stubbs index method was the application of modal frequencies. The goal was to improve the robustness of the traditional method. To demonstrate the effectiveness and practicality of the proposed IMSE method, both numerical and experimental studies were conducted for different damage scenarios using a jacket platform structure. The results demonstrated the effectiveness of the IMSE method in damage location when only limited, spatially incomplete, and noise-polluted modal data is available. Comparative studies showed that the IMSE index outperformed the Stubbs index and exhibited stronger robustness, confirming the superiority of the proposed approach.

  10. Emissions of methane from offshore oil and gas platforms in Southeast Asia

    OpenAIRE

    Nara, Hideki; Tanimoto, Hiroshi; Tohjima, Yasunori; Mukai, Hitoshi; Nojiri, Yukihiro; Machida, Toshinobu

    2014-01-01

    Methane is a substantial contributor to climate change. It also contributes to maintaining the background levels of tropospheric ozone. Among a variety of CH4 sources, current estimates suggest that CH4 emissions from oil and gas processes account for approximately 20% of worldwide anthropogenic emissions. Here, we report on observational evidence of CH4 emissions from offshore oil and gas platforms in Southeast Asia, detected by a highly time-resolved spectroscopic monitoring technique deplo...

  11. Computational Fluid Dynamic Analysis of a Floating Offshore Wind Turbine Experiencing Platform Pitching Motion

    OpenAIRE

    Thanhtoan Tran; Donghyun Kim; Jinseop Song

    2014-01-01

    The objective of this study is to illustrate the unsteady aerodynamic effects of a floating offshore wind turbine experiencing the prescribed pitching motion of a supporting floating platform as a sine function. The three-dimensional, unsteady Reynolds Averaged Navier-Stokes equations with the shear-stress transport (SST) k-ω turbulence model were applied. Moreover, an overset grid approach was used to model the rigid body motion of a wind turbine blade. The current simulation results are com...

  12. Thermo-economic assessment of the integration of steam cycles on offshore platforms

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van; Tock, Laurence; Breuhaus, Peter;

    2014-01-01

    The integration of steam bottoming cycles on oil platforms is often seen as a possible route to mitigate the CO2-emissions offshore. In this paper, a North Sea platform and its energy requirements are systematically analysed. The site-scale integration of steam networks is assessed by using...... thermodynamic and economic performance indicators. The results illustrate the benefits of converting the gas turbines into a combined cycle. Using seawater results in smaller power generation and greater CO2-emissions than using process water, as the additional power generation in the combined cycle is...

  13. Emissions of methane from offshore oil and gas platforms in Southeast Asia.

    Science.gov (United States)

    Nara, Hideki; Tanimoto, Hiroshi; Tohjima, Yasunori; Mukai, Hitoshi; Nojiri, Yukihiro; Machida, Toshinobu

    2014-01-01

    Methane is a substantial contributor to climate change. It also contributes to maintaining the background levels of tropospheric ozone. Among a variety of CH4 sources, current estimates suggest that CH4 emissions from oil and gas processes account for approximately 20% of worldwide anthropogenic emissions. Here, we report on observational evidence of CH4 emissions from offshore oil and gas platforms in Southeast Asia, detected by a highly time-resolved spectroscopic monitoring technique deployed onboard cargo ships of opportunity. We often encountered CH4 plumes originating from operational flaring/venting and fugitive emissions off the coast of the Malay Peninsula and Borneo. Using night-light imagery from satellites, we discovered more offshore platforms in this region than are accounted for in the emission inventory. Our results demonstrate that current knowledge regarding CH4 emissions from offshore platforms in Southeast Asia has considerable uncertainty and therefore, emission inventories used for modeling and assessment need to be re-examined. PMID:25266041

  14. Dynamic Analysis of Tension Leg Platform for Offshore Wind Turbine Support as Fluid-Structure Interaction

    Institute of Scientific and Technical Information of China (English)

    HUANG Hu; ZHANG She-rong

    2011-01-01

    Tension leg platform(TLP)for offshore wind turbine support is a new type structure in wind energy utilization.The strong-interaction method is used in analyzing the coupled model,and the dynamic characteristics of the TLP for offshore wind turbine support are recognized.As shown by the calculated results:for the lower modes,the shapes are water's vibration,and the vibration of water induces the structure's swing;the mode shapes of the structure are complex,and can largely change among different members;the mode shapes of the platform are related to the tower's.The frequencies of the structure do not change much after adjusting the length of the tension cables and the depth of the platform;the TLP has good adaptability for the water depths and the environment loads.The change of the size and parameters of TLP can improve the dynamic characteristics,which can reduce the vibration of the TLP caused by the loads.Through the vibration analysis,the natural vibration frequencies of TLP can be distinguished from the frequencies of condition loads,and thus the resonance vibration can be avoided,therefore the offshore wind turbine can work normally in the complex conditions.

  15. Fuzzy Optimum Model of Semi-Structural Decision for Lectotype Optimization of Offshore Platforms

    Institute of Scientific and Technical Information of China (English)

    陈守煜; 伏广涛; 王建明; 刘刚

    2001-01-01

    In the process of concept design of offshore platforms, it is necessary to select the best from feasible alternatives through comparison and filter. The criterion set, used to evaluate and select the satisfying alternative, consists of many qualitative and quantitative factors. Therefore, the selection is a problem of multicriteria and semi-structural decision-making. Different from traditional methods in semi-structural decision-making, a new framework and methodology is presented in this paper for evaluation of offshore platform alternatives. First, the criterion set is established for the evaluation of alternatives. Next, the approach is studied to construct the relative membership degree matrix, in which both qualitative and quantitative factors are consistent with the uniform calculating standard. And then a new weight-assessing method is developed for calculation of the weights based on the relative membership degree matrix.Finally, a multi-hierarchy fuzzy optimum model is adopted to select the satisfying offshore platform alternative. A case study shows that the new framework and methodology are scientific, reasonable and easy to use in practice.

  16. Reliability-Based Full-Life Cycle Optimum Design of Offshore Jacket Platform

    Institute of Scientific and Technical Information of China (English)

    王立成; 宋玉普

    2004-01-01

    Based on the consideration of operation environment and structural property, an optimum design model of offshore jacket platform is developed in this paper, namely, the reliability-based full-life cycle optimum design model. In this model, the time-dependent reliability assessment method for structural members is established by combination of the decrease of sectional size and performance deterioration of material. The initial investment, maintenance cost and failure loss cost are assembled into the model. The total cost of the platform structure system in its full service period is chosen as the objective function, and the initial reliabilities of the layer elements partitioned in advance are taken as the design variables. Different models are obtained, depending on whether the system reliability constraint is considered or not. This optimum design model can result in the lowest full-life cost and the optimal initial layer reliability of an offshore jacket platform in the design of marine structures. The feasibility of this model is illustrated with an actual jacket platform in the Liaodong Gulf as an example.

  17. Infrared inspection applied to offshore platforms: Petrobras experience at Campos Basin

    Science.gov (United States)

    Verdini, Edson A.; Veratti, Attilio B.

    2002-03-01

    Bacia de Campos (Rio de Janeiro - Brazil) is one of the biggest offshore petroleum fields in the world today. In June 2001, Bacia de Campos, having more than 490 oil wells, 34 offshore platforms and 7 modified ships in operation, reached 1,3 million barrels/day. If compared to OPEP countries only nine of them got an average production higher than 1 million barrels/day in 2000, which means it can be placed on the 10th position in the rank of oil producers. In this context this work aims not only to show the results achieved within the introduction of thermographic inspections in offshore oil production (platforms and ships), but also the financial results (ROI - Return of Investment) considering the use of this particular technique. Bacia de Campos got a ROI around 7 million dollars in the last 4 years, which means a hundred times higher than the total cost of thermographic services in the same period. As far as we know this is one of the best results already reported in the world. We also present the methodology applied to analyze thermal anomalies in electrical components and data management software, including advanced Digital Reports sent via Internet.

  18. Computationally Inexpensive Approach for Pitch Control of Offshore Wind Turbine on Barge Floating Platform

    Science.gov (United States)

    Zuo, Shan; Song, Y. D.; Wang, Lei; Song, Qing-wang

    2013-01-01

    Offshore floating wind turbine (OFWT) has gained increasing attention during the past decade because of the offshore high-quality wind power and complex load environment. The control system is a tradeoff between power tracking and fatigue load reduction in the above-rated wind speed area. In allusion to the external disturbances and uncertain system parameters of OFWT due to the proximity to load centers and strong wave coupling, this paper proposes a computationally inexpensive robust adaptive control approach with memory-based compensation for blade pitch control. The method is tested and compared with a baseline controller and a conventional individual blade pitch controller with the “NREL offshore 5 MW baseline wind turbine” being mounted on a barge platform run on FAST and Matlab/Simulink, operating in the above-rated condition. It is shown that the advanced control approach is not only robust to complex wind and wave disturbances but adaptive to varying and uncertain system parameters as well. The simulation results demonstrate that the proposed method performs better in reducing power fluctuations, fatigue loads and platform vibration as compared to the conventional individual blade pitch control. PMID:24453834

  19. Variable Torque Control of Offshore Wind Turbine on Spar Floating Platform Using Advanced RBF Neural Network

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2014-01-01

    Full Text Available Offshore floating wind turbine (OFWT has been a challenging research spot because of the high-quality wind power and complex load environment. This paper focuses on the research of variable torque control of offshore wind turbine on Spar floating platform. The control objective in below-rated wind speed region is to optimize the output power by tracking the optimal tip-speed ratio and ideal power curve. Aiming at the external disturbances and nonlinear uncertain dynamic systems of OFWT because of the proximity to load centers and strong wave coupling, this paper proposes an advanced radial basis function (RBF neural network approach for torque control of OFWT system at speeds lower than rated wind speed. The robust RBF neural network weight adaptive rules are acquired based on the Lyapunov stability analysis. The proposed control approach is tested and compared with the NREL baseline controller using the “NREL offshore 5 MW wind turbine” model mounted on a Spar floating platform run on FAST and Matlab/Simulink, operating in the below-rated wind speed condition. The simulation results show a better performance in tracking the optimal output power curve, therefore, completing the maximum wind energy utilization.

  20. Ultimate Strength of Fixed Offshore Platforms Subjected to Near-Fault Earthquake Ground Vibration

    Directory of Open Access Journals (Sweden)

    Hesam Sharifian

    2015-01-01

    Full Text Available The pile foundation nonlinearity and its influence on the ultimate capacity of fixed platforms have not comprehensively been covered by previous researchers. In this study, the seismic behavior and capacity of a newly designed and installed Jacket Type Offshore Platform (JTOP located in the Persian Gulf is investigated by conducting Incremental Dynamic Analysis (IDA using a suit of near-fault ground motions. Additionally, two modified models of the original platform are created by slightly increasing the diameter of the pile foundation and also softening the jacket part for evaluating the importance of the pile foundation and seismic soil-pile structure interaction on the dynamic characteristics of the JTOPs. Valuable discussions are provided to explore various aspects of the dynamic behavior of JTOPs by presenting individual and multirecords IDA curves using effective Engineering Demand Parameters (EDPs. Comparing the results of the three platform collapse fragility curves, it is concluded that the pile foundation plays a very important role in the dynamic response of offshore platforms and can drastically alter the ultimate strength of the platform together with its collapse capacity. It is observed that the proportional distribution of nonlinear behavior in the pile foundation and jacket part is the key factor in the enhancement of the ultimate strength of JTOPs. On the basis of the results derived from this paper, it is recommended that some basic requirements should be developed in order to ensure that the coupling ductility of pile foundation and jacket part is optimized during the design process. Furthermore, according to the findings from this study, some practice recommendations are presented to be devised within the design step.

  1. Experimental Modeling of Pile-Leg Interaction in Jacket Type Offshore Platforms Cyclic Inelastic Behavior

    Directory of Open Access Journals (Sweden)

    M. R. Honarvar

    2008-01-01

    Full Text Available Offshore platforms in seismically active areas should be designed to survive in the event of severe ground excitations with no global structural failure. The annulus between the pile and leg in jacket-type offshore platforms can be filled with cement grout as a means of reducing horizontal deflections, inhibiting corrosion and preventing local damages. This paper discusses an experimental approach which can be used to demonstrate the effect of grouting on enhanced structural performance of jackets. In this regard, the lateral load bearing behavior of grouted and un-grouted jackets are investigated experimentally with special attention to effect of grout on pile-leg interaction. Results are presented on the cyclic inelastic behavior of two scaled frame models of a representative platform which was recently installed in the Persian gulf. The objective of this effort was to improve the understanding of the behavior of jackets subjected to lateral motions and specially the effects of exact real pile-leg interaction. it should be noted that this paper addresses the exact and realistic pile-leg interaction. It is concluded that grouting can not be considered as a definite method of improving strength and structural nonlinear dynamic behavior. Although it generally increases the lateral stiffness, but some side effects and points are to be considered. In this paper, the two separate lateral load bearing mechanisms -namely portal (braced mechanism and frame bending mechanism- are distinguished and the effect of grout on each one is shown.

  2. P-{Delta} effects on the reliability of oil offshore jacket platforms in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    De Leon-Escobedo, D. [Universidad Autonoma del Estado de Mexico, Toluca, Estado de Mexico (Mexico)]. E-mail: daviddeleonescobedo@yahoo.com.mx; Campos, D. [Instituto Mexicano del Petroleo (Mexico)]. E-mail: dcampos@imp.mx

    2012-07-15

    Given the important economic consequences of an oil platform failure, all the aspects of its structural behavior and safety issues need to be carefully considered. In particular, P-{Delta} effects on the deck legs of marine offshore jacket platforms may be relevant when the deck height and the vertical load are significant. In this paper, the impact of the moment amplification, due to slenderness of the deck legs, on the platform safety is examined and appraised from the viewpoint of the structural reliability. The formulation is applied to a typical tall deck marine platform under the environmental loading at the Bay of Campeche, Mexico, and its reliability index is calculated with and without the P-{Delta} effect. The results presented herein may be used to improve the current practice in the design and assessment of offshore marine platforms in Mexico and to update the current version of the code. [Spanish] Dadas las importantes consecuencias economicas de la falla de una plataforma petrolera, todos los aspectos de su comportamiento estructural y aspectos de seguridad necesitan considerarse cuidadosamente. En particular, los efectos P-{Delta} en las piernas de la cubierta de plataformas marinas costa fuera petroleras tipo jacket pueden ser relevantes cuando la altura de la cubierta y la intensidad de cargas verticales son significativas. En este articulo se examina el impacto que sobre la seguridad de la plataforma tiene la amplificacion de momentos, debido a la esbeltez de las piernas de la cubierta, y se evalua este impacto desde el punto de vista de confiabilidad estructural. La formulacion se aplica a una plataforma marina tipica, con cubierta alta, bajo la carga ambiental de la Bahia de Campeche, Mexico y se calcula su indice de confiabilidad con y sin el efecto P-{Delta}. Los resultados presentados aqui pueden usarse para mejorar las practicas actuales de diseno y evaluacion de plataformas marinas costa fuera en Mexico y para actualizar la version actual

  3. Preliminary Design of Offshore Wind Turbine Tension Leg Platform In the South China Sea

    OpenAIRE

    Hai-feng Wang; You-hua Fan

    2013-01-01

    China has the richest offshore wind resource in the world. Much of undeveloped resource should consider floating tension leg platform (TLP) wind turbine because of its advantage and potential in cost and safety for deep sea, but the related research is short in China. In this thesis we assess a preliminary design for a type of TLP structure in the South China Sea (SCS-TLP) closed to Guangdong province basing on NREL 5MW wind turbine. By coupled analysis in the time domain, the pla...

  4. Job Satisfaction, Organizational Commitment and Stress among Offshore Oil and Gas Platform Employees

    Directory of Open Access Journals (Sweden)

    Haryanni Harun

    2014-05-01

    Full Text Available Working offshore on an oil rig is perceived as a challenge to many people. Having to live and work at the same site, shift-work schedule with long working hours, high risks and remote work environment; are some common features of an offshore job. High job satisfaction (JS, strong organizational commitment (OC and minimal stress (St are key factors to retain the offshore oil and gas platform employees. This is critical to oil and gas companies as skilled and experienced employees are highly demanded in the industry. This study aimed to examine the level of job satisfaction, organizational commitment and stress among oil rig employees (n=214 situated in the coast of East Malaysia. This study also analyzed the relationship between the three variables. The data was collected using a self-administered questionnaire. The findings suggested a moderate level of stress and job satisfaction, while organizational commitment was found to be quite high among the respondents. Job satisfaction was found to have significant positive association with organizational commitment, on the other hand stress was found to be negatively correlated to OC & JS. The implications of these findings for practice and theory in the field of Human Resource Management are discussed.

  5. Intelligent system for start-up of a petroleum offshore platform.

    Science.gov (United States)

    Campos, M C; Satuf, E; de Mesquita, M

    2001-01-01

    It is difficult to control and to manage the start-up of a petroleum offshore platform. In order to solve this problem an intelligent system can play an important role, since available qualitative operator and design knowledge can be easily implemented to assist the operator during start-up. This paper describes the integration of an expert system with a fuzzy controller applied to such a process. The intelligent system has many heuristic rules to implement the automation of the start-up procedures, like the opening of many on-off valves while simultaneously monitoring process variables. It also has a fuzzy controller to optimize the opening of the oil wells, in order to minimize the start-up time. This intelligent system is being implemented in the platform P-19 of Petrobras, the Brazilian oil company, in Campos Basin, Brazil. The prototype has been operating since October 1998. PMID:11515945

  6. Preliminary Design of Offshore Wind Turbine Tension Leg Platform In the South China Sea

    Directory of Open Access Journals (Sweden)

    Hai-feng Wang

    2013-12-01

    Full Text Available China has the richest offshore wind resource in the world. Much of undeveloped resource should consider floating tension leg platform (TLP wind turbine because of its advantage and potential in cost and safety for deep sea, but the related research is short in China. In this thesis we assess a preliminary design for a type of TLP structure in the South China Sea (SCS-TLP closed to Guangdong province basing on NREL 5MW wind turbine. By coupled analysis in the time domain, the platform displacement and tower base force are obtained and analyzed. As a result, SCS-TLP has good features in the dynamic response except yaw motion, it needs to improve the yaw direction damping to induce motion in this direction.

  7. Long-Term Effect of TMD on Vibration Control of An MDOF Offshore Fixed Platform

    Institute of Scientific and Technical Information of China (English)

    SHI Xiang(石湘); Tetsuya MATSUI; WU Minger

    2003-01-01

    A three-dimensional fixed offshore platform in deep water modeled by the finite element method is studied in this paper. Analysis of the dynamic response of the MDOF structure is realized taking the non-linearity of the wave drag force and the wave-structure interaction into account. The structural response statistics, which have Gaussian distributions, are used to evaluate the vibration effect of the structure without TMD and with TMD. And an optimal method to design TMD controlling the first mode of the multi-mode structure is proposed. Moreover, the probabilities of occurrence of sea states at the platform site are considered for prediction of the long-term effect of a TMD. Simulation results demonstrate that the long-term effect of a well-designed TMD is good and the practical use is possible due to the good stability of its optimal parameters under different sea states.

  8. Research on the seismic fortification level of offshore platform in Bohai Sea and adjacent areas

    Institute of Scientific and Technical Information of China (English)

    PENG Yan-ju; L(U) Yue-jun; TANG Rong-yu; SHA Hai-jun

    2005-01-01

    API code is introduced at first, and then a comparison of seismic character and seismic hazard between Bohai and Southern California is carried out. The analysis indicates both the seismic frequency and intensity and the seismic hazard of Bohai are much weaker than that of Southern California. API code states the strength level and deformation level of permanent structures in Southern California takes 200 a and several hundred to a few thousand years respectively. But in the reference codes in China, the seismic levels take 500 a and 10 000 a for strength design and deformation design, and it seems too conservative. In China, the deformation level of class A structure takes 2%~3% probabilities of exceedance in reference period 100 a, and that of class B and C often takes 2%~3% in 50 a.Now that offshore platforms may cause server subsequent risk, it is safe to take 1% in 30 a as its deformation design level. On the basis of the above analyses and social economic level and the consistency with present codes,the strength design level and deformation design level of Chinese offshore platforms is suggested to take 200 a and 3 000 a respectively.

  9. Screening of biosurfactant-producing bacteria from offshore oil and gas platforms in North Atlantic Canada.

    Science.gov (United States)

    Cai, Qinhong; Zhang, Baiyu; Chen, Bing; Song, Xing; Zhu, Zhiwen; Cao, Tong

    2015-05-01

    From offshore oil and gas platforms in North Atlantic Canada, crude oil, formation water, drilling mud, treated produced water and seawater samples were collected for screening potential biosurfactant producers. In total, 59 biosurfactant producers belong to 4 genera, namely, Bacillus, Rhodococcus, Halomonas, and Pseudomonas were identified and characterized. Phytogenetic trees based on 16S ribosomal deoxyribonucleic acid (16S rDNA) were constructed with isolated strains plus their closely related strains and isolated strains with biosurfactant producers in the literature, respectively. The distributions of the isolates were site and medium specific. The richness, diversity, and evenness of biosurfactant producer communities in oil and gas platform samples have been analyzed. Diverse isolates were found with featured properties such as effective reduction of surface tension, producing biosurfactants at high rate and stabilization of water-in-oil or oil-in-water emulsion. The producers and their corresponding biosurfactants had promising potential in applications such as offshore oil spill control, enhancing oil recovery and soil washing treatment of petroleum hydrocarbon-contaminated sites. PMID:25903403

  10. Detecting damage to offshore platform structures using the time-domain data

    Institute of Scientific and Technical Information of China (English)

    CHENG Yuan-sheng; WANG Zhen

    2008-01-01

    A new method that uses time-domain response data under random loading is proposed for detecting damage to the structural elements of offshore platforms. In our study, a time series model with a fitting order was first constructed using the time-domain of noise data. A sensitivity matrix consisting of the first differential of the autoregressive coefficients of the time series models with respect to the stiffness of structural elements was then obtained based on time-domain response data. Locations and severity of damage may then be estimated by solving the damage vector whose components express the degrees of damage to the structural elements. A unique aspect of this detection method is that it requires acceleration history data from only one or a few sensors. This makes it feasible for a limited array of sensors to obtain sufficient data. The efficiency and reliability of the proposed method was demonstrated by applying it to a simplified offshore platform with damage to one element. Numerical simulations show that the use of a few sensors' acceleration history data, when compared with recorded levels of noise, is capable of detecting damage efficiently. An increase in the number of sensors helps improve the diagnosis success rate.

  11. Mitigation of Ice-Induced Vibrations for Offshore Platforms Using Tuned Mass Damper

    Institute of Scientific and Technical Information of China (English)

    ZHANG Li; YUE Qian-jin; ZHANG Wen-shou

    2008-01-01

    The problems of ice-induced vibration have been noticed and concerned since the 1960s, but it has not been well resolved. One reason is that the dynamic interaction between ice and structure is so complicated that practical ice force model has not been developed. The recent full-scale tests conducted on jacket platforms in the Bohai Sea presented that ice could cause intense vibrations which endanger the facilities on the deck and make discomfort for the crew. In this paper, the strategy of mitigation of ice-induced offshore structure vibration is discussed. Based on field observations and understanding of the interaction between ice and structure, the absorption mitigation method to suppress ice-induced vibration is presented. The numerical simulations were conducted for a simplified model of platform attached with a Tuned Mass Damper (TMD) under ice force function and ice force time history. The simulation results show that TMD can favorably reduce ice-induced vibrations, therefore, it can be considered to be an alternative approach to utilize. Finally, the application possibilities of utilizing TMDs on other miniature offshore structures in ice-covered areas of marginal oil fields are discussed.

  12. Reliability-Based Earthquake Design of Jacket-Type Offshore Platforms Considering Pile-Soil-Structure Interaction

    Directory of Open Access Journals (Sweden)

    Behrouz Asgarian

    2009-01-01

    Full Text Available There are plenty of uncertainties in environmental condition of ocean and also in platform element capacities. Reliability-based method could consider these uncertainties. A reliability-based earthquake design method was used to determine the earthquake LRFD parameters for two conventional, steel, pile-supported (template-type offshore platforms located in the Persian Gulf. The pile-soil-structure interaction, the buckling and postbuckling behavior of the braces were considered. Two steel platforms were simulated accurately by the finite element program Opensees. Field data were assumed based on past studies. Sensitiveness of reliability-based method was studied. It was found that the geometry of jacket and different types of braces was important in the capacity and the behavior of offshore platforms. Finally the calculated LRFD elements resistance factors for these two platforms were compared with API recommended factors and it was observed that API recommended element resistance factors were more appropriate for SSL 3.

  13. Application of the SPH method to solitary wave impact on an offshore platform

    Science.gov (United States)

    Pan, K.; IJzermans, R. H. A.; Jones, B. D.; Thyagarajan, A.; van Beest, B. W. H.; Williams, J. R.

    2016-04-01

    This paper investigates the interaction between large waves and floating offshore structures. Here, the fluid-structure interaction is considered using the weakly compressible smoothed particle hydrodynamics (SPH) method. To ensure the applicability of this method, we validate its prediction for fluid forces and rigid-body motion against two sets of experimental data. These are impact due to dam break, and wave induced motion of a floating cube. For the dam break problem, the SPH method is used to predict impact forces on a rectangular column located downstream. In the second case of a floating cube, the SPH method simulates the motion of a buoyant cube under the action of induced waves, where a wall placed upstream of the cube is displaced sinusoidally to induce waves. In both cases, the SPH framework implemented is able to accurately reproduce the experimental results. Following validation, we apply this framework to simulation of a toy model of a tension-leg platform upon impact of a large solitary wave. This analysis shows that the platform may be pulled into the water by stretched tension legs, where the extension of the tension legs also governs the rotational behavior of the platform. The result also indicates that a tension-leg platform is very unlikely to topple over during the arrival of an extreme wave.

  14. Reliability-Based Earthquake Design of Jacket-Type Offshore Platforms Considering Pile-Soil-Structure Interaction

    OpenAIRE

    Behrouz Asgarian; Hossein Agheshlui

    2009-01-01

    There are plenty of uncertainties in environmental condition of ocean and also in platform element capacities. Reliability-based method could consider these uncertainties. A reliability-based earthquake design method was used to determine the earthquake LRFD parameters for two conventional, steel, pile-supported (template-type) offshore platforms located in the Persian Gulf. The pile-soil-structure interaction, the buckling and postbuckling behavior of the braces were considered. Two steel pl...

  15. Investigation on tempering of granular bainite in an offshore platform steel

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yanlei; Jia, Tao; Zhang, Xiangjun [The State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, No. 11, Lane 3, Wenhua Road, HePing District, Shenyang 110819 (China); Liu, Zhenyu, E-mail: zyliu@mail.neu.edu.cn [The State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, No. 11, Lane 3, Wenhua Road, HePing District, Shenyang 110819 (China); Misra, R.D.K. [Department of Metallurgical and Materials Engineering, University of Texas at El Paso, 500 W. University Avenue, El Paso, TX 79968-0521 (United States)

    2015-02-25

    Granular bainite, where M-A constituents dispersed in bainitic ferrite matrix usually presents at the half thickness region in thermo-mechanically processed heavy gauge offshore platform steel. In the present work, the decomposition of M-A constituents during tempering at 600 °C was firstly revealed by transmission electron microscopy (TEM) analysis, which primarily involves the precipitation of cementite, recovery and recrystallization of highly dislocated ferrite matrix. Then, the effect of tempering on mechanical properties was investigated by tempering at different temperature for 60 min. Results indicated that, at tempering temperature of 500–600 °C, large quantity of micro-alloying carbides precipitated and partially compensated the loss of strength mainly due to the decomposition of M-A constituents. Compared with the as-rolled state, the decomposition of M-A constituents and softening of bainitic ferrite matrix after tempering have resulted in higher density of microvoids and substantial plastic deformation before impact failure.

  16. Design and optimization of air bottoming cycles for waste heat recovery in off-shore platforms

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Haglind, Fredrik

    2014-01-01

    This paper aims at comparing two methodologies to design an air bottoming cycle recovering the waste heat from the power generation system on the Draugen off-shore oil and gas platform. Firstly, the design is determined using the theory of the power maximization. Subsequently, the multi......-objective optimization approach is employed to maximize the economic revenue, the compactness and the power production of the air bottoming cycle. The system compactness is assessed by introducing a detailed model of the shell and tube recuperator and including geometric quantities in the set of optimization variables....... Findings indicate that using the power production, the volume of the recuperator and the net present value as objective functions the optimal pressure ratio (2.52) and the exhaust gas temperature (178.8 °C) differ from the values (2.80 and 145.5 °C) calculated using the theory of the power maximization...

  17. Modelling and analysis of offshore energy systems on North Sea oil and gas platforms

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van; Elmegaard, Brian; Pierobon, Leonardo;

    2012-01-01

    Offshore processes are associated with significant energy consumption and large CO2 emissions. Conventional North Sea oil and gas facilities include the following operations: crude oil separation, gas compression and purification, wastewater treatment, gas lifting, seawater injection, oil and gas...... export, and power generation. In this paper, a generic model of a North Sea oil and gas platform is described and the most thermodynamically inefficient processes are identified by performing an exergy analysis. Models and simulations are built and run with the tools Aspen Plus R, DNA and Aspen HYSYS R....... Results reveal that the total exergy destruction of the system is particularly sensitive to the gas-to-oil ratio and amounts to 55-65 MW, while the total exergy losses amount to 15-20 MW. The gas compression train and the production manifold module are the most exergy-destructive operations of the oil...

  18. Considerations in evaluating potential socioeconomic impacts of offshore platform decommissioning in California.

    Science.gov (United States)

    Kruse, Sarah A; Bernstein, Brock; Scholz, Astrid J

    2015-10-01

    The 27 oil and gas platforms offshore southern California will eventually reach the end of their useful lifetimes (estimated between 2015 and 2030) and will be decommissioned. Current state and federal laws and regulations allow for alternative uses in lieu of the complete removal required in existing leases. Any decommissioning pathway will create a complex mix of costs, benefits, opportunities, and constraints for multiple user groups. To assist the California Natural Resources Agency in understanding these issues, we evaluated the potential socioeconomic impacts of the 2 most likely options: complete removal and partial removal of the structure to 85 feet below the waterline with the remaining structure left in place as an artificial reef-generally defined as a manmade structure with some properties that mimic a natural reef. We estimated impacts on commercial fishing, commercial shipping, recreational fishing, nonconsumptive boating, and nonconsumptive SCUBA diving. Available data supported quantitative estimates for some impacts, semiquantitative estimates for others, and only qualitative approximations of the direction of impact for still others. Even qualitative estimates of the direction of impacts and of user groups' likely preferred options have been useful to the public and decision makers and provided valuable input to the project's integrative decision model. Uncertainty surrounds even qualitative estimates of the likely direction of impact where interactions between multiple impacts could occur or where user groups include subsets that would experience the same option differently. In addition, we were unable to quantify effects on ecosystem value and on the larger regional ecosystem, because of data gaps on the population sizes and dynamics of key species and the uncertainty surrounding the contribution of platforms to available hard substrate and related natural populations offshore southern California. PMID:25914391

  19. Absorption refrigeration cycle applied to offshore platforms; Refrigeracao por absorcao aplicada a plataformas de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Maximino Joaquim Pina [KROMAV Engenharia, Rio de Janeiro, RJ (Brazil); Pinto, Luiz Antonio Vaz; Belchior, Carlos Rodrigues Pereira [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE)

    2004-07-01

    To produce cold from the heat seems a task unlikely or even impossible. However, absorption systems produce cooling from heat sources and it exist since the century XIX. In industrial places is very important to improve the energy use, even more in places where the activities involve great costs and incomes. Traditionally the alternatives conflict in the aspects of initial and operational costs. This paper describes the absorption systems operation and its main advantages and disadvantages, when compared to the traditional systems with compressor. The known fact that a vapor compressor system presents larger efficiency is not enough to validate it for all of the applications. In this sense, the initial and operational analysis of the costs of the absorption systems becomes interesting. In spite of, double effect absorption systems are demonstrating the evolution of the absorption cycle in order to obtain better performance. Turbo-generators and Turbo-compressors of the offshore platforms are thermal machines that reject great amount of heat in the exhaust gases. This heat is used for heating of water used in the Process Plant. The processes of separation of the mixture water-oil-gas from the well, for instance, use that heat. Even after the passage of the water in the Plant of Process, the residual heat is still enough for the use in absorption systems. A simulation is done using real data of an offshore platform. Two possible alternatives are compared under technical and economical aspects. Sensibility analysis is also performed in order to verify possible impacts of variations of electric power cost. (author)

  20. Design and optimization of air bottoming cycles for waste heat recovery in off-shore platforms

    International Nuclear Information System (INIS)

    Highlights: • Theory of power maximization used to design an air bottoming cycle. • Theory of power maximization extended by a multi-objective optimization method. • Three objective functions considered: net power output, recuperator volume and net present value. • Comparison between the theory of power maximization and the multi-objective optimization method. • Case study: a methodology applied to recover exhaust heat on off-shore platforms. - Abstract: This paper aims at comparing two methodologies to design an air bottoming cycle recovering the waste heat from the power generation system on the Draugen off-shore oil and gas platform. Firstly, the design is determined using the theory of the power maximization. Subsequently, the multi-objective optimization approach is employed to maximize the economic revenue, the compactness and the power production of the air bottoming cycle. The system compactness is assessed by introducing a detailed model of the shell and tube recuperator and including geometric quantities in the set of optimization variables. Findings indicate that using the power production, the volume of the recuperator and the net present value as objective functions the optimal pressure ratio (2.52) and the exhaust gas temperature (178.8 °C) differ from the values (2.80 and 145.5 °C) calculated using the theory of the power maximization. The highest net present value (2.8 M$) is found for a volume of the recuperator of 128 m3. Thus, it can be concluded that the multi-objective optimization approach enables extending the theory of power maximization bridging the gap between a mere optimization of the thermodynamic cycle and the practical feasibility of a power generation system

  1. Molecular Analysis of the Bacterial Communities in Crude Oil Samples from Two Brazilian Offshore Petroleum Platforms

    Science.gov (United States)

    Korenblum, Elisa; Souza, Diogo Bastos; Penna, Monica; Seldin, Lucy

    2012-01-01

    Crude oil samples with high- and low-water content from two offshore platforms (PA and PB) in Campos Basin, Brazil, were assessed for bacterial communities by 16S rRNA gene-based clone libraries. RDP Classifier was used to analyze a total of 156 clones within four libraries obtained from two platforms. The clone sequences were mainly affiliated with Gammaproteobacteria (78.2% of the total clones); however, clones associated with Betaproteobacteria (10.9%), Alphaproteobacteria (9%), and Firmicutes (1.9%) were also identified. Pseudomonadaceae was the most common family affiliated with these clone sequences. The sequences were further analyzed by MOTHUR, yielding 81 operational taxonomic units (OTUs) grouped at 97% stringency. Richness estimators also calculated by MOTHUR indicated that oil samples with high-water content were the most diverse. Comparison of bacterial communities present in these four samples using LIBSHUFF and Principal Component Analysis (PCA) indicated that the water content significantly influenced the community structure only of crude oil obtained from PA. Differences between PA and PB libraries were observed, suggesting the importance of the oil field as a driver of community composition in this habitat. PMID:22319534

  2. The Feasibility of Wind and Solar Energy Application for Oil and Gas Offshore Platform

    Science.gov (United States)

    Tiong, Y. K.; Zahari, M. A.; Wong, S. F.; Dol, S. S.

    2015-04-01

    Renewable energy is an energy which is freely available in nature such as winds and solar energy. It plays a critical role in greening the energy sector as these sources of energy produce little or no pollution to environment. This paper will focus on capability of renewable energy (wind and solar) in generating power for offshore application. Data of wind speeds and solar irradiation that are available around SHELL Sabah Water Platform for every 10 minutes, 24 hours a day, for a period of one year are provided by SHELL Sarawak Sdn. Bhd. The suitable wind turbine and photovoltaic panel that are able to give a high output and higher reliability during operation period are selected by using the tabulated data. The highest power output generated using single wind energy application is equal to 492 kW while for solar energy application is equal to 20 kW. Using the calculated data, the feasibility of renewable energy is then determined based on the platform energy demand.

  3. Nonlinear coupled dynamic response of offshore Spar platforms under regular sea waves

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, A.K.; Jain, A.K. [Indian Inst. of Technology, Dept. of Civil Engineering, New Delhi (India)

    2003-03-01

    Oil and gas exploration of large reservoirs in deep water has accelerated the need to explore structures suitable for these depths, which operate more economically in deep water. A Spar platform is one such compliant offshore floating structure used for deep water applications for the drilling, production, processing, storage and offloading of ocean deposits. The Spar is modeled as a rigid body with 6 degrees-of-freedom, connected to the sea floor by multi-component catenary mooring lines, which are attached to the Spar at the fairleads. The response-dependent stiffness matrix consists of three parts: (a) the hydrostatics provide restoring force in heave, roll and pitch; (b) the mooring lines provide the restoring force which are represented here by nonlinear horizontal; and (c) vertical springs. An unidirectional regular wave model is used for computing the incident wave kinematics by Airy's wave theory and force by Morison's equation. The response analysis is performed in time domain to solve the dynamic behavior of a moored Spar platform as an integrated system using the iterative incremental Newmark's Beta approach. Numerical studies are conducted for several regular waves. (Author)

  4. Spar-type platform design for the offshore floating nuclear power plant

    International Nuclear Information System (INIS)

    There exists the potential for substantial gains in safety, physical security, and economics for nuclear electricity supply through the development of an Offshore Floating Nuclear Plant (OFNP). Utilizing the most reliable and efficient construction techniques, this plant can be built from modular components in a shipyard as a partially submerged floating spar platform. The plant can then be floated to a site between 5 and 10 miles off the coast, moored in approximately 100-meter deep water, and connected to the grid via an underwater transmission line. The OFNP is designed to take full advantage of its environment to include passive cooling systems that eliminate the loss of ultimate heat sink accident, thereby decreasing the likelihood of severe accidents. The platform’s structural design, mooring system, and siting protect it against severe weather systems and render it immune to tsunamis and seismic activity. Furthermore, the OFNP containment design and venting procedures effectively eliminate the threat of serious land contamination, should a severe accident actually occur. The OFNP overall design builds on decades of offshore oil drilling experience and is derived from a shortened cylindrical spar platform. The platform has a skirt diameter of 75 m, a waterline diameter of 45 m, an operational draft of 48.5 m, and a total weight of about 38,200 tons when the skirt is empty. The spar design maximizes hydrodynamic stability, has been tested in various locations around the world in oil extraction, and offers significant protection to critical systems from external threats. The reactor containment is located below sea level and centered in a hull surrounded by seawater. This positioning offers both considerable physical security as well as unique opportunities in passive cooling. Watertight levels house safety critical systems (e.g. reactor, spent fuel pool, control room, battery room), the steam cycle, the condensate storage tank, and the desalination plant

  5. Joint Offshore Wind Field Monitoring with Spaceborne SAR and Platform-Based Doppler LIDAR Measurements

    Science.gov (United States)

    Jacobsen, S.; Lehner, S.; Hieronimus, J.; Schneemann, J.; Kuhn, M.

    2015-04-01

    The increasing demand for renewable energy resources has promoted the construction of offshore wind farms e.g. in the North Sea. While the wind farm layout consists of an array of large turbines, the interrelation of wind turbine wakes with the remaining array is of substantial interest. The downstream spatial evolution of turbulent wind turbine wakes is very complex and depends on manifold parameters such as wind speed, wind direction and ambient atmospheric stability conditions. To complement and validate existing numerical models, corresponding observations are needed. While in-situ measurements with e.g. anemometers provide a time-series at the given location, the merits of ground-based and space- or airborne remote sensing techniques are indisputable in terms of spatial coverage. Active microwave devices, such as Scatterometer and Synthetic Aperture Radar (SAR), have proven their capabilities of providing sea surface wind measurements and particularly SAR images reveal wind variations at a high spatial resolution while retaining the large coverage area. Platform-based Doppler LiDAR can resolve wind fields with a high spatial coverage and repetition rates of seconds to minutes. In order to study the capabilities of both methods for the investigation of small scale wind field structures, we present a direct comparison of observations obtained by high resolution TerraSAR-X (TS-X) X-band SAR data and platform-based LiDAR devices at the North Sea wind farm alpha ventus. We furthermore compare the results with meteorological data from the COSMO-DE model run by the German Weather Service DWD. Our study indicates that the overall agreement between SAR and LiDAR wind fields is good and that under appropriate conditions small scale wind field variations compare significantly well.

  6. A Robust Damage Detection Method Developed for Offshore Jacket Platforms Using Modified Artificial Immune System Algorithm

    Institute of Scientific and Technical Information of China (English)

    Mojtahedi,A.; Lotfollahi Yaghin,M.A.; Hassanzadeh,Y.; Abbasidoust,F.; Ettefagh,M.M.; Aminfar,M.H.

    2012-01-01

    Steel jacket-type platforms are the common kind of the offshore structures and health monitoring is an important issue in their safety assessment.In the present study,a new damage detection method is adopted for this kind of structures and inspected experimentally by use of a laboratory model.The method is investigated for developing the robust damage detection technique which is less sensitive to both measurement and analytical model uncertainties.For this purpose,incorporation of the artificial immune system with weighted attributes (AISWA) method into finite element (FE) model updating is proposed and compared with other methods for exploring its effectiveness in damage identification.Based on mimicking immune recognition,noise simulation and attributes weighting,the method offers important advantages and has high success rates.Therefore,it is proposed as a suitable method for the detection of the failures in the large civil engineering structures with complicated structural geometry,such as the considered case study.

  7. Electrical equipment safety on offshore platform%探讨海洋石油钻井平台电气设备安全

    Institute of Scientific and Technical Information of China (English)

    马谧

    2015-01-01

    本文围绕海洋石油钻井平台电器设备安全问题展开探讨,以提高海洋石油钻井效率与安全。%The safety issues of electrical equipment on offshore platform are discussed in this paper to improve the efficiency and security of offshore drilling.

  8. An integrated approach for gas dispersion, gas explosion and structural impact analysis for an offshore production platform on the Dutch continental shelf

    OpenAIRE

    Korndörffer, W.; Schaap, D.; Van der Heijden, A.M.A.; Versloot, N.H.A.

    2004-01-01

    The design of an offshore gas production platform has been subjected to an extensive quantitative risk analysis in particular with regard to its resistance to gas explosions loads. It was demonstrated that integration of the physical and structural effects of a gas explosion in an early stage of the design results in a safe and economical design. Copyright 2004, Offshore Technology Conference.

  9. Comparison of Simulations and Offshore Measurement Data of a Combined Floating Wind and Wave Energy Demonstration Platform

    DEFF Research Database (Denmark)

    Yde, Anders; Larsen, Torben J.; Hansen, Anders Melchior;

    2015-01-01

    In this paper, results from comparisons of simulations and measured offshore data from a floating combined wind and wave energy conversion system are presented. The numerical model of the platform is based on the aeroelastic code, HAWC2, developed by DTU Wind Energy, which is coupled with a special...... external system that reads the output generated directly by the wave analysis software WAMIT. The main focus of the comparison is on the statistical trends of the platform motion, mooring loads, and turbine loads in measurements and simulations during different operational conditions. Finally, challenges...... and possible approaches for further model development and validation are discussed....

  10. Exergy destruction and losses on four North Sea offshore platforms: A comparative study of the oil and gas processing plants

    DEFF Research Database (Denmark)

    Voldsund, Mari; Nguyen, Tuong-Van; Elmegaard, Brian;

    2014-01-01

    destruction take place in the gas treatment sections, 13%-29% take place in the gas recompression sections and 10%-24% occur in the production manifolds. The exergy losses with flared gas are significant for two of the platforms. The exact potential for energy savings and for enhancing system performances...... installation of flare gas recovery systems. © 2014 Elsevier Ltd. All rights reserved....... differs across offshore platforms. However, the results indicate that the largest rooms for improvement lie in (i) gas compression systems where large amounts of gas may be compressed and recycled to prevent surge, (ii) production manifolds where well-streams are depressurised and mixed, and (iii) in the...

  11. AFSC/NMML/CCEP: Characterizing and quantifying California sea lion and Pacific harbor seal use of offshore oil and gas platforms in California, 2013-2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — California sea lions (Zalophus californianus) and Pacific harbor seals (Phoca vitulina) use offshore oil and gas platforms as resting and foraging areas. Both...

  12. Soil non-linearity and its effect on the dynamic behaviour of offshore platform foundations

    Energy Technology Data Exchange (ETDEWEB)

    Madshus, Christian

    1997-07-01

    This thesis focuses on non-linear soil response to the type of cyclic loading experienced under offshore gravity base platform foundations. These loads are dominated by a cyclic component around the main wave frequency, which may well mobilize soil non-linearity under severe sea-states. Superimposed on this main component are lower level higher frequency loads caused by resonant oscillations of the platform. The thesis presents results of specially designed triaxial tests to simulate this loading condition. The tests simultaneously applied two cyclic load components at different frequencies and amplitudes. The measured soil response to each component has been isolated through a frequency domain separation. It was found that the soil responds to the superimposed high frequency low level component as if the soil had a cyclically time-varying stiffness. If the superimposed component does not lead to load reversals, this stiffness variation is controlled by the frequency and amplitude of the main load component and by the hysteretic non-linearity of the soil. If the superimposed component causes reversals, the influence of the hysteretic non-linearity on the stiffness variation is reduced. The higher the degree of reversal, the more this influence it taken over by the variation in the instantaneous unloading-reloading stiffness of the soil. It was also found that this type of two-frequency cyclic soil testing is generally superior over conventional single-frequency testing in the way it enforces the soil to reveal several of its inherent properties not deducible from ordinary tests. Benefits of analyzing non-linear response in the frequency domain is demonstrated throughout this thesis. The ability of various theoretical soil models to simulate the observed soil behaviour under two-frequency cyclic loading has, been investigated through numerical analyses. It was found that only those models that are based on kinematic hardening are able to reproduce what was observed

  13. Social impact assessment: identification, management and follow-up of community concerns associated with construction of the Hibernia offshore platform

    International Nuclear Information System (INIS)

    Social impact Assessment (SIA) is the systematic analysis, in advance of the likely impacts of a proposed action, that considers 'all social and cultural consequences to human populations of any public or private actions that alter the ways in which people live, work, play, relate to one another, organize to meet their needs, and generally cope as members of society' (US Department of Commerce 1994). Through the SIA for the construction of the Hibernia offshore oil platform concern, and values of local area residents were identified and a management strategy designed to minimise social disruption associated with the project. Monitoring studies showed that the strategy was effective and that few negative social impacts occurred. The Hibernia offshore oil field, was discovered on the Grand Banks, east of the island of Newfoundland, in 1979. The distance from shore (315 km), its isolation, the periodic presence of sea ice, icebergs and fog, and frequently severe wave and wind conditions, make these waters an extremely hostile work environment. Primarily to maximize human safety, the final engineering design chosen for the project was a fixed, gravity base system (GBS). The platform functions as the main drilling and production unit, the first stage processing facility, oil storage and accommodations base for the offshore crews. The concrete base of the platform, one of the five super-modules that make up the top-sides of the platform and eight of tile smaller top-sides-mounted modules, were fabricated in Newfoundland and the entire platform assembled at Bull Arm, Trinity Bay. (author)

  14. Computationally Inexpensive Approach for Pitch Control of Offshore Wind Turbine on Barge Floating Platform

    OpenAIRE

    Shan Zuo; Song, Y. D.; Lei Wang; Qing-wang Song

    2013-01-01

    Offshore floating wind turbine (OFWT) has gained increasing attention during the past decade because of the offshore high-quality wind power and complex load environment. The control system is a tradeoff between power tracking and fatigue load reduction in the above-rated wind speed area. In allusion to the external disturbances and uncertain system parameters of OFWT due to the proximity to load centers and strong wave coupling, this paper proposes a computationally inexpensive robust adapti...

  15. Theoretical and Experimental Studies of Wave Impact underneath Decks of Offshore Platforms

    Energy Technology Data Exchange (ETDEWEB)

    Baarholm, Rolf Jarle

    2001-07-01

    The main objective of this thesis has been to study the phenomenon of water impact underneath the decks of offshore platforms due to propagating waves. The emphasis has been on the impact loads. Two theoretical methods based on two-dimensional potential theory have been developed, a Wagner based method (WBM) and a nonlinear boundary element method (BEM). A procedure to account for three-dimensional effects is suggested. The deck is assumed to be rigid. Initial studies of the importance of hydroelasticity for wave loads on an existing deck structure have been performed. For a given design wave, the local structural responses were found to behave quasi-static. Global structural response has not been studied. In the Wagner based method gravity is neglected and a linear spatial distribution of the relative impact velocity along the deck is assumed. The resulting boundary value problem is solved analytically for each time step. A numerical scheme for stepping the wetted deck area in time is presented. The nonlinear boundary element method includes gravity, and the exact impact velocity is considered. The incident wave velocity potential is given a priori, and a boundary value problem for the perturbation velocity potential associated with the impact is defined. The boundary value problem is solved for each time step by applying Green's second identity. The exact boundary conditions are imposed on the exact boundaries. A Kutta condition is introduced as the fluid flow reaches the downstream end of the deck. At present, the BEM is only applicable for fixed platform decks. To validate the theories, experiments have been carried out in a wave flume. The experiments were performed in two-dimensional flow condition with a fixed horizontal deck at different vertical levels above the mean free surface. The vertical force on the deck and the wetting of the deck were the primary parameters measured. Only regular propagating waves were applied. When a wave hits the deck, the

  16. Marine Fouling Assemblages on Offshore Gas Platforms in the Southern North Sea: Effects of Depth and Distance from Shore on Biodiversity.

    Science.gov (United States)

    van der Stap, Tim; Coolen, Joop W P; Lindeboom, Han J

    2016-01-01

    Offshore platforms are known to act as artificial reefs, though there is on-going debate on whether this effect is beneficial or harmful for the life in the surrounding marine environment. Knowing what species exist on and around the offshore platforms and what environmental variables influence this species assemblage is crucial for a better understanding of the impact of offshore platforms on marine life. Information on this is limited for offshore platforms in the southern North Sea. This study aims to fill this gap in our knowledge and to determine how the composition and the abundance of species assemblages changes with depth and along a distance-from-shore gradient. The species assemblages on five offshore gas platforms in the southern North Sea have been inventoried using Remotely Operated Vehicles inspection footage. A total of 30 taxa were identified. A Generalised Additive Model of the species richness showed a significant non-linear relation with water depth (p = 0.001): from a low richness in shallow waters it increases with depth until 15-20 m, after which richness decreases again. Using PERMANOVA, water depth (p≤0.001), community age (p≤0.001) and the interaction between distance from shore and community age (p≤0.001) showed a significant effect on the species assemblages. Future research should focus on the effect additional environmental variables have on the species assemblages. PMID:26745870

  17. The Role of Faulting on the Growth of a Carbonate Platform: Evidence from 3D Seismic Analysis and Section Restoration

    Science.gov (United States)

    Nur Fathiyah Jamaludin, Siti; Pubellier, Manuel; Prasad Ghosh, Deva; Menier, David; Pierson, Bernard

    2014-05-01

    Tectonics in addition to other environmental factors impacts the growth of carbonate platforms and plays an important role in shaping the internal architecture of the platforms. Detailed of faults and fractures development and healing in carbonate environment have not been explored sufficiently. Using 3D seismic and well data, we attempt to reconstruct the structural evolution of a Miocene carbonate platform in Central Luconia Province, offshore Malaysia. Luconia Province is located in the NW coast of Borneo and has become one of the largest carbonate factories in SE Asia. Seismic interpretations including seismic attribute analysis are applied to the carbonate platform to discern its sedimentology and structural details. Detailed seismic interpretations highlight the relationships of carbonate deposition with syn-depositional faulting. Branching conjugate faults are common in this carbonate platform and have become a template for reef growth, attesting lateral facies changes within the carbonate environments. Structural restoration was then appropriately performed on the interpreted seismic sections based on sequential restoration techniques, and provided images different from those of horizon flattening methods. This permits us to compensate faults' displacement, remove recent sediment layers and finally restore the older rock units prior to the fault motions. It allows prediction of platform evolution as a response to faulting before and after carbonate deposition and also enhances the pitfalls of interpretation. Once updated, the reconstructions allow unravelling of the un-seen geological features underneath the carbonate platform, such as paleo-structures and paleo-topography which in turn reflects the paleo-environment before deformations took place. Interestingly, sections balancing and restoration revealed the late-phase (Late Oligocene-Early Miocene) rifting of South China Sea, otherwise difficult to visualize on seismic sections. Later it is shown that

  18. Fuzzy Fatigue Reliability Analysis of Offshore Platforms in Ice-Infested Waters

    Institute of Scientific and Technical Information of China (English)

    方华灿; 段梦兰; 贾星兰; 谢彬

    2003-01-01

    The calculation of fatigue stress ranges due to random waves and ice loads on offshore structures is discussed, and the corresponding accumulative fatigue damages of the structural members are evaluated. To evaluate the fatigue damage to the structures more accurately, the Miner rule is modified considering the fuzziness of the concerned parameters, and a new model for fuzzy fatigue reliability analysis of offshore structures members is developed. Furthermore, an assessment method for predicting the dynamics of the fuzzy fatigue reliability of structural members is provided.

  19. Parametric study on the effects of pile inclination angle on the response of batter piles in offshore jacket platforms

    Science.gov (United States)

    Aminfar, Ali; Ahmadi, Hamid; Aminfar, Mohammad Hossein

    2016-06-01

    Offshore jacket-type platforms are attached to the seabed by long batter piles. In this paper, results from a finite element analysis, verified against experimental data, are used to study the effect of the pile's inclination angle, and its interaction with the geometrical properties of the pile and the geotechnical characteristics of the surrounding soil on the behavior of the inclined piles supporting the jacket platforms. Results show that the inclination angle is one of the main parameters affecting the behavior of an offshore pile. We investigated the effect of the inclination angle on the maximum von Mises stress, maximum von Mises elastic strain, maximum displacement vector sum, maximum displacement in the horizontal direction, and maximum displacement in the vertical direction. The pile seems to have an operationally optimal degree of inclination of approximately 5°. By exceeding this value, the instability in the surrounding soil under applied loads grows extensively in all the geotechnical properties considered. Cohesive soils tend to display poorer results compared to grained soils.

  20. Toxicity of sediment pore water associated with offshore oil and gas platforms in the Gulf of Mexico

    International Nuclear Information System (INIS)

    As a part of a multidisciplinary program to assess the long-term impacts of offshore petroleum production in the Gulf of Mexico, a series of sediment porewater toxicity tests were conducted. Sediments were samples from five petroleum production platforms along five radial transects. Pore water was extracted from the sediment using a pressure extraction device, centrifuged, and frozen for later toxicity testing and chemical analysis. The sea urchin (Arbacia punctulata) embryological development assay and fertilization assay were used to assess porewater toxicity. Significant decreases in normal development of embryos was observed at 14 stations and fertilization was reduced at three stations. All stations with reduced fertilization also showed impaired development in the embryological development assay. All but three toxic sites were within 150 m of the platform. The six most toxic stations were at one platform near the Flower Garden reef, occurring near the platform along three radii; toxicity was always greater at the first site on a radium than at the second. Toxicity is discussed in relation to metal and hydrocarbon concentrations in whole sediment and in pore water

  1. Polymer cantilever platform for dielectrophoretic assembly of carbon nanotubes

    DEFF Research Database (Denmark)

    Johansson, Alicia; Calleja, M.; Dimaki, Maria;

    2004-01-01

    A polymer cantilever platform for dielectrophoretic assembly of carbon nanotubes has been designed and realized. Multi-walled carbon nanotubes from aqueous solution have been assembled between two metal electrodes that are separated by 2 mu m and embedded in the polymer cantilever. The entire chip......, except for the metallic electrodes and wiring, was fabricated in the photoresist SU-8. SU-8 allows for an inexpensive, flexible and fast fabrication method, and the cantilever platform provides a hydrophobic surface that should be well suited for nanotube assembly. The device can be integrated in a micro...

  2. Can Producing Oil Store Carbon? Greenhouse Gas Footprint of CO2EOR, Offshore North Sea.

    Science.gov (United States)

    Stewart, R Jamie; Haszeldine, R Stuart

    2015-05-01

    Carbon dioxide enhanced oil recovery (CO2EOR) is a proven and available technology used to produce incremental oil from depleted fields while permanently storing large tonnages of injected CO2. Although this technology has been used successfully onshore in North America and Europe, there are currently no CO2EOR projects in the United Kingdom. Here, we examine whether offshore CO2EOR can store more CO2 than onshore projects traditionally have and whether CO2 storage can offset additional emissions produced through offshore operations and incremental oil production. Using a high-level Life Cycle system approach, we find that the largest contribution to offshore emissions is from flaring or venting of reproduced CH4 and CO2. These can already be greatly reduced by regulation. If CO2 injection is continued after oil production has been optimized, then offshore CO2EOR has the potential to be carbon negative--even when emissions from refining, transport, and combustion of produced crude oil are included. The carbon intensity of oil produced can be just 0.056-0.062 tCO2e/bbl if flaring/venting is reduced by regulation. This compares against conventional Saudi oil 0.040 tCO2e/bbl or mined shale oil >0.300 tCO2e/bbl. PMID:25789442

  3. Determination and environmental estimation of NORMs in marine sediment environment of offshore platforms; Determinacao e avaliacao ambiental de NORMs em sedimento marinho entorno de plataformas offshore

    Energy Technology Data Exchange (ETDEWEB)

    Vegueria, Sergio F. Jerez, E-mail: sfjerez@vm.uff.br [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Departamento de Quimica Analitica; Godoy, Jose M., E-mail: rccampos@puc-rio.br, E-mail: jmgodoy@puc-rio.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    The natural radioactive materials (NORM known as) are found in the earth's crust, and during the process of production of oil and gas are concentrated in the produced water and the fouling (scale) pipes used for extraction. The production of oil and gas from produced water comes, comprising: forming water (water naturally present in the well ); injection water , usually sea water previously injected into the well to maintaining the pressure while the oil is removed; and water condensed in some cases of gas production. A high radioactivity of {sup 226}Ra (natural grade of {sup 238}U) and {sup 228}Ra (from the natural series of {sup 232}Th) is detected in produced water due to the high solubility of radio in formation water as uranium and thorium, which are insoluble in this medium, remain the rock matrix. The study was conducted in the area of offshore oil production in the state of Rio de January and included the determination of uranium, {sup 226}Ra, {sup 210}Pb and {sup 228}Ra in marine sediment near the points of discharge of produced water from oil platforms. After the pre-treatment and digestion of samples, the determination of the natural uranium was performed on a mass spectrometer with inductively coupled plasma (ICP -MS). The activities of {sup 226}Ra and {sup 228}Ra were determined by high resolution gamma spectrometry through {sup 214}Bi and {sup 228}Ac , respectively. And in the case of {sup 210}Pb, a correction was made for self-absorption employing an external source of this radionuclide. The results showed that there is no impact in sediments in the vicinity of the studied platforms.

  4. The Effect of Symmetrical and Asymmetrical Shape in Buckling Strength on Fixed Offshore Platform

    OpenAIRE

    Muis Alie, Muhammad Zubair; Juswan; Daud, Silfiani; Sriadi, Widya Utami; Ratnawati

    2015-01-01

    The jacket, or template, structures are still the most common offshore structures used for drilling and production. Some structures contain enlarged legs, which are suitable for self-buoyancy during its installation at the site. Fixed jacket structures consist of tubular members interconnected to form a three-dimensional space frame. Hence, the jacket structure can be categorized into a column structure. These structures usually have four to eight legs battered to achieve stability against no...

  5. JOINT OFFSHORE WIND FIELD MONITORING WITH SPACEBORNE SAR AND PLATFORM-BASED DOPPLER LIDAR MEASUREMENTS

    OpenAIRE

    Jacobsen, S.; Lehner, S.; J. Hieronimus; Schneemann, J.; Kühn, M. (Michaela)

    2015-01-01

    The increasing demand for renewable energy resources has promoted the construction of offshore wind farms e.g. in the North Sea. While the wind farm layout consists of an array of large turbines, the interrelation of wind turbine wakes with the remaining array is of substantial interest. The downstream spatial evolution of turbulent wind turbine wakes is very complex and depends on manifold parameters such as wind speed, wind direction and ambient atmospheric stability conditions. ...

  6. Structural Dynamic behaviour of a floating platform for Offshore wind turbines

    OpenAIRE

    Abón Olivera, Guillermo

    2013-01-01

    In this minor thesis, the use of concrete as material for floating wind platforms is proposed as an alternative that can provide, great  resistance to corrosion and virtually non maintenance.  After selecting the best suitable floating platform type for shallow waters a static analysis is done in order to choose the geometry and dimensions that best fits the needs expressed.  Then with the selected model, a dynamic analysis is  performed in order to check the platform interaction with waves. ...

  7. A study of wave forces on an offshore platform by direct CFD and Morison equation

    Directory of Open Access Journals (Sweden)

    Zhang D.

    2015-01-01

    The next step is the presentation of 3D multiphase RANS simulation of the wind-turbine platform in single-harmonic regular waves. Simulation results from full 3D simulation will be compared to the results from Morison’s equation. We are motivated by the challenges of a floating platform which has complex underwater geometry (e.g. tethered semi-submersible. In cases like this, our hypothesis is that Morison’s equation will result in inaccurate prediction of forces, due to the limitations of 2D coefficients of simple geometries, and that 3D multiphase RANS CFD will be required to generate reliable predictions of platform loads and motions.

  8. PROVANN: Model System for Chronic Exposure of Larval and Adult Fish to Releases from Offshore Petroleum Platforms

    International Nuclear Information System (INIS)

    Produced water from offshore oil and gas production platforms contains a variety of hydrocarbons, heavy metals, and production chemicals. Vertical and horizontal mixing generally brings concentrations in discharge plumes below level associated with acute effects within 500 or 1000 m of the source. Chronic effects outside this region remain a potential problem. The purpose of PROVANN, the system of models described in this paper, is to assess the potential for chronic effects from produced water. The preliminary focus is on potential bioaccumulation and boimagnification of produced water constituents in the marine food web. Other possible types of chronic effects, such as reduced fecundity, or pheromone response interference, can also be assessed to the extent that such effects may be correlated with exposure. PROVANN simulates 3-dimensional transport, dilution, and degradation of chemicals released into the water, from one or more simultaneous sources. 8 refs., 10 figs., 3 tabs

  9. A multi-attribute decision analysis for decommissioning offshore oil and gas platforms.

    Science.gov (United States)

    Henrion, Max; Bernstein, Brock; Swamy, Surya

    2015-10-01

    The 27 oil and gas platforms off the coast of southern California are reaching the end of their economic lives. Because their decommissioning involves large costs and potential environmental impacts, this became an issue of public controversy. As part of a larger policy analysis conducted for the State of California, we implemented a decision analysis as a software tool (PLATFORM) to clarify and evaluate decision strategies against a comprehensive set of objectives. Key options selected for in-depth analysis are complete platform removal and partial removal to 85 feet below the water line, with the remaining structure converted in place to an artificial reef to preserve the rich ecosystems supported by the platform's support structure. PLATFORM was instrumental in structuring and performing key analyses of the impacts of each option (e.g., on costs, fishery production, air emissions) and dramatically improved the team's productivity. Sensitivity analysis found that disagreement about preferences, especially about the relative importance of strict compliance with lease agreements, has much greater effects on the preferred option than does uncertainty about specific outcomes, such as decommissioning costs. It found a near-consensus of stakeholders in support of partial removal and "rigs-to-reefs" program. The project's results played a role in the decision to pass legislation enabling an expanded California "rigs-to-reefs" program that includes a mechanism for sharing cost savings between operators and the state. PMID:26415010

  10. Instrumental neutron activation analysis of Malaysian off-shore carbonate samples irradiated in a nuclear reactor

    International Nuclear Information System (INIS)

    The elemental abudances of the USGS standard rock AGV-1 and two Malaysian off-shore drill core carbonate samples (off Sarawak) are studied by the method of Neutron Activation Analysis. One major element (Fe) and 23 trace elements (Sc, Cr, Co, Rb, Sr, Zr, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Ho, Yb, Lu, Hf, Ta, Au, Th and U) have been determined using reactor irradiations and high-resolution gamma-ray spectrometry. (author)

  11. WHTSubmersible: a simulator for estimating transient circulation temperature in offshore wells with the semi-submersible platform

    Science.gov (United States)

    Song, Xun-cheng; Liu, Yong-wang; Guan, Zhi-chuan

    2015-10-01

    Offshore wellbore temperature field is significant to drilling fluids program, equipment selection, evaluations on potential risks caused by casing thermal stress, etc. This paper mainly describes the theoretical basis, module structure and field verification of the simulator WHTSubmersible. This computer program is a useful tool for estimating transient temperature distribution of circulating drilling fluid on semi-submersible platform. WHTSubmersible is based on a mathematical model which is developed to consider radial and axial two-dimensional heat exchange of the inner drill pipe, the annulus, the drill pipe wall, the sea water and the formation in the process of drilling fluid circulation. The solution of the discrete equations is based on finite volume method with an implicit scheme. This scheme serves to demonstrate the numerical solution procedure. Besides, the simulator also considers the heating generated by drilling fluid circulation friction, drill bit penetrating rocks, friction between the drill column and the borehole wall, and the temperature effect on thermal physical properties and rheology of the drilling fluid. These measures ensure more accurate results. The simulator has been programmed as a dynamic link library using Visual C++, the routine interface is simple, which can be connected with other computer programs conveniently. The simulator is validated with an actual well temperature filed developed on a semi-submersible platform in South China, and the error is less than 5 %.

  12. Numerical Prediction of Experimentally Observed Behavior of a Scale Model of an Offshore Wind Turbine Supported by a Tension-Leg Platform: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Prowell, I.; Robertson, A.; Jonkman, J.; Stewart, G. M.; Goupee, A. J.

    2013-01-01

    Realizing the critical importance the role physical experimental tests play in understanding the dynamics of floating offshore wind turbines, the DeepCwind consortium conducted a one-fiftieth-scale model test program where several floating wind platforms were subjected to a variety of wind and wave loading condition at the Maritime Research Institute Netherlands wave basin. This paper describes the observed behavior of a tension-leg platform, one of three platforms tested, and the systematic effort to predict the measured response with the FAST simulation tool using a model primarily based on consensus geometric and mass properties of the test specimen.

  13. Carbon Dioxide Observational Platform System (CO-OPS), feasibility study

    Science.gov (United States)

    Bouquet, D. L.; Hall, D. W.; Mcelveen, R. P.

    1987-01-01

    The Carbon Dioxide Observational Platform System (CO-OPS) is a near-space, geostationary, multi-user, unmanned microwave powered monitoring platform system. This systems engineering feasibility study addressed identified existing requirements such as: carbon dioxide observational data requirements, communications requirements, and eye-in-the-sky requirements of other groups like the Defense Department, the Forestry Service, and the Coast Guard. In addition, potential applications in: earth system science, space system sciences, and test and verification (satellite sensors and data management techniques) were considered. The eleven month effort is summarized. Past work and methods of gathering the required observational data were assessed and rough-order-of magnitude cost estimates have shown the CO-OPS system to be most cost effective (less than $30 million within a 10 year lifetime). It was also concluded that there are no technical, schedule, or obstacles that would prevent achieving the objectives of the total 5-year CO-OPS program.

  14. Exergy analysis of offshore processes on North Sea oil and gas platforms

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van; Pierobon, Leonardo; Elmegaard, Brian

    2012-01-01

    Offshore processes are associated with significant energy consumption and large CO2 emissions. Conventional North Sea oil and gas facilities include the following operations: crude oil separation, gas compression and purification, wastewater treatment, gas lifting, seawater injection and power...... exergy losses amount to 22.3 MW. The gas lifting train and the production-separation module are the most exergy-destructive operations of the oil and gas processing system, consuming 8.83 MW and 8.17 MW respectively, while the power generation system alone is responsible for 46.7 MW. The exergetic...... efficiency of the oil and gas processing is about 39%, while the exergetic efficiency of the utility system is about 21-27%....

  15. Cretaceous tropical carbonate platform changes used as paleoclimatic and paleoceanic indicators: the three lower Cretaceous platform crises

    Science.gov (United States)

    Arnaud-Vanneau, A.; Vrielynck, B.

    2009-04-01

    Carbonate platform sediments are of biogenic origin. More commonly the bioclasts are fragments of shells and skeletons. The bioclastic composition of a limestone may reflect the nature of biota inhabiting the area and a carbonate platform can be estimated as a living factory, which reflects the prevailing ecological factors. The rate of carbonate production is highest in the tropics, in oligotrophic environments, and in the photic zone. The rate of carbonate production varies greatly with temperature and nutrient input. Three types of biotic carbonate platform can be distinguished. The highest carbonate production is linked to oligotrophic carbonate platform characterized by the presence of assemblages with hermatypic corals. This type of platform is developed in shallow marine environment, nutrient poor water and warm tropical sea. A less efficient production of carbonate platform is related to mesotrophic environments in cooler and/or deeper water and associated to nutrient flux with, sometime, detrital input. The biota includes red algae, solitary coral and branching ahermatypic corals, common bryozoans, crinoids and echinoids. The less productive carbonate platform is the eutrophic muddy platform where the mud is due to the intense bacterial activity, probably related to strong nutrient flux. All changes of type of carbonate platform can be related to climatic and oceanic changes. Three platform crises occurred during lower Cretaceous time. They are followed by important turnover of microfauna (large benthic foraminifers) and microflora (marine algae). They start with the demise of the previous oligotrophic platform, they continue with oceanic perturbations, expression of which was the widespread deposition of organic-rich sediments, well expressed during Late Aptian/Albian and Cenomanian Turonian boundary and the replacement of previous oligotrophic platforms by mesotrophic to eutrophic platforms. The first crisis occurred during Valanginian and Hauterivian

  16. Vertically Aligned Carbon Nanofiber based Biosensor Platform for Glucose Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Al Mamun, Khandaker A.; Tulip, Fahmida S.; MacArthur, Kimberly; McFarlane, Nicole; Islam, Syed K.; Hensley, Dale

    2014-03-01

    Vertically aligned carbon nanofibers (VACNFs) have recently become an important tool for biosensor design. Carbon nanofibers (CNF) have excellent conductive and structural properties with many irregularities and defect sites in addition to exposed carboxyl groups throughout their surfaces. These properties allow a better immobilization matrix compared to carbon nanotubes and offer better resolution when compared with the FET-based biosensors. VACNFs can be deterministically grown on silicon substrates allowing optimization of the structures for various biosensor applications. Two VACNF electrode architectures have been employed in this study and a comparison of their performances has been made in terms of sensitivity, sensing limitations, dynamic range, and response time. The usage of VACNF platform as a glucose sensor has been verified in this study by selecting an optimum architecture based on the VACNF forest density. Read More: http://www.worldscientific.com/doi/abs/10.1142/S0129156414500062

  17. Differences in plankton community structure and carbon cycling along a climate gradient from the Greenland Ice Sheet to offshore waters

    DEFF Research Database (Denmark)

    Arendt, K.E.; Nielsen, Torkel Gissel; Rysgaard, S.;

    . Protozooplankton accounts for 20-38% of the carbon turnover in the offshore and inland areas. However, protozooplankton like copepods has low ability to turn over the primary production close to the Ice Sheet. Increased run of from the Greenland Ice Sheet due to global warming could displace the existing climate......Huge differences in plankton community structures and biomasses are observed along a climate gradient from the Greenland Ice Sheet to offshore waters at the West Greenland coast. The offshore region has a high biomass of copepods dominated by Calanus spp., which are capable of consuming 55% of the...

  18. Seismic Performance Evaluation of the Jacket Type Offshore Platforms through Incremental Dynamic Analysis considering Soil-Pile-Structure Interaction

    International Nuclear Information System (INIS)

    Of great interest in Performance-Based Earthquake Engineering (PBEE) is the accurate estimation of the seismic performance of structures. A performance prediction and evaluation procedure is based on nonlinear dynamics and reliability theory. In this method, a full integration over the three key stochastic models is as follow: ground motion hazard curve, nonlinear dynamic displacement demand, and displacement capacity. Further, both epistemic and aleatory uncertainties are evaluated and carried through the analysis.In this paper, jacket and soil-pile system have been modeled using Finite Element program (OpenSees) and the incremental dynamic analysis (IDA) are performed to investigate nonlinear behavior of offshore platforms. The system demand is determined by performing time history response analyses of the jacket under a suite of FEMA/SAC uniform hazard ground motions. The system capacity in terms of the drift ratio against incipient collapse is generally difficult to predict since the structural response goes into nonlinear range before collapse. All the analyses are performed in two directions and the results are compared with each others. The confidence level of a jacket in each direction for a given hazard level is calculated using the procedure described

  19. Seismic Performance Evaluation of the Jacket Type Offshore Platforms through Incremental Dynamic Analysis considering Soil-Pile-Structure Interaction

    Science.gov (United States)

    Asgarian, Behrouz; Shokrgozar, Hamed R.; Talarposhti, Ali Shakeri

    2008-07-01

    Of great interest in Performance-Based Earthquake Engineering (PBEE) is the accurate estimation of the seismic performance of structures. A performance prediction and evaluation procedure is based on nonlinear dynamics and reliability theory. In this method, a full integration over the three key stochastic models is as follow: ground motion hazard curve, nonlinear dynamic displacement demand, and displacement capacity. Further, both epistemic and aleatory uncertainties are evaluated and carried through the analysis. In this paper, jacket and soil-pile system have been modeled using Finite Element program (OpenSees) and the incremental dynamic analysis (IDA) are performed to investigate nonlinear behavior of offshore platforms. The system demand is determined by performing time history response analyses of the jacket under a suite of FEMA/SAC uniform hazard ground motions. The system capacity in terms of the drift ratio against incipient collapse is generally difficult to predict since the structural response goes into nonlinear range before collapse. All the analyses are performed in two directions and the results are compared with each others. The confidence level of a jacket in each direction for a given hazard level is calculated using the procedure described.

  20. Microbial dolomite crusts from the carbonate platform off western India

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.; Kessarkar, P.M.; Krumbein, W.E.; Krajewski, K.P.; Schneider, R.J.

    of Oceanography, Dona Paula-403 004, Goa, India (E-D1ail: vprao@darya.nio.org) tGeoD1icrobiology, ICBM, Carl von Ossietzky-University of Oldenburg, Oldenburg, GerD1any tInstitute of Geological Sciences, Polish AcadeD1Y of Sciences, Twarda 51/55, 00-818 Warsaw... bial mediation of dolomite. In this paper, we advance the microbial dolomite model by report ing' on late Pleistocene dolomite cmsts from the carbonate platform off western India and suggest that dolomitization by benthic microbial commu nities...

  1. Characterizing pinniped use of offshore oil and gas platforms as haulouts and foraging areas in waters off southern California from 2013-01-01 to 2015-01-31 (NCEI Accession 0138984)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — California sea lions (Zalophus californianus) and Pacific harbor seals (Phoca vitulina) use offshore oil and gas platforms as resting and foraging areas. Both...

  2. Application of an elastic 2D tube-waveform tomography to estimate the shear modulus in the vicinity of the FINO3 offshore platform

    Science.gov (United States)

    Köhn, D.; Wilken, D.; Rabbel, W.

    2012-04-01

    The FINO3 project is aimed at the construction of an offshore research platform in the north-sea, hosting research projects dealing with offshore wind energy topics. As part of FINO3 our sub-project deals with the development of new seismic acquisition and inversion concepts for offshore-building foundation soil analysis. We are focussed on the determination of seismic parameters and structural information of the building plot of the platform. Possible changes of the shear modulus of the sediments in the vicinity of the FINO3 monopile due to mechanic loads on the platform are estimated by a tube-waveform tomography. The tube-waves are excited by a hammer blow at the internal wall of the FINO3 monopile above the water line. The tube-waves are propagating through the water column and the sediments and are measured in situ by hydrophones at the external wall of the monopile. Homogenous long wavelength starting models for the waveform tomography are estimated using simple 2D finite difference models. Possible shear-wave velocity starting models range from 150-300 m/s. The resolution of the tube-waveform tomography is estimated by simple chequerboard and random media models. Additionally first results of the data application in the vicinity of the monopile are presented.

  3. An Integrated Approach to Fatigue Life Prediction of Whole System for Offshore Platforms

    Institute of Scientific and Technical Information of China (English)

    方华灿; 段梦兰; 许发彦; 吴永宁; 樊晓东

    2001-01-01

    The failure of one or even more components usually does not lead to the collapse of the whole structure. Most of theanalysis of fatigue is centered on only a single component which the researchers are interested in or much attentionshould be paid to. However, the collapse of a structure is the result of failure of a series of components in a specific orderor path. This paper proposes an integrated approach to fatigue life prediction of whole structural system for offshoreplatforms, mainly describing the basic principles and prediction method. A method is presented for determining the fail-ure path of the whole structure system and calculating the fatigue life in the determined failure path. The correspondingfinal collapse criteria for the whole structure system are discussed. A simple method of equivalent fatigue stress range cal-culation and a mathematical model of structural component fatigue life estimation in consideration of sea wave and seaice loads are provided. As an application of the proposed approach, a fixed production platform Bohai No. 8 is chosenfor the predication of fatigue life of the whole structure system by means of the software OSFAC developed based on thepresent methods.

  4. Authigenic carbonates in the sediments of Goa offshore basin, western continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Kocherla, M.

    stream_size 32255 stream_content_type text/plain stream_name Curr_Sci_102_1205.pdf.txt stream_source_info Curr_Sci_102_1205.pdf.txt Content-Encoding UTF-8 Content-Type text/plain; charset=UTF-8 RESEARCH COMMUNICATIONS... from the sediments of Goa offshore basin characterized by shallow gas charged sediments 14,27 . In the present study, we report the occurrence of dispersed authigenic carbonates in RESEARCH COMMUNICATIONS CURRENT SCIENCE, VOL. 102, NO. 8, 25...

  5. Geriatric infrastructure, BRAC, and ecosystem service markets? End-of-life decisions for dams, roads, and offshore platforms (Invited)

    Science.gov (United States)

    Doyle, M. W.

    2010-12-01

    US infrastructure expanded dramatically in the mid-20th century, and now includes more than 79,000 dams, 15,000 miles of levees, 3.7 million miles of roads, 600,000 miles of sewer pipe, 500,000 onshore oil wells, and over 4,000 offshore oil platforms. Many structures have been in place for 50 years or more, and an increasing portion of national infrastructure is approaching or exceeding its originally intended design life. Bringing national infrastructure to acceptable levels would cost nearly 10% of the US annual GDP. Decommissioning infrastructure can decrease public spending and increase public safety while facilitating economic expansion and ecological restoration. While most infrastructure remains critical to the national economy, a substantial amount is obsolete or declining in importance. Over 11,000 dams are abandoned, and of nearly 400,000 miles of road on its lands, the U.S. Forest Service considers one-fourth non-essential and often non-functional. Removing obsolete infrastructure allows greater focus and funding on maintaining or improving infrastructure most critical to society. Moreover, a concerted program of infrastructure decommissioning promises significant long-term cost savings, and is a necessary step before more substantial, systematic changes are possible, like those needed to address the new energy sources and shifting climate. One key challenge for infrastructure reform is how to prioritize and implement such a widespread and politically-charged series of decisions. Two approaches are proposed for different scales. For small, private infrastructure, emerging state and federal ecosystem service markets can provide an economic impetus to push infrastructure removal. Ecosystem market mechanisms may also be most effective at identifying those projects with the greatest ecological bang for the buck. Examples where this approach has proved successful include dam removal for stream mitigation under the Clean Water Act, and levee decommissioning on

  6. Structural steels for fixed offshore platforms: technical challenges at the Brazilian national supply chain; Acos estruturais para plataformas fixas offshore: desafios tecnicos junto a cadeia de suprimentos nacional brasileira

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Fabio Modesti Orsini de [Promon Engenharia Ltda., Rio de Janeiro, RJ (Brazil)

    2012-07-01

    This paper presents the main technical requirements for structural steel applied to the construction of bottom fixed offshore platforms, based on the most widely adopted and recognized actual standards. The mechanical properties and lab tests necessary to fulfill the Risk Management and E and P companies requirements are presented aiming to build the theoretical bases necessary for the engineering design of projects of this kind. The main types of steel available in the national market are presented at the end, giving an overall look at the Brazilian steel supply chain. (author)

  7. Chicxulub Impact Crater and Yucatan Carbonate Platform - PEMEX Oil Exploratory Wells Revisited

    Science.gov (United States)

    Pérez-Drago, G.; Gutierrez-Cirlos, A. G.; Pérez-Cruz, L.; Urrutia-Fucugauchi, J.

    2008-12-01

    Geophysical oil exploration surveys carried out by PEMEX in the 1940's revealed occurrence of an anomalous pattern of semi-circular concentric gravity anomalies. The Bouguer gravity anomalies covered an extensive area over the flat carbonate platform in the northwestern Yucatan Peninsula; strong density contrasts were suggestive of a buried igneous complex or basement uplift beneath the carbonates, which was referred as the Chicxulub structure. The exploration program carried out afterwards included a drilling program, starting with Chicxulub-1 well in 1952 and comprising eight deep boreholes through the 1970s. An aeromagnetic survey in late 1970's showed high amplitude anomalies in the gravity anomaly central sector. Thus, research showing Chicxulub as a large complex impact crater formed at the K/T boundary was built on the PEMEX decades-long exploration program. Despite frequent reference to PEMEX information and samples, original data and cores have not been openly available for detailed evaluation and integration with results from recent investigations. Core samples largely remain to be analyzed and interpreted in the context of recent marine, aerial and terrestrial geophysical surveys and the drilling/coring projects of UNAM and ICDP. In this presentation we report on the stratigraphy and paleontological data for PEMEX wells: Chicxulub- 1 (1582m), Sacapuc-1 (1530m), Yucatan-6 (1631m), Ticul-1 (3575m) Yucatan-4 (2398m), Yucatan-2 (3474m), Yucatan-5A (3003m) and Yucatan-1 (3221m). These wells remain the deepest drilled in Chicxulub, providing samples of impact lithologies, carbonate sequences and basement, which give information on post- and pre-impact stratigraphy and crystalline basement. We concentrate on stratigraphic columns, lateral correlations and integration with UNAM and ICDP borehole data. Current plans for deep drilling in Chicxulub crater target the peak ring and central sector, with offshore and onshore boreholes proposed to the IODP and ICDP

  8. Model Development and Loads Analysis of an Offshore Wind Turbine on a Tension Leg Platform with a Comparison to Other Floating Turbine Concepts: April 2009

    Energy Technology Data Exchange (ETDEWEB)

    Matha, D.

    2010-02-01

    This report presents results of the analysis of a 5-MW wind turbine located on a floating offshore tension leg platform (TLP) that was conducted using the fully coupled time-domain aero-hydro-servo-elastic design code FAST with AeroDyn and HydroDyn. The report also provides a description of the development process of the TLP model. The model has been verified via comparisons to frequency-domain calculations. Important differences have been identified between the frequency-domain and time-domain simulations, and have generated implications for the conceptual design process. An extensive loads and stability analysis for ultimate and fatigue loads according to the procedure of the IEC 61400-3 offshore wind turbine design standard was performed with the verified TLP model. This report compares the loads for the wind turbine on the TLP to those of an equivalent land-based turbine. Major instabilities for the TLP are identified and described.

  9. Atmospheric metallic and arsenic pollution at an offshore drilling platform in the Bo Sea: A health risk assessment for the workers.

    Science.gov (United States)

    Xu, Hong; Han, Suqin; Bi, Xiaohui; Zhao, Zhijing; Zhang, Lei; Yang, Wenjie; Zhang, Min; Chen, Jing; Wu, Jianhui; Zhang, Yufen; Feng, Yinchang

    2016-03-01

    To investigate the ambient metal pollution at the offshore drilling platform in the Bo Sea, which few studies have focused on, PM2.5 samples were collected and ten heavy metals, as well as As, were analyzed. High concentration levels of metals were observed, and the heavy metal pollution was quite serious compared to air quality standards and other marine areas. Back trajectories and wind dependent and PCA analyses showed that the marine sources included ship traffic emissions and corrosive stainless steels from the equipment at the platform as well as industrial emissions from stainless steel production and coal combustion sources, which were transported from the surrounding mainland. Both contributed greatly to the ambient metallic particles at the offshore platform. The Hazard Index values of the metals, which were much less than 1, the Carcinogenic Risk data, which were lower than the EPA's acceptable range, and the fact that the metal concentrations did not the exceed the permissible exposure limits of OSHA, indicated that the health risks from the ambient metallic particles for the oil-drilling workers were not significant. PMID:26547617

  10. 海洋平台上安全阀的设计与选型%The Design and Selection of Pressure Relief Valve for Offshore Platform

    Institute of Scientific and Technical Information of China (English)

    李治贵; 宫俭纯; 姜来举

    2015-01-01

    Pressure relief valve is the last line of defense in protecting the safe production of offshore Platform. It introduce the basic principles in design and selection of pressure relief valve in this article. The calculation and selection of pressure relief valve on BZ3-2 platform is analyzed as the example.%压力泄放设施是保障海洋平台安全生产的最后防线。本文介绍了安全阀的选型原则,并以BZ13-1平台为例分析了海洋平台上安全阀选型计算的具体过程。

  11. Middle Eocene seagrass facies from Apennine carbonate platforms (Italy)

    Science.gov (United States)

    Tomassetti, Laura; Benedetti, Andrea; Brandano, Marco

    2016-04-01

    Two stratigraphic sections located in the Latium-Abruzzi (Monte Porchio, Central Apennines, Central Italy) and in the Apulian carbonate platform (S. Cesarea-Torre Tiggiano, Salento, Southern Italy) were measured and sampled to document the sedimentological characteristic and the faunistic assemblages of Middle Eocene seagrass deposits. The faunistic assemblages are dominated by porcellaneous foraminifera Orbitolites, Alveolina, Idalina, Spiroloculina, Quinqueloculina, Triloculina and abundant hooked-shaped gypsinids, associated with hooked red algae and green algae Halimeda. Fabiania, rotaliids and textulariids as well as nummulitids are subordinated. The samples were assigned to Lutetian (SBZ13-16) according to the occurrence of Nummulites cf. lehneri, Alveolina ex. gr. elliptica, Idalina berthelini, Orbitolites complanatus, Slovenites decastroi and Medocia blayensis. At Santa Cesarea reticulate nummulites occur in association with Alveolina spp. and Halkyardia minima marking the lower Bartonian (SBZ17). Three main facies associations have been recognised: I) larger porcellaneous foraminiferal grainstones with orbitolitids and alveolinids deposited into high-energy shallow-water settings influenced by wave processes that reworked the sediments associated with a seagrass; II) grainstone to packstone with small porcellaneous foraminifera and abundant permanently-attached gypsinids deposited in a more protected (e.g., small embayment) in situ vegetated environment; III) bioclastic packstone with parautochthonous material reworked from the seagrass by rip currents and accumulated into rip channels in a slightly deeper environment. The biotic assemblages suggest that the depositional environment is consistent with tropical to subtropical vegetated environments within oligotrophic conditions.

  12. 基于遗传算法的海洋平台损伤诊断%Damage Diagnosis for Offshore Platform Based on Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    刘娟; 黄维平; 石湘

    2012-01-01

    海洋平台结构在环境因素下可能出现局部破损,提出一种快速诊断结构损伤的损伤探测方法,而遗传算法因其方法简单及较强的鲁棒性成为近年来发展较快的一种全局优化方法.以海洋平台实测的固有频率和振型为诊断依据,将海洋结构的损伤诊断归结为优化问题,采用遗传算法进行优化搜索.考虑到平台结构刚度的方向性,针对测量噪声和海洋平台模态的特点,提出了一种修正的目标函数作为遗传算法进行损伤诊断的适应度函数.数值模拟和物理模型试验结果表明,该方法能够准确地诊断出导管架海洋平台结构的损伤,改进了进化搜索的鲁棒性,提高了海洋平台结构损伤诊断的可靠性.%In the exploitation of ocean oil and gas, many offshore structures maybe damaged due to severe environment, an effective method for diagnosing structural damage is needed to locate the damage and e-valuate its severity. And genetic algorithm has become one of the most important global optimization tools and is widely used in many fields in resent years because of its simple operation and strong robustness. Based on the natural frequencies and mode shapes of the structure, the damage diagnosis of jacket offshore platform is attributed to an optimization problem and studied using genetic algorithm. According to the principle that the structure stiffness of a certain direction can be affected only when the brace bar of corresponding direction is damaged, an improved objective function is proposed based on noise measurement and the characteristics of modal identification for offshore platform, it is used as fitness function of genetic algorithm. Both numerical simulation and physical model test results show that the improved method can locate the structural damage and evaluate its severity of jacket offshore platform, thus it can improve the robustness of evolutionary searching and the reliability of damage diagnosis.

  13. High precipitation rate in a Middle Triassic carbonate platform: Implications on the relationship between seawater saturation state and carbonate production

    Science.gov (United States)

    Franceschi, Marco; Preto, Nereo; Marangon, Alessandro; Gattolin, Giovanni; Meda, Marco

    2016-06-01

    Three-dimensional geological modeling of the Middle Triassic Latemar carbonate platform is coupled with facies modal analysis to estimate its carbonate precipitation rate (G). The 3D model, strongly constrained by field data, encompasses a specific stratigraphic interval of the platform, bounded by two isochronous surfaces. Modal analysis of thin sections allows estimating the proportion of syndepositional vs postdepositional carbonate in the facies associations of the platform. This, together with the 3D facies distribution in the model that takes into account lateral and vertical facies variability, permits to calculate the volumes of syndepositional carbonate preserved at Latemar between the two considered isochrones. Given the peculiar characteristics of the platform, that does not show evidences of strong dissolution processes or large carbonate mass loss through export in the nearby basins, results can be used to estimate the average precipitation rate of the platform in the considered time interval. This estimate allows discussion in relation to models of ocean water saturation state (Ω) with respect to carbonates in the geological past, and comparison to the calculated precipitation rates of modern tropical coral reef ecosystems at global and reef scale. A high G value is found at Latemar and represents the first empirical confirmation that, in the Triassic, extremes in Ω may have triggered high carbonate precipitation in shallow water settings; moreover, comparison to modern reefs points to a possible common relationship that may link seawater Ω and precipitation rate in carbonate platform ecosystems through geological time.

  14. Remote Sensing Analysis of Recent Carbonate Platforms, East of Sabah: Potential Analogues for Miocene Carbonate Platforms of the South China Sea

    Directory of Open Access Journals (Sweden)

    Aicha Chalabi

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v7i3.141Recent carbonate platforms may provide useful analogues for fossil platforms and reefs, and could allow the generation of quantitative tools for the prediction of facies distribution, reservoir volumes, and reservoir quality. Data from these modern analogues would greatly enhance our ability to construct more reliable and calibrated reservoir models for carbonate fossil fields, such as the Miocene carbonate platforms of Central Luconia Province, Sarawak. In this study, carbonate facies maps and quantitative reservoir data will be generated by using remote sensing techniques. Satellite imageries over the carbonate platforms east of Sabah have been acquired and processed for generating facies maps. In order to produce a reliable facies map, the composition and grain size distribution of the sediments that make up individual facies must be known in order to determine the classes that have been identified on the initial facies maps. Samples collected from the Gaya and Selekan platforms were analyzed and the results of grain size analysis are illustrated.

  15. Climbing ripple structure and associated storm-lamination from a Proterozoic carbonate platform succession: Their environmental and petrogenetic significance

    Indian Academy of Sciences (India)

    Asru K Chaudhuri

    2005-06-01

    The Mesoproterozoic Pandikunta Limestone, a shallow water carbonate platform succession in the Pranhita–Godavari Valley, south India, displays well developed climbing ripple lamination and storm deposited structures, such as HCS, wave ripple-lamination, combined-flow ripple-lamination and low angle trough cross-stratification. Different types of stratification developed in calcisiltite with minor amounts of very fine quartz sand and silt. The climbing ripple structures exhibit a complex pattern of superposition of different types (type A, B and S) within cosets pointing to a fluctuating rate of suspension deposition versus bedform migration, and an unsteady character of the flow. Close association of climbing ripple structures, HCS with anisotropic geometry, wavy lamination and combined-flow ripple-lamination suggest that the structures were formed by storm generated combined-flow in a mid-shelf area above the storm wave base. The combined-flow that deposited the climbing ripple structures had a strong unidirectional flow component of variable magnitude. The climbing ripple structure occurs as a constituent of graded stratified beds with an ordered vertical sequence of different types of lamination, reflecting flow deceleration and increased rate of suspension deposition. It is inferred that the beds were deposited from high-density waning flows in the relatively deeper part of the ancient shelf. The structures indicate that the Pandikunta platform was subjected to open marine circulation and intense storm activities. The storm deposited beds, intercalated with beds of lime-mudstone, consist primarily of fine sand and silt size carbonate particles that were hydrodynamically similar to quartz silt. Detrital carbonate particles are structureless and are of variable roundness. The particles were generated as primary carbonate clasts in coastal areas by mechanical disintegration of rapidly lithified beds, stromatolites or laminites, and the finest grade was

  16. Mechanical professionals competency in off-shore platforms of petroleum production; Competencias dos profissionais de mecanica em plataformas off-shore de producao de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Marcio do Evangelho [PETROBRAS, Macae, RJ (Brazil)]. E-mail: marc@petrobras.com.br

    2003-07-01

    The present study approaches subjects relative to the industrial work and productive restructuring. The worker's role demanded in the flexible productive process was enlarged in other domains and abilities, as the relative ones to the cognition and the personality, in opposition to the model of the worker's training for execution of restricted tasks, conceptualized by the previous paradigm. This conjunction of domains, of technique and cognition is delineated by the term competence. The objective of the work is to describe present competencies of the mechanics medium level industrial technicians at their duties in petroleum production platforms. (author)

  17. Carbonate platform evidence of ocean acidification at the onset of the early Toarcian oceanic anoxic event

    Science.gov (United States)

    Trecalli, Alberto; Spangenberg, Jorge; Adatte, Thierry; Föllmi, Karl B.; Parente, Mariano

    2012-12-01

    The early Toarcian oceanic anoxic event (Early Jurassic;˜183 Myr ago) is associated with one of the largest negative carbon isotope excursion (CIE) in the whole Phanerozoic (3-7‰). Estimates of the magnitude and rate of CO2 injection in the ocean-atmosphere system are compatible with a scenario of ocean acidification. Many carbonate platforms drowned in the Pliensbachian, well before the early Toarcian event. In this paper we test the hypothesis of surface water ocean acidification by presenting data from a resilient carbonate platform: the Apennine Carbonate Platform of southern Italy. The studied sections document a dramatic shift of the carbonate factory from massive biocalcification to chemical precipitation. Lithiotis bivalves and calcareous algae (Palaeodasycladus mediterraneus), which were the most prolific carbonate producers of Pliensbachian carbonate platforms, disappear during the first phase of the early Toarcian CIE, before the most depleted values are reached. We discuss the local versus supraregional significance of this shift and propose a scenario involving abrupt decline of carbonate saturation, forced by CO2 release at the beginning of the early Toarcian CIE, followed by a calcification overshoot, driven by the recovery of ocean alkalinity. Attribution of the demise of carbonate platform hypercalcifiers to ocean acidification is supported by palaeophysiology and reinforced by experimental data on the detrimental effects of ocean acidification on recent shellfishes and calcareous algae.

  18. The U.S. Department of Energy's Reference Facility for Offshore Renewable Energy (RFORE): A New Platform for Research and Development (Invited)

    Science.gov (United States)

    Shaw, W. J.

    2013-12-01

    Offshore renewable energy represents a significant but essentially untapped electricity resource for the U.S. Offshore wind energy is attractive for a number of reasons, including the feasibility of using much larger and more efficient wind turbines than is possible on land. In many offshore regions near large population centers, the diurnal maximum in wind energy production is also closely matched to the diurnal maximum in electricity demand, easing the balancing of generation and load. Currently, however, the cost of offshore wind energy is not competitive with other energy sources, including terrestrial wind. Two significant contributing reasons for this are the cost of offshore wind resource assessment and fundamental gaps in knowledge of the behavior of winds and turbulence in the layer of the atmosphere spanned by the sweep of the turbine rotor. Resource assessment, a necessary step in securing financing for a wind project, is conventionally carried out on land using meteorological towers erected for a year or more. Comparable towers offshore are an order of magnitude more expensive to install. New technologies that promise to reduce these costs, such as Doppler lidars mounted on buoys, are being developed, but these need to be validated in the environment in which they will be used. There is currently no facility in the U.S. that can carry out such validations offshore. Research needs include evaluation and improvement of hub-height wind forecasts from regional forecast models in the marine boundary layer, understanding of turbulence characteristics that affect turbine loads and wind plant efficiency, and development of accurate representations of sea surface roughness and atmospheric thermodynamic stability on hub height winds. In response to these needs for validation and research, the U.S. Department of Energy is developing the Reference Facility for Offshore Renewable Energy (RFORE). The RFORE will feature a meteorological tower with wind, temperature

  19. A Comparison of Platform Options for Deep-water Floating Offshore Vertical Axis Wind Turbines: An Initial Study.

    Energy Technology Data Exchange (ETDEWEB)

    Bull, Diana L; Fowler, Matthew; Goupee, Andrew

    2014-08-01

    This analysis utilizes a 5 - MW VAWT topside design envelope created by Sandia National Laborator ies to compare floating platform options fo r each turbine in the design space. The platform designs are based on two existing designs, the OC3 Hywind spar - buoy and Principal Power's WindFloat semi - submersible. These designs are scaled using Froude - scaling relationships to determine an appropriately sized spar - buoy and semi - submersible design for each topside. Both the physical size of the required platform as well as mooring configurations are considered. Results are compared with a comparable 5 - MW HAWT in order to identify potential differences in the platform and mooring sizing between the VAWT and HAWT . The study shows that there is potential for cost savings due to reduced platform size requirements for the VAWT.

  20. Carbonate Platform Development and Stromatolite Morphogenesis: Constraints on Environmental and Biological Evolution

    Science.gov (United States)

    Grotzinger, John P.

    2003-01-01

    Work has been completed on the digital mapping of a terminal Proterozoic reef complex in Namibia. This complex formed an isolated carbonate platform developed downdip on a carbonate ramp of the Nama Group. The stratigraphic evolution of the platform was digitally reconstructed from an extensive dataset that was compiled by using digital surveying technologies. The platform comprises three accommodation cycles in which each subsequent cycle experienced progressively greater influence of a long-term accommodation increase. Aggradation and progradation during the first cycle resulted in a flat, uniform, sheet-like platform. The coarsening and shallowing-upward sequence representing the first cycle is dominated by columnar stromatolitic thrombolites and massive dolostones with interbedded mudstone-grainstone at the base of the sequence grading into cross-bedded dolostones. The second cycle features aggradation, formation of a distinct margin containing thrombolite mounds and domes, and the development of a bucket geometry. Columnar stromatolitic thrombolites dominate the platform interior. The final stage of platform development shows a deepening trend with initial aggradation and formation of well-bedded, thin deposits in the interior and mound development at the margins. While the interior drowned, the platform margin kept up with rising sea level and a complex pinnacle reef formed containing fused and coalesced thrombolite mounds flanked by bioclastic grainstones (containing Cloudina and Namacalathus fossils) and collapse breccias. A set of isolated large thrombolite mounds flanked by shales indicate the final stage of the carbonate platform. During a progressive increase in accommodation, a flat-topped isolated carbonate platform becomes aerially less extensive by either backstepping or formation of smaller pinnacles or a combination of both. The overall geometric evolution of the studied platform from flat-topped to bucket with elevated margins is recorded in many

  1. Integrated TLWP-FPSO (Tension Leg Wellhead Platform-Floating Production, Storage and Offloading Vessel) solution for deep water field development offshore Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Neil; Heidari, Homayoun; Large, Sean [SBM Atlantia, Houston, TX (United States)

    2008-07-01

    A development strategy for some deep water fields offshore Brazil consists of a TLWP (Tension-Leg Wellhead Platform) connected by a fluid transfer line to a nearby FPSO. The TLWP provides dry tree riser support, drilling capability, manifolding, test separation, and multiphase pumping, while all other functions including full processing, accommodations, gas compression, power generation, water and chemical injection, storage and offloading, and gas export are provided by the FPSO. In one such scenario, the TLWP and FPSO could be connected using SBM's GAP mid-water fluid transfer line technology, with SBM Atlantia's FourStar{sup TM} hull concept for the TLWP. The FourStar{sup TM} is designed to be quayside- or float over-integrable, thus eliminating the need for a heavy lift installation vessel; while being structurally and hydrodynamically superior to other TLP alternatives. This paper presents a description of the technical development of the FourStar{sup TM} TLP and an overview of the GAP technology, and discusses the characteristics of an integrated TLWP-GAP-FPSO field development solution for a typical application offshore Brazil (author)

  2. Environmental data for the planning of off-shore wind parks from the EnerGEO Platform of Integrated Assessment (PIA)

    International Nuclear Information System (INIS)

    The EU-sponsored EnerGEO project aims at providing decision makers with a modelling platform to assess the environmental impacts of different sources of renewable energy. One of the pillars of the project is the Wind Energy Pilot, addressing the effects of offshore wind parks on air pollution and energy use. The methods used in the pilot and the underlying environmental databases are integrated into a WebGIS client tool and made available to the public. This paper is dedicated to describing the environmental databases and supporting data incorporated in the client tool. A 27-km resolution, 11-year wind database is created using the WRF model. The wind database is used to assess the wind climate in the north-west Atlantic region and to derive the potential power output from offshore wind parks. Auxiliary data concerning water depth, distance to shore and distance to the nearest suitable port are created to aid the planning and maintenance phases. Seasonal workability conditions are assessed using a 20-year wave database. The distance at which future wind parks should be placed to exhibit different wind climates is investigated. (orig.)

  3. The Preparation and Survey of Towing Operation for Offshore Mobile Platform%移动平台拖航作业准备及检验

    Institute of Scientific and Technical Information of China (English)

    韩志强

    2001-01-01

    According to the rules requirement and practical experience,the preparation and survey of towing operation for offshore mobile platform are summarized and discussed.These items include the analysis of towing stability,the selection of weather condition,the estimation of towing force and the equipping of towing facilities.Some relevant proposals are put forward in this paper as well.%根据各种规定及实际工作经验,对移动平台迁航作业中的拖航稳性分析、气象条件的合理选择、拖带力的估算、拖曳设备配备及检验等问题进行了总结和探讨,并提出了相关建议,可作为实际工作的参考。

  4. Evolution of multi-mineral formation evaluation using LWD data in complex carbonates offshore Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ferraris, Paolo; Borovskaya, Irina [Schlumberger, Houston, TX (United States)

    2012-07-01

    Petrophysical Formation Evaluation using Logging While Drilling (LWD) measurements is a new requisite when drilling in carbonates reservoirs offshore Brazil. These reservoirs are difficult to characterize due to an unusual mixture of the minerals constituting the matrix and affecting rock texture. As wells are getting deeper and more expensive, an early identification of the drilled targets potential is necessary for valuable decisions. Brazil operators have been especially demanding towards service providers, pushing for development of suitable services able to positively identify and quantify not only the presence of hydrocarbons but also their flowing capability. In addition to the standard gamma ray / resistivity / porosity and density measurements, three new measurements have proven to be critical to evaluate complex carbonate formations: Nuclear Magnetic Resonance (NMR), Spectroscopy and Capture Cross-Section (sigma). Under appropriate logging conditions, NMR data provides lithology independent porosity, bound and free fluids fractions, reservoir texture and permeability. Capture Spectroscopy allows assessment of mineral composition in terms of calcite, dolomite, quartz and clay fractions, and in addition highlights presence of other heavier minerals. Finally, sigma allows performing a volumetric formation evaluation without requiring custom optimization of the classical exponents used in all forms of resistivity saturation equations. All these new measurements are inherently statistical and if provided by wireline after drilling the well they may result in significant usage of rig time. When acquired simultaneously while drilling they have three very clear advantages: 1) no extra rig time, 2) improved statistics due to long formation exposure (drilling these carbonates is a slow process and rate of penetration (ROP) rarely exceeds 10 m/hr), 3) less invasion effect and better hole condition. This paper describes the development of two LWD tools performing the

  5. 海洋石油平台涂装工程涂料损耗分析%Analysis of Paint Loss During Coating Operation in Offshore Platform

    Institute of Scientific and Technical Information of China (English)

    钱洪飞

    2012-01-01

    The paint loss control always be the key step of coating work, due to various factors of paint loss, it is difficult for the designers, constructors and paint manufacturers to calculate the paint loss percentage accurately, against for construction management and cost control. Offshore Engineering is the emerging industry, the paint loss rate in shipbuilding industry is always be adopted for calculation of offshore coating activities, but they are different in coating process, structures and coating equipment, leading to big difference in paint loss between two industries. Based on the accumulating usage data of offshore paint in many domestic offshore platforms, the factors affecting the paint loss, such as surface roughness, coating process, steelwork geometry, operation technology, environmental factors, paint waste and paint maintenance, etc. Were analysed to try to calculate paint loss accurately. By working out measure to decrease wastage and strict control in application, it can be ensured that the paint loss factor for new built offshore platforms will be con-troled within 1.0 to 1.5, and make the paint loss control much accurately.%涂料的损耗控制一直都是涂装施工的重要环节,由于造成损耗的因素过多,设计方、施工方、涤料制造商都很难精确地计算损耗系数,很不利于施工管理和成本控制.海洋工程是个新兴的产业,施工中涂料的损耗常借鉴造船行业的经验,但由于二者在涂装工艺、结构、涂装设备等方面存在着很大的不同,导致损耗的差别很大.通过对国内石油行业多个海洋石油平台的涂装工程施工,积累了海洋工程涂料的使用数据,对影响涂料损耗的表面粗糙度、涂装方式、钢结构的几何形状、操作技术、环境因素、涂料浪费、修补等各项因素进行分析,尝试对涂料的损耗系数进行精确的统计.通过制定减少损耗的措施,在施工中严格控制,保证了新建海洋石油平台

  6. Ice-Induced Fatigue Analysis by Spectral Approach for Offshore Jacket Platforms with Ice-Breaking Cones

    Institute of Scientific and Technical Information of China (English)

    YUE Qian-jin; LIU Yuan; ZHANG Ri-xiang; QU Yan; WANG Rui-xue

    2007-01-01

    The spectral methods and ice-induced fatigue analysis are discussed based on Miner's linear cumulative fatigue hypothesis and S-N curve data.According to the long-term data of full-scale tests on the platforms in the Bohai Sea,the ice force spectrum of conical structures and the fatigue environmental model are established.Moreover,the finite element model of JZ20-2MSW platform,an example of ice-induced fatigue analysis,is built with ANSYS software.The mode analysis and dynamic analysis in frequency domain under all kinds of ice fatigue work conditions are carried on,and the fatigue life of the structure is estimated in detail.The methods in this paper can be helpful in ice-induced fatigue analysis of ice-resistant platforms.

  7. Organic carbon isotopes of the Sinian and Early Cambrian black shales on Yangtze Platform, China

    Institute of Scientific and Technical Information of China (English)

    李任伟; 卢家烂; 张淑坤; 雷加锦

    1999-01-01

    Organic matter of the Sinian and early Cambrian black shales on the Yangtze Platform belongs to the light carbon group of isotopes with the δ13C values from - 27 % to -35 % , which are lower than those of the contemporaneously deposited carbonates and phosphorites. A carbon isotope-stratified paleooceanographic model caused by upwelling is proposed, which can be used not only to interpret the characteristics of organic carbon isotopic compositions of the black shales, but also to interpret the paleogeographic difference in the organic carbon isotope compositions of various types of sedimentary rocks.

  8. 海上平台火炬放空天然气回收利用研究%Study on Rescyling of Flaring Gas from Offshore Platforms

    Institute of Scientific and Technical Information of China (English)

    胡徐彦

    2015-01-01

    对现有闲置的12"输油海管线进行了分析校核,并通过工艺改造将其用于天然气的输送。工艺、强度、防腐、结构等方面的校核结果表明,该海管在最大操作压力不超过1.0 MPa,最大操作温度不超过40℃时,符合规范要求,具备安全使用条件。经适当的工艺改造后该12"海管最大输气量为28.6万方/天,完全满足天然气的输送要求,实现该海上平台伴生气全部回收利用,达到零排放的目标,对海洋油气田的开发生产、改造具有良好的参考价值。%The idle 12" oil pipeline was checked, and transformation process was studied to transform it to natural gas. Conditions, strength, corrosion and structure of the oil pipeline were studied. The result showed that it can be safety working under the pressure 1.0 MPa and under the temperature 40 ℃. After appropriate process modification, the oil pipeline can transport 286 thousand cubic meters as maximum peer day, and fully met the requirements for transport of natural gas to completely recycle associated gas of the offshore platforms, the goal of zero emissions can be achieved. It will be a good reference for the development and transformation of offshore oilfield.

  9. Meals on Wheels? A Decade of Megafaunal Visual and Acoustic Observations from Offshore Oil & Gas Rigs and Platforms in the North and Irish Seas.

    Science.gov (United States)

    Todd, Victoria Louise Georgia; Warley, Jane Clare; Todd, Ian Boyer

    2016-01-01

    A decade of visual and acoustic detections of marine megafauna around offshore Oil & Gas (O&G) installations in the North and Irish Seas are presented. Marine megafauna activity was monitored visually and acoustically by Joint Nature Conservation Committee (JNCC) qualified and experienced Marine Mammal Observers (MMO) and Passive Acoustic Monitoring (PAM) Operators respectively, with real-time towed PAM in combination with industry standard software, PAMGuard. Monitoring was performed during routine O&G industrial operations for underwater noise mitigation purposes, and to ensure adherence to regulatory guidelines. Incidental sightings by off-effort MMOs and installation crew were also reported. Visual and acoustic monitoring spanned 55 non-consecutive days between 2004 and 2014. A total of 47 marine mammal sightings were recorded by MMOs on dedicated watch, and 10 incidental sightings of marine megafauna were reported over 10 years. Species included: harbour porpoise (Phocoena phocoena), Atlantic white-sided dolphin (Lagenorhynchus acutus), white beaked dolphin (Lagenorhynchus albirostris), common dolphin (Delphinus delphis), minke whale (Balaenoptera acutorostrata), common seal (Phoca vitulina), grey seal (Halichoerus grypus) and, basking shark (Cetorhinus maximus). Passive Acoustic Monitoring was conducted on two occasions in 2014; 160 PAM hours over 12 days recorded a total of 308 individual clicks identified as harbour porpoises. These appear to be the first such acoustic detections obtained from a North Sea drilling rig whilst using a typically configured hydrophone array designed for towing in combination with real-time PAMGuard software. This study provides evidence that marine megafauna are present around mobile and stationary offshore O&G installations during routine operational activities. On this basis, Environmental Impact Assessments (EIAs) for decommissioning O&G platforms should be carried-out on a case-by-case basis, and must include provisions for

  10. Meals on Wheels? A Decade of Megafaunal Visual and Acoustic Observations from Offshore Oil & Gas Rigs and Platforms in the North and Irish Seas

    Science.gov (United States)

    Todd, Victoria Louise Georgia; Todd, Ian Boyer

    2016-01-01

    A decade of visual and acoustic detections of marine megafauna around offshore Oil & Gas (O&G) installations in the North and Irish Seas are presented. Marine megafauna activity was monitored visually and acoustically by Joint Nature Conservation Committee (JNCC) qualified and experienced Marine Mammal Observers (MMO) and Passive Acoustic Monitoring (PAM) Operators respectively, with real-time towed PAM in combination with industry standard software, PAMGuard. Monitoring was performed during routine O&G industrial operations for underwater noise mitigation purposes, and to ensure adherence to regulatory guidelines. Incidental sightings by off-effort MMOs and installation crew were also reported. Visual and acoustic monitoring spanned 55 non-consecutive days between 2004 and 2014. A total of 47 marine mammal sightings were recorded by MMOs on dedicated watch, and 10 incidental sightings of marine megafauna were reported over 10 years. Species included: harbour porpoise (Phocoena phocoena), Atlantic white-sided dolphin (Lagenorhynchus acutus), white beaked dolphin (Lagenorhynchus albirostris), common dolphin (Delphinus delphis), minke whale (Balaenoptera acutorostrata), common seal (Phoca vitulina), grey seal (Halichoerus grypus) and, basking shark (Cetorhinus maximus). Passive Acoustic Monitoring was conducted on two occasions in 2014; 160 PAM hours over 12 days recorded a total of 308 individual clicks identified as harbour porpoises. These appear to be the first such acoustic detections obtained from a North Sea drilling rig whilst using a typically configured hydrophone array designed for towing in combination with real-time PAMGuard software. This study provides evidence that marine megafauna are present around mobile and stationary offshore O&G installations during routine operational activities. On this basis, Environmental Impact Assessments (EIAs) for decommissioning O&G platforms should be carried-out on a case-by-case basis, and must include provisions for

  11. Neuro-fuzzy control strategy for an offshore steel jacket platform subjected to wave-induced forces using magneto rheological dampers

    International Nuclear Information System (INIS)

    Magnetorheological (MR) damper is a prominent semi-active control device to vibrate mitigation of structures. Due to the inherent non-linear nature of MR damper, an intelligent non-linear neuro-fuzzy control strategy is designed to control wave-induced vibration of an offshore steel jacket platform equipped with MR dampers. In the proposed control system, a dynamic-feedback neural network is adapted to model non-linear dynamic system, and the fuzzy logic controller is used to determine the control forces of MR dampers. By use of two feed forward neural networks required voltages and actual MR damper forces are obtained, in which the first neural network and the second one acts as the inverse dynamics model, and the forward dynamics model of the MR dampers, respectively. The most important characteristic of the proposed intelligent control strategy is its inherent robustness and its ability to handle the non-linear behavior of the system. Besides, no mathematical model needed to calculate forces produced by MR dampers. According to linearized Morison equation, wave-induced forces are determined. The performance of the proposed neuro-fuzzy control system is compared with that of a traditional semi-active control strategy, i.e., clipped optimal control system with LQG-target controller, through computer simulations, while the uncontrolled system response is used as the baseline. It is demonstrated that the design of proposed control system framework is more effective than that of the clipped optimal control scheme with LQG-target controller to reduce the vibration of offshore structure. Furthermore, the control strategy is very important for semi-active control

  12. Bridging operation and design. The encounter between practical and discipline-based knowledge in offshore platform design

    Energy Technology Data Exchange (ETDEWEB)

    Husemoen, Mette Suzanne

    1997-12-31

    This thesis investigates the relationship between operations and design and the design process, taking as case studies the two new platforms of Phillips Petroleum Company Norway on Ekofisk II, the Ekofisk 2/4 X drilling and wellhead platform and the Ekofisk 2/4 J processing and transportation platform. The emphasis has been on how to take into account operational experience in design. The two research questions are: (1) Are operations and design two communities-of-practice based on different kinds of knowledge?, and (2) What are the conditions for bridging knowledge in operations and design? From the theory reviewed and the field data presented the study concludes that physical closeness and integration of operations and design personnel, experience from the other community-of-practice, and mutual sympathy, trust, and respect, are important factors in bridging knowledge of the operations and design communities-of-practice and creating innovative solutions in design which transcend the existing knowledge in operations and design. 66 refs., 28 figs., 8 tabs.

  13. Mesozoic carbonate-siliciclastic platform to basin systems of a South Tethyan margin (Egypt, East Mediterranean)

    Science.gov (United States)

    Tassy, Aurélie; Crouzy, Emmanuel; Gorini, Christian; Rubino, Jean-Loup

    2015-04-01

    The Mesozoïc Egyptian margin is the south margin of a remnant of the Neo-Tethys Ocean, at the African northern plate boundary. East Mediterranean basin developed during the late Triassic-Early Jurassic rifting with a NW-SE opening direction (Frizon de Lamotte et al., 2011). During Mesozoïc, Egypt margin was a transform margin with a NW-SE orientation of transform faults. In the Eastern Mediterranean basin, Mesozoïc margins are characterized by mixed carbonate-siliciclastics platforms where subsidence and eustacy are the main parameters controlling the facies distribution and geometries of the platform-to-basin transition. Geometries and facies on the platform-slope-basin system, today well constrained on the Levant area, where still poorly known on the Egyptian margin. Geometries and stratigraphic architecture of the Egyptian margin are revealed, thanks to a regional seismic and well data-base provided by an industrial-academic group (GRI, Total). The objective is to understand the sismostratigraphic architecture of the platform-slope-basin system in a key area from Western Desert to Nile delta and Levant margin. Mapping of the top Jurassic and top Cretaceous show seismic geomorphology of the margin, with the cartography of the hinge line from Western Desert to Sinaï. During the Jurassic, carbonate platform show a prograding profile and a distally thickening of the external platform, non-abrupt slope profiles, and palaeovalleys incisions. Since the Cretaceous, the aggrading and retrograding mixed carbonate-siliciclastic platform show an alternation of steep NW-SE oblique segments and distally steepened segments. These structures of the platform edge are strongly controlled by the inherited tethyan transform directions. Along the hinge line, embayments are interpreted as megaslides. The basin infilling is characterised by an alternation of chaotic seismic facies and high amplitude reflectors onlaping the paleoslopes. MTC deposits can mobilize thick sedimentary

  14. 海洋平台立管系统的三维动态响应仿真研究%Research on Three-dimensional Dynamic Response Simulation of Offshore Platform Riser System

    Institute of Scientific and Technical Information of China (English)

    董鹏; 朱克强; 秦道武

    2011-01-01

    Offshore platform riser system is an important part of production system. The dynamics characteristics may affect the stability and security of production platform directly. In that case, the numerical analysis of dynamic response characteristics is very important. The lumped-parameter time-domain analysis method is applied for three-dimensional simulation of offshore platform riser system. The 4th Runge-Kutta method is adopted for solution of integral equation. Analysis is made for the dynamic response of offshore platform riser system in inertial coordinate system.%海洋平台立管是其生产系统的主要组成部分,立管系统的动力学特性直接影响生产平台的稳定性和安全性,针对海洋平台立管系统动态响应特性的数值分析显得尤为重要.本研究以凝集参数时域分析法对海洋平台立管系统进行三维仿真模拟,用四阶Runge—Kutta法进行积分求解,分析惯性坐标系下海洋平台立管系统的动态响应.

  15. Carbon isotope stratigraphy of an ancient (Ordovician) Bahamian-type carbonate platform: Implications for preservation of global seawater trends

    Science.gov (United States)

    Saltzman, M.; Leslie, S. A.; Edwards, C. T.; Diamond, C. W.; Trigg, C. R.; Sedlacek, A. R.

    2013-12-01

    Carbon isotope stratigraphy has a unique role in the interpretation of Earth history as one of the few geochemical proxies that have been widely applied throughout the geologic time scale, from the Precambrian to the Recent, as both a global correlation tool and proxy for the carbon cycle. However, in addition to consideration of the role of diagenesis, numerous studies have raised awareness of the fact that C-isotope trends derived from ancient carbonate platforms may not be representative of dissolved inorganic carbon from a well-mixed global ocean reservoir. Furthermore, the larger carbon isotopic fractionation in the formation of aragonite versus calcite from seawater must be taken into account. All three of these variables (diagenesis, water mass residence time, % aragonite) may change in response to sea level, producing trends in C-isotopes on ancient carbonate platforms that are unrelated to the global carbon cycle. Global carbon cycle fluxes may also have a cause-effect relationship with sea level changes, further complicating interpretations of stratigraphic trends in carbon isotopes from ancient platform environments. Studies of C-isotopes in modern carbonate platform settings such as the Great Bahama Bank (GBB) provide important analogues in addressing whether or not ancient platforms are likely to preserve a record of carbon cycling in the global ocean. Swart et al. (2009) found that waters of the GBB had generally the same or elevated values (ranging from +0.5‰ to +2.5‰) compared to the global oceans, interpreted as reflecting differential photosynthetic fractionation and precipitation of calcium carbonate (which lowers pH and converts bicarbonate into 12-C enriched carbon dioxide, leaving residual bicarbonate heavier). Carbonate sediments of the GBB have elevated C-isotopes, not only because of the high C-isotope composition of the overlying waters, but also due to the greater fractionation associated with precipitation of aragonite versus calcite

  16. Carbon and oxygen isotope geochemistry of Ediacaran outer platform carbonates, Paraguay Belt, central Brazil

    Directory of Open Access Journals (Sweden)

    Claudio Riccomini

    2007-09-01

    Full Text Available After the late Cryogenian glaciation the central region of Brazil was the site of extensive deposition of platformal carbonates of the Araras Group. This group includes a basal cap carbonate sequence succeeded by transgressive, deep platform deposits of bituminous lime mudstone and shale. Facies and stratigraphic data combined with carbon and oxygen isotopic analyses of the most complete section of the transgressive deposits, exposed in the Guia syncline, were used to evaluate the depositional paleoenvironment and to test the correlation of these deposits along the belt and with other units worldwide. The studied succession consists of 150 m thick tabular beds of black to grey lime mudstone and shale with predominantly negative delta13C PDB values around -2.5 to -1‰ . The delta13C PDB profile of Guia syncline shows a clear correlation with the upper portion of Guia Formation in the Cáceres region, about 200 km to the southwest. The delta13C PDB profile of the Araras Group is comparable with delta13C PDB profiles of Ediacaran units of the southern Paraguay Belt, western Canada, and the Congo and Kalahari cratons. Moreover, facies distribution, stratigraphy and the carbon isotopic profile of the Araras Group match the middle Tsumeb Subgroup in Namibia, which reinforces the Ediacaran age assigned to the Araras Group.Após a glaciação do final do Criogeniano, a região central do Brasil foi palco de extensa deposição de carbonatos plataformais do Grupo Araras. Este grupo inclui na sua base uma seqüência de capa carbonática sucedida por depósitos transgressivos de calcilutitos betuminosos e folhelhos de plataforma profunda. Dados de fácies e estratigráficos combinados com análises isotópicas de carbono e oxigênio da seção mais completa desses depósitos transgressivos, expostos no sinclinal da Guia, foram empregados para avaliar o paleambiente deposicional e para testar a correlação desses depósitos ao longo da faixa e tamb

  17. Developing a molecular platform for potential carbon dioxide fixing

    DEFF Research Database (Denmark)

    Mikkelsen, Mette; Jørgensen, Mikkel; Krebs, Frederik C

    2010-01-01

    This paper presents an attempt to develop a new system for fixing carbon dioxide from the atmosphere. The proposed molecular system has been designed to have the capacity to spontaneously bind CO2 from the atmosphere with high affinity. The molecular system is furthermore designed to have the...... ability to liberate CO2 at a later stage in the process, i.e., in a separate compartment. The liberated CO2 presents a carbon neutral way of obtaining pure CO2. The proposed molecular system is based on a small stable organic molecule that potentially have two forms: one without bound CO2 and one with...

  18. Carbon nanotubes/pentacyaneferrate-modified chitosan nanocomposites platforms for reagentless glucose biosensing.

    Science.gov (United States)

    Parra-Alfambra, A M; Casero, E; Ruiz, M A; Vázquez, L; Pariente, F; Lorenzo, E

    2011-08-01

    The design, characterization and applicability of a nanostructured biosensor platform are described. The biosensor is developed through the immobilization of three components: a polymeric chitosan network previously modified with a redox mediator (denoted as PCF-Pyr-Ch), an enzyme (glucose oxidase, chosen as a model) and carbon nanotubes onto a solid glassy carbon electrode (C). In order to assess the influence of the nanomaterial in the performance of the resulting analytical device, a second biosensor, free of carbon nanotubes, is developed. The characterization of both biosensing platforms was performed in aqueous phosphate buffer solutions using atomic force microscopy technique. In the presence of glucose, both systems exhibit a clear electrocatalytic activity, and glucose could be amperometrically determined at +0.35 V versus Ag/AgCl. The performance of both biosensors was evaluated in terms of sensitivity, detection limit and linear response range. Finally, the enhancement of the analytical response induced by the presence of carbon nanotubes was evaluated. PMID:21633839

  19. Late Pleistocene stratigraphy of a carbonate platform margin, Exumas, Bahamas

    Science.gov (United States)

    Aalto, K. R.; Dill, Robert F.

    1996-05-01

    Detailed field studies of the southern Exuma Cays on the eastern margin of the Great Bahama Bank show a complex history of late Pleistocene island construction. Pleistocene rocks include island core eolianites, overlain at island margins by fossil patch reefs and reef sands, which in turn are overlain by, and/or grade laterally into, talus breccia cones derived from the erosion of island core eolianite at paleo-seacliffs situated at approximately 5-6 m above present mean high tide. Laminated pedogenic calcrete widely caps Pleistocene rocks. Minor zones of penetrative subsurface calcretization, developed in association with root growth, occur along permeable horizons, including: contacts between talus units or crossbed sets, along tension joints, and (possibly) at the Pleistocene reef-eolianite contact. Among Pleistocene eolianite samples studied in thin-section, the relative proportions of ooids-intraclasts+grapestones-skeletal grains-peloids are approximately 48:39:6:7. Marginal to the Exuma Sound and on the Brigantine Cays, a greater proportion of ooids have peloidal nuclei and cortices with numerous laminae, which may reflect ooid derivation from shelf margin and broad platform interior regions that were characterized by high wave energy during ooid formation. Between these two areas, ooids are more commonly superficial and have cortices with few laminae and nuclei composed of subrounded micrite or pelmicrite intraclasts. Such ooid nuclei are most likely derived from storm erosion of partially cemented seafloor muds. Some skeletal-rich eolianite in this region may reflect local sediment input from platform margin reefs, or may be part of an older(?) stratigraphic unit.

  20. Offshore-Grid

    OpenAIRE

    Theisen, Matias Ebbe

    2011-01-01

    This thesis has been conducted in cooperation with the Norwegian transmission system operator, Statnett, and their research on two new interconnectors linking Norway to England and Germany. The work presented in this thesis has considered one of these interconnectors, with a third terminal connected offshore to allow for integration of offshore wind power and oil platforms, as shown in fig.~ref{fig:theGrid}.Investigation of the voltage source converters (VSCs) control ability as well as opera...

  1. Pore Type Classification on Carbonate Reservoir in Offshore Sarawak using Rock Physics Model and Rock Digital Images

    International Nuclear Information System (INIS)

    It has been recognized that carbonate reservoirs are one of the biggest sources of hydrocarbon. Clearly, the evaluation of these reservoirs is important and critical. For rigorous reservoir characterization and performance prediction from geophysical measurements, the exact interpretation of geophysical response of different carbonate pore types is crucial. Yet, the characterization of carbonate reservoir rocks is difficult due to their complex pore systems. The significant diagenesis process and complex depositional environment makes pore systems in carbonates far more complicated than in clastics. Therefore, it is difficult to establish rock physics model for carbonate rock type. In this paper, we evaluate the possible rock physics model of 20 core plugs of a Miocene carbonate platform in Central Luconia, Sarawak. The published laboratory data of this area were used as an input to create the carbonate rock physics models. The elastic properties were analyzed to examine the validity of an existing analytical carbonate rock physics model. We integrate the Xu-Payne Differential Effective Medium (DEM) Model and the elastic modulus which was simulated from a digital carbonate rock image using Finite Element Modeling. The results of this integration matched well for the separation of carbonate pore types and sonic P-wave velocity obtained from laboratory measurement. Thus, the results of this study show that the integration of rock digital image and theoretical rock physics might improve the elastic properties prediction and useful for more advance geophysical techniques (e.g. Seismic Inversion) of carbonate reservoir in Sarawak

  2. Relative sea level changes and carbonate factories of the Urgonian platform, Hauterivian-Aptian, Vercors, France

    Energy Technology Data Exchange (ETDEWEB)

    Jacquin, T.; Vail, P.R. (Rice Univ., Houston, TX (United States))

    1993-09-01

    Long term second-order and short term third-order relative sea level changes control the development of the Urgonian platform in the French western Alps. At a second-order scale the Urgonian platform develops over the drowned late Berriasian-middle Valanginian platform. During the regressive phase, the platform progrades tens of kilometers toward the southeast. During the transgressive phase, the platform aggrades, backsteps, and then drowns. Subsidence analysis indicates this second-order cycle is controlled by changes in rates of subsidence or possibly tectono-eustasy. At a third-order scale, two types of carbonate factories alternate within the Urgonian platform, highstand and lowstand. The Urgonian facies is a product of highstand factories which changes laterally into platform-rim buildups with corals and stromatoporids and rapidly thins basinward by sediment starvation. Both the bioclastic turbidites and the large seismic-scale clinoforms visible in the outcrops of the southern Vercors are the products of the lowstand factories. These lowstand turbidites and shoal-water prograding grainstones consist of three distinct units: a lower basinal sheet of platform-derived massive grainstones, a thick apron of fine-grained turbidites and mudstones with proximal channels, some of which are filled with coarse grainstones, and a prograding unit pinching out at the offlap break of the previous highstand in the area of the stromatoporids. The prograding grainstones are matrix-poor cross-stratified beds in the shallow water areas and facies change to mudstones in the basin. The lack of boundstones in the proximal parts of the lowstand prograding intervals, together with the lack of well-developed early cementation, ooids, and aggregates suggest that these lowstand factories were temperate-water systems. They contrast with the Urgonian highstand factories that were particularly well equipped to keep up with sea level rises such as modern tropical carbonates.

  3. Functionalized carbon nanotubes: Facile development of gas sensor platform

    Science.gov (United States)

    Rushi, Arti D.; Gaikwad, S.; Deshmukh, M.; Patil, H.; Bodkhe, G.; Shirsat, Mahendra D.

    2016-05-01

    In the present investigation, research efforts were directed towards the facile fabrication of sensor devices for the detection of gaseous analytes. Single Wall Carbon nanotubes, the highest prominent representative of functional nanomaterials, were employed for the sensor development. High surface to volume ratio of CNTs facilitate to improve overall sensor performance. To achieve enhanced sensing characteristics, CNTs were functionalized with tetraphenyl porphyrin. Fabricated sensor devices were subjected to the structural, electrical as well as sensing characteristics. Observed results infer that the fabricated sensor shows excellent sensing characteristics towards propanone below their PEL level.

  4. 基于状态反馈的海洋平台TMD振动控制技术研究%The Study on Vibration Control of Offshore Platform with TMD Based on States Feedback

    Institute of Scientific and Technical Information of China (English)

    李宁; 王树青

    2011-01-01

    The structural vibration control of offshore platform under random wave loading by using Tuned Mass Damper (TMD) is investigated. The model of offshore platform -TMD is established. Tuned Mass Damper (TMD) is installed on the offshore platform for sharing the energy of main structure* so that vibration of the main structure can be controlled. Optimal TMD parameters can be determined by analyzing the energy dissipation and transmission of the structure-TMD. Meanwhile, states feedback is introduced in the structure -TMD. Optimal controlling force is determined based on feedback from structural responses. By use of pole assignment method, feedback gain is selected suitably. The vibration could be reduced further.%研究了随机波浪载荷作用下海洋平台的TMD振动控制,建立了TMD-海洋平台振动模型,从TMD能量分析的角度对TMD参数进行了优化设计;同时将状态反馈引入系统,依据结构响应的反馈信息确定控制力,运用极点配置法,选取适当的反馈增益K,从而进一步达到控制结构振动的目的.

  5. Research on systematization and advancement of shipbuilding production management for flexible and agile response for high value offshore platform

    Science.gov (United States)

    Song, Young-Joo; Woo, Jong-Hun; Shin, Jong-Gye

    2011-09-01

    Recently, the speed of change related with enterprise management is getting faster than ever owing to the competition among companies, technique diffusion, shortening of product lifecycle, excessive supply of market. For the example, the compliance condition (such as delivery date, product quality, etc.) from the ship owner is getting complicated and the needs for the new product such as FPSO, FSRU are coming to fore. This paradigm shift emphasize the rapid response rather than the competitive price, flexibility and agility rather than effective and optimal perspective for the domestic shipbuilding company. So, domestic shipbuilding companies have to secure agile and flexible ship production environment that could respond change of market and requirements of customers in order to continue a competitive edge in the world market. In this paper, I'm going to define a standard shipbuilding production management system by investigating the environment of domestic major shipbuilding companies. Also, I'm going to propose a unified ship production management and system for the operation of unified management through detail analysis of the activities and the data flow of ship production management. And, the system functions for the strategic approach of ship production management are investigated through the business administration tools such as performance pyramid, VDT and BSC. Lastly, the research of applying strategic KPI to the digital shipyard as virtual execution platform is conducted.

  6. Cambrian Series 3 carbonate platform of Korea dominated by microbial-sponge reefs

    Science.gov (United States)

    Hong, Jongsun; Lee, Jeong-Hyun; Choh, Suk-Joo; Lee, Dong-Jin

    2016-07-01

    Metazoans have been considered as negligible components of Cambrian Series 3 and Furongian microbial-dominated reefs, in contrast to their presence in earlier Terreneuvian-Cambrian Series 2 microbial-archaeocyath reefs. However, recent discoveries of sponges in Cambrian Series 3-Furongian reefs of Australia, China, Iran, USA, and Korea have raised question regarding their contribution in terms of carbonate platform development, which have never been assessed. This study examines Cambrian Series 3 deposits of the Daegi Formation, Korea to elucidate this question. The 100-m-thick middle part of the Daegi Formation is dominated by boundstone facies, which occupies 45% of the study interval, as well as bioclastic wackestone to packstone, bioclastic grainstone, and ooid packstone to grainstone facies. The Daegi reefs are primarily thrombolitic in composition, with 90% (n = 26/29) of the reefs containing an average of 9% sponges in aerial percentage calculated from thin sections. Lithistid sponges composed of peloidal fabrics, some desma spicules, and spicule networks commonly occupy the interstitial space in microbial clusters, are encrusted by mesoclots and Epiphyton, and are surrounded by micrite. Subordinate non-lithistid demosponges occur within clusters of microbial elements. The middle Daegi Formation can be largely subdivided into shoal environment dominated by grainstone to packstone facies and shallow subtidal platform interior environment located behind shoal with wackestone to packstone facies. The microbial-sponge reefs mainly developed around platform interior as patch reefs. The current study indicates that metazoans in the form of lithistid and non-lithistid demosponges are nearly ubiquitously incorporated in Daegi reefs and contributed greatly to the formation of microbial-sponge reefs as well as carbonate platform during the time. Study of these microbial-sponge reefs and their distribution within the carbonate platform may help us to understand how

  7. Cellphones as a Distributed Platform for Black Carbon Data Collection

    Science.gov (United States)

    Ramanathan, N.; Ramana, M.; Lukac, M. L.; Siva, P.; Ahmed, T.; Kar, A.; Rehman, I.; Ramanathan, V.

    2010-12-01

    Black carbon (BC), the visible component of soot that gives emissions such as diesel engine exhaust their dark color, has come to be recognized as a major contributor to global warming, and a frontline concern for climate change strategies (Ramanathan 2001, Jacobson 2010). We have developed a new low-cost instrument for gathering and measuring atmospheric BC concentrations that leverages cellphones to transmit data from an air filtration unit to a centralized database for analysis. Our new system relies on image processing techniques, as opposed to other more expensive optical methods, to interpret images of filters captured with a cellphone camera. As a result, the entire system costs less than $500 (and is orders of magnitude cheaper than an Aethalometer, the prevailing method for measuring atmospheric BC). We are working with three community groups in Los Angeles, and will recruit three groups in the San Francisco Bay Area, to enable 40 citizens to be actively engaged in monitoring BC across California. We are working with The Energy Resources Institute, an international NGO based in India, to deploy this instrument with 60 people in conjunction with Project Surya, which aims to deploy clean cookstoves and rigorously evaluate their impact on BC emissions. Field tests of this new instrument performed in California report an average error of 0.28 µg/m3 when compared with an Aethelometer. These excellent results hold the promise of making large-scale data collection of BC feasible and relatively easy to reproduce (Ramanathan et al., forthcoming). The use of cellphones for data collection permits monitoring of BC to occur on a greater, more comprehensive scale not previously possible, and serves as a means of instituting more precise, variation-sensitive evaluations of emissions. By storing the data in a publicly available repository, our system will provide real-time access to mass-scale BC measurements to researchers and the public. Through our pilot

  8. 海洋平台往复压缩机振动特征研究%Study of vibration characteristics of the reciprocating compressor for offshore platform

    Institute of Scientific and Technical Information of China (English)

    黄业华; 戴国华

    2013-01-01

    为研究海洋平台往复压缩机的振动特征,应用谐波小波包变换对往复压缩机的振动进行分析,探讨不同频率下振动信号的能量分布特征.结果表明,在水平方向和垂直方向,往复压缩机振动能量主要集中在25 Hz和50 Hz的低频处,其他频率振动能量小,变化平稳;在轴向,往复压缩机振动能量向中高频扩展,在225 Hz处出现较大值.因此,谐波小波包变换可用于往复压缩机振动特征研究.%In order to investigate the vibration characteristics of the reciprocating compressors for the offshore platform,the vibration from the reciprocating compressor is analyzed by applying the harmonic wavelet packet transform.The energy distribution characteristics of vibration signal under the different frequencies are discussed.Results show that the vibration energy of the reciprocating compressor is mainly concentrated in the low frequencies of 25 Hz and 50Hz in the horizontal and vertical directions,and the vibration energy in other frequencies is small and smooth.In the axial direction,the vibration energy of the reciprocating compressors extends to the medium-high frequency,and the large energy appears in the 225 Hz.Therefore,the harmonic wavelet packet transform can be used to research the vibration characteristics of the reciprocating compressor.

  9. High-Ti basalt from the Abrolhos platform, offshore Brazil 18/sup 0/S: implications for mantle metasomatism and heterogeneity, South Atlantic region

    Energy Technology Data Exchange (ETDEWEB)

    Fodor, R.V.; Ragland, J.P.

    1985-01-01

    Surface and core samples of the Abrolhos islands and platform (30,000 km/sup 2/), offshore Brazil 18/sup 0/S, yields 35-65 Ma mafic flows and hypabyssal and cumulate rocks. (a) Basalt has very high TiO/sub 2/ attended by high FeO* but not proportionate amounts of incompatible elements; extreme Ti is shown by TiO/sub 2/ 5% at FeO*/MgOapprox. 2.5; LREE enrichment, La/sub (n)/ 80-110, La/Yb/sub (n)/approx. 8.5, Zr/Nbapprox. 6, Zr/Y approx. 7 are those of P-type MORB. (b) Cpx is transitional, Fs/sub 14-23/Wo/sub 42-36/, TiO/sub 2/ 1-2%, Al/sub 2/O/sub 3/ 2-5%. (c) Cumulates are clinopyroxenite and wehrlite, with cpx compositions like those of the basalts. The unusually high Ti, several trace elements, and mineral compositions correspond to certain high-TiO/sub 2/ flows and dikes in neighboring Serra Geral CFB province. Age differences and approx. 2 x higher P, Ba, and Sr in Serra Geral point to Abrolhos representing (re-)melting of an enriched CFB source-area similar to that for Serra Geral CFB but differing in metasomatic phases such as ap, amph, and mica. Extensive fractionation of enriched tholeiites with major-element compositions of certain S. Atlantic basin basalts accounts for Abrolhos compositions except for extreme Ti. Cumulates attest to the chamber environment necessary for fractionation, but high Ti must reflect the mantle source. Because Abrolhos rocks have compositional links to both continental and oceanic magmatism that occurred since Gondwanaland rifting, source-regions for each may have been similar throughout South Atlantic history, but with notable anomalies, due in part to localized Fe-Ti metasomatism.

  10. Status of Coral Reef Communities on Two Carbonate Platforms (Tun Sakaran Marine Park, East Sabah, Malaysia)

    OpenAIRE

    Menier, D.; B. Pierson; C. Tourrand; Montagne, A; Naim, O.

    2013-01-01

    This study concerns three sites, located on carbonate platforms, east Sabah: Gaya West, Gaya East, and Mantabuan. At each site, the dominant coral shapes and their health were recorded (lagoons and outer slopes). Densities of echinoderms, Tridacna, and nudibranchs were recorded while fish density was estimated. Generally, the coral vitality is low (≤50% living corals). Massive corals dominate all sites, except the Gaya West-outer slope where coral coverage and diversity are the highest. On th...

  11. Chicxulub Impact, Yucatan Carbonate Platform, Cretaceous-Paleogene Boundary and Paleocene-Eocene Thermal Maximum

    Science.gov (United States)

    Fucugauchi, J. U.; Perez-Cruz, L. L.

    2015-12-01

    Chicxulub formed 66 Ma ago by an asteroid impact on the Yucatan carbonate platform, southern Gulf of Mexico. Impact produced a 200 km diameter crater, platform fracturing, deformation and ejecta emplacement. Carbonate sedimentation restarted and crater was covered by up to 1 km of sediments. Drilling programs have sampled the Paleogene sediments, which record the changing sedimentation processes in the impact basin and platform. Here, results of a study of the Paleocene-Eocene sediments cored in the Santa Elena borehole are used to characterize the K/Pg and PETM. The borehole reached a depth of 504 m and was continuously cored, sampling the post-impact sediments and impact breccias, with contact at 332 m. For this study, we analyzed the section from ~230 to ~340 m, corresponding to the upper breccias and Paleocene-Eocene sediments. The lithological column, constructed from macroscopic and thin-section petrographic analyses, is composed of limestones and dolomitized limestones with several thin clay layers. Breccias are melt and basement clast rich, described as a suevitic unit. Section is further investigated using paleomagnetic, rock magnetic, X-ray fluorescence geochemical and stable isotope analyses. Magnetic polarities define a sequence of reverse to normal, which correlate to the geomagnetic polarity time scale from chrons 29r to 26r. The d13 C values in the first 20 m interval range from 1.2 to 3.5 %0 and d18 O values range from -1.4 to -4.8 %0. Isotope values show variation trends that correlate with the marine carbon and oxygen isotope patterns for the K-Pg boundary and early Paleocene. Positive carbon isotopes suggest relatively high productivity, with apparent recovery following the K-Pg extinction event. Geochemical data define characteristic trends, with Si decreasing gradually from high values in the suevites, low contents in Paleocene sediments with intervals of higher variability and then increased values likely marking the PETM. Variation trends are

  12. Formation of carbonate concretions in surface sediments of two mud mounds, offshore Costa Rica: a stable isotope study

    Science.gov (United States)

    Mavromatis, Vasileios; Botz, Reiner; Schmidt, Mark; Liebetrau, Volker; Hensen, Christian

    2014-10-01

    The surface sediments of two mud mounds ("Mound 11" and "Mound 12") offshore southwest Costa Rica contain abundant authigenic carbonate concretions dominated by high-Mg calcite (14-20 mol-% MgCO3). Pore fluid geochemical profiles (sulfate, sulfide, methane, alkalinity, Ca and Mg) indicate recent carbonate precipitation within the zone of anaerobic oxidation of methane (AOM) at variable depths. The current location of the authigenic carbonate concretions is, however, not related to the present location of the AOM zone, suggesting mineral precipitation under past geochemical conditions as well as changes in the flow rates of upward migrating fluids. Stable oxygen and carbon isotope analysis of authigenic carbonate concretions yielded δ18Ocarbonate values ranging between 34.0 and 37.7 ‰ Vienna standard mean ocean water (VSMOW) and δ13Ccarbonate values from -52.2 to -14.2 ‰ Vienna Pee Dee belemnite (VPDB). Assuming that no temperature changes occurred during mineral formation, the authigenic carbonate concretions have been formed at in situ temperature of 4-5 °C. The δ18Ocarbonate values suggest mineral formation from seawater-derived pore fluid (δ18Oporefluid = 0 ‰ VSMOW) for Mound 12 carbonate concretions but also the presence of an emanating diagenetic fluid (δ18Oporefluid ≈5 ‰) in Mound 11. A positive correlation between δ13Ccarbonate and δ18Ocarbonate is observed, indicating the admixing of two different sources of dissolved carbon and oxygen in the sediments of the two mounds. The carbon of these sources are (1) marine bicarbonate (δ13Cporefluid ≈0 ‰) and (2) bicarbonate which formed during the AOM (δ13Cporefluid ≈-70 ‰). Furthermore, the δ18Oporefluid composition, with values up to +4.7 ‰ Vienna standard mean ocean water (VSMOW), is interpreted to be affected by the presence of emanating, freshened and boron-enriched fluids. Earlier, it has been shown that the origin of 18O-enriched fluids are deep diagenetic processes as it was

  13. Lightweight Efficient Offshore Fenders

    DEFF Research Database (Denmark)

    Banke, Lars; Simonsen, Bo Cerup

    1996-01-01

    At offshore platforms the purpose of fenders is to protect the oil-risers against minor accidental collisions from supply vessels.Normally the fender is designed by use of thin-walled tubes. However, the tube itself is not normally capable of resisting the impact load from of the boat. Therefore ...

  14. Sedimentary Iron Cycling and the Origin and Preservation of Magnetization in Platform Carbonate Muds, Andros Island, Bahamas

    OpenAIRE

    Maloof, Adam C.; Kopp, Robert E.; Grotzinger, John P.; Fike, David A; Bosak, Tanja; Vali, Hojotollah; Poussart, Pascale M.; Weiss, Benjamin P.; Kirschvink, Joseph L

    2007-01-01

    Carbonate muds deposited on continental shelves are abundant and well-preserved throughout the geologic record because shelf strata are difficult to subduct and peritidal carbonate units often form thick, rheologically strong units that resist penetrative deformation. Much of what we know about pre-Mesozoic ocean chemistry, carbon cycling, and global change is derived from isotope and trace element geochemistry of platform carbonates. Paleomagnetic data from the same sediments would be invalu...

  15. "Nonlinear coupled dynamic response of offshore spar platforms under regular sea waves" by A.K. Agarwal and A.K. Jain. Ocean Engineering 30; 2003; 517-555

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.

    the analysis of dynamic response of offshore spar plat- form under regular waves. They have rightly highlighted the features of present generation Spar. They also reviewed in detail (about three-and-half pages) on Spar for which itself could have been a review... have to be taken care to withstand worse weather conditions. Some assumptions carried out by the authors may hold good for the sake Fig 1. Three prominent motions of Spar platform 792 Letter to the editor / Ocean Engineering 31 (2004) 791...

  16. Timing of Early Aptian demise of northern Tethyan carbonate platforms - chemostratigraphic versus biostratigraphic evidence

    Science.gov (United States)

    Huck, Stefan; Immenhauser, Adrian; Heimhofer, Ulrich; Rameil, Niels

    2010-05-01

    (carbon, strontium) and detailed sedimentological analysis. The lower part of the studied interval of both sections comprises limestones rich in rudist bivalves and intercalated oncoidal beds (including Lithocodium-Bacinella). The upper part consists of open to slightly protected lagoonal limestones (peloidal-foraminiferal grainstones) alternating with Orbitolina-rich intervals (Lower Orbitolina limestones?). Rudist shells are well preserved and relatively common. In the uppermost part, pulsed shedding of silt-sized siliciclastics is recorded and both sections are finally truncated and capped by the helvetic Garschella Formation, represented by siliciclastic glauconite-rich sedimentary rocks alternating with more argillaceous intervals. In essence, this stratigraphic succession is typical for the drowned Lower Aptian platforms observed along the northern Tethyan margin. Due to the lack of ammonites and a debated biostratigraphic control based on orbitolinids, a high-resolution chemostratigraphic framework (carbon and strontium) for the studied sections is established. Carbon-isotope chemostratigraphy is based on carbonate bulk samples. The obtained ages derived by 86Sr/87Sr isotope ratios (Strontium Isotope Stratigraphy, SIS) from screened rudists' low-Mg calcite are used to calibrate the carbon isotope stratigraphy as well as to pinpoint the timing of platform drowning. With respect to the timescale of Gradstein et al. (2004) preliminary chemostratigraphic data from Urgonian shoalwater sections in SE France indicate that the platforms at the northern margin of the Tethys Ocean drowned at the onset of OAE 1a black shale interval (Deshayesites weissi zone, close to the Aptian/Barremian boundary). This points to a near-coeval nature of pelagic black shale deposition, Oman and Istrian Lithocodium-Bacinella facies and platform demise in the northern Tethyan realm. References Föllmi, K.B. (2008) A synchronous, middle Early Aptian age for the demise of the Helvetic Urgonian

  17. 近海捕贝作业平台技术经济论证模型及应用%Technical and economical evaluation model of offshore scallops capture operation platform and its application

    Institute of Scientific and Technical Information of China (English)

    张光发; 张斌; 许家帅; 吕健

    2016-01-01

    为了辅助一种近海捕贝作业平台的方案决策,使其达到较佳经济效果,以解决近海扇贝养殖捕捞生产中的能耗大、劳动强度高、捕捞效率低以及捕捞效果差的问题,该文根据给定的营运条件、捕捞能力和贝类资源情况,对其进行了技术经济论证研究。选取捕贝平台的拖网主机功率、平台跨距、平台锚次横移时间、平台总建造成本、平台拖网速度作为论证的参数,以单位面积捕捞油耗、单位捕捞成本、捕捞效率为经济评价指标,建立了近海捕贝作业平台技术经济论证模型。基于该模型利用比较论证方法对渔船捕捞方式与捕贝作业平台捕捞方式进行了经济性计算,然后对选取的技术经济参数进行了敏感性分析。结果表明:当平台拖网主机功率400~470 kW、平台跨距0.5~3.0 km、平台锚次横移时间2.0 h以下、平台捕捞拖网速度1.4 kn以上、平台总建造成本低于2750万元时,平台捕捞方案比渔船捕捞方案具有明显的优势。实例计算证明,利用该文提出的技术经济论证模型,通过比较分析论证方法,可得到捕捞作业平台的技术参数范围,为新型近海捕贝作业平台的技术参数设计与实施提供参考。%At present, trawl fishing as a traditional method is widely used in shellfish harvesting at home and abroad. However, using this method to catch the scallops has many disadvantages, such as huge energy consumption, high labor intensity, and poor fishing efficiency, which have become the key questions to restrict the sustainable development of marine fishing industry. Therefore, it’s very worth researching alternative scallop fishing equipment to meet the requirements of green development. The offshore scallop capture equipment is made up of platform deck, floating body and mooring, which is a kind of floating offshore engineering structure. This equipment occupies multiple

  18. Carbon nanofiber mesoporous films: efficient platforms for bio-hydrogen oxidation in biofuel cells.

    Science.gov (United States)

    de Poulpiquet, Anne; Marques-Knopf, Helena; Wernert, Véronique; Giudici-Orticoni, Marie Thérèse; Gadiou, Roger; Lojou, Elisabeth

    2014-01-28

    The discovery of oxygen and carbon monoxide tolerant [NiFe] hydrogenases was the first necessary step toward the definition of a novel generation of hydrogen fed biofuel cells. The next important milestone is now to identify and overcome bottlenecks limiting the current densities, hence the power densities. In the present work we report for the first time a comprehensive study of herringbone carbon nanofiber mesoporous films as platforms for enhanced biooxidation of hydrogen. The 3D network allows mediatorless hydrogen oxidation by the membrane-bound hydrogenase from the hyperthermophilic bacterium Aquifex aeolicus. We investigate the key physico-chemical parameters that enhance the catalytic efficiency, including surface chemistry and hierarchical porosity of the biohybrid film. We also emphasize that the catalytic current is limited by mass transport inside the mesoporous carbon nanofiber film. Provided hydrogen is supplied inside the carbon film, the combination of the hierarchical porosity of the carbon nanofiber film with the hydrophobicity of the treated carbon material results in very high efficiency of the bioelectrode. By optimization of the whole procedure, current densities as high as 4.5 mA cm(-2) are reached with a turnover frequency of 48 s(-1). This current density is almost 100 times higher than when hydrogenase is simply adsorbed at a bare graphite electrode, and more than 5 times higher than the average of the previous reported current densities at carbon nanotube modified electrodes, suggesting that carbon nanofibers can be efficiently used in future sustainable H2/O2 biofuel cells. PMID:24296569

  19. Middle-Upper Triassic carbonate platforms in Minorca (Balearic islands): Implications for Western Tethys correlations

    Science.gov (United States)

    Escudero-Mozo, M. J.; Martín-Chivelet, J.; Goy, A.; López-Gómez, J.

    2014-08-01

    In order to progress in the knowledge of the Middle to Upper Triassic evolution of the western Tethys realm, an integrated approach which includes new sedimentological, sequence stratigraphic and biostratigraphic data, has been accomplished in the carbonate marine successions (Muschelkalk facies) of that age in Minorca (Balearic Islands, Spain). The new biostratigraphy, which includes six successive ammonoid biozones, allowed to assign these carbonate successions to the uppermost Anisian-lower Carnian interval. The integration of the new chronostratigraphic framework with the sedimentological analysis allowed to recognize five main successive stages of carbonate platform evolution: 1) Initial marine transgression and shallow ramp development (uppermost Anisian); 2) Carbonate ramp drowning (Anisian-Ladinian boundary); 3) Prevalence of open sea conditions (Ladinian-early Carnian); 4) Abrupt sea-level drop (intra-lower Carnian) and; 5) Shallow carbonate ramp and transition to sabkha systems (Keuper facies). Furthermore, the sequence stratigraphic analysis allowed to divide some of these stages into depositional sequences. Minorca was located in the westernmost Tethys area during the Triassic, in a key paleogeographic location close to the present-day Iberia, Sardinia and the Cottian and Southern Alps. The new data have allowed an interregional comparative analysis among these areas, with recognition of major suprarregional events and episodes in the framework of the western Tethys evolution.

  20. Impact of Submarine Geohazards on Organic Carbon Burial Offshore Southwestern Taiwan

    Science.gov (United States)

    Su, C. C.; Tsai, P. H.; Liu, J. T.; Hsu, S. K.; Chiu, S. D.

    2015-12-01

    The tectonically active setting and climatic conditions give Taiwan a high exposure to severe natural hazards. After the Pingtung Earthquake and Morakot Typhoon which occurred in 2006 and 2009, the turbidity currents caused a series of submarine cable breaks along the Gaoping and Fangliao Submarine Canyons off SW Taiwan. Large amounts of terrestrial sediments were fast transported bypass the narrow continental shelf and rapidly moved southward through submarine canyons to the deep sea. Two piston cores which were taken from the Tsangyao Ridge and its adjacent area (OR5-1302-2-MT7 and MT6) might shed light on understanding the export of terrestrial organic carbon to the abyss by submarine geo-hazards. The 210Pb profile of MT7 in conjunction with the grain size data indicates the existence of the Pingtung Earthquake and Morakot Typhoon related deposits. The sedimentation rate of these two cores which derived from 210Pb is approximately 0.05 cm/yr. The cores collected from the Gaoping Submarine Canyon, Gaoping Slope and Fangliao Submarine Canyon are used for analyzing TOC, organic C/N and δ13C ratios. The concentrations of total organic carbon are ~0.5%, and C/N rations almost remain between 4 and 8. The high TOC (~1%) and C/N ratio (>10) are observed in the samples with plant debris. The fluctuation of TOC and C/N ratios in near-shore samples is higher than deep sea. In terms of δ13C-values, it progressively decreases with distances from coastal zone to the deep sea. Due to the larger proportions of land-derived organic carbon, the δ13C-values in the surface sediment of upper Gaoping Submarine Canyon, Gaoping Slope, and the turbidite layers at the head of Fangliao Submarine Canyon are lighter. Furthermore, we use the TOC concentrations and δ13C-values to estimate the fractional contributions of terrestrial organic carbon by a simple two component mixing model, and integrate with the 210Pb-derived sediment accumulation rates to evaluate the organic carbon burial

  1. 海上平台油污损害赔偿国际立法及适用%International Legislation and Its Application Concerning Offshore Platform Oil Pollution Damages

    Institute of Scientific and Technical Information of China (English)

    贾爱玲; 黄珍

    2014-01-01

    The marine environment has become the main battlefield for human access to energy sources in the 2 1 st century.The disputes over oil pollution damages have gone beyond the national boundaries. There are legislative practices in international community concerning oil pollution damages.Because the offshore oil operations started late and oil spill rate remains low,the compensation for damages caused by the oil spill of the offshore platforms in the international community has not been paid enough attention to,thus leading to the plights in applying the law.By developing international special entity convention on oil pollution compensation or by bringing"offshore platform"oil pollution damages into the adj usted scope of the convention on"ship"oil pollution damages,we can make up for the absence of applicable international law concerning the offshore platform oil pollution damages.To ensure the effective implementation of international conventions,the domestic laws should positively respond to the international conventions.%21世纪海洋环境成为人类获取能源的主战场,油污损害赔偿纠纷已从一国国内走向国际化。对于油污损害赔偿问题国际社会存在一些立法实践,由于海上石油作业起步晚、溢油率低,对海上平台溢油事件所导致的损害赔偿问题在国际社会尚未引起足够的重视,出现法律适用的困境。通过制定海上平台油污损害赔偿的国际专项实体公约或者将“海上平台”油污损害纳入“船舶”油污损害公约的调整范围,以弥补海上平台油污损害赔偿国际法适用的缺失。为确保国际公约的有效实施,一国内国法对国际公约应给予积极的回应。

  2. Rovearinids (stemless crinoids) in the Albian carbonates of the offshore Santos Basin, southeastern Brazil: stratigraphic, palaeobiogeographic and palaeoceanographic significance

    Science.gov (United States)

    Dias-Brito, D.; Ferré, B.

    2001-06-01

    Microfacies analysis of marine carbonates cored by Petrobras well 1-SPS-6 in the offshore Santos Basin (southeastern Brazil) has revealed a remarkable fossil assemblage of calpionellids (colomiellids), favusellids, hedbergellids, globigerinelloidids, buliminids, radiolarians, inoceramid prisms, roveacrinids, and saccocomids(?) preserved in lower Albian calcimudstones-wackestones of the lower part of the Guarujá Formation. This assemblage represents an allochtonous accumulation in a deep neritic to shallow bathyal hypoxic environment. Besides 'saccocomid-like' sections, the only determinable sections of roveacrinids are thecal plates of Poecilocrinus dispandus elongatus Peck, 1943. This species was previously only known from the Weno Formation of Texas. The Brazilian material extends its records farther south from at least the lower Albian, which then represents the earliest occurrence of this peculiar family in the South Atlantic region. Taking into account their Albian global distribution and the location of their oldest representative (Hauterivian near Alicante, Spain), the Roveacrinidae dispersed westward throughout all of Cretaceous Tethys. The Tethyan origin of Roveacrinidae is further evidence that, during late Aptian-Albian times, the northern South Atlantic (north of the Walvis-São Paulo Ridge) was supplied by a Tethyan water mass.

  3. 基于动态风险平衡的海洋平台事故连锁风险研究%On the risk chain of the offshore oil-drilling platform accidents based on the dynamic risk balance

    Institute of Scientific and Technical Information of China (English)

    郭恒; 陈国明; 朱渊

    2012-01-01

    The present paper is aimed at introducing a dynamic model for the offshore oil-drilling platform accidents proposed by the authors based on the two concepts, that is, the accident impetus and accident obstruction. As is well known, due to its own restricted conditions, offshore platforms, on the event of fire or explosion, are likely to suffer tragic casualties and material losses, letting alone the environmental contamination. Based on investigating and analyzing plenty of offshore platform accidents both at home and abroad, we have brought forward a new approach to dealing with such tragic accidents, that is, to finding the accident dynamic model characterized as dynamic nature and transient stability. As a matter of fact, a regular oil-drilling platform tends to present a dynamic equilibrium state between the accident impetus and the accident obstruction, while the accident dynamic state indicates a kind of energy that tends to lead to the happening of an accident whereas there exists some kind of transmitting impetus that passes on the energy that may obstruct or prevent the accident from occurring. In view of the dynamic risk balance, we have come up with the accident dynamic model consisting of four steps: first of all, the offshore platform likely to lead to grave accidents are chosen as an object of study, and next, the corresponding factors likely to cause the accidents are analyzed from the points of view of accident-incidence process, and, last of all, the countermeasures were taken in engineering, technology and management. What's more, the risk statistical data and information concerning the accident chains are to be built up when the elementary accident impetus has been determined. And, by this moment, it would be necessary to work out the probability distribution of all transmitting impetus and obstruction factors in the circumstance that the elementary accident-incidence dynamic has been calculated. Furthermore, the analysis results should be made

  4. Bacterial Cellulose: A Robust Platform for Design of Three Dimensional Carbon-Based Functional Nanomaterials.

    Science.gov (United States)

    Wu, Zhen-Yu; Liang, Hai-Wei; Chen, Li-Feng; Hu, Bi-Cheng; Yu, Shu-Hong

    2016-01-19

    Three dimensional (3D) carbon nanomaterials exhibit great application potential in environmental protection, electrochemical energy storage and conversion, catalysis, polymer science, and advanced sensors fields. Current methods for preparing 3D carbon nanomaterials, for example, carbonization of organogels, chemical vapor deposition, and self-assembly of nanocarbon building blocks, inevitably involve some drawbacks, such as expensive and toxic precursors, complex equipment and technological requirements, and low production ability. From the viewpoint of practical application, it is highly desirable to develop a simple, cheap, and environmentally friendly way for fabricating 3D carbon nanomaterials in large scale. On the other hand, in order to extend the application scope and improve the performance of 3D carbon nanomaterials, we should explore efficient strategies to prepare diverse functional nanomaterials based on their 3D carbon structure. Recently, many researchers tend to fabricate high-performance 3D carbon-based nanomaterials from biomass, which is low cost, easy to obtain, and nontoxic to humans. Bacterial cellulose (BC), a typical biomass material, has long been used as the raw material of nata-de-coco (an indigenous dessert food of the Philippines). It consists of a polysaccharide with a β-1,4-glycosidic linkage and has a interconnected 3D porous network structure. Interestingly, the network is made up of a random assembly of cellulose nanofibers, which have a high aspect ratio with a diameter of 20-100 nm. As a result, BC has a high specific surface area. Additionally, BC hydrogels can be produced on an industrial scale via a microbial fermentation process at a very low price. Thus, it can be an ideal platform for design of 3D carbon-based functional nanomaterials. Before our work, no systematic work and summary on this topic had been reported. This Account presents the concepts and strategies of our studies on BC in the past few years, that is

  5. Functionalization and characterization of pyrolyzed polymer based carbon microstructures for bionanoelectronics platforms

    International Nuclear Information System (INIS)

    In this study, the investigation of surface-treatment of chemically inert graphitic carbon microelectrodes (derived from pyrolyzed photoresist polymer) for improving their attachment chemistry with DNA molecular wires and ropes as part of a bionanoelectronics platform is reported. Polymer microelectrodes were fabricated on a silicon wafer using standard negative lithography procedures with negative-tone photoresist. These microelectrode structures were then pyrolyzed and converted to a form of conductive carbon that is referred to as PP (pyrolyzed polymer) carbon throughout this paper. Functionalization of the resulting pyrolyzed structures was done using nitric, sulfuric, 4-amino benzoic acids (4-ABA), and oxygen plasma etching and the surface modifications confirmed with Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and electron dispersion x-ray spectroscopy (EDS). Post surface-treatment analysis of microelectrodes with FTIR and Raman spectroscopy showed signature peaks characteristics of carboxyl functional groups while EDS showed an increase in oxygen content in the surface-treatment procedures (except 4-ABA) indicating an increase in carboxyl functional group. These functional groups form the basis for peptide bond with aminated oligonucleotides that in turn could be used as molecular wires and interconnects in a bionanoelectronics platform. Post-pyrolysis analysis using EDS showed relatively higher oxygen concentrations at the edges and location of defects compared to other locations on these microelectrodes. In addition, electrochemical impedance measurements showed metal-like behavior of PP carbon with high conductivity (|Z| <1 KΩ) and no detectable detrimental effect of oxygen plasma surface-treatment on electrical characteristic. In general, characterization results—taken together—indicated that oxygen plasma surface-treatment produced more reliable, less damaging, and consistently repeatable generation of carboxyl functional

  6. Platform christened

    International Nuclear Information System (INIS)

    On Friday May 9, 1997, a ceremony took place in which the Hibernia platform was officially christened by Aline Chretien, the wife of the Prime Minister of Canada. The ceremony highlighted the successful completion of Hibernia and the tremendous accomplishment of this offshore structure which will be towed out of Bull Arm, Newfoundland, in June 1997 to its offshore location. Drilling for the first well will begin in August with first oil expected by December 1997. Other guests at the ceremony included Hibernia owner companies Mobil Oil, Chevron, Petro-Canada, Canada Hibernia Holding Corp., Murphy Oil and Norsk Hydro. The Hibernia project paves the way for other offshore ventures and employment opportunities in Newfoundland

  7. Offshoring Process

    DEFF Research Database (Denmark)

    Slepniov, Dmitrij; Sørensen, Brian Vejrum; Katayama, Hiroshi

    2011-01-01

    The purpose of this chapter is to contribute to the knowledge on how production offshoring and international operations management vary across cultural contexts. The chapter attempts to shed light on how companies approach the process of offshoring in different cultural contexts. In order...... of globalisation. Yet there are clear differences in how offshoring is conducted in Denmark and Japan. The main differences are outlined in a framework and explained employing cultural variables. The findings lead to a number of propositions suggesting that the process of offshoring is not simply a uniform...

  8. Requalification of offshore structures. Formulation of decision problems - offshore structures

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, J.D.; Bloch, A. [Aalborg Univ. (Denmark); Engelund, S.; Faber, M.F. [COWI Raadgivende Ingenioerer A/S, Lyngby (Denmark)

    1999-12-01

    The report gives a general description of some decision problems relevant for offshore structures. The problems are described using reliability-based formulations. The basis for the formulations is Bayesian decision theory, especially preposterior formulations. For offshore steel platforms fatique cracks can be very important for the reliability. Further inspection and repair of cracks are expensive. Therefore cost optimal planning of inspections and repair is of great practical interest. Models for inspection and maintenance planning are described. During the lifetime of an offshore structure a number of the premises for the design may change, e.g. the load on the topsite is increased or more equipment below MWL (e.g. conductors) can be placed on the platform. These changes cause increasing the wave and current loads. Another very ofen ocurring decision problem is related to possible extension of the lifetime of the platform. These problems are formulated in a decision theoretical framework using FORM/SORM techniques to evaluate probabilities. (ln)

  9. GlobAllomeTree: international platform for tree allometric equations to support volume, biomass and carbon assessment

    OpenAIRE

    Henry M; Bombelli A; Trotta C,; Alessandrini A; Birigazzi L; Sola G; Vieilledent G; Santenoise P; Longuetaud F; Valentini R; Picard N; Saint-André L

    2013-01-01

    GlobAllomeTree is an international platform for tree allometric equations. It is the first worldwide web platform designed to facilitate the access of the tree allometric equation and to facilitate the assessment of the tree biometric characteristics for commercial volume, bio-energy or carbon cycling. The webplatform presents a database containing tree allometric equations, a software called Fantallomatrik, to facilitate the comparison and selection of the equations, and documentation to fac...

  10. Significant developments in offshore geosciences

    Energy Technology Data Exchange (ETDEWEB)

    Kolk, H.J. [Fugro Engineers B.B., Leidschendam (Netherlands); Campbell, K.J. [Fugro-McClelland Marine Geosciences, Inc., Houston, TX (United States)

    1997-12-31

    The paper presents recent advances in three key areas of offshore geosciences: engineering geology determination of soil parameters and geotechnical design methods. Determination of soil parameters is separated into geotechnical investigation techniques and subsequent actual determination of soil parameters from these results. Design methods are limited to foundation of offshore platforms. Current and required research and development efforts in these three areas are described. Future expected trends in offshore geoscience practice are outlined. It is concluded that, in general, engineering geology capabilities, geotechnical investigation techniques and design methods are currently relatively stronger developed than the capability to determine in-situ soil parameters reliably. (author)

  11. Modern sediments and Pleistocene reefs from isolated carbonate platforms (Iles Eparses, SW Indian Ocean): A preliminary study

    Science.gov (United States)

    Jorry, Stéphan J.; Camoin, Gilbert F.; Jouet, Gwénaël; Roy, Pascal Le; Vella, Claude; Courgeon, Simon; Prat, Sophie; Fontanier, Christophe; Paumard, Victorien; Boulle, Julien; Caline, Bruno; Borgomano, Jean

    2016-04-01

    Isolated carbonate platforms occur throughout the geologic record, from Archean to present. Although the respective roles of tectonics, sediment supply and sea-level changes in the stratigraphical architecture of these systems are relatively well constrained, the details of the nature and controls on the variability of sedimentological patterns between and within individual geomorphologic units on platforms have been barely investigated. This study aims at describing and comparing geomorphological and sedimentological features of surficial sediments and fossil reefs from three isolated carbonate platforms located in the SW Indian Ocean (Glorieuses, Juan de Nova and Europa). These carbonate platforms are relatively small and lack continuous reef margins, which have developed only on windward sides. Field observations, petrographic characterization and grain-size analyses are used to illustrate the spatial patterns of sediment accumulation on these platforms. The internal parts of both Glorieuses and Juan de Nova platforms are blanketed by sand dunes with medium to coarse sands with numerous reef pinnacles. Skeletal components including coral, green algae, and benthic foraminifera fragments prevail in these sediments. Europa platform exhibits a similar skeletal assemblage dominated by coral fragments, with the absence of wave-driven sedimentary bodies. Fossil reefs from the Last interglacial (125,000 years BP) occur on the three platforms. At Glorieuses, a succession of drowned terraces detected on seismic lines is interpreted as reflecting the last deglacial sea-level rise initiated 20,000 years ago. These findings highlight the high potential of these platforms to study past sea-level changes and the related reef response, which remain poorly documented in the SW Indian Ocean.

  12. Relationship between Late Pleistocene sea-level variations, carbonate platform morphology and aragonite production (Maldives, Indian Ocean)

    DEFF Research Database (Denmark)

    Paul, A.; Reijmer, J.J.G.; Fürstenau, J.; Kinkel, Hanno; Betzler, C.

    2012-01-01

    A piston core from the Maldives carbonate platform was investigated for carbonate mineralogy, grain-size distributions, calcium carbonate content and organic carbon. The sedimentary record was linked to Late Pleistocene sea-level variations, using an age model based on oxygen isotopes obtained from...... planktonic foramanifera, nannofossil biostratigraphy and C age determinations. The correlation between the sedimentary record and Late Pleistocene sea-level showed that variations in aragonite and mud during the past 150000years were clearly related to flooding and sea floor exposure of the main lagoons of...... show that sediments on the Maldives carbonate platform contain a continuous record of Pleistocene sea-level variations. These sediments may, therefore, contribute to a better understanding of regional and even global sea-level changes, and yield new insights into the interplay between ocean currents...

  13. 近海捕贝作业平台技术经济论证模型及应用%Technical and economical evaluation model of offshore scallops capture operation platform and its application

    Institute of Scientific and Technical Information of China (English)

    张光发; 张斌; 许家帅; 吕健

    2016-01-01

    为了辅助一种近海捕贝作业平台的方案决策,使其达到较佳经济效果,以解决近海扇贝养殖捕捞生产中的能耗大、劳动强度高、捕捞效率低以及捕捞效果差的问题,该文根据给定的营运条件、捕捞能力和贝类资源情况,对其进行了技术经济论证研究。选取捕贝平台的拖网主机功率、平台跨距、平台锚次横移时间、平台总建造成本、平台拖网速度作为论证的参数,以单位面积捕捞油耗、单位捕捞成本、捕捞效率为经济评价指标,建立了近海捕贝作业平台技术经济论证模型。基于该模型利用比较论证方法对渔船捕捞方式与捕贝作业平台捕捞方式进行了经济性计算,然后对选取的技术经济参数进行了敏感性分析。结果表明:当平台拖网主机功率400~470 kW、平台跨距0.5~3.0 km、平台锚次横移时间2.0 h以下、平台捕捞拖网速度1.4 kn以上、平台总建造成本低于2750万元时,平台捕捞方案比渔船捕捞方案具有明显的优势。实例计算证明,利用该文提出的技术经济论证模型,通过比较分析论证方法,可得到捕捞作业平台的技术参数范围,为新型近海捕贝作业平台的技术参数设计与实施提供参考。%At present, trawl fishing as a traditional method is widely used in shellfish harvesting at home and abroad. However, using this method to catch the scallops has many disadvantages, such as huge energy consumption, high labor intensity, and poor fishing efficiency, which have become the key questions to restrict the sustainable development of marine fishing industry. Therefore, it’s very worth researching alternative scallop fishing equipment to meet the requirements of green development. The offshore scallop capture equipment is made up of platform deck, floating body and mooring, which is a kind of floating offshore engineering structure. This equipment occupies multiple

  14. Meals on Wheels? A Decade of Megafaunal Visual and Acoustic Observations from Offshore Oil & Gas Rigs and Platforms in the North and Irish Seas

    OpenAIRE

    Todd, Victoria Louise Georgia; Warley, Jane Clare; Todd, Ian Boyer

    2016-01-01

    A decade of visual and acoustic detections of marine megafauna around offshore Oil & Gas (O&G) installations in the North and Irish Seas are presented. Marine megafauna activity was monitored visually and acoustically by Joint Nature Conservation Committee (JNCC) qualified and experienced Marine Mammal Observers (MMO) and Passive Acoustic Monitoring (PAM) Operators respectively, with real-time towed PAM in combination with industry standard software, PAMGuard. Monitoring was performed during ...

  15. Graphene and carbon nanodots in mesoporous materials: an interactive platform for functional applications

    Science.gov (United States)

    Innocenzi, Plinio; Malfatti, Luca; Carboni, Davide

    2015-07-01

    The present review is focused on a specific class of nanocomposites obtained through integration of graphene or carbon-based nanomaterials (such as carbon nanodots) with mesoporous inorganic or hybrid materials, obtained via template assisted self-assembly. The task of integrating graphene and carbon nanodots with a self-assembly process is still very challenging and this review shows some of the solutions which have been envisaged so far. These nanocomposite materials are an ideal interactive platform for developing innovative functional applications; they have a high capability of undergoing integration into advanced devices, which well exploits the advantage of tuning the wide properties and flexibility of the soft-chemistry route. A wide range of applications have been developed so far which span from sensing to electronics up to optics and biomedicine. Even though a large number of proof-of-concepts have been reported to date, an even greater expansion of applications in the field is expected to happen in the near future.

  16. Carbon-isotope stratigraphy of Early Cretaceous (Urgonian) shoal-water deposits: Diachronous changes in carbonate-platform production in the north-western Tethys

    Science.gov (United States)

    Huck, S.; Heimhofer, U.; Immenhauser, A.; Weissert, H.

    2013-05-01

    Carbonate platforms are highly sensitive ecological systems that typically show rapid and characteristic response modes to environmental and climatic changes acting both on a regional scale and global scale. A widely accepted hypothesis proposes that the Late Barremian stepwise establishment of the Urgonian carbonate platform on the Northern Tethyan shelf was related to a gradual change from predominantly humid towards more arid greenhouse conditions. This climate change resulted in the reorganisation of the carbonate platform ecosystem from heterozoan towards photozoan-dominated assemblages and a decrease of organic-matter burial in Tethyan and Boreal basins. In order to decipher the palaeoenvironmental and climatic boundary conditions of these major changes in neritic and pelagic settings, a precise chronostratigraphy of Urgonian carbonate platform evolution is needed. Here, we provide an integrated stratigraphic framework of Lower Barremian to Lower Aptian Urgonian carbonate platform sections (Cluses, Forclaz) located at the northern rim of the Tethys (Subalpine Chains, ESE France), with special focus on sedimentological analyses and high-resolution carbon-isotope stratigraphy. A characteristic Barremian-Aptian carbon-isotope pattern permits precise platform-to-basin correlation with cyclostratigraphic and ammonite-dated pelagic and hemipelagic Tethyan sections in the Vocontian Trough (Angles/Combe-Lambert/Glaise) and Umbria Marche Basin (Gorgo a Cerbara). Similar to Helvetic shoal-water settings, the carbonate platform in the Subalpine Chains experienced a gradual transition from heterozoan- to photozoan-dominated ecosystems. This biogenic pattern points to a gradual change of the carbonate platform after the so-called "Early Barremian crisis" towards an oligotrophic rimmed platform system (Urgonian Limestone Formation). According to the chronostratigraphy of Urgonian carbonate platform evolution in the Subalpine Chains established here, the installation of a

  17. Selection Design of Large -type Centrifugal Compressor in Various Conditions for Offshore Platform%海上平台多工况大型离心压缩机的选型设计

    Institute of Scientific and Technical Information of China (English)

    安维峥; 赵新君

    2013-01-01

      基于南海某大型气田的实际工程需求,对多种工况下大型气田外输离心压缩机进行选型设计。在压缩机选型设计时考虑了实际配产的逐年流量和压力以及最大规模下的流量与压力。同时,海洋平台对机组的数量要求严格,过多的机组数量将导致平台面积增大,采用较少的机组并满足所有工况点的运行才是合理可行的选型方案。本文通过选型分析,在减少机组数量的前提下,完成了海上平台外输压缩机组的合理与配置,机组选型兼顾了实际配产与设计规模,该方案不仅降低了项目投资,还使得机组在不同运行工况下保持较高的运行效率。%Based on the actual engineering requirements in a gas field of South China sea, the selection and design for large-type gas field pipeline centrifugal compressor under various conditions is carried out. The selection and design has considered the flow and pressure of actual production year by year and the flow and pressure under maximum scale. At the same time, offshore platform is strict on the sets of unit, more compressors sets will make offshore platform layout bigger, so the reasonable selection should include fewer sets and cover all the operation conditions. Through the analysis, providing reducing sets of unit, the arrangement of offshore platform centrifugal compressor unit is performed reasonably. The unit selection has considered the actual production and design scale. This scheme not only reduce the project investment, but also maintain the unit with higer operating efficiency under different conditions.

  18. Methodology for evaluation of the stability of electric systems of offshore oil platforms in interconnected operations; Metodologia para a avaliacao dos sistemas eletricos das plataformas de petroleo offshore em operacao interligada

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Dalmo Junior; Mendes, Pedro Paulo de Carvalho [Universidade Federal de Itajuba (UNIFEI), MG (Brazil)

    2004-07-01

    The electric system of the platforms usually operates in an isolated way, requesting therefore a redundancy in the generating units so that a can have a reliable and uninterrupted system of their loads. A way to improve the quality in operation in terms of safety, reliability and economy can be the connection of the platforms of petroleum that are close, since it is viable. The objective of this work is to show the methodology for the stability study of the electric system in interlinked operation in way to detail the data of the equipment that are necessary, as: One line Diagram; Transmission lines; Transformers; Power system compensator; Generating; Speed regulators; Voltage regulators; Turbines and other. Another focus of the work is to show some control models and regulation of the electric system to maintain it stable and to show models for the interconnection of two or more platforms. (author)

  19. Application of Modular Construction Technology in Offshore Oil Platform Fabrication%模块化建造技术在海洋平台建造中的应用

    Institute of Scientific and Technical Information of China (English)

    张国中; 高指林; 孙瑜; 韩小康; 郑晓娟

    2014-01-01

    Traditional ways of offshore oil platform construction often feature long construction period, large human resource inputs, lots of temporary construction facilities, greater impact on surrounding environment, numerous cross-operations and great difficulty in safety management and project management. In the paper, the idea of modular design and construction was applied in the construction process of oil platforms. Through simultaneous construction of these modules in different locations, assembling and debugging on slides, the whole platform was finished. In the end, the modular construction process, application of modularization in design and construction of platforms and relative noti-fications were proposed and advantages of modular construction were summarized to provide references for the con-struction of offshore platforms and similar structures.%针对传统的海洋石油平台建造工期长,人力、建造资源投入量大,需要建设大量的临时施工设施,对周边环境影响较大,在同一时间、同一地点存在大量的交叉作业,安全管理和项目管理难度较大等特点,将模块化设计、建造技术的建造思路应用于石油平台的建造过程中,在不同的地点并行建造模块,尽可能多地完成模块上工作,然后在滑道上进行总装和调试,进而完成整平台的建造。提出模块化建造流程、模块化在平台设计与建造中的应用及注意事项,总结了模块化建造的优势,为海洋平台及类似结构物的建造提供借鉴。

  20. Acriflavine immobilized onto polyethyleneimine-wrapped carbon nanotubes/gold nanoparticles as an eletrochemical sensing platform

    Indian Academy of Sciences (India)

    Azadeh Azadbakht; Amirreza Abbasi

    2016-02-01

    Multi-walled carbon nanotubes wrapped by polyethyleneimine (PEI) and functionalized with a carboxylic acid group (CNT-COOH) were deposited with gold nanoparticles (AuNPs) which has been utilized as a platform to immobilize poly(acriflavine)(PAF) and used as modified electrode (AuNPs/PEI/CNTCOOH/PAF). Electrocatalytic reduction of hydrogen peroxide(H2O2) on the surface of the modified electrode was investigated by cyclic voltammetry and electrochemical impedance spectroscopy (EIS) methods. The cyclic voltammetric results indicated the ability of modified Au electrode to catalyze the reduction of H2O2. AuNPs/PEI/CNT-COOH nanocomposite combined the advantages of PEI, well dispersed CNT-COOH and in situ formed AuNPs, endowed with high stability to the enzyme-free sensor.

  1. Storm-generated bedforms and relict dissolution pits and channels on the Yucatan carbonate platform

    Science.gov (United States)

    Gulick, S. P.; Goff, J. A.; Stewart, H. A.; Perez-Cruz, L. L.; Davis, M. B.; Duncan, D.; Saustrup, S.; Sanford, J. C.; Fucugauchi, J. U.

    2013-12-01

    The Yucatan 2013 (cruise number 2013/4_ECORD) geophysical and geotechnical hazard site survey took place aboard the R/V Justo Sierra in April 2013. Our study was conducted within the Chicxulub impact crater, encompassing three potential IODP drilling sites. The survey was located ~32 km northwest of Progreso, Mexico; data acquired included ~15.6 km2 of complete multibeam bathymetry coverage, ~435 line km of side scan sonar and CHIRP data, 204 line kilometers of magnetometer data, and 194 line kilometers of surface tow boomer profiles. Based on these data, this portion of the Yucatan Shelf consists of flat-lying, hard limestone rock overlain by isolated ribbons of carbonate sand cenote or sink hole. The NW sector of the survey area exhibits a more complex morphology than the alternating ribbon/bare rock morphology elsewhere, including linear scarps (up to ~1 m relief), deeper pitting (up to ~1 m relief), and sinuous, dendritic channeling (up to ~2 m relief). The geologic origin of these features will require further investigation. Sand drifts are present in this region, but are thinner and cover less area. These observations show the dominant modern sediment formation and transport processes on this starved platform are from large storms and hurricanes that place large regions of the platform at wave base. Remaining observed features were generated during times of lower sea level.

  2. Dominant role of eddies and filaments in the offshore transport of carbon and nutrients in the California Current System

    Science.gov (United States)

    Nagai, Takeyoshi; Gruber, Nicolas; Frenzel, Hartmut; Lachkar, Zouhair; McWilliams, James C.; Plattner, Gian-Kasper

    2015-08-01

    The coastal upwelling region of the California Current System (CalCS) is a well-known site of high productivity and lateral export of nutrients and organic matter, yet neither the magnitude nor the governing processes of this offshore transport are well quantified. Here we address this gap using a high-resolution (5 km) coupled physical-biogeochemical numerical simulation (ROMS). The results reveal (i) that the offshore transport is a very substantial component of any material budget in this region, (ii) that it reaches more than 800 km into the offshore domain, and (iii) that this transport is largely controlled by mesoscale processes, involving filaments and westward propagating eddies. The process starts in the nearshore areas, where nutrient and organic matter-rich upwelled waters pushed offshore by Ekman transport are subducted at the sharp lateral density gradients of upwelling fronts and filaments located at ˜25-100 km from the coast. The filaments are very effective in transporting the subducted material further offshore until they form eddies at their tips at about 100-200 km from the shore. The cyclonic eddies tend to trap the cold, nutrient, and organic matter-rich waters of the filaments, whereas the anticyclones formed nearby encapsulate the low nutrient and low organic matter waters around the filament. After their detachment, both types of eddies propagate further in offshore direction, with a speed similar to that of the first baroclinic mode Rossby waves, providing the key mechanism for long-range transport of nitrate and organic matter from the coast deep into the offshore environment.

  3. The Oligocene-Miocene stratigraphic evolution of the Majella carbonate platform (Central Apennines, Italy)

    Science.gov (United States)

    Brandano, Marco; Cornacchia, Irene; Raffi, Isabella; Tomassetti, Laura

    2016-03-01

    The stratigraphic architecture of the Bolognano Formation documents the evolution of the Majella carbonate platform in response to global and local changes that affected the Mediterranean area during the Oligocene-Miocene interval. The Bolognano Formation consists of a homoclinal ramp that developed in a warm, subtropical environment. Five different lithofacies associations have been identified: Lepidocyclina calcarenites, cherty marly limestones, bryozon calcarenites, hemipelagic marls and marly limestones, and Lithothamnion limestones. Each association corresponds to a single lithostratigraphic unit except for the Lepidocyclina calcarenites that form two distinct lithostratigraphic units (Lepidocyclina calcarenites 1 and 2). These six units reflect alternation of shallow-water carbonate production and drowning. Specifically, two of the three stages of shallow-water carbonate production regard the development of wide dune fields within the middle ramp, one stage dominated by red algae and a sea-grass carbonate factory, whereas the two drowning phases are represented by marly cherty limestones and calcareous marls. A new biostratigraphic framework for Bolognano Formation is presented, based on high-resolution analysis of calcareous nannofossil assemblages, which proved to be very useful for biostratigraphic constraints also in shallow-water settings. Using this approach, we have linked the first drowning phase, late Chattian-Aquitanian p.p. in age, to western Mediterranean volcanism and the Mi-1 event, and the second drowning phase, late Burdigalian-Serravallian in age, to the closure of the Indo-Pacific passage and the occurrence of the global Monterey event. These results permit a new deciphering, in terms of sequence stratigraphy, of the Bolognano Formation that is interpreted as a 2nd-order super-sequence that can be subdivided into 3 transgressive-regressive sequences.

  4. Electrochemical sensing and biosensing platform based on biomass-derived macroporous carbon materials.

    Science.gov (United States)

    Wang, Li; Zhang, Qinying; Chen, Shuiliang; Xu, Fugang; Chen, Shouhui; Jia, Jianbo; Tan, Hongliang; Hou, Haoqing; Song, Yonghai

    2014-02-01

    A three-dimensional (3D) macroporous carbon (3D-KSCs) derived from kenaf stem (KS) is proposed as a novel supporting material for electrochemical sensing and a biosensing platform. A series of 3D-KSCs/inorganic nanocomposites such as Prussian blue (PB) nanoparticles (NPs)-carboxylic group-functionalized 3D-KSCs (PBNPs-3D-FKSCs), CuNiNPs-3D-KSCs, and CoNPs-3D-KSCs were prepared by a facile two-step route consisting of carbonization and subsequent chemical synthesis or one-step carbonization of KS-metal ion complex. The obtained 3D-KSCs/inorganic nanocomposites were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, scanning electron microscopy, and Fourier transform-infrared spectroscopy. A whole piece of 3D-KSCs/nanocomposites was used to prepare an integrated 3D-KSCs/nanocomposite electrode. Compared to the electrode modified by graphene, carbon nanotubes and their derivatives, which can form close-packed structure after assembled on electrode surface, the integrated 3D-KSCs/nanocomposite electrode shows a 3D honeycomb porous structure. Such structure provides a large specific surface area, effectively supports a large number of electro-active species, and greatly enhances the mass and electron transfer. The electrochemical behaviors and electrocatalytic performances of the integrated 3D-KSCs/inorganic nanocomposite electrode were evaluated by cyclic voltammetry and the amperometric method. The resulted PBNPs-3D-FKSCs, CuNiNPs-3D-KSCs, and CoNPs-3D-KSCs electrode show good electrocatalytic performances toward the reduction of H2O2, the oxidation of glucose and amino acid, respectively. Therefore, the low-cost, renewable, and environmentally friendly 3D-KSCs should be promising supporting materials for an electrochemical sensor and biosensor. PMID:24422469

  5. Characterization of pipes and adhesives of glass fiber reinforced plastics used in offshore platforms; Caracterizacao de tubo e adesivo utilizados em tubulacoes de plastico reforcado com fibras de vidro aplicados em plataformas maritimas

    Energy Technology Data Exchange (ETDEWEB)

    Pessanha, Maikon C.R.; Dias, Dylmar P. [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos de Goytacazes, RJ (Brazil). Lab. de Engenharia Civil]. E-mail: maikon@uenf.br; Filgueira, Marcello; Paranhos, Ronaldo P.R. [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos de Goytacazes, RJ (Brazil). Lab. de Materiais Avancados; Farias, Otavio L. de [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2008-01-15

    Glass fiber reinforced plastics (GFRP) have been applied in the offshore industry owing to their high resistance to corrosion and high specific mechanical strength. The present work aimed at characterizing pipes and adhesives used in offshore platforms in order to evaluate the thermo-mechanical performance of these materials. The techniques used were: Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis (TGA), dynamic mechanical thermal analysis (DMTA) and Vicat softening temperature. Specimens of GFRP pipe and adhesive components (referred to as A and B) were evaluated individually. The adhesive samples were made in the following ratios (% weight): 40% A-60% B, 50% A-50% B and 60%A-40% B. The results showed it to be possible to determinate the composition and structure of the materials, as well as the mechanical behavior regarding thermal degradation. The adhesive and pipe exhibited satisfactory performance at room temperature, with regard to degradation and stiffness. Nevertheless, at higher temperatures, both materials, especially the adhesives, presented abrupt strength reduction. (author)

  6. Morphometric patterns in Modern carbonate platforms can be applied to the ancient rock record: Similarities between Modern Alacranes Reef and Upper Palaeozoic platforms of the Barents Sea

    Science.gov (United States)

    Purkis, Sam; Casini, Giulio; Hunt, Dave; Colpaert, Arnout

    2015-05-01

    In recent years, considerable research has been undertaken in order to gain a better quantitative understanding of morphometric patterns within modern carbonate depositional systems. The industrial application of the scaling/juxtaposition relationships derived from the Modern to subsurface Cenozoic carbonate reservoirs appears relatively straightforward, given that many key biota are common to both. However, the direct application of Modern sedimentary insight further back into the geologic rock record is more controversial, given the enormous changes in the biota, climate, sea level, water chemistry and so on, that have taken place. To justify such an approach, we contend that similar morphometric patterns should be observed in both the Modern and ancient data. In the Norwegian Barents Sea, numerous seismic surveys have imaged Upper Palaeozoic carbonate buildups arranged in polygonal networks, or reticular patterns. These patterns are observed in both warm water photozoan and cool water heterozoan carbonate stratigraphies, and are developed atop platforms founded on stable shelves, in tectonically active settings and platforms developed over basinal evaporites. GIS mapping of multiple seismic horizons allows the Palaeozoic reticulated morphology to be numerically compared to that mapped in Alacranes Reef from QuickBird satellite imagery. QuickBird's metre-scale resolution allows identification of subtle cross-platform trends, such as windward-leeward differences in the packing density of ridge-and-pond complexes, which can be correlated with the kilometre-scale patterning extracted in the Barents subsurface. Despite different controls and architecture, the patterning of reticular networks is statistically inseparable between the two systems, once the metre-scale Modern dataset is down-sampled to seismic resolution. Whilst other controls cannot unequivocally be ruled out, these results suggest that biotic self-organisation is a fundamental driver of sedimentary

  7. Offshore concrete structures

    International Nuclear Information System (INIS)

    In the offshore industry there are two possible materials for the construction of the hull of a structure; the steel and concrete, with the first one widely used until now, as in the rest of the shiphuidling industry of merchant ships, warships, etc. Materials such as aluminum, GRP or timber areused in small units with lengths lower than 100 m, and in less adverse conditions than in the offshore industry. Nevertheless, some ships/barges have been built of concrete in the past, but have been rather isolated cases which have not changed the practice in the industry. In the First and Second World War were built by the scarcity of materials, while the series of barges by Alfred A. Yee was a rare exception. Other units were also made in concrete, but almost anecdotal. Still, the behaviour of these concrete structures, especially in terms of maintenance, has been excellent. Therefore, the fact that the concrete has not had an adequate reception so far in shipbuilding, does not mean that in will not be the material best suited for the offshore industry in the future. The extra displacement and associated fuel costs in concrete ships have been found prohibitive in the past. But the loss of mobility of a concrete hull in relation to a steel hull can be perfectly offset by the advantages offered by the concrete, as the shipping and offshore industry have very different priorities. One of the main differences in these priorities is in terms of maintenance and resistance to fatigue, precisely where the concrete performs better. ships can easily be dry docked for maintenance and repair, while in the offshore platforms these works have to be done in situ so maintenance and fatigue are crucial to them. Besides these, the concrete has other advantages according to findings of several studies. And although they are interested in the conclusions that the makes as they came from people in the concrete industry, the fact that in recent years concrete offshore unit shave been built

  8. Increasing restriction of the Egyptian shelf during the Early Eocene? - New insights from a southern Tethyan carbonate platform

    NARCIS (Netherlands)

    Höntzsch, S.; Scheibner, C.; Guasti, E.; Kuss, J.; Marzouk, A.M.; Rasser, M.W.

    2011-01-01

    The evolution of the isolated Galala carbonate platform has been studied intensively with respect to the Paleocene-Eocene Thermal Maximum (PETM) and the strong climatic variability from the Late Paleocene to the Early Eocene. In this study, we compare the results of different approaches which deal w

  9. Progressive drowning of carbonate platform in the Moravo-Silesian Basin (Czech Republic) before the Frasnian/Famennian event: facies, compositional variations and gamma-ray spectrometry

    Czech Academy of Sciences Publication Activity Database

    Bábek, O.; Přikryl, T.; Hladil, Jindřich

    2007-01-01

    Roč. 53, č. 2 (2007), s. 293-316. ISSN 0172-9179 Institutional research plan: CEZ:AV0Z30130516 Keywords : Devonian carbonate platform drowning * Frasnian/Famennian extinction * carbonate platform drowning Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.989, year: 2007

  10. Peritidal carbonate cycles induced by carbonate productivity variations:A conceptual model for an isolated Early Triassic greenhouse platform in South China

    Institute of Scientific and Technical Information of China (English)

    Wan Yang; Dan JLehrmann

    2014-01-01

    Eustasy has commonly been invoked to explain peritidal carbonate cyclicity, but is dififcult to explain cycles formed in a greenhouse climate when eustasy is minimal. We propose that peritidal cycles on an Early Triassic isolated carbonate platform in Guizhou, South China, were formed by hierarchical carbonate productivity variations. Most of the 149 shallowing-upward cycles are typically terminated by lfooding over intertidal facies and con-tain rare supratidal facies and no prolonged subaerial exposure. Low-diversity benthos in the platform interior during the post-end-Permian biotic recovery were sensitive to environmental perturbations, which caused variations in benthic sediment productivity in the subtidal carbon-ate factory. The perturbations may be driven by changes in salinity and degree of eutrophica-tion, or repeated platform mini-drowning by anoxic and/or CO2-charged deep water upwelled onto the banktop. They were modulated by Milankovitch orbitally-driven climatic and oceano-graphic factors as suggested by the hierarchical stacking pattern and spectral signals of these cycles. A one-dimensional conceptual model shows that hierarchical productivity variations alone may generate hierarchical peritidal carbonate cycles under conditions of constant sub-sidence and no sea-level lfuctuation.

  11. Offshore offloading of CO₂: Review of single point mooring types and suitability

    OpenAIRE

    Brownsort, Peter

    2015-01-01

    There are many types of single point mooring (SPM) and loading systems that have been developed in the offshore Oil and Gas sector for the transfer of hydrocarbon and other fluids from production wells, platforms or floating storages to tankers. Several of them can probably be adapted for transfer, in the opposite direction, of carbon dioxide (CO2) transported by ship as a refrigerated liquid, to injection wells for enhanced oil recovery (EOR) or geological storage. However, no clearly favour...

  12. Metre-scale cyclicity in Middle Eocene platform carbonates in northern Egypt: Implications for facies development and sequence stratigraphy

    Science.gov (United States)

    Tawfik, Mohamed; El-Sorogy, Abdelbaset; Moussa, Mahmoud

    2016-07-01

    The shallow-water carbonates of the Middle Eocene in northern Egypt represent a Tethyan reef-rimmed carbonate platform with bedded inner-platform facies. Based on extensive micro- and biofacies documentation, five lithofacies associations were defined and their respective depositional environments were interpreted. Investigated sections were subdivided into three third-order sequences, named S1, S2 and S3. Sequence S1 is interpreted to correspond to the Lutetian, S2 corresponds to the Late Lutetian and Early Bartonian, and S3 represents the Late Bartonian. Each of the three sequences was further subdivided into fourth-order cycle sets and fifth-order cycles. The complete hierarchy of cycles can be correlated along 190 km across the study area, and highlighting a general "layer-cake" stratigraphic architecture. The documentation of the studied outcrops may contribute to the better regional understanding of the Middle Eocene formations in northern Egypt and to Tethyan pericratonic carbonate models in general.

  13. Increasing power supply from land to offshore installations

    International Nuclear Information System (INIS)

    The report analyses how increasing the amount of power supplied from land to the offshore petroleum installations will affect the emissions of carbon dioxide from power production on land. At first, such power transmission will increase the emission of carbon dioxide from the existing power stations outside Norway. Since the price of the power also increases, the growth in consumption will be dampened. This means that the total emission will not increase as much as it would if the power supply to the offshore platforms had been based solely on the production in the existing coal power works. If in the long term new conventional gas power works can be built commercially, then increased power transmission to the offshore installations will cause the emissions from Norwegian onshore power production to increase. If conventional gas power plants are not granted concession, then the effect will be increased production in existing plants in other countries and reduced growth in consumption. The net increase in consumption implies increased emission of carbon dioxide from production in coal, oil or gas power stations in Denmark, Finland, Germany or Poland

  14. Technologies for waste heat recovery in off-shore applications

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Haglind, Fredrik; Kandepu, Rambabu; Fermi, Alessandro; Rossetti, Nicola

    2013-01-01

    In off-shore oil and gas platforms the selection of the gas turbine to support the electrical and mechanical demand on site is often a compromise between reliability, efficiency, compactness, low weight and fuel flexibility. Therefore, recovering the waste heat in off-shore platforms presents both...

  15. Peritidal carbonate cycles induced by carbonate productivity variations:A conceptual model for an isolated Early Triassic greenhouse platform in South China

    Institute of Scientific and Technical Information of China (English)

    Wan; Yang; Dan; J.Lehrmann

    2014-01-01

    Eustasy has commonly been invoked to explain peritidal carbonate cyclicity,but is difficult to explain cycles formed in a greenhouse climate when eustasy is minimal.We propose that peritidal cycles on an Early Triassic isolated carbonate platform in Guizhou,South China,were formed by hierarchical carbonate productivity variations.Most of the 149 shallowing-upward cycles are typically terminated by flooding over intertidal facies and contain rare supratidal facies and no prolonged subaerial exposure.Low-diversity benthos in the platform interior during the post-end-Permian biotic recovery were sensitive to environmental perturbations,which caused variations in benthic sediment productivity in the subtidal carbonate factory.The perturbations may be driven by changes in salinity and degree of eutrophication,or repeated platform mini-drowning by anoxic and/or CO2-charged deep water upwelled onto the banktop.They were modulated by Milankovitch orbitally-driven climatic and oceanographic factors as suggested by the hierarchical stacking pattern and spectral signals of these cycles.A one-dimensional conceptual model shows that hierarchical productivity variations alone may generate hierarchical peritidal carbonate cycles under conditions of constant subsidence and no sea-level fluctuation.

  16. DESIGN OF ENERGY COMPLEXES ON OFFSHORE STRUCTURES

    Directory of Open Access Journals (Sweden)

    Kalashnikov Pavel Kirillovich

    2016-03-01

    Full Text Available This research studies offshore oil and gas plat-forms after the exhaustion of hydrocarbon reserves. As an alternative to dismantling ways of reequipment of the promising facilities in the Arctic region for power generation are presented. Also a common problem of the infrastructure of offshore oil and gas fields after the end of their operation life is considered. One of the dif-ficult issues that is faced by oil-producing organizations is how to utilize the offshore platform? The hypothesis of infrastructure functionality of offshore platform was put forward for the other types of energy production. In the future, reequipment of offshore platforms will pro-vide an opportunity to reduce costs in the field of con-servation and optimize the environment. The methods for the development of design so-lutions selected by the authors allow us to consider an offshore platform after its operation as an element of culture development and a tool of ecological rehabilita-tion of the offshore area. This makes it possible to con-sider the prospects for the marine infrastructure growth and to improve the economy of coastal areas. The re-construction of offshore platforms with the change of their function will allow forming a developed maritime infrastructure in coastal waters. The ability to transport some of the offshore platforms after the oil and gas end will allow building a network 50 km away from the coastline. The authors carried out design experiments based mostly on fixed offshore platforms, regulated by the rules of the Rus-sian Maritime Register of Shipping and by SNIP 2.07.01—89*1. The authors developed the basic requirements for the selection of priority projects for the analysis, which are the characteristics of the waters suitable for the use of renewable energy sources and location of offshore platforms less than 50 km away from the coast with a small average water depth of 50 to 110 meters. Thus, the presented the concept of reconstruc

  17. Status of Coral Reef Communities on Two Carbonate Platforms (Tun Sakaran Marine Park, East Sabah, Malaysia

    Directory of Open Access Journals (Sweden)

    A. Montagne

    2013-01-01

    Full Text Available This study concerns three sites, located on carbonate platforms, east Sabah: Gaya West, Gaya East, and Mantabuan. At each site, the dominant coral shapes and their health were recorded (lagoons and outer slopes. Densities of echinoderms, Tridacna, and nudibranchs were recorded while fish density was estimated. Generally, the coral vitality is low (≤50% living corals. Massive corals dominate all sites, except the Gaya West-outer slope where coral coverage and diversity are the highest. On the Mantabuan-mesh reef, a diverse Acropora assemblage dominates the landscape. On the reef flat of Gaya East, monospecific circa 10 meter coral patches occur. Primary producers are scarce on all sites. Sea urchins, dominated by Diadema, are abundant on the Gaya East-reef flat and the Gaya West-mesh reef. Sea stars and holothurids are the most prevalent in Gaya West-outer slope, although they remain scarce. Crinoids are only abundant in Mantabuan. Stegastes damselfish highly characterizes the sites of Gaya East (reef flat and inner slope and the Mantabuan-mesh reef. On the Mantabuan-outer slope, parrotfish and other fishes are plentiful. No sign of eutrophication has been detected and natural hypersedimentation and/or eventual ancient bleaching events appear to be the direct principal causes of coral death or coral degradation.

  18. 浅谈海洋石油多功能支持平台的安全管理%Discussion on safety management about multi-functional support platform of offshore oil

    Institute of Scientific and Technical Information of China (English)

    周伟兴

    2012-01-01

    简单介绍了海洋石油多功能支持平台的基本情况,总结了多功能支持平台现有的三种安全管理工具,分别是工作许可证、工作安全风险分析( JSA)和“五想五不干”行为安全观察卡;同时结合海洋石油多功能支持平台自身特点,分析了如何做好平台的安全教育培训、安全检查和班组安全建设以及应急演练等安全管理工作;通过增强全员的安全意识、及时消除事故隐患及增强基层的安全管理和加强平台的应急反应能力,提高海洋石油多功能支持平台的安全管理水平,以期达到海洋石油平台安全、健康、和谐发展的目的,可供同行借鉴和参考.%In this paper, the basic status of the multi-functional support platform was introduced, and the three safety management tools of the multifunctional platform were summarized, including permit to work , JSA and five "no work" behavior observation card. Considering the overall of the multi-functional platform, how to do well the safety management was discussed, including the safety educationm, the safety check, the safety construction of the team and emergency drills. By enhancing the safety consciousness of all the staff, removing the hidden perils of the accident and enhancing emergency response ability, we can improve the safety management level of the platform, and achieve the objective of safety, health, and harmonious development in the offshore oil multi-functional support platform, which might be reference to the profession.

  19. Application of the Aero-Hydro-Elastic Model, HAWC2-WAMIT, to Offshore Data from Floating Power Plants Hybrid Wind- and Wave-Energy Test Platform, P37

    DEFF Research Database (Denmark)

    Bellew, Sarah; Yde, Anders; Verelst, David Robert

    2014-01-01

    pitching wave energy devices, not only to increase and smooth the power output from the platform, but also to take the energy from the waves in a controlled manner, resulting in a stable platform for the wind turbine and a safe harbour for O&M. They are currently developing the nal design for their rst...... full-scale prototype, the P80, which has a width of 80 m. As part of the development, Floating Power Plant have completed 4 oshore test-phases (totalling over 2 years oshore operation) on a 37 m wide scaled test device, the P37. This paper focuses on the comparison of one of the leading numerical...... models for oating wind turbines, developed by DTU Wind Energy, to the oshore data from P37. The nu- merical model couples DTU's own aeroelastic code, HAWC2, with a special external system that reads the output les generated directly by the commercial wave analysis software, WAMIT....

  20. Offshore Outsourcing

    DEFF Research Database (Denmark)

    Petersen, Bent; Benito, Gabriel R. G.; Dovgan, Olesya;

    While the extant literature on offshore outsourcing deals with this operation mode in isolation, and typically with a focus on cost effects, we address the broader question of how companies choose and use outsourcing as part of foreign operation mode development and as a contributor to internatio......While the extant literature on offshore outsourcing deals with this operation mode in isolation, and typically with a focus on cost effects, we address the broader question of how companies choose and use outsourcing as part of foreign operation mode development and as a contributor to...

  1. Comparison of API & IEC Standards for Offshore Wind Turbine Applications in the U.S. Atlantic Ocean: Phase II; March 9, 2009 - September 9, 2009

    Energy Technology Data Exchange (ETDEWEB)

    Jha, A.; Dolan, D.; Gur, T.; Soyoz, S.; Alpdogan, C.

    2013-01-01

    This report compares two design guidelines for offshore wind turbines: Recommended Practice for Planning, Designing, and Constructing Fixed Offshore Platform Structures and the International Electrotechnical Commission 61400-3 Design Requirements for Offshore Wind Turbines.

  2. Carbon Electrode-Molecule Junctions: A Reliable Platform for Molecular Electronics.

    Science.gov (United States)

    Jia, Chuancheng; Ma, Bangjun; Xin, Na; Guo, Xuefeng

    2015-09-15

    . At the molecular level, to form robust covalent bonds between electrodes and molecules and improve device stability, we developed a reliable system to immobilize individual molecules within a nanoscale gap of either SWCNTs or graphene through covalent amide bond formation, thus affording two classes of carbon electrode-molecule single-molecule junctions. One unique feature of these devices is the fact that they contain only one or two molecules as conductive elements, thus forming the basis for building new classes of chemo/biosensors with ultrahigh sensitivity. We have used these approaches to reveal the dependence of the charge transport of individual metallo-DNA duplexes on π-stacking integrity, and fabricate molecular devices capable of realizing label-free, real-time electrical detection of biological interactions at the single-event level, or switching their molecular conductance upon exposure to external stimuli, such as ion, pH, and light. These investigations highlight the unique advantages and importance of these universal methodologies to produce functional carbon electrode-molecule junctions in current and future researches toward the development of practical molecular devices, thus offering a reliable platform for molecular electronics and the promise of a new generation of multifunctional integrated circuits and sensors. PMID:26190024

  3. THE JURASSIC SEDIMENTARY EVOLUTION OF A CARBONATE PLATFORM INTO A DEEP-WATER BASIN, MT. MANGART (SLOVENIAN-ITALIAN BORDER

    Directory of Open Access Journals (Sweden)

    ANDREJ SMUC

    2005-03-01

    Full Text Available A complete Jurassic succession, recording the evolution from platform margin to a deep-water basin, is exposed at Mt. Mangart in the Julian Alps. The succession is a part of the Julian Nappe, where the Southern Alps overlap with the Dinarides. In the Jurassic, the area comprised part of the south Tethyan passive continental margin. The section was studied sedimentologically in detail and dated with radiolarians. It is divided into five lithostratigraphic units: Unit 1: Lower Jurassic shallow-water peloidal and oncoidal limestones; Unit 2: Pliensbachian distal shelf limestones rich in juvenile ammonites and sponge spicules topped by an Fe-Mn hardground; Unit 3: lower to possibly middle Toarcian sequence of black shales with interbedded siliceous limestone; Unit 4: upper Bajocian/Bathonian to lower Tithonian cherts, cherty limestones, and carbonate gravity-flow deposits; Unit 5: upper Tithonian red nodular cherty limestones with abundant calpionellids and aptychi. A stratigraphic gap, comprising the late Toarcian to early Bajocian, separates Unit 4 from Unit 3. In general, the succession correlates well with known Tethyan transgressive/regressive facies cycles. In addition, two periods of accelerated subsidence were recognized, the first, in the Pliensbachian, drowned the platform, the second, prior to the late Bajocian, created accommodation space for resedimented carbonate deposits from the adjacent Friuli Carbonate Platform. The present day position of the succession is between the Belluno Basin to the west and the Slovenian Basin to the south. The hitherto described successions of these two basins were located more distally from the Friuli Carbonate Platform than the Mt. Mangart succession. 

  4. Offshore Outsourcing

    DEFF Research Database (Denmark)

    Benito, Gabriel; Dovgan, Olesya; Petersen, Bent;

    2013-01-01

    Based on a case study of the Danish company SimCorp and the development of its operations in Kiev, Ukraine, we analyze offshore outsourcing in a broader, longitudinal foreign operation mode context, and how it may contribute to mode change in the host country over a certain span of time. Sim...

  5. Modelling and simulation of CO2 (carbon dioxide) bottoming cycles for offshore oil and gas installations at design and off-design conditions

    International Nuclear Information System (INIS)

    Improved energy efficiency is an issue of increasing importance in offshore oil and gas installations. The power on offshore installations is generated by gas turbines operating in a simple cycle. There is an obvious possibility for heat recovery for further power generation from the exhaust heat. However, the limited space and weight available makes the inclusion of bottoming cycles challenging. Due to its high working pressure and thereby compact components CO2 (carbon dioxide) could be a viable solution, combining compactness and efficiency. An in-house simulation tool is used to evaluate the performance of CO2 bottoming cycles at design and off-design conditions. Both a simple recuperated single stage cycle and a more advanced dual stage system are modelled. Results from simulations show a potential for 10–11%-points increase in net plant efficiency at 100% gas turbine load. Also off-design simulations taking the variation in heat exchanger performance into account are performed showing that the bottoming cycle improves the off-design performance compared to the standard gas turbine solution. Even at 60% GT (gas turbine) load, the combined cycle with CO2 bottoming cycle can achieve up to 45% net plant efficiency, compared to 31% for only the gas turbine. - Highlights: • Modeling of CO2 bottoming cycles. • Comparison of single and dual stage CO2 bottoming cycles. • Efficiencies comparable to steam systems. • Good off-design characteristics

  6. Morphology-dependent Electrochemical Enhancements of Porous Carbon as Sensitive Determination Platform for Ascorbic Acid, Dopamine and Uric Acid

    Science.gov (United States)

    Cheng, Qin; Ji, Liudi; Wu, Kangbing; Zhang, Weikang

    2016-02-01

    Using starch as the carbon precursor and different-sized ZnO naoparticles as the hard template, a series of porous carbon materials for electrochemical sensing were prepared. Experiments of scanning electron microscopy, transmission electron microscopy and Nitrogen adsorption-desorption isotherms reveal that the particle size of ZnO has big impacts on the porous morphology and surface area of the resulting carbon materials. Through ultrasonic dispersion of porous carbon and subsequent solvent evaporation, different sensing interfaces were constructed on the surface of glassy carbon electrode (GCE). The electrochemical behaviors of ascorbic acid (AA), dopamine (DA) and uric acid (UA) were studied. On the surface of porous carbon materials, the accumulation efficiency and electron transfer ability of AA, DA and UA are improved, and consequently their oxidation signals enhance greatly. Moreover, the interface enhancement effects of porous carbon are also controlled by the particle size of hard template. The constructed porous carbon interface displays strong signal amplification ability and holds great promise in constructing a sensitive platform for the simultaneous determination of AA, DA and UA.

  7. Offshore Space Center (offshore launch site)

    Science.gov (United States)

    Harvey, D. G.

    1980-01-01

    Any activity requiring the development of the HLLV can benefit by operations from an offshore space center (OSC) since operating near the equator provides a twenty percent increase in payload in an ecliptic plan orbit. Some OSC concepts considered include a moored floating (semisubmersible) design, a stationary design supported by fixed piles, and a combination of these two. The facility supports: a 15,000 foot long, 300 foot wide runway, designed to accommodate a two staged winged launch vehicle, with a one million pound payload capacity to low earth orbit; an industrial area for HLLV maintenance; an airport terminal, control and operation center, and observation tower; liquid hydrogen and liquid oxygen production and storage, and fuel storage platforms; a power generation station, docks with an unloading area; two separate launch sites; and living accommodations for 10,000 people. Potential sites include the Paramount Seamount in the Pacific Ocean off the north coast of South America. Cost estimates are considered.

  8. Chicxulub Impact Crater and Yucatan Carbonate Platform - Stratigraphy and Petrography of PEMEX Borehole Cores

    Science.gov (United States)

    Gutierrez-Cirlos, A. G.; Perez-Drago, G.; Perez-Cruz, L.; Urrutia-Fucugauchi, J.

    2008-12-01

    Chicxulub impact crater is the best preserved of the three large multi-ring structures documented in the terrestrial record. Chicxulub, formed 65 Ma ago, is associated with the Cretaceous/Tertiary (K/T) boundary layer and the impact related to the organism extinctions and events marking the boundary. The crater is buried under Tertiary sediments in the Yucatan carbonate platform in the southern Gulf of Mexico. The structure was initially recognized from gravity and magnetic anomalies in the PEMEX exploration surveys of the northwestern Yucatan peninsula. The exploration program included eight deep boreholes completed from 1952 through the 1970s. The investigations showing Chicxulub as a large complex impact crater formed at the K/T boundary have relayed on the PEMEX decades-long exploration program. However, despite frequent use of PEMEX information and core samples, significant parts of the database and cores remain to be evaluated, analyzed and incorporated with results from recent efforts. Access to PEMEX Core Repository has permitted to study the cores and collect new samples from some of the boreholes. We analyzed cores from Yucatan-6, Chicxulub-1, Sacapuc-1, Ticul-1, Yucatan-1 and Yucatan-4 boreholes to make new detailed stratigraphic correlations and petrographic characterization, using information from PEMEX database and the recent studies. In C-1 cores, breccias show 4-8 cm clasts of fine grained altered melt dispersed in a medium to coarse grained matrix composed of pyroxene and feldspar with little macroscopic alteration. Clasts contain 0.2 to 0.1 cm fragments of silicate material (basement) that show variable degrees of digestion. Melt samples from C-1 N10 comes from interval 1,393-1,394 m, and show a fine-to-medium grained coherent microcrystalline groundmass. Melt and breccias in Y-6 extend from about 1,100 m to more than 1,400 m. Sequence is well sorted, with an apparent gradation in both the lithic and melt clasts. In this presentation we report on

  9. Seismic stratigraphy of Lower Cretaceous carbonate platforms and margins, eastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Corso, W.; Buffler, R.T.

    1985-02-01

    Detailed seismic stratigraphic studies document the development of Lower Cretaceous platforms and margins along the Florida Escarpment and Jordan Knoll in the eastern Gulf of Mexico. Four different areas are characterized by relating seismic facies to depositional models: (1) northwest of DeSoto Canyon a rimmed platform margin with low paleo-relief (about 1500 m over a distance of 20 km) grew in a stationary manner and developed an accretionary slope, (2) a rimmed platform with high paleo-relief (about 2500 m over a distance of 6 km) is exposed along the Florida Escarpment from DeSoto Canyon south to about 24/sup 0/30'N (this part of the platform margin also grew in a stationary manner but developed a bypass slope), (3) a rimmed platform margin with moderate paleo-relief evolved from about 24/sup 0/30'N south to the Straits of Florida, and (4) an isolated platform with steep paleo-relief formed on a basement high at Jordan Knoll west of the Florida Escarpment. This platform also grew in a stationary manner and developed bypass slopes. The evolution of the various types of platform margins is related to their overall tectonic setting. Two episodes of platform drowning have been identified: (1) middle to late Albian(.) with the development of intrashelf basins and (2) middle Cenomanian when the platforms were terminally drowned due to a rapid change in relative sea level. Erosional truncation of reflections along the base of the Florida Escarpment suggests that parts of the platform margin have retreated up to 2-5 km since the middle Cenomanian.

  10. Response of proto-North Atlantic carbonate-platform ecosystems to OAE1a-related stressors

    Science.gov (United States)

    Huck, Stefan; Stein, Melody; Immenhauser, Adrian; Skelton, Peter W.; Christ, Nicolas; Föllmi, Karl B.; Heimhofer, Ulrich

    2014-11-01

    Integrated biostratigraphic-chemostratigraphic studies provide evidence that the proto-North Atlantic realm witnessed major changes in carbonate platform production in the run-up of the Early Aptian oceanic anoxic event (OAE) 1a. Whereas pervasive growth of Lithocodium microencrusters represents an early harbinger of OAE1a-related environmental perturbation, the subsequent replacement of oligotrophic rudist-coral-nerineid by mesotrophic orbitolinid-oyster communities was clearly associated with the event itself. In order to test the supra-regional relevance of this major community replacement, two shallow-water sections in the southern Lusitanian Basin (Portugal) are investigated by means of geochemistry (carbon and oxygen isotopes), cement petrography and detailed sedimentological analysis. The focus is on a regional, prominent discontinuity surface (S4) at the transition between oligotrophic and mesotrophic carbonate platform production, which might indicate that the major biotic change could have been associated with a phase of non-sedimentation and possibly erosion. The studied sections (São Julião, Crismina) provide evidence that the major Early Aptian biotic turnover was preceded by numerous subordinate but significant changes in platform ecology, which mirrored a series of progressive short-term environmental changes in the course of OAE1. Several transient mass occurrences of orbitolinids indicate repeated phases of ecological stress arguably due to enhanced nutrient input and deepening. Small-scale sea-level changes at parasequence level below the major discontinuity surface are revealed by alternations of rudist assemblages dominated by clinger or recumbent forms as well as intercalated hardground and subaerial exposure stages. Expanded phases of subaerial exposure, however, can be largely ruled out following the geochemical and cement-petrographic data presented here. Enhanced continent-derived siliciclastic input characterising the lower orbitolinid

  11. The petroleum systems of the Pechora Platform Foreland, Russia

    Energy Technology Data Exchange (ETDEWEB)

    Martirosyan, V.; Popova, L.; Vepreva, M. [Sevmorneftegeofizika, Murmansk (Russian Federation)

    1998-11-01

    The Timan-Pechora hydrocarbon basin is one of the most petroliferous provinces of Russia. It is at a mature stage of exploration onshore but is still poorly explored offshore. The exploration within the offshore extension of the Pechora Platform commenced in 1988 and has resulted in five commercial discoveries of oil and gas/condensate, the Severo-Gulyaevskoye, Pomorskoye, Prirazlomnoye, Varandey-More and Medyn-More fields. Hydrocarbon accumulations within the offshore extension of the Pechora Platform are related to at least two petroleum systems: the Domanik-Permo-Carboniferous and the Silurian-Lower Devonian. Reservoir rocks range from the Lower Devonian to the Upper Permian and are mostly carbonates. Throughout the onshore areas of the Pechora Platform, Silurian-Lower Devonian formations and Domanik shales are known as the main source rocks. This paper concerns the easternmost petroleum systems of the Pechora Platform that stretch west of the Novaya Zemlya Orogen and encompass more than 100 oil and gas fields. (Author)

  12. Isotopic evolution of the terminal Neoproterozoic and early Cambrian carbon cycle on the northern Yangtze Platform, South China

    Institute of Scientific and Technical Information of China (English)

    GUO Qingjun; LIU Congqiang; Harald STRAUSS; Tatiana GOLDBERG

    2003-01-01

    Profound geotectonic, climatic and biological changes occur during the terminal Neoproterozoic and its transition into the early Cambrian. These are reflected in temporal variations of the chemical and isotopic composition of seawater. We are studying a sequence of sedimentary rocks at the Shatan section, northern Yangtze Platform, Sichuan Province of China. This succession comprises, in ascending stratigraphic order, predominantly calcareous sediments of the Sinian upper Dengying Formation and black shales of the lower Cambrian Guojiaba Formation (time equivalent of Niutitang Fm.). Paleoenvironmental setting represents shallow-water shelf deposits. The objective of our study is to provide temporal records for the isotopic compositions of organic and carbonate carbon throughout this time interval. Organic carbon isotope values display a range between -35.8‰ and -30.1‰ with clear stratigraphic variations. Carbonate carbon isotope data vary between -3.5‰ and +0.5‰. These secular variations are interpreted to reflect perturbations of the global carbon cycle, specifically changes in the fractional burial of organic carbon. However, local conditions have further affected the isotopic signals.

  13. Functionalization of single-walled carbon nanotubes with protein by click chemistry as sensing platform for sensitized electrochemical immunoassay

    International Nuclear Information System (INIS)

    Highlights: ► Single-walled carbon nanotubes were functionalized with protein by click chemistry. ► The SWNTs conjugated with protein showed excellent dispersion in water and kept good bioacitvity. ► A competitive electrochemical immunoassay for the determination of anti-IgG was developed with high sensitivity and good stability. - Abstract: The application of the Cu(I)-catalyzed [3 + 2] Huisgen cycloaddition to the functionalization of single-walled carbon nanotubes (SWNTs) with the protein and the use of the artificial SWNTs as a sensing platform for sensitive immunoassay were reported. Covalent functionalization of azide decorated SWNTs with alkyne modified protein was firstly accomplished by the Cu(I)-catalyzed [3 + 2] Huisgen cycloaddition. FT-IR spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron micrograph were used to characterize the protein-functionalized SWNTs. It was found that the SWNTs conjugated with the proteins showed excellent dispersion in water and kept good bioacitivity when immunoglobulin (IgG) and horseradish peroxidase (HRP) were chosen as model proteins. As a proof-of-concept, IgG-functionalized SWNTs were immobilized onto the surface of a glassy carbon electrode by simple casting method as immunosensing platform and a sensitive competitive electrochemical immunoassay was developed for the determination of anti-immunoglobulin (anti-IgG) using HRP as enzyme label. The fabrication of the immunosensor were characterized by cyclic voltammetry and electrochemical impedance spectroscopy with the redox probe [Fe(CN)6]3−/4−. The SWNTs as immobilization platform showed better sensitizing effect, a detection limit of 30 pg mL−1 (S/N = 3) was obtained for anti-IgG. The proposed strategy provided a stable immobilization method and sensitized recognition platform for analytes. This work demonstrated that the click coupling of SWNTs with protein was an effective strategy

  14. Preliminary Design of a Multi-Column TLP Foundation for a 5-MW Offshore Wind Turbine

    OpenAIRE

    Yanping He; Jianmin Yang; Yongsheng Zhao

    2012-01-01

    Currently, floating wind turbines (FWTs) may be the more economical and suitable systems with which to exploit offshore wind energy in deep waters. Among the various types of floating foundations for offshore wind farms, a tension leg platform (TLP) foundation can provide a relatively stable platform for currently available offshore wind turbines without requiring major modifications. In this study, a new multi-column TLP foundation (WindStar TLP) was developed for the NREL 5-MW offshore wind...

  15. Platform decommissioning costs

    International Nuclear Information System (INIS)

    There are over 6500 platforms worldwide contributing to the offshore oil and gas production industry. In the North Sea there are around 500 platforms in place. There are many factors to be considered in planning for platform decommissioning and the evaluation of options for removal and disposal. The environmental impact, technical feasibility, safety and cost factors all have to be considered. This presentation considers what information is available about the overall decommissioning costs for the North Sea and the costs of different removal and disposal options for individual platforms. 2 figs., 1 tab

  16. DSJ300-1海洋钻井平台节流压井管汇设计%Design of the Throttling Kill Manifold of the DSJ300-1 Offshore Drilling Platform

    Institute of Scientific and Technical Information of China (English)

    冯利杰; 薛苏玲; 杜渊; 张辉; 陈钢

    2013-01-01

    在充分考虑海洋钻井平台特点、行业标准和用户要求的基础上,设计了DSJ300-1海洋钻井平台节流压井管汇.管汇布置采用倒L形结构,降低了阀门高度,方便操作、维修和维护;阀门采用比系统更高一级额定工作压力,为平台在不同海域、不同方位和不同水深作业时系统升级提供便利;阀门与四通、管线采用螺栓连接,提高设备的互换性;阀门与钢质垫环的密封槽采用堆焊不锈钢工艺,使设备具有抗H2S腐蚀的能力;采用双节流、双压井的冗余式结构,可利用高压钻井系统和固井系统的水泥浆进行压井作业,完成部分试井和试油工作.现场试验结果表明,该节流压井管汇具有可靠的井控功能,可保障平台作业人员和设备的安全.%On the basis of fully considering the features of offshore drilling platform,industrial standard and user demand,the throttling kill manifold of the DSJ300-1 offshore drilling platform was designed.The manifold layout adopts the inverted-L structure,reducing valve height.It is convenient in operation,repair and maintenance.The rated working pressure of the valve adopted is higher than that of the system,providing the convenience for system upgrading in different oceans,directions and water depths.The valve,cross tee and pipeline are connected by bolts,improving the interchangeability of equipment.The seal groove of valve and backing ring adopts surfacing stainless steel technology,enabling the equipment to resist against the H2S corrosion.The redundant structure of double throttling and double killing is adopted.The cement slurry of high pressure drilling system and cementing system can be used to conduct killing.The well testing and formation testing have been completed partially.The field test findings show that the manifold has the reliable well control function and it can guarantee the safety of platform operators and equipment.

  17. Urgonian platform carbonates (Barremian-Early Aptian) of southeastern France: description of a new project and first data

    Science.gov (United States)

    Bastide, F.; Massonnat, G.; Föllmi, K.; Adatte, T.; Dumont, T.; Arnaud-Vanneau, A.; Virgone, A.; Arnaud, H.

    2012-04-01

    Urgonian platform carbonates are widespread in southeastern France. They were deposited along the northern Tethyan margin and bordered the Vocontian basin. They are predominantly composed of rudistic wackestone and bioclastic/ooid grainstone. The Urgonian Formation in southeastern France has been studied by various authors since 1847 (A. Orbigny, A. Arnaud-Vanneau, H. Arnaud, J. Charollais, B. Clavel, W. Kilian, J.P. Masse, R. Schroeder...). The goal of this project is to complement existing observations and produce a synthesis of the development of the Urgonian platform for the whole southeastern sector of France. This will be achieved by a sedimentological, palaeontological and stratigraphical study on 54 sections and dedicated wells, i.e., 2418 thin sections or 10.5 km of sections in total, through the entire Urgonian series, from the transgressive system track of Ba3 (early late Barremian) to the highstand system track of Ap2 (early Aptian). The sections and wells are located in five main sectors of southeastern France: Gard, Ardèche, Vercors, Vaucluse and Provence. A biostratigraphic chart relevant to all five sectors has been realized in order to correlate between the sections. In addition, the geochemistry (carbon and oxygen isotopes, whole-rock and clay mineralogies, and phosphorus contents) of five key sections (one in each main sector) has been analysed to evaluate palaeoenvironmental conditions and corroborate the stratigraphic correlation throughout southeastern France. An additional study will be performed on the global and regional geotectonic constellation during the late Barremian and the early Aptian, and finally a numerical model will be developed based on the stratigraphic correlation between the sections and consistent with their palaeoenvironmental and paleaoclimatic context. With this interdisciplinary approach, we hope to be able to reconstruct and understand the development of the Urgonian platform in terms of its palaeoenvironment, palaeo

  18. Waste heat recovery for offshore applications

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Kandepu, Rambabu; Haglind, Fredrik

    2012-01-01

    vary in the range 20-30%. There are several technologies available for onshore gas turbines (and low/medium heat sources) to convert the waste heat into electricity. For offshore applications it is not economical and practical to have a steam bottoming cycle to increase the efficiency of electricity...... present paper, a review of the technologies available for waste heat recovery offshore is made. Further, the challenges of implementing these technologies on offshore platforms are discussed from a practical point of view. Performance estimations are made for a number of combined cycles consisting of a...

  19. Magnetic susceptibility variations of the Ediacaran cap carbonates in the Yangtze platform and their implications for paleoclimate

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Magnetic susceptibility (MS) data were obtained from 11 sections of the Doushantuo (Ediacaran) cap carbonate that directly overlies the Nantuo glacial diamictite in the southeastern margin of the Yangtze platform. The MS data revealed two regionally correlatable peaks at the bottom and top of the cap carbonate, separated by an interval of low values. The lower MS peak coincides with high percentage of insoluble siliciclastic residues that are compositionally identical to the matrix of the underlying diamictite, suggesting its origin controlled mainly by detrital components during the first phase of cap carbonate deposition at the end of the glaciation. The upper MS peak is associated with high clay content and iron sulfides, and can be interpreted as either derived from enhanced greenhouse weathering that could have brought more terrigenous components into the ocean, or the result of ocean anoxia at the late stage of cap carbonate deposition that could led to formation of abundant iron sulfides. The regionally consistent MS curves from the cap carbonates provided the first geophysical record for the rapid climate change from icehouse to greenhouse conditions in the aftermath of the Neoproterozoic "snowball Earth" event.

  20. Application of central air conditioner system on modular drilling rig of offshore ifxed platform%集中空调系统在海洋固定平台模块钻机上的应用研究

    Institute of Scientific and Technical Information of China (English)

    罗立臣; 许瑞杰; 马冬辉

    2014-01-01

    Based on the air conditioner selection of Lu Feng7-2 oil ifeld modular drilling rig project, this paper determines two sets of selection of air conditioner by preliminary study, which are central and separation air conditioner systems, respectively. With comparison between the central air conditioner and the split air conditioner in cost, effciency, comfort, space, etc., it concludes that the central air conditioner system has the advantages of lower operation cost, higher energy effciency ratio, better comfort capability, smaller space occupation and so on. It also analyzes its superiority and prospect of application on the modular drilling rig of offshore ifxed platform, which can provide a certain reference for the room cooling design and the equipment selection.%结合陆丰7-2油田模块钻机项目空调选型,通过前期调查研究制定了两套空调选型方案:集中空调系统方案和分体空调系统方案。通过对比两者在费用、工作效率、舒适性、占用空间等方面的特点,得出集中空调系统具有初始投入及运行成本低、能效比高、舒适性好、占地面积小等方面的优点,并分析了集中空调在海洋固定平台模块钻机上使用的优越性以及应用前景,对海洋固定平台模块钻机的房间制冷设计及设备选型提供了一定的参考。

  1. APPLICATION OF BP NEURAL NETWORK TO ASSESS THE POLLUTION LEVEL OF OIL SPILL ON THE OFFSHORE PLATFORM%BP网络海上石油平台溢油污染等级评估方法

    Institute of Scientific and Technical Information of China (English)

    郎印海; 刘洁; 贾永刚; 崔文林

    2011-01-01

    Assessment index system of oil spill for the offshore oil platform was established for the first time by analyzing the influenced factors related to the degree of oil pollution. To solve the problem of non-samples, every assessment index was divided into several grades and the Rand function was used to generate enough training samples and test samples. A more reasonable network structure was established and a BP neural network model of the degree of oil pollution was finally set up. The results showed that the model had good generalization, and it not only could be used to evaluate unknown samples but also had a strong practical value.%通过分析与溢油污染程度有关的影响因素,首次构建了海上石油平台溢油污染程度评价指标体系.针对模型无样本的难题,对评价指标进行分级,利用Rand函数在各分级标准内随机生成足够数量的训练和测试样本,建立了较合理的网络结构,构建了石油平台溢油污染等级BP网络模型.研究结果表明BP网络模型具有很强的泛化能力,能够用于评判未知样本,具有较强的实用性.

  2. On noise prediction and equipment layout optimization of typical cabin for offshore platforms by SEA%基于SEA的海洋平台典型舱室噪声预报及设备优化布置研究

    Institute of Scientific and Technical Information of China (English)

    吴彬; 谢晓忠; 陈林; 李卓; 孙丰

    2014-01-01

    Based on the Statistical Energy Analysis, this paper predicts the cabin noise of the typical cabin structure of the offshore platform under the air noise effect of the split air-conditioning outdoor unit with VA ONE software. Under the premise of the given structure size and the magnitude of load, this paper changes the air outlet orientation of the split air-conditioning outdoor unit, compares and analyzes the cabin noise. It concludes that the air outlet orientation has a great influence on cabin noise, which provides the certain reference for the cabin noise prediction and the equipment layout in Naval Architecture and Marine Engineering.%基于统计能量法,利用VAONE软件对海洋平台典型舱室结构在分体空调室外机空气噪声作用下的舱室噪声进行预报。在保证结构尺寸与载荷大小的前提下,改变分体空调室外机出风口朝向、对比分析舱室噪声,得出分体空调室外机出风口朝向会对舱室噪声产生较大影响。该研究对船舶与海洋工程舱室噪声预报及设备布置方面具有一定的参考价值。

  3. Optimization Design of Clamping Teeth of Offshore Discarded Platform Piles Removal Wire Saw%海洋废弃平台桩基拆除绳锯机夹紧齿优化设计研究

    Institute of Scientific and Technical Information of China (English)

    王海波; 张岚; 孟庆鑫; 王

    2014-01-01

    海洋废弃平台桩基拆除绳锯机是一种近年发展起来的新型水下作业机具,它主要由绳锯机本体和液压控制系统构成,绳锯机夹紧瓣上的夹紧齿可以使绳锯机安全、稳定地工作。介绍了夹紧齿的结构,分析得到了夹紧齿尺寸和齿周过渡曲线的优化数学模型,采用有限元法优化得到了夹紧齿关键参数。根据优化结果设计制造了夹紧齿,实验结果表明:该夹紧齿能够满足要求,为绳锯机的安全稳定工作打下了一定的基础。%Offshore discarded platform piles removal wire saw is a new underwater work tools which is developed in recent years. Its main structure includes the wire saw body and a hydraulic control system,the clamping teeth of clamping flap can make wire saw safely and stably work. Clamping teeth structure was described,the optimization mathematical models of clamping tooth size and tooth transition curve were obtained by analyzing,and the clamping tooth key optimization parameters were derived using the finite element method. Clamping teeth was designed and manufactured according to the optimization results. The experiment result shows that the clamping teeth is able to meet the requirements,which lays foundation for the security and stability of the wire saw.

  4. 海洋废弃平台桩基拆除切割方法的研究和发展%Research and development of cutting methods for removing piles of offshore discarded platform

    Institute of Scientific and Technical Information of China (English)

    王海波; 张岚; 孟庆鑫; 王喆

    2011-01-01

    桩基切割是海洋废弃平台拆除作业中的一项比较困难的工作.综述了可用于平台桩基切割的潜水员水下火焰切割、聚能爆破切割、旋转式内部机械切割、磨料高压射流切割和金刚石绳锯机切割五种方法.详细叙述了金刚石绳锯机切割海洋结构物的发展历程,对用于废弃平台桩基切割的绳锯机进行了结构及功能的上的全面介绍,并且分析了国外此方面的最新成果,展示了一些典型的绳锯机切割桩基工程实例.通过对比分析可知金刚石绳锯机切割桩基是一种比较安全可靠、先进环保的方法.%Piles cutting is a more difficult work in removal operations on offshore discarded platform.Five cutting ways are described in it which include divers underwater flarne cutting,shaped blasting cut ting,rotary internal mechanical cutting, high pressure abrasive jet cutting and diamond wire saw cutting. The development course of diamond wire saw cutting marine structures is expounded in it,the structure and function of the wire saw for cutting discarded platform piles is comprehensively introduced as well. then the latest foreign achievements in this area are analyzed as well as some typical engineering cases of wire saw cutting piles are showed.It is known that diamond wire saw cutting is a more safer, reliable, advanced as well as environmentally-friendly cutting method by contrast analyzing.

  5. Offshore concrete structures; Estructuras Offshore (mar adentro) de Hormigon

    Energy Technology Data Exchange (ETDEWEB)

    Lamas Pardo, M.; Carral Couce, L. M.

    2011-07-01

    In the offshore industry there are two possible materials for the construction of the hull of a structure; the steel and concrete, with the first one widely used until now, as in the rest of the shipbuilding industry of merchant ships, warships, etc. Materials such as aluminum, GRP or timber areused in small units with lengths lower than 100 m, and in less adverse conditions than in the offshore industry. Nevertheless, some ships/barges have been built of concrete in the past, but have been rather isolated cases which have not changed the practice in the industry. In the First and Second World War were built by the scarcity of materials, while the series of barges by Alfred A. Yee was a rare exception. Other units were also made in concrete, but almost anecdotal. Still, the behaviour of these concrete structures, especially in terms of maintenance, has been excellent. Therefore, the fact that the concrete has not had an adequate reception so far in shipbuilding, does not mean that in will not be the material best suited for the offshore industry in the future. The extra displacement and associated fuel costs in concrete ships have been found prohibitive in the past. But the loss of mobility of a concrete hull in relation to a steel hull can be perfectly offset by the advantages offered by the concrete, as the shipping and offshore industry have very different priorities. One of the main differences in these priorities is in terms of maintenance and resistance to fatigue, precisely where the concrete performs better. ships can easily be dry docked for maintenance and repair, while in the offshore platforms these works have to be done in situ so maintenance and fatigue are crucial to them. Besides these, the concrete has other advantages according to findings of several studies. And although they are interested in the conclusions that the makes as they came from people in the concrete industry, the fact that in recent years concrete offshore unit shave been built

  6. Continuous measurements of atmospheric oxygen and carbon dioxide on a North Sea gas platform

    OpenAIRE

    van der Laan-Luijkx, I. T.; R. E. M. Neubert; S. Van der Laan; Meijer, H. A. J.; D. Toohey

    2010-01-01

    A new atmospheric measurement station has been established on the North Sea oil and gas production platform F3, 200 km north off the Dutch coast (54 degrees 51' N, 4 degrees 44' E). Atmospheric concentrations of O(2) and CO(2) are continuously measured using fuel cell technology and compact infrared absorption instruments, respectively. Furthermore, the station includes an automated air flask sampler for laboratory analysis of the atmospheric concentrations of CO(2), CH(4), CO and O(2) and is...

  7. 爆炸荷载作用下海洋平台结构的动力响应分析%Dynamic Response Analysis of Offshore Platform under Blast

    Institute of Scientific and Technical Information of China (English)

    许继祥; 赵金城

    2013-01-01

    采用理想化的压力—时间曲线模拟爆炸冲击荷载,压力—时间曲线为简化的三角形荷载形式.考虑应变率效应对钢材的影响,应用LS-DYNA有限元分析软件,对导管架海洋平台在爆炸冲击荷载作用下的动力响应进行数值模拟和分析,得到了不同峰值爆炸荷载作用下,海洋平台结构上层甲板、中层甲板和立面结构重要节点的动力响应时程曲线.结果表明:上层甲板和中层甲板节点竖向位移的绝对值随着爆炸荷载峰值压力的增大而增大,当爆炸荷载峰值压力为20~70 kPa时,节点区域内均处于弹性状态,当爆炸荷载峰值压力为80 kPa时,节点区域内进入了塑性状态.立面平台节点的水平位移随着爆炸荷载峰值压力的增大而增大,当爆炸荷载峰值压力为20~80kPa时,节点区域内进入塑性状态.%Idealized pressure-time curve is adopted to simulate explosion load.The pressure-time curve represents simplified triangular load.Considering the influence of strain rate effect on steel,numerical simulation and analysis of dynamic response of jacket offshore platform under blast are performed by LS-DYNA software.Dynamic time-history response curves of key nodes in the upper deck,middle deck and vertical structure under different blast load are obtained.Results show that the absolute values of vertical displacements of the upper deck and middle deck nodes increase with increase of explosion load peak pressure.When the explosion load peak pressure ranges from 20 to 70 kPa,the material near these nodes is in the elastic stage.When explosion load peak pressure reaches 80kpa,the material enters the plastic stage.Horizontal displacements of elevation platform nodes increase with increase of explosion load peak pressure.Material near monitoring points in elevation platform enters plastic stage when explosion load peak pressure varies from 20 to 80 kPa.

  8. Demise of the northern Tethyan Urgonian carbonate platform and subsequent transition towards pelagic conditions: the sedimentary record of the Col de la Plaine Morte area, central Switzerland

    OpenAIRE

    Föllmi K.B.; Gainon F.

    2008-01-01

    The sedimentary succession of the Col de la Plaine Morte area (Helvetic Alps, central Switzerland) documents the disappearance of the northern Tethyan Urgonian platform in unprecedented detail and suggests stepwise platform demise, with each drowning phase documented by erosion and phosphogenesis. The first identified drowning phase terminated Urgonian carbonate production in a predominantly photozoan mode. Using a correlation of the whole-rock δ13C record with the well-dated record from SE F...

  9. Highly-sensitive electrochemical sensing platforms for food colourants based on the property-tuning of porous carbon

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Qin [Key Laboratory for Large-Format Battery Materials and System, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074 (China); Xia, Shanhong; Tong, Jianhua [State Key Laboratory of Transducer Technology, Institute of Electronics, Chinese Academy of Science, Beijing, 100190 (China); Wu, Kangbing, E-mail: kbwu@hust.edu.cn [Key Laboratory for Large-Format Battery Materials and System, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074 (China)

    2015-08-05

    It is very challenging to develop highly-sensitive analytical platforms for toxic synthetic colourants that widely added in food samples. Herein, a series of porous carbon (PC) was prepared using CaCO{sub 3} nanoparticles (nano-CaCO{sub 3}) as the hard template and starch as the carbon precursor. Characterizations of scanning electron microscopy and transmission electron microscopy indicated that the morphology and porous structure were controlled by the weight ratio of starch and nano-CaCO{sub 3}. The electrochemical behaviours of four kinds of widely-used food colourants, Sunset yellow, Tartrazine, Ponceau 4R and Allura red, were studied. On the surface of PC samples, the oxidation signals of colourants enhanced obviously, and more importantly, the signal enhancement abilities of PC were also dependent on the starch/nano-CaCO{sub 3} weight ratio. The greatly-increased electron transfer ability and accumulation efficiency were the main reason for the enhanced signals of colourants, as confirmed by electrochemical impedance spectroscopy and chronocoulometry. The prepared PC-2 sample by 1:1 starch/nano-CaCO{sub 3} weight ratio was more active for the oxidation of food colourtants, and increased the signals by 89.4-fold, 79.3-fold, 47.3-fold and 50.7-fold for Sunset yellow, Tartrazine, Ponceau 4R and Allura red. As a result, a highly-sensitive electrochemical sensing platform was developed, and the detection limits were 1.4, 3.5, 2.1 and 1.7 μg L{sup −1} for Sunset yellow, Tartrazine, Ponceau 4R and Allura red. The practical application of this new sensing platform was demonstrated using drink samples, and the detected results consisted with the values that obtained by high-performance liquid chromatography. - Highlights: • PC samples with different morphology and electrochemical activities were prepared. • Highly sensitive electrochemical sensing platform was developed for food colourants. • The accuracy and practicability was testified to be good by HPLC.

  10. Highly-sensitive electrochemical sensing platforms for food colourants based on the property-tuning of porous carbon

    International Nuclear Information System (INIS)

    It is very challenging to develop highly-sensitive analytical platforms for toxic synthetic colourants that widely added in food samples. Herein, a series of porous carbon (PC) was prepared using CaCO3 nanoparticles (nano-CaCO3) as the hard template and starch as the carbon precursor. Characterizations of scanning electron microscopy and transmission electron microscopy indicated that the morphology and porous structure were controlled by the weight ratio of starch and nano-CaCO3. The electrochemical behaviours of four kinds of widely-used food colourants, Sunset yellow, Tartrazine, Ponceau 4R and Allura red, were studied. On the surface of PC samples, the oxidation signals of colourants enhanced obviously, and more importantly, the signal enhancement abilities of PC were also dependent on the starch/nano-CaCO3 weight ratio. The greatly-increased electron transfer ability and accumulation efficiency were the main reason for the enhanced signals of colourants, as confirmed by electrochemical impedance spectroscopy and chronocoulometry. The prepared PC-2 sample by 1:1 starch/nano-CaCO3 weight ratio was more active for the oxidation of food colourtants, and increased the signals by 89.4-fold, 79.3-fold, 47.3-fold and 50.7-fold for Sunset yellow, Tartrazine, Ponceau 4R and Allura red. As a result, a highly-sensitive electrochemical sensing platform was developed, and the detection limits were 1.4, 3.5, 2.1 and 1.7 μg L−1 for Sunset yellow, Tartrazine, Ponceau 4R and Allura red. The practical application of this new sensing platform was demonstrated using drink samples, and the detected results consisted with the values that obtained by high-performance liquid chromatography. - Highlights: • PC samples with different morphology and electrochemical activities were prepared. • Highly sensitive electrochemical sensing platform was developed for food colourants. • The accuracy and practicability was testified to be good by HPLC

  11. 75 FR 418 - Certificate of Alternative Compliance for the Offshore Supply Vessel KELLY ANN CANDIES

    Science.gov (United States)

    2010-01-05

    ...'s ability to maneuver within close proximity of offshore platforms and conduct helicopter operations... SECURITY Coast Guard Certificate of Alternative Compliance for the Offshore Supply Vessel KELLY ANN CANDIES... Alternative Compliance was issued for the offshore supply vessel KELLY ANN CANDIES as required by 33...

  12. EU-NORSEWInD - Investigation of Flow Distoration Effects on Offshore Instrumentation

    DEFF Research Database (Denmark)

    Stickland, Matt; Scanlon, Tom; Fabre, Sylvie;

    to assess the local wind conditions. Part of the overall NORSEWInD project is the use of LiDAR remote sensing (RS) systems mounted on offshore platforms to measure wind velocity profiles at a number of locations offshore. The data acquired from the offshore RS measurements will be fed into a large...

  13. System for modelling and monitoring of offshore discharge water

    International Nuclear Information System (INIS)

    This paper presents the results of a feasibility and definition study of the EUREKA project Modelling and Monitoring of Discharges from Offshore Oil and Gas Platforms (M and M). The study, executed between October 1990 and June 1991, concluded that the development of a system to predict the behaviour and effect of discharges from offshore oil and gas platforms is feasible. Such a M and M system could be accomplished by adapting existing software and hardware modules and developing the necessary interfaces

  14. Reliability-Analysis of Offshore Structures using Directional Loads

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Bloch, Allan; Sterndorff, M. J.

    2000-01-01

    Reliability analyses of offshore structures such as steel jacket platforms are usually performed using stochastic models for the wave loads based on the omnidirectional wave height. However, reliability analyses with respect to structural failure modes such as total collapse of a structure...... heights from the central part of the North Sea. It is described how the stochastic model for the directional wave heights can be used in a reliability analysis where total collapse of offshore steel jacket platforms is considered....

  15. Community replacement instead of drowning: Evolution of proto-North Atlantic carbonate-platform production in the run-up to of the Early Aptian OAE1a

    Science.gov (United States)

    Huck, Stefan; Stein, Melody; Adatte, Thierry; Föllmi, Karl B.; Immenhauser, Adrian; Heimhofer, Ulrich

    2014-05-01

    In the proto-North Atlantic realm (Lusitanian Basin, Portugal), carbonate platform production witnessed a major biotic turnover during the Early Aptian. Here, Urgonian-type rudist-nerinid dominated limestones were replaced by an orbitolinid-rich, oyster and serpulid-bearing marly facies. Integrated biostratigraphic-chemostratigraphic studies (Burla et al., 2008; Huck et al., 2012) provided evidence that this change coincides with the Early Aptian carbonate platform drowning episode in the run-up of oceanic anoxic event (OAE) 1a (transition D. forbesi to D. deshayesi ammonite zones), which has been recorded, from many localities in the Tethyan Ocean (Godet, 2013). Unlike Helvetic and Arabian carbonate platforms, which are characterised by a punctuated mass occurrence of orbitolinids marking the onset of the Aptian (Rawil and Hawar members, respectively), orbitolinids are an abundant constituent of the proto-North Atlantic carbonate platform community from the Late Barremian onwards. Orbitolinid-rich packstones and marls showing mass-occurrences of orbitolinids indicate repeated short-term installation of specific environmental conditions (eutrophication and/or deepening). In order to critically assess the influence of regional palaeoenvironmental against global palaeoclimatic and palaeoceanographic changes on the Proto-North Atlantic carbonate platform evolution, several outcrop successions in the Lusitanian Basin covering the critical interval have been investigated in detail with regard to facies and petrographic characteristics and geochemical (C-/O-isotopes, P content, bulk-rock and clay mineralogy,) inventory. The aims of the present study are three-fold: (1) to characterise proto-North Atlantic Lower Aptian shallow-water carbonates with respect to diagenetic history, microfacies, and distribution of fossils useful for the analysis of palaeoenvironments (corals, rudists and orbitolinids); (2) to evaluate the influence of sea-level and humidity changes

  16. Dynamic analysis and design of offshore structures

    CERN Document Server

    Chandrasekaran, Srinivasan

    2015-01-01

    This book  attempts to provide readers with an overall idea of various types of offshore platform geometries. It covers the various environmental loads encountered by these structures, a detailed description of the fundamentals of structural dynamics in a class-room style, estimate of damping in offshore structures and their applications in the preliminary analysis and design. Basic concepts of structural dynamics are emphasized through simple illustrative examples and exercises. Design methodologies and guidelines, which are FORM based concepts are explained through a few applied example structures. Each chapter also has tutorials and exercises for self-learning. A dedicated chapter on stochastic dynamics will help the students to extend the basic concepts of structural dynamics to this advanced domain of research. Hydrodynamic response of offshore structures with perforated members is one of the recent research applications, which is found to be one of the effective manner of retrofitting offshore structur...

  17. Morphologies and depositional/erosional controls on evolution of Pliocene-Pleistocene carbonate platforms: Northern Carnarvon Basin, Northwest Shelf of Australia

    Science.gov (United States)

    Goktas, P.; Austin, J. A.; Fulthorpe, C. S.; Gallagher, S. J.

    2016-08-01

    The detailed morphologies, evolution and termination of latest Neogene tropical carbonate platforms in the Northern Carnarvon Basin (NCB), on the passive margin of the Northwest Shelf (NWS) of Australia, defined based upon mapping using 3D seismic images, reveal the history of local/regional oceanographic processes, fluctuations in relative sea-level and changing climate. Cool-water carbonate deposition, dominant during the early-middle Miocene, was followed by a siliciclastic influx, which prograded across the NWS beginning in the late-middle Miocene, during a period of long-term global sea-level fall. The resulting prograding clinoform sets, interpreted as delta lobes, created relict topographic highs following Pliocene termination of the siliciclastic influx. These highs constituted multiple favorable shallow-water environments for subsequent photozoan carbonate production. Resultant platform carbonate development, in addition to being a response to cessation of siliciclastic influx and the existence of suitable shallow-water substrate, was also influenced by development of the warm-water Leeuwin Current (LC), flowing southwestward along this margin. Four flat-topped platforms are mapped; each platform top is a sequence boundary defined by reflection onlap above and truncation below. Successive platforms migrated southwestward through time, along margin strike. All platforms exhibit predominantly progradational seismic geometries. Mapped tops are ≥10 km wide. Seismic evidence of karst on three of four platform tops, e.g., v-shaped troughs up to 50 m deep and ~1 km wide, and broader basins with areas up to 20 km2, suggests episodic subaerial exposure that may have contributed to platform demise. Platform 4, the most recent, is unique in having interpreted biohermal build-ups superimposed on the progradational platform base. The base of these interpreted patch reefs now lies at a water depth of ~153 m; therefore, we suggest that these reefs developed post

  18. GlobAllomeTree: international platform for tree allometric equations to support volume, biomass and carbon assessment

    Directory of Open Access Journals (Sweden)

    Henry M

    2013-07-01

    Full Text Available GlobAllomeTree is an international platform for tree allometric equations. It is the first worldwide web platform designed to facilitate the access of the tree allometric equation and to facilitate the assessment of the tree biometric characteristics for commercial volume, bio-energy or carbon cycling. The webplatform presents a database containing tree allometric equations, a software called Fantallomatrik, to facilitate the comparison and selection of the equations, and documentation to facilitate the development of new tree allometric models, improve the evaluation of tree and forest resources and improve knowledge on tree allometric equations. In the Fantallometrik software, equations can be selected by country, ecological zones, input parameters, tree species, statistic parameters and outputs. The continuously updated database currently contains over 5000 tree allometric equations classified according to 73 fields. The software Fantallometrik can be also used to compare equations, insert new data and estimate the selected output variables using field inventory. The GlobAllomeTree products are freely available at the URL: http://globallometree.org for a range of users including foresters, project developers, scientist, student and government staff.

  19. Tectonic triggering of slump sheets in the Upper Cretaceous carbonate succession of the Porto Selvaggio area (Salento peninsula, southern Italy): Synsedimentary tectonics in the Apulian Carbonate Platform

    Science.gov (United States)

    Mastrogiacomo, G.; Moretti, M.; Owen, G.; Spalluto, L.

    2012-08-01

    Soft-sediment deformation structures crop out in the Upper Cretaceous carbonate succession in Porto Selvaggio cove in the western Salento peninsula, Apulian foreland, southern Italy. The deformed interval is about 13 m thick and occurs between shallow-water limestones and dolostones formed in peritidal and shallow subtidal environments. It comprises well-bedded grey mudstones interlayered with dark grey laminated microbioclastic wackestones characterized by couplets of closely spaced dark and bright laminae marked by the parallel orientation of calcareous microbioclasts and thin-shelled bivalves. The low biological diversity, scarcity of burrowing biota, and presence of a well preserved fish fauna provide evidence of anoxic conditions occurring in morphological depressions within the platform, and a stagnant, stratified water body affected by weak bottom currents, indicating the sudden development of a localised and short-lived intraplatform basin. Two soft-sediment deformation horizons (slump sheets) separated by undeformed limestones with similar facies occur in this part of the succession. The lower, thicker slump sheet (1.0-1.3 m thick) contains asymmetric and box folds. Well-developed décollement surfaces (locally containing thick brecciated zones) cut the folds, forming small-scale thrust-sheets and indicating mixed plastic to brittle behaviour. The upper, thinner slump sheet (0.25-0.35 m thick) contains only asymmetric folds, indicating plastic behaviour only. The differences in deformation style are attributed to differences in facies. Measurements of fold-axis orientations in the slump sheets show that they moved in similar directions, recording the development of a local, gently dipping palaeoslope. Autogenic (internal) trigger mechanisms are ruled out by a detailed consideration of facies. The slump sheets were triggered by allogenic, tectonic effects, either the weakening of sediment by seismic activity or the tectonically induced steepening of slopes

  20. Offshore wind energy developments

    DEFF Research Database (Denmark)

    Stolpe, Mathias; Buhl, Thomas; Sumer, B. Mutlu;

    2014-01-01

    This chapter will give a brief overview of a few of the activities within offshore wind energy research, specifically 1) Support structure optimization, 2) Blade coatings for wind turbines; 3) Scour protection of foundations, 4) Offshore HVDC and 5) Offshore wind services.......This chapter will give a brief overview of a few of the activities within offshore wind energy research, specifically 1) Support structure optimization, 2) Blade coatings for wind turbines; 3) Scour protection of foundations, 4) Offshore HVDC and 5) Offshore wind services....

  1. Offshoring and International Competitiveness

    DEFF Research Database (Denmark)

    Ørberg Jensen, Peter D.; Pedersen, Torben

    2012-01-01

    advanced offshoring, exploring what causes firms to offshore some of their more advanced tasks. Our findings indicate that while the lower cost of unskilled, labor-intensive processes is the main driver for firms that offshore less advanced tasks, the offshoring of advanced tasks is part of firms’ strategy...... to achieve international competitiveness through access to cross-border knowledge flows and foreign knowledge resources. Furthermore, offshoring of advanced manufacturing tasks seems to be more widespread and experience-based than the offshoring of advanced service tasks....

  2. Poly(lactic acid)/Carbon Nanotube Fibers as Novel Platforms for Glucose Biosensors

    OpenAIRE

    Valtencir Zucolotto; Eliton Souto Medeiros; Luiz Henrique Capparelli Mattoso; Juliano Elvis Oliveira

    2012-01-01

    The focus of this paper is the development and investigation of properties of new nanostructured architecture for biosensors applications. Highly porous nanocomposite fibers were developed for use as active materials in biosensors. The nanocomposites comprised poly(lactic acid)(PLA)/multi-walled carbon nanotube (MWCNT) fibers obtained via solution-blow spinning onto indium tin oxide (ITO) electrodes. The electrocatalytic properties of nanocomposite-modified ITO electrodes were investigated to...

  3. Lithographically patterned thin activated carbon films as a new technology platform for on-chip devices.

    Science.gov (United States)

    Wei, Lu; Nitta, Naoki; Yushin, Gleb

    2013-08-27

    Continuous, smooth, visibly defect-free, lithographically patterned activated carbon films (ACFs) are prepared on the surface of silicon wafers. Depending on the synthesis conditions, porous ACFs can either remain attached to the initial substrate or be separated and transferred to another dense or porous substrate of interest. Tuning the activation conditions allows one to change the surface area and porosity of the produced carbon films. Here we utilize the developed thin ACF technology to produce prototypes of functional electrical double-layer capacitor devices. The synthesized thin carbon film electrodes demonstrated very high capacitance in excess of 510 F g(-1) (>390 F cm(-3)) at a slow cyclic voltammetry scan rate of 1 mV s(-1) and in excess of 325 F g(-1) (>250 F cm(-3)) in charge-discharge tests at an ultrahigh current density of 45,000 mA g(-1). Good stability was demonstrated after 10,000 galvanostatic charge-discharge cycles. The high values of the specific and volumetric capacitances of the selected ACF electrodes as well as the capacity retention at high current densities demonstrated great potential of the proposed technology for the fabrication of various on-chip devices, such as micro-electrochemical capacitors. PMID:23815346

  4. Poly(lactic acid/Carbon Nanotube Fibers as Novel Platforms for Glucose Biosensors

    Directory of Open Access Journals (Sweden)

    Valtencir Zucolotto

    2012-02-01

    Full Text Available The focus of this paper is the development and investigation of properties of new nanostructured architecture for biosensors applications. Highly porous nanocomposite fibers were developed for use as active materials in biosensors. The nanocomposites comprised poly(lactic acid(PLA/multi-walled carbon nanotube (MWCNT fibers obtained via solution-blow spinning onto indium tin oxide (ITO electrodes. The electrocatalytic properties of nanocomposite-modified ITO electrodes were investigated toward hydrogen peroxide (H2O2 detection. We investigated the effect of carbon nanotube concentration and the time deposition of fibers on the sensors properties, viz., sensitivity and limit of detection. Cyclic voltammetry experiments revealed that the nanocomposite-modified electrodes displayed enhanced activity in the electrochemical reduction of H2O2, which offers a number of attractive features to be explored in development of an amperometric biosensor. Glucose oxidase (GOD was further immobilized by drop coating on an optimized ITO electrode covered by poly(lactic acid/carbon nanotube nanofibrous mats. The optimum biosensor response was linear up to 800 mM of glucose with a sensitivity of 358 nA·mM−1 and a Michaelis-Menten constant (KM of 4.3 mM. These results demonstrate that the solution blow spun nanocomposite fibers have great potential for application as amperometric biosensors due to their high surface to volume ratio, high porosity and permeability of the substrate. The latter features may significantly enhance the field of glucose biosensors.

  5. Triazine-Carbon Nanotubes: New Platforms for the Design of Flavin Receptors.

    Science.gov (United States)

    Lucío, María Isabel; Pichler, Federica; Ramírez, José Ramón; de la Hoz, Antonio; Sánchez-Migallón, Ana; Hadad, Caroline; Quintana, Mildred; Giulani, Angela; Bracamonte, Maria Victoria; Fierro, Jose L G; Tavagnacco, Claudio; Herrero, María Antonia; Prato, Maurizio; Vázquez, Ester

    2016-06-20

    The synthesis of functionalised carbon nanotubes as receptors for riboflavin (RBF) is reported. Carbon nanotubes, both single-walled and multi-walled, have been functionalised with 1,3,5-triazines and p-tolyl chains by aryl radical addition under microwave irradiation and the derivatives have been fully characterised by using a range of techniques. The interactions between riboflavin and the hybrids were analysed by using fluorescence and UV/Vis spectroscopic techniques. The results show that the attached functional groups minimise the π-π stacking interactions between riboflavin and the nanotube walls. Comparison of p-tolyl groups with the triazine groups shows that the latter have stronger interactions with riboflavin because of the presence of hydrogen bonds. Moreover, the triazine derivatives follow the Stern-Volmer relationship and show a high association constant with riboflavin. In this way, artificial receptors in catalytic processes could be designed through specific control of the interaction between functionalised carbon nanotubes and riboflavin. PMID:27168484

  6. Seismic interpretation of dinantian carbonate platforms in the Netherlands; implications for the palaeogeographical and structural development of the Northwest European Carboniferous Basin

    NARCIS (Netherlands)

    Kombrink, H.; Lochem, H. van; Zwan, K.J. van der

    2010-01-01

    The Northwest European Carboniferous Basin is characterized by a series of carbonate platforms and intervening shale-dominated troughs during the Dinantian Sub-period. These structures have been mainly found along the margins of the basin. Here we present the results of an investigation of high-qual

  7. Accessing offshoring advantages

    DEFF Research Database (Denmark)

    Mykhaylenko, Alona; Motika, Agnes; Wæhrens, Brian Vejrum;

    2015-01-01

    Purpose – The purpose of this paper is to advance the understanding of factors that affect offshoring performance results. To do so, this paper focuses on the access to location-specific advantages, rather than solely on the properties of the offshoring company, its strategy or environment....... Assuming that different levels of synergy may exist between particular offshoring strategic decisions (choosing offshore outsourcing or captive offshoring and the type of function) and different offshoring advantages, this work advocates that the actual fact of realization of certain offshoring advantages...... (getting or not getting access to them) is a more reliable predictor of offshoring success. Design/methodology/approach – Aset of hypotheses derived from the extant literature is tested on the data from a quantitative survey of 1,143 Scandinavian firms. Findings – The paper demonstrates that different...

  8. The Chicxulub multi-ring impact crater, Yucatan carbonate platform, Gulf of Mexico

    OpenAIRE

    Jaime Urrutia-Fucugauchi; Antonio Camargo-Zanoguera; Ligia Pérez-Cruz; Guillermo Pérez-Cruz

    2011-01-01

    The Chicxulub impact crater is part of a select group of unique geological sites, being a natural laboratory to investigate crater formation processes and global effects of large-scale impacts. Chicxulub is one of only three multi-ring craters documented in the terrestrial record and impact has been related to the global environmental/climatic effects and mass extinction that mark the Cretaceous/Paleogene (K/Pg) boundary. The crater is buried under ~1.0 km of carbonate sediments in the Yucata...

  9. Offshore wind energy developments

    OpenAIRE

    Stolpe, Mathias; Buhl, Thomas; Sumer, B. Mutlu; Kiil, Søren; Holbøll, Joachim; Piirainen, Kalle

    2014-01-01

    This chapter will give a brief overview of a few of the activities within offshore wind energy research, specifically 1) Support structure optimization, 2) Blade coatings for wind turbines; 3) Scour protection of foundations, 4) Offshore HVDC and 5) Offshore wind services.

  10. Continuous measurements of atmospheric oxygen and carbon dioxide on a North Sea gas platform

    Directory of Open Access Journals (Sweden)

    I. T. Luijkx

    2009-07-01

    Full Text Available A new atmospheric measurement station has been established on the North Sea oil and gas production platform F3, 200 km north off the Dutch coast (54°51' N, 4°44' E. Atmospheric mixing ratios of O2 and CO2 are continuously measured using fuel cell technology and compact infrared absorption instruments, respectively. Furthermore, the station includes an automated air flask sampler for laboratory analysis of the atmospheric mixing ratios of CO2, CH4, CO and O2 and isotope measurements of δ13C, δ18O and Δ14C from CO2. This station is – to our knowledge – the first fixed sea based station with on-site continuous O2 and CO2 measurements and therefore yields valuable additional information about the CO2 uptake in coastal marine regions, specifically the North Sea. This paper presents the measurement station and the used methodologies in detail. Additionally, the first data is presented showing the seasonal cycle as expected during August 2008 through June 2009. In comparison to land-based stations, the data show low day-to-day variability, as they are practically free of nightly inversions. Therefore, the data set collected at this measurement station serves directly as background data for the coastal northwest European region. Additionally, some short-term O2 and CO2 signals are presented, including very large (over 200 per meg and fast negative atmospheric O2 excursions.

  11. Emergency response in the Newfoundland offshore industry

    International Nuclear Information System (INIS)

    This presentation reviewed current offshore oil activities with respect to safety issues regarding year-round marine operations in a harsh environment. Considerable logistics support is required for all offshore activities, including seismic and geotechnical surveys; exploration and production drilling; well testing; subsea construction; on-site production; and, delivery to market. Response to an offshore emergency must address the urgency of the incident along with stakeholder concerns. This presentation described the different types of emergencies and addressed issues regarding contingency planning; preventative measures; response philosophy; response scope; response at site; emergency management; communications links; and, oil spill response. The following current operations were highlighted: ExxonMobil's production drilling from the gravity-based concrete platform at Hibernia; Petro-Canada's production drilling at the Terra Nova FPSO; Husky Energy's production drilling at White Rose; and Chevron Canada's exploration drilling at the Orphan Basin. It was noted that in an emergency situation, the focus is on the welfare of offshore personnel. On an average day, the total offshore population is in the order of 1000 workers, all registered in the Personnel Logistics System which is updated with the departure of every helicopter from St. John's, Newfoundland or from the offshore platform. It is possible to prepare for foreseeable emergency incidents such as fire, explosion or gas leaks; spills to the marine environment; structural damage or collisions; persons lost at sea; helicopter or support vessel accidents; vessel sinking; sabotage; serious injuries or loss of life; severe ice events; and, loss of well control. The establishment of permanent safety zones at the Hibernia, White Rose and Terra Nova production fields are among the preventative measures, along with standby vessels that provide a rescue service for offshore installations. Supply vessels are also

  12. The influence of paleo currents upon the Santaren Channel and the adjacent carbonate platforms, Bahamas.

    Science.gov (United States)

    Paulat, Marco; Lüdmann, Thomas; Betzler, Christian; Eberli, Gregor; Lindhorst, Sebastian

    2015-04-01

    The closure of the Central American Seaway and the reorganization of the ocean currents had a global impact on earth's climate. The sedimentation of the Great Bahama Bank (GBB) and the smaller Cay Sal Bank (CSB) are influenced by the Atlantic North Equatorial Current and the Florida Current. New high-resolution multichannel seismic data sets tied to the IODP leg 166 wells document that the shape of Bahama Banks and the sedimentation processes in the Santaren Channel (SC) between GBB and CSB are strongly related to changes in the strength of these currents. Since the Upper Miocene, the SC is filled up by a huge package of drift sediments, namely the Santaren Drift (SD). The buildup of the SD causes a local high in the recent bathymetry perpendicular to the surrounding steep platform slopes. The SD shows a typical mounded morphology and progrades northwards in direction of the Florida Channel. The SD was established during the late Miocene. Seismic facies and internal configuration indicate an environment of a stable north flowing current with a major depocenter related to the center of the SC. Additionally, a second depocenter at the central eastern flank of CSB established and preserved till early Pleistocene when the slope sedimentation starts to dominate. This depocenter points to a strengthened countercurrent component in the eastern SC. From the lower Pliocene to the upper Pleistocene the volume of the SD expanded, associated with an intensification of the current in the SC along its eastern flank, indicated by deep erosional channels parallel to the margin of GBB in the northern part of the survey area. This trend probably was initiated as a consequence of current reorganization due to the final closure of the Central American Seaway. Lower slope sediments from GBB are eroded or only minor parts are preserved from lower Pliocene to upper Pleistocene. With late Pliocene falling sea-level, gravitational slope sedimentation from GBB into the SC increased with

  13. Polyethylenimine-carbon nanotubes composite as an electrochemical sensing platform for silver nanoparticles.

    Science.gov (United States)

    Duan, Shuo; Yue, Rui; Huang, Yuming

    2016-11-01

    For the first time, polyethylenimine (PEI) and carbon nanotubes (CNT) composites (PEI-CNTs) were employed for investigation of electrochemical response of silver nanoparticles (AgNPs) in this work. The PEI-CNTs were easily prepared by sonicating the mixture of PEI and CNTs solution and characterized by SEM, Raman and electrochemical impedance spectroscopy (EIS). The PEI-CNTs/GCE enhanced the electrochemical response for three AgNPs with different capping agents, including citrate-AgNPs (Cit-AgNPs), humic acid-AgNPs (HA-AgNPs) and gum acacia-AgNPs (GA-AgNPs), by cyclic voltammetry (CV), linear sweep voltammetry (LSV) and chronocoulometry (CC). On these findings, a new electrochemical method based on LSV was developed for the detection of AgNPs. Under the optimum conditions, the proposed method showed a good linear range from 5 to 200ng/L, and the limits of detection (LODs) were 4.77ng/L for Cit-AgNPs, 2.48ng/L for HA-AgNPs and 1.01ng/L for GA-AgNPs, respectively. The potential of using the PEI-CNTs modified GCE for determining AgNPs in water samples has been successfully demonstrated. PMID:27591657

  14. Triassic beds in the basement of the Adriatic-Dinaric carbonate platform of Mt. Svilaja (Croatia

    Directory of Open Access Journals (Sweden)

    Vladimir Jelaska

    2003-12-01

    Full Text Available On the southwestern slope of Mt. Svilaja a Triassic sequence is exposed. It is composed of Lower Triassic carbonate siliciclastic shelf beds that are unconformably overlain by Anisian breccia. The overlying pelagic Anisian and Ladinian strata with pyroclastic rockscan be interpreted as a result of rift tectonics of Adria micro-plate. A 500 m thick sequence is capped by an emersion surface by karstification and terrigenous sediments including conglomerate as a result of Late Triassic transgression and marking the lower boundaryof a new, Late Mesozoic, megasequence of the External Dinarides.By means of conodont study, in the lowermost part of the studied Mesozoic sequence, a Lower Triassic shallow-water conodont fauna yielding Pachycladina obliqua apparatus was recorded. Pelagic limestone beds overlying the »Otarnik breccia« are marked byconodont elements of the Anisian constricta Zone. The Ladinian interval is characterized (from bottom to top: trammeri A. Z., hungaricus A. Z. and mungoensis A. Z. The uppermost part of the section below the emersion surface is identified by Pseudofurnishiusmurchianus, indicating the Upper Ladinian-Lower Carnian murchianus Zone.

  15. Carbon nanotube-hydroxyapatite nanocomposite: a novel platform for glucose/O2 biofuel cell.

    Science.gov (United States)

    Zhao, H Y; Zhou, H M; Zhang, J X; Zheng, W; Zheng, Y F

    2009-10-15

    This study demonstrates a novel carbon nanotubes-hydroxyapatite (CNTs-HA) nanocomposite-based compartment-less glucose/O(2) biofuel cell (BFC) with the glucose oxidase (GOD) as the anodic biocatalysts and the laccase as the cathodic biocatalysts. CNTs-HA nanocomposite prepared by the self-assembly method via an aqueous solution reaction has been used as the co-immobilization matrix to incorporate biocatalysts, i.e. GOD and laccase successfully. Moreover, the three-dimensional configuration of the CNTs-HA films electrode would be advantageous to the glucose oxidation on the bioanode and O(2) electroreduction on the biocathode of BFC. The maximum power density delivered by the assembled glucose/O(2) BFC could reach 15.8 muWcm(-2) at a cell voltage of 0.28 V with 10 mM glucose. The results indicate that the CNTs-HA nanocomposite is believed to be very useful for the development of novel BFC device. PMID:19713096

  16. Magnetic Carbon Nanotubes as a Theranostic Platform for Drug Delivery and Magnetic Resonance Imaging

    KAUST Repository

    Alkattan, Nedah

    2014-06-01

    Carbon nanotubes (CNTs) have special characteristics that made them good agents especially for biomedical applications. In this study, Fe3O4 nanoparticles were incorporated onto the surface of CNTs followed by polyethylene glycol (PEG) grafting forming CNTs-Fe3O4-PEG hybrids. The PEGylation improves their biocompatibility, water solubility, and increases blood circulation. CNTs-Fe3O4-PEG was used as T2-contrat agent for magnetic resonance imaging (MRI). In addition, doxorubicin (DOX) was loaded onto CNTs-Fe3O4-PEG. The release of DOX from DOX-loaded CNTs-Fe3O4-PEG was tested under different pH conditions (7.4, 6.3 and 5.2). The release increased at acidic pH compared to neutral pH, which shows the sensitivity of the system to pH change. Triggering the release by Near Infra-Red (NIR) irradiation was furthermore investigated. The release increased after irradiation with NIR compared to control sample. These result prove that the designed system can be triggered by an internal stimuli (pH) and external stimuli (NIR irradiation) making it a promising candidate to be used for biomedical applications.

  17. Pore space evolution and elastic properties of platform carbonates (Urgonian limestone, Barremian-Aptian, SE France)

    Science.gov (United States)

    Fournier, François; Léonide, Philippe; Kleipool, Luuk; Toullec, Renault; Reijmer, John J. G.; Borgomano, Jean; Klootwijk, Thomas; Van Der Molen, Jeroen

    2014-07-01

    A dataset of 214 ultrasonic velocity and porosity measurements on Barremian-Aptian carbonates from Provence (SE France) provides well-constrained velocity-porosity transforms and allows the quantification of the impact of pore type and diagenetic history on these velocities. A numerical approach (EPAR: equivalent pore aspect ratio) was used to link diagenetic transformations, pore network evolution and elastic properties. Three categories of samples characterized by their dominant pore type were discriminated from the velocity and porosity database by means of the EPAR values derived from bulk (K-EPAR) and shear (μ-EPAR) moduli: 1) purely microporous limestones (low K- and μ-EPAR 0.3). Three velocity-porosity trajectories related to three diagenetic paths were defined and quantified from the Urgonian database: 1) EPAR-preserving micro-scale cementation of micrite, 2) non-EPAR-preserving dissolution with moldic pore development and 3) EPAR-preserving sparry calcite cementation of molds. Equivalent Pore Aspect Ratio can therefore be regarded as a robust tool to decipher diagenetic trends in velocity-porosity transforms and may help predicting pore architecture from subsurface data.

  18. Methionine – Au Nanoparticle Modified Glassy Carbon Electrode: a Novel Platform for Electrochemical Detection of Hydroquinone

    Directory of Open Access Journals (Sweden)

    Jiahong HE

    2014-12-01

    Full Text Available A high sensitive electrochemical sensor based on methionine/gold nanoparticles (MET/AuNPs modified glassy carbon electrode (GCE was fabricated for the quantitative detection of hydroquinone (HQ. The as-modified electrode was characterized by scanning electron microscopy (SEM and X-ray diffraction (XRD techniques. The electrochemical performance of the sensor to HQ was investigated by using cyclic and differential pulse voltammetry, which revealed its excellent electrocatalytic activity and reversibility towards HQ. The separation of anodic and cathodic peak (∆Ep was decreased from 471 mV to 75 mV. The anodic peak current achieved under the optimum conditions was linear with the HQ concentration ranging from 8 μM to 400 μM with the detection limit 0.12 μM (3σ. The as-fabricated sensor also showed a good selectivity towards HQ without demonstrating interference from other coexisting species. Furthermore, the sensor showed a good performance for HQ detection in environmental water, which suggests its potential practical application. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6477

  19. PEaCH4 v.2.0: A modelling platform to predict early diagenetic processes in marine sediments with a focus on biogenic methane - Case study: Offshore Namibia

    Science.gov (United States)

    Arning, Esther T.; Häußler, Steffen; van Berk, Wolfgang; Schulz, Hans-Martin

    2016-07-01

    The modelling of early diagenetic processes in marine sediments is of interest in marine science, and in the oil and gas industry, here, especially with respect to methane occurrence and gas hydrate formation as resources. Early diagenesis in marine sediments evolves from a complex web of intertwining (bio)geochemical reactions. It comprises microbially catalysed reactions and inorganic mineral-water-gas interactions. A model that will describe and consider all of these reactions has to be complex. However, it should be user-friendly, as well as to be applicable for a broad community and not only for experts in the field of marine chemistry. The presented modelling platform PeaCH4 v.2.0 combines both aspects, and is Microsoft Excel©-based. The modelling tool is PHREEQC (version 2), a computer programme for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations. The conceptual PEaCH4 model is based on the conversion of sediment-bound degradable organic matter. PEaCH4 v.2.0 was developed to quantify and predict early diagenetic processes in marine sediments with the focus on biogenic methane formation and its phase behaviour, and allows carbon mass balancing. In regard to the irreversible degradation of organic matter, it comprises a "reaction model" and a "kinetic model" to predict methane formation. Both approaches differ in their calculations and outputs as the "kinetic model" considers the modelling time to integrate temperature dependent biogenic methane formation in its calculations, whereas the "reaction model" simply relies on default organic matter degradation. With regard to the inorganic mineral-water-gas interactions, which are triggered by irreversible degradation of organic matter, PEaCH4 v.2.0 is based on chemical equilibrium thermodynamics, appropriate mass-action laws, and their temperature dependent equilibrium constants. The programme is exemplarily presented with the example of upwelling sediments off Namibia

  20. Seismic interpretation of the sedimentation systems, structural geology and stratigraphic of the Chicxulub crater, carbonate platform of Yucatan, Mexico.

    Science.gov (United States)

    Iza, Canales-Garcia; Jaime, Urrutia-Fucugauchi; Joaquin Eduardo, Aguayo-Camargo; Angel, Alatorre-Mendieta Miguel

    2016-04-01

    In order to describe the structural and stratigraphic features of the Chicxulub crater, was performed the present work of seismic interpretation, seismic attributes and generation of 3D surfaces. Load data it was performed in SEG-Y format, to display a total of 19 seismic reflection profiles were worked at domain time; the corresponding interpretation was carried out by separating five packages with textural differences, for this separation were used five horizons with seismic response representing the base of these packages, the correlation of horizons was made for all lines, creating composed lines so that all profiles were interpret together at intersections for form a grid. Multiple fault zones, were interpreted with the help of seismic attributes, like RMS amplitude, complex trace analysis, gradient of the trace and cosine phase. Was obtained the structural and stratigraphic interpretation , 3D models of the surfaces interpreted with which it is possible to observe the morphology of the base of the basin, it is controlled by the effect of the impact that formed the crater, has the features as a multi-ring crater. Shallower horizons shows that the topography of the base of the crater continues to affect the upper relief, which tends to be horizontal as it approaches the surface but is modeled by themselves sedimentary processes of the carbonate platform of Yucatán; packages below the base of the crater show the characteristics that own carbonated breccia, product the rupture of the material at impact, the material was deposited in a chaotic way, at this level we found the faults and fractures zone.

  1. Conference on offshore wind power in France and Germany

    International Nuclear Information System (INIS)

    The French-German office for Renewable energies (OFAEnR) organised a conference on offshore wind power in France and Germany. In the framework of this French-German exchange of experience, about 120 participants exchanged views on the planning and authorisation procedures implemented in both countries and on the installation, connection to the grid and maintenance of offshore wind turbines. environmental impacts and usage conflicts linked with offshore wind farms exploitation were addressed as well. This document brings together the available presentations (slides) made during this event: 1 - Update: Offshore Wind In Germany (Ronny Meyer); 2 - Offshore wind development in France (Timothee Furois); 3 - The Licensing Procedure for Offshore Wind Farms in the German EEZ (Nico Nolte); 4 - Spatial Planning and Permitting in France: What leverage for more efficiency? (Frederic Lanoe); 5 - Results of 10 years environmental research on FINO-platforms (Bjoern Lehmann-Matthaei); 6 - Offshore Grid Connection - Status Quo and Overview (Andree Ifflaender); 7 - Grid connection of Offshore Wind in France: Situation, perspectives and recommendations (Alexandre Courcambeck); 8 - Controlling risks and warranting safety: Best practices for the installation, exploitation and maintenance of offshore wind turbines (Norbert Giese); 9 - Offshore wind Bremerhaven experience: An essential asset for the development of a complete Wind Offshore industry in France (Philippe Kavafyan); 10 - Standardizing and Cost Reduction -Lessons Learned from London Array (Niels Bjaert); 11 - Offshore Wind energy in Germany: System Benefits and Cost Reduction Potentials. Presentation of study results from prognos/fichtner and Fraunhofer-IWeS (Andreas Wagner); 12 - Offshore Wind energy financing - opportunities and risks (Jerome Guillet)

  2. Unzipping and binding of small interfering RNA with single walled Carbon Nanotube: a platform for small interfering RNA delivery

    CERN Document Server

    Santosh, Mogurampelly; Bhattacharyya, Dhananjay; Sood, A K; Maiti, Prabal K; 10.1063/1.3682780

    2012-01-01

    In an effort to design efficient platform for siRNA delivery, we combine all atom classical and quantum simulations to study the binding of small interfering RNA (siRNA) by pristine single wall carbon nanotube (SWCNT). Our results show that siRNA strongly binds to SWCNT surface via unzipping its base-pairs and the propensity of unzipping increases with the increase in the diameter of the SWCNTs. The unzipping and subsequent wrapping events are initiated and driven by van der Waals interactions between the aromatic rings of siRNA nucleobases and the SWCNT surface. However, MD simulations of double strand DNA (dsDNA) of the same sequence show that the dsDNA undergoes much less unzipping and wrapping on the SWCNT in the simulation time scale of 70 ns. This interesting difference is due to smaller interaction energy of thymidine of dsDNA with the SWCNT compared to that of uridine of siRNA, as calculated by dispersion corrected density functional theory (DFT) methods. After the optimal binding of siRNA to SWCNT, t...

  3. Unzipping and binding of small interfering RNA with single walled carbon nanotube: A platform for small interfering RNA delivery

    Science.gov (United States)

    Santosh, Mogurampelly; Panigrahi, Swati; Bhattacharyya, Dhananjay; Sood, A. K.; Maiti, Prabal K.

    2012-02-01

    In an effort to design efficient platform for siRNA delivery, we combine all atom classical and quantum simulations to study the binding of small interfering RNA (siRNA) by pristine single wall carbon nanotube (SWCNT). Our results show that siRNA strongly binds to SWCNT surface via unzipping its base-pairs and the propensity of unzipping increases with the increase in the diameter of the SWCNTs. The unzipping and subsequent wrapping events are initiated and driven by van der Waals interactions between the aromatic rings of siRNA nucleobases and the SWCNT surface. However, molecular dynamics (MD) simulations of double strand DNA (dsDNA) of the same sequence show that the dsDNA undergoes much less unzipping and wrapping on the SWCNT in the simulation time scale of 70 ns. This interesting difference is due to smaller interaction energy of thymidine of dsDNA with the SWCNT compared to that of uridine of siRNA, as calculated by dispersion corrected density functional theory (DFT) methods. After the optimal binding of siRNA to SWCNT, the complex is very stable which serves as one of the major mechanisms of siRNA delivery for biomedical applications. Since siRNA has to undergo unwinding process with the effect of RNA-induced silencing complex, our proposed delivery mechanism by SWCNT possesses potential advantages in achieving RNA interference.

  4. Carbon Nanotube-Plasma Polymer-Based Amperometric Biosensors: Enzyme-Friendly Platform for Ultrasensitive Glucose Detection

    Science.gov (United States)

    Muguruma, Hitoshi; Matsui, Yasunori; Shibayama, Yu

    2007-09-01

    An amperometric enzyme biosensor fabricated with carbon nanotubes (CNTs) and plasma-polymerized thin films (PPFs) is reported. A mixture of the enzyme glucose oxidase (GOD) and a CNT film is sandwiched with 10-nm-thick acetonitrile PPFs. Under PPF layer was deposited onto a sputtered gold electrode. To facilitate the electrochemical communication between the CNT layer and GOD, CNT was treated with oxygen plasma. The device with single-walled CNTs showed a sensitivity higher than that of multiwalled CNTs. The glucose biosensor showed ultrasensitivity (a sensitivity of 40 μA mM-1 cm-2, a correlation coefficient of 0.992, a linear response range of 0.025-1.9 mM, a detection limit of 6.2 μM at S/N = 3, +0.8 V vs Ag/AgCl), and a rapid response (< 4 s in reaching 95% of maximum response). This high performance is attributed to the fact that CNTs have excellent electrocatalytic activity and enhance electron transfer, and that PPFs and/or the plasma process for CNTs are the enzyme-friendly platform, i.e., a suitable design of the interface between GOD and CNTs.

  5. Demise of the northern Tethyan Urgonian carbonate platform and subsequent transition towards pelagic conditions: The sedimentary record of the Col de la Plaine Morte area, central Switzerland

    Science.gov (United States)

    Föllmi, Karl B.; Gainon, François

    2008-04-01

    The sedimentary succession of the Col de la Plaine Morte area (Helvetic Alps, central Switzerland) documents the disappearance of the northern Tethyan Urgonian platform in unprecedented detail and suggests stepwise platform demise, with each drowning phase documented by erosion and phosphogenesis. The first identified drowning phase terminated Urgonian carbonate production in a predominantly photozoan mode. Using a correlation of the whole-rock δ13C record with the well-dated record from SE France, its age is inferred to as Middle Early Aptian (near the boundary between the weissi and deshayesi zones). A subsequent drowning phase is dated by ammonites and by a correlation of the whole-rock δ13C record as Late Early Aptian (late deshayesi to early furcata zone). A third drowning phase provides an ammonite-based age of Early Late Aptian ( subnodosocostatum and melchioris zones) and is part of a widely recognized phase of sediment condensation and phosphogenesis, which is dated as latest Early to Middle Late Aptian (late furcata zone to near the boundary of the melchioris and nolani zones). The fourth and final drowning phase started in the latest Aptian ( jacobi zone) as is also indicated by ammonite findings at the Col de la Plaine Morte. The phases of renewed platform-carbonate production intervening between the drowning phases were all in a heterozoan mode. During the ultimate drowning phase, phosphogenesis continued until the Early Middle Albian, whereas condensation processes lasted until the Middle Turonian. Coverage of the external margin of the drowned Urgonian platform by a drape of pelagic carbonates started only in the Late Turonian. During the Santonian, the external part of the drowned platform underwent normal faulting and saw the re-exposure of already lithified Urgonian carbonates at the seafloor. Based on the here-inferred ages, the first drowning phase just precedes oceanic anoxic episode 1a (OAE 1a or "selli event") in time, and the second

  6. AE Signal Identification of Offshore Platform Tubular Joints Crack Propagation Based on Wavelet Energy Coefficient%基于小波能量系数的海洋平台管节点疲劳裂纹扩展AE信号识别

    Institute of Scientific and Technical Information of China (English)

    刘贵杰; 徐萌; 李思乐; 吴乃龙

    2013-01-01

    An identification method of the offshore platform tubular joints fatigue crack propagation was proposed.Wavelet allocation scalogram and wavelet energy coefficient method were applied for the feature extraction of acoustic emission(AE) signal of marine structures typical fatigue crack propagation and fracture at the same time.The method could improve the aggregation of scalogram by excluding noise.By making the typical tubular joints model fracture experiments of the offshore platforms and using PXWAE AE detector to monitor the whole process of the specimen fracture, the paper successfully extracted the AE signals of crack propagation and fracture process.The analysis results demonstrated that the variation of wavelet energy coefficient and the change of crack propagation state were in a good consistency and could characterize the AE signals characteristics of different stages of crack propagation accurately, intuitively, and clearly.It could be used effectively in online real-time monitoring and fault diagnosis of offshore platform tubular joints fatigue crack.%提出一种海洋平台管节点疲劳裂纹扩展状况识别方法,将小波分配尺度谱和小波能量系数应用于海洋结构件的典型疲劳裂纹扩展和断裂声发射信号的特征提取,提高了尺度图像的聚集性,排除了噪声干扰;通过海洋平台典型管节点模型断裂试验,运用PXWAE声发射检测仪对试件断裂全过程进行监测,成功提取到裂纹扩展和断裂过程中的声发射信号.结果表明,小波能量系数的变化与裂纹发展状态的变化呈现良好的一致性,能够准确、直观、清晰地表征出裂纹扩展不同阶段AE信号的特征,能够有效应用于海洋平台管节点疲劳损伤状态的在线实时监测和故障诊断.

  7. From Offshoring to Backshoring

    DEFF Research Database (Denmark)

    Slepniov, Dmitrij; Madsen, Erik Skov

    2015-01-01

    The purpose of this paper is to examine the evolution of offshoring over time. The paper employs qualitative methodology and on the basis of two case studies of Danish companies, it develops a framework conceptualizing the stages of offshoring and highlights the factors driving the transition...... between these stages. The framework challenges the linear nature of offshoring and proposes the existence of ‘the pendulum effect’. The pendulum effect suggests that the modes of offshoring (i.e. captive and non-captive) and geographies of offshoring (i.e. home and abroad) are not static; rather, they...... attention of academia and practitioners. The paper discusses the possible implications of offshoring in the next era of Chinese manufacturing and closes with limitations and possible future extensions of the study....

  8. Offshore waste treatment guidelines

    International Nuclear Information System (INIS)

    These guidelines were prepared to aid offshore oil and gas operators in the management of waste materials related to petroleum drilling and production operations in offshore areas regulated by the Canada-Newfoundland and Labrador Offshore Petroleum Board (CNLOPB) and the Canada-Nova Scotia Offshore Petroleum Board (CNSOPB). A description of the relevant sections of the regulatory regime applicable to Canada's offshore oil and gas operations was included. Offshore operators are expected to take all reasonable measures to minimize the volumes of waste materials generated by their operations. The guidelines included recommendations for identifying, monitoring, and reporting discharges; performance expectations for specific discharges; requirements for greenhouse gas (GHG) and other air emissions; methods of characterizing and monitoring produced water, drilling muds, and desalination brine. Operational discharges associated with the installation and maintenance of subsea systems were also reviewed, and qualifications of analytical laboratories were presented. 24 refs., 2 appendices.

  9. Let the giants sleep. Platform technology

    Energy Technology Data Exchange (ETDEWEB)

    Hamlen, Steven

    1997-12-31

    The article relates to offshore platform technology. As the industry generally moves away from creating the lumbering giants that were the original breed of production platforms, operators are seeking more decommissioning-friendly and simple solutions which offer the economic and environmental advantages of being lighter, liftable and reusable on future development projects. 3 figs.

  10. Blow Hole Cave: An unroofed cave on San Salvador Island, the Bahamas, and its importance for detection of paleokarst caves on fossil carbonate platforms

    Czech Academy of Sciences Publication Activity Database

    Bosák, Pavel; Mylroie, J. E.; Hladil, Jindřich; Carew, J. L.; Slavík, Ladislav

    2002-01-01

    Roč. 31, č. 3 (2002), s. 51-74. ISSN 0583-6050. [Karstological School - Classical Karst: Types of Karst /10./. Pstojna, 26.06.2002-28.06.2002] R&D Projects: GA AV ČR IAA3013809; GA AV ČR IAA3013209 Keywords : carbonate platforms * unroofed caves * gamma-ray spectrometry and wellogging Subject RIV: DB - Geology ; Mineralogy http://carsologica.zrc-sazu.si/downloads/313/slavik.pdf

  11. Why offshore wind energy?

    OpenAIRE

    Esteban Pérez, María Dolores; Diez Gonzalez, Jose Javier; López Gutiérrez, José Santos; Negro Valdecantos, Vicente

    2011-01-01

    At the beginning of 2010, only 2000 wind megawatts had been installed offshore. Although the first offshore wind farm experiment took place in 1990, most of the facilities built up to now have been pilot projects. Then, offshore wind power can be considered as an incipient market. However, just at this moment, the growth of this technology finally seems to be happening, being several countries at the top of its development (the United Kingdom, Denmark, Holland, Sweden and Germany). This curre...

  12. Offshore vindindustri i Danmark

    DEFF Research Database (Denmark)

    Drejer, Ina; Andersen, Poul Houman; Gjerding, Allan Næs

    Rapporten giver en karakteristik af forretningssystemet for offshore vindenergi i Danmark, og undersøger som et led heri hvordan virksomhedernes aktiviteter er organiseret, og i hvilken retning systemet udvikler sig. Rapporten præsenterer en status over danskbaserede virksomheder med aktiviteter...... inden for offshore vindenergi og giver et indblik i hvilke udviklingsudfordringer, offshore vindområdet står overfor....

  13. Verdivurdering av BW Offshore

    OpenAIRE

    Kalleberg, Carl-Fredrik; Storebø, Mats

    2015-01-01

    Målet med oppgaven var å gjennomføre en verdivurdering av BW Offshore. Problemstillingen var å finne egenkapitalverdien for en privat investor i BW Offshore og deretter komme med en handelsanbefaling på BWO aksjen. For å gjennomføre verdivurderingen valgte vi en fundamentalanalyse ved bruk av den diskonterte kontantstrømmodellen. Vi supplerte verdivurderingen med en komparativ- og sensitivitetsanalyse. BW Offshore opererer innenfor exploration & production (E&P) i offshorebr...

  14. Panorama 2012 - Offshore hydrocarbons

    International Nuclear Information System (INIS)

    Technological progress is enabling production from offshore oil and gas fields at increasingly ambitious depths (3, 000 metres). Investment in offshore production is running at around $100 billion per year, accounting for one-fifth of all investment in oil exploration and development worldwide. However, the global economic crisis that broke at the end of 2008 and the accident involving the Macondo well temporarily disrupted the race to deep offshore technology. (author)

  15. A magnetic/fluorometric bimodal sensor based on a carbon dots-MnO2 platform for glutathione detection

    Science.gov (United States)

    Xu, Yang; Chen, Xi; Chai, Ran; Xing, Chengfen; Li, Huanrong; Yin, Xue-Bo

    2016-07-01

    A novel magnetic/fluorometric bimodal sensor was built from carbon dots (CDs) and MnO2. The resulting sensor was sensitive to glutathione (GSH), leading to apparent enhancement of magnetic resonance (MR) and fluorescence signals along with visual changes. The bimodal detection strategy is based on the decomposition of the CDs-MnO2 through a redox reaction between GSH and MnO2. This process causes the transformation from non-MR-active MnO2 to MR-active Mn2+, and is accompanied by fluorescence restoration of CDs. Compared with a range of other CDs, the polyethylenimine (PEI) passivated CDs (denoted as pCDs) were suitable for detection due to their positive surface potential. Cross-validation between MR and fluorescence provided detailed information regarding the MnO2 reduction process, and revealed the three distinct stages of the redox process. Thus, the design of a CD-based sensor for the magnetic/fluorometric bimodal detection of GSH was emphasized for the first time. This platform showed a detection limit of 0.6 μM with a linear range of 1-200 μM in the fluorescence mode, while the MR mode exhibited a linear range of 5-200 μM and a GSH detection limit of 2.8 μM with a visible change being observed rapidly at 1 μM in the MR images. Furthermore, the introduction of the MR mode allowed the biothiols to be easily identified. The integration of CD fluorescence with an MR response was demonstrated to be promising for providing detailed information and discriminating power, and therefore extend the application of CDs in sensing and imaging.A novel magnetic/fluorometric bimodal sensor was built from carbon dots (CDs) and MnO2. The resulting sensor was sensitive to glutathione (GSH), leading to apparent enhancement of magnetic resonance (MR) and fluorescence signals along with visual changes. The bimodal detection strategy is based on the decomposition of the CDs-MnO2 through a redox reaction between GSH and MnO2. This process causes the transformation from non

  16. Carbon dots incorporated polymeric hydrogels as multifunctional platform for imaging and induction of apoptosis in lung cancer cells.

    Science.gov (United States)

    Sachdev, Abhay; Matai, Ishita; Gopinath, P

    2016-05-01

    Multifunctional hydrogels offer a seemingly efficient system for delivery of drugs and bioimaging modalities. The present study deals with the facile development of chitosan-based hydrogel formulation composed of highly fluorescent carbon dots (CDs) and loaded with a model anticancer drug, 5-Fluorouracil (5-FU). Herein, CDs were embedded firmly within the hydrogel matrices (CD-HY) via non-covalent interactions during the ionic cross-linking reaction. Furthermore, these hydrogels could effectively encapsulate 5-FU through hydrophobic interactions to form 5-FU@CD-HY. In this way, it was possible to combine the merits of both CDs and 5-FU on a common platform for monitoring the cellular uptake as well as therapeutic effects. Field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) illustrated the porous nature and formation of 5-FU@CD-HY. Besides, functional characteristics of 5-FU@CD-HY such as surface area, mechanical strength, swelling behavior and drug release were investigated. In vitro studies revealed the multifunctional aspects of 5-FU@CD-HY in monitoring the cellular uptake and inflicting apoptosis in A549 cells. Green fluorescence of CDs in 5-FU@CD-HY aided the qualitative and quantitative assessment of cellular uptake. In addition to this, the fluorescence of CDs could be used to detect apoptosis instigated by 5-FU, eliminating the need for multiplex dyes. Induction of apoptosis in 5-FU@CD-HY treated cells was evidenced by changes in cell cycle distributions and visualization of characteristic apoptotic bodies through FE-SEM. Apoptotic gene expression studies further elucidate the molecular mechanism involved in eliciting apoptosis. Thus, hydrogels mediated integration of fluorescent CDs with chemotherapeutic agents provides a new dimension for the potential use of hydrogels in cancer theranostics. PMID:26854583

  17. Neutron elastic scattering cross-sections measurement on carbon and fluorine in epithermal energy range using PEREN platform

    International Nuclear Information System (INIS)

    Molten Salt Reactor (MSR) based on Th/U cycle is one of the new generation concepts for nuclear energy production. A typical MSR is a graphite-moderated core with liquid fuel (7LiF +ThF4 + UF4). Many numerical studies based on Monte-Carlo codes are currently carried out but the validity of these numerical result relies on the precise knowledge of neutron cross sections used such as elastic scattering on carbon (σC), fluorine (σF) and lithium 7 (σLi). The goal of this work is to obtain σC and σF between 1 eV and 100 keV. Such measurements have been performed at the Laboratoire de Physique Subatomique et de Cosmologie (LPSC) de Grenoble on the experimental platform PEREN using slowing-down time spectrometers (C and CF2) associated to a pulsed neutron generator (GENEPI). Capture rates are obtained for reference materials (Au, Ag, Mo and In) using YAP scintillator coupled to a photo-multiplier. Very precise simulations (MCNP code) of the experimental setup have been performed and comparison with experiments has led to the determination of σC and σF with accuracies of 1% and 2% respectively. These results show a small discrepancy to evaluated nuclear data file (ENDF). Measures of total cross-sections σC and σF at higher energy (200 - 600 keV) were also carried out at Centre des Etudes Nucleaires de Bordeaux using a transmission method. Mono-energetic neutrons were produced by protons accelerated by a Van de Graaff accelerator on a LiF target and transmitted neutrons are counted in a proportional hydrogen gaseous detector. Discrepancies of 5% and 9% for σC and σF respectively with ENDF have been shown. (author)

  18. 基于粗糙理论的海上石油平台溢油污染风险评价权重确定%Determining Weight of Risk Assessment of Oil Spill on Offshore Platform Based on Rough Set Theory

    Institute of Scientific and Technical Information of China (English)

    陈琼; 陆能枝

    2013-01-01

    Establishes assessment index system of oil spill for the offshore oil plat form by analyzing the influenced factors related to the degree of oil pollution. Combining with attribute rough set sig-nificance, translates determining weight into estimating significance of attributes among rough sets. Establishes a relation data model about Oil Spill on Offshore Platform risk assessment, cal-culates the risk assessment model weights. The proposed approach overcomes the subjectivity of traditional determination to weight, and makes risk assessment more objective, the model could provide new method for oil pollution index weight calculation.%通过分析与溢油污染程度有关的影响因素,构建海上石油平台溢油污染程度评价指标体系。结合粗糙集属性重要度理论,将权重确定问题转化为粗糙集中属性重要性评价问题,建立海上石油平台溢油风险的关系数据模型,计算出风险评价模型的权重。该方法克服了传统权重确定方法的主观性,使风险评价方法更具客观性,为计算溢油污染指标权重提供新方法。

  19. 基于声发射信号模糊函数综合相关系数的海洋平台各类损伤识别方法%Damage Identification Method of Offshore Platforms by Ambiguity Function Integrated Correlation Coefficient of the Acoustic Emission Signals

    Institute of Scientific and Technical Information of China (English)

    李潇; 杨国安; 吴贞焕; 张杨; 马斓擎

    2014-01-01

    As the critical working environment and the diversity of the background noises, traditional non-destructive testing (NDT) methods don’t work well for the monitoring of offshore platforms. A damage identification method for offshore platforms with an ambiguity function integrated correlation coefficient of the acoustic emission(AE) signals is proposed. Some tests are taken to get the AE signals that are produced by the cracks, corrosion, impact and friction what may happen on offshore platforms frequently, then the templates of the ambiguity function images are built, and an expression to calculate the correlation coefficient of these images is created. Analyzing the testing samples with the templates, the faults are identified correctly, and the validity of this method is proved. Providing the reliable theoretical basis and method to build the identification system based on the correlation coefficient of the ambiguity function images template library of AE signals. Meanwhile, the cross-component is restrained effectively in ambiguity function domain, and improving the treatment efficiency of offshore platforms for real-time monitoring and big data analysis.%海洋平台工作环境恶劣且背景噪声多样,传统的无损检测方法对海洋平台结构监测效果并不理想。针对海洋平台损伤识别现状,提出一种基于声发射信号模糊函数综合相关系数的海洋平台损伤识别方法。通过试验测取海洋平台服役过程中可能会出现的裂纹、腐蚀、撞击和摩擦四类故障或海况所产生的声发射信号,建立起声发射源信号模糊函数图像模板,构造出基于模糊函数图像的归一化相关系数表达式。将测试样本与模糊函数图像模板进行相关分析,准确有效地识别出各类损伤,验证了该方法的有效性,为建立基于声发射源信号模糊函数图像模板库的相关系数自动识别系统提供可靠的理论依据和方法。同时,该方

  20. Efficient preliminary floating offshore wind turbine design and testing methodologies and application to a concrete spar design

    OpenAIRE

    Matha, Denis; Sandner, Frank; Molins i Borrell, Climent; Campos Hortigüela, Alexis; Cheng, Po Wen

    2015-01-01

    The current key challenge in the floating offshore wind turbine industry and research is on designing economic floating systems that can compete with fixed-bottom offshore turbines in terms of levelized cost of energy. The preliminary platform design, as well as early experimental design assessments, are critical elements in the overall design process. In this contribution, a brief review of current floating offshore wind turbine platform pre-design and scaled testing methodologies is provide...

  1. Climate change impacts on northern offshore petroleum operations

    International Nuclear Information System (INIS)

    A review is presented of the possible impacts of climate change on Arctic offshore petroleum operations, focusing on those in the Beaufort Sea region. About 140 wells have been drilled to date in this area, about half from artificial islands, a third from ships, and the rest from offshore platforms. The presence of ice cover nine months of the year, coupled with the variability of the open-water season, makes offshore operations in the Beaufort costly and requires unconventional technological approaches, including the use of ice itself as a construction material for offshore platforms. Changes to be expected in the Beaufort region under climate change scenarios involving a doubling of atmospheric CO2 are summarized. In the Atmospheric Environment Service/Canadian Climate Centre model, results show a 8 degree C rise in February temperatures, a decrease in ice thickness, a 30-d increase in the open water season at 72 degree North Latitude, and higher extreme wave heights. In general, if ice conditions become less severe under a climate warming scenario, offshore petroleum operations will become easier and less costly. Specific examples of easier and less costly operations are illustrated. There would be a tendency to a greater use of floating systems, a longer open-water season would facilitate construction and tanker transport, and could reduce ice-load factors on platforms. The economics of Beaufort operations would still be in question, as conventional offshore technology would still not be possible. 16 refs., 2 figs., 3 tabs

  2. Current meter components and other data from FIXED PLATFORMS in support of the Physical Oceanography Field Program Offshore North Carolina from 22 February 1992 to 18 February 1993 (NODC Accession 9300089)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter components data were collected from FIXED PLATFORMS from 22 February 1992 to 18 February 1993. Data were collected by the Science Applications, Inc....

  3. Offshoring research directions

    NARCIS (Netherlands)

    Velthuijsen, Hugo

    2012-01-01

    Outsourcing and offshoring provide companies with ways to achieve their business objectives better or more cost effectively or despite a shortage of specific resources. From a research point of view, outsourcing and offshoring have mostly been studied as something that large companies do, not small

  4. Deep Panuke offshore gas development comprehensive study report : Executive summary

    International Nuclear Information System (INIS)

    A project was proposed by EnCana Corporation (EnCana) for the development of the Deep Panuke Offshore Gas Development Project. Located offshore the Scotian Shelf, approximately 175 kilometres southeast of Goldboro, Nova Scotia and 250 kilometres southeast of Halifax, the development of this natural gas reservoir would allow EnCana to derive economic benefit from licences issued under the Canada-Nova Scotia Offshore Petroleum Resources Accord Implementation Act and the Canada-Nova Scotia Offshore Petroleum Resources Accord Implementation (Nova Scotia) Act. The Canadian Environmental Assessment Act required that a comprehensive study report be prepared, and the results were presented in this document. Consisting of three bottom-founded platforms in a water depth of approximately 40 metres, the wellhead platform would be used for dry wellheads, wellhead control system, and production manifolds. All power generation and processing equipment would be located on the production platform, and the accommodations platform would consist of the utilities, helicopter landing pad, refueling station and crew accommodations. It was determined that the Deep Panuke project was unlikely to result in adverse environmental effects. The offshore oil and gas industry in Atlantic Canada would benefit from this development as a result of the establishment of a viable facility and operation

  5. Offshore risk assessment

    CERN Document Server

    Vinnem, Jan-Erik

    2014-01-01

      Offshore Risk Assessment was the first book to deal with quantified risk assessment (QRA) as applied specifically to offshore installations and operations. Risk assessment techniques have been used for more than three decades in the offshore oil and gas industry, and their use is set to expand increasingly as the industry moves into new areas and faces new challenges in older regions.   This updated and expanded third edition has been informed by a major R&D program on offshore risk assessment in Norway and summarizes research from 2006 to the present day. Rooted with a thorough discussion of risk metrics and risk analysis methodology,  subsequent chapters are devoted to analytical approaches to escalation, escape, evacuation and rescue analysis of safety and emergency systems.   Separate chapters analyze the main hazards of offshore structures: fire, explosion, collision, and falling objects as well as structural and marine hazards. Risk mitigation and control are discussed, as well as an illustrat...

  6. Design of offshore structures in ice environments

    International Nuclear Information System (INIS)

    The design of offshore structures in ice environments was addressed in this presentation with particular reference to permanent steel GBS solutions in 15 metre to 150 metre water depth; permanent steel drilling/production/storage solutions in 150 metre to 1000 metres; and platform costs for 30 metres to 1000 metre water depth in the Canadian Beaufort. Major design concerns in the Canadian and United States Beaufort involve ice loads, foundation capacity, and float instability. In the Sakhalin, major design concerns involve waves, foundation capacity, earthquakes, and float instability. The presentation included several charts illustrating permanent production platform costs in the Canadian Beaufort; design ice loads; base design criteria; and evolution of Arctic structures. It included illustrations and photographs of a MAT skirt system; skirt detail showing thin bladed design; stiffener post yield failure response; and ice load equaling 50 per cent buoyancy. The presentation also provided a comparison of the principal properties of tripod and vertical tension leg platforms. The criteria for 1000 metre permanent platform in the Canadian Beaufort include: no catastrophic failure under 1000 year ice load; less than 1 degree rotation under 100 year ice load; capability to operate in the weakest foundation conditions; and a target cost of less than $2 billion. Potential uses include development drilling and production platform; storage and loading platform for tanker transportation; production platform with pipeline to shore; and platform base for satellite drilling. tabs., figs

  7. Screening Criteria and Considerations of Offshore Enhanced Oil Recovery

    Directory of Open Access Journals (Sweden)

    Pan-Sang Kang

    2016-01-01

    Full Text Available 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, CO2 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.

  8. Strategic Trajectories in the Offshoring and Offshore Outsourcing Process

    DEFF Research Database (Denmark)

    Slepniov, Dmitrij; Sørensen, Brian Vejrum

    2006-01-01

    In this paper we examine the offshoring and offshore outsourcing process and the strategic trajectories underlying it, including both the internal venturing and the external outsourcing process. We define and present various perspectives on the offshoring and offshore outsourcing process. We then...

  9. New approach to the transportation and installation of heavy-weighted equipment offshore

    OpenAIRE

    Chernov, Dmitrii

    2015-01-01

    Installation of offshore equipment is a huge branch of business in the oil and gas industry. Almost every offshore project requires heavy-weighted equipment, which should be installed on the seabed. Recently, oil and gas companies instead of producing from platforms prefer to develop fields as subsea factories. Mentioned changes result in growing opportunities for offshore service companies, working in the field of transportation and installation, as the workload constantly ...

  10. CARBONATE FACIES ZONATION OF THE UPPER JURASSIC-LOWER CRETACEOUS APULIA PLATFORM MARGIN (GARGANO PROMONTORY, SOUTHERN ITALY

    Directory of Open Access Journals (Sweden)

    MICHELE MORSILLI

    1997-07-01

    Full Text Available The Late Jurassic-Early Cretaceous Apulia platform margin and the transition to adjacent basinal deposits (inner platform to basin are well exposed in the Gargano Promontory. Detailed field work has allowed to recognize eight main facies associations which reflect various depositional environments, and which document a differentiated zonation, from the inner platform to the basin. A shallow lagoon existed in the internal part of the Gargano Promontory with a transition to tidal flat areas (F1. Oolitic shoals (F2 bordered this internal peritidal area passing seaward to a reef-flat with abundant corals (F3. A reef-front, associated with a coral rubble zone, has been found in some areas (F4. In the external margin zone, massive wackestones with Ellipsactinia occur (F5 and pass gradually to a rudstone facies on the proximal slope (F6. The base-of-slope facies association consists of pelagic sediments interbedded with gravity-displaced deposits (F7 and F8. The depositional profile of the Apulia Platform is typical of the Tethyan Jurassic-Early Cretaceous platforms, with slope declivities in the order of 25°-28°. The remarkable progradation of the platform in the northern tract of the Gargano (Lesina and Varano lakes area and its substantial stability east- and southwards (Mattinata area suggest a possible windward position of the margin in this latter portion and, in contrast, a leeward position of the northern portion.   

  11. Assessing offshore wind potential

    International Nuclear Information System (INIS)

    Quantifying wind potential is a pivotal initial step in developing and articulating a state’s policies and strategies for offshore wind industry development. This is particularly important in the Great Lakes States where lessons from other offshore environments are not directly applicable. This paper presents the framework developed for conducting a preliminary assessment of offshore wind potential. Information on lake bathymetry and wind resources were combined in simulating alternative scenarios of technically feasible turbine construction depths and distance concerns by stakeholders. These yielded estimates of developable offshore wind areas and potential power generation. While concerns about the visibility of turbines from shore reduce the power that can be generated, engineering solutions that increase the depths at which turbines can be sited increase such potential power output. This paper discusses the costs associated with technical limitations on depth and the social costs related to public sentiments about distance from the shoreline, as well as the possible tradeoffs. The results point to a very large untapped energy resource in the Michigan’s Great Lakes, large enough to prompt policy action from the state government. - Highlights: ▶ We build a theoretical framework for modeling offshore wind power production. ▶ Illustration of the impact of technology and social limitations on offshore wind energy development. ▶ Geospatial modeling of the offshore wind potential of the Great Lakes.

  12. Comparison of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polybrominated diphenylethers, and organochlorine pesticides in Pacific sanddab (Citharichthys sordidus) from offshore oil platforms and natural reefs along the California coast

    Science.gov (United States)

    Gale, Robert W.; Tanner, Michael J.; Love, Milton S.; Nishimoto, Mary M.; Schroeder, Donna M.

    2013-01-01

    Recently, the relative exposure of Pacific sanddab (Citharichthys sordidus) to polycyclic aromatic hydrocarbons (PAHs) at oil-production platforms was reported, indicating negligible exposure to PAHs and no discernible differences between exposures at platforms and nearby natural areas sites. In this report, the potential for chronic PAH exposure in fish is reported, by measurement of recalcitrant, higher molecular weight PAHs in tissues of fish previously investigated for PAH metabolites in bile. A total of 34 PAHs (20 PAHs, 11 alkylated PAHs, and 3 polycyclic aromatic thiophenes) were targeted. In addition, legacy contaminants—polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs),—and current contaminants, polybrominated diphenylethers (PBDEs) linked to endocrine disruption, were measured by gas chromatography with electron-capture or mass spectrometric detection, to form a more complete picture of the contaminant-related status of fishes at oil production platforms in the Southern California Bight. No hydrocarbon profiles or unresolved complex hydrocarbon background were found in fish from platforms and from natural areas, and concentrations of aliphatics were low less than 100 nanograms per gram (ng/g) per component]. Total-PAH concentrations in fish ranged from 15 to 37 ng/g at natural areas and from 8.7 to 22 ng/g at platforms. Profiles of PAHs were similar at all natural and platform sites, consisting mainly of naphthalene and methylnaphthalenes, phenanthrene, fluoranthene, and pyrene. Total-PCB concentrations (excluding non-ortho-chloro-substituted congeners) in fish were low, ranging from 7 to 22 ng/g at natural areas and from 10 to 35 ng/g at platforms. About 50 percent of the total-PCBs at all sites consisted of 11 congeners: 153 > 138/163/164 > 110 > 118 > 15 > 99 > 187 > 149 > 180. Most OCPs, except dichlorodiphenyltrichloroethane (DDT)-related compounds, were not detectable or were at concentrations of less than 1 ng/g in fish. p

  13. Offshore wind energy prospects

    International Nuclear Information System (INIS)

    In last two years offshore wind energy is becoming a focal point of national and non national organisations particularly after the limitations of fossil fuel consumption, adopted by many developed countries after Kyoto conference at the end of 1997 on global climate change. North Europe is particularly interested in offshore for the limited land areas still available, due to the intensive use of its territory and its today high wind capacity. Really the total wind capacity in Europe could increase from the 1997 value of 4450 MW up to 40 000 MW within 2010, according the White Paper 1997 of the European Commission; a significant percentage (25%) could be sited offshore up to 10 000 MW, because of close saturation of the land sites at that time. World wind capacity could increase from the 1997 value of 7200 MW up to 60 000 MW within 2010 with a good percentage (20%) offshore 12 000 MW. In last seven years wind capacity in shallow water of coastal areas has reached 34 MW. Five wind farms are functioning in the internal seas of Netherlands, Denmark, Sweden; however such siting is mostly to be considered as semi-offshore condition. Wind farms in real offshore sites, open seas with waves and water depth over 10 m, are now proposed in North Sea at 10-20 km off the coasts of Netherlands, Denmark using large size wind turbine (1-2 MW). In 1997 an offshore proposal was supported in Netherlands by Greenpeace after the OWEMES '97 seminar, held in Italy on offshore wind in the spring 1997. A review is presented in the paper of European offshore wind programs with trends in technology, economics and siting effects. (Author)

  14. 76 FR 79206 - Commercial Renewable Energy Transmission on the Outer Continental Shelf (OCS) Offshore Mid...

    Science.gov (United States)

    2011-12-21

    ... qualified entities that compete with the proposed AWC ROW, it may decide to move forward with the ROW grant... competing nominations, BOEM may decide to move forward with the ROW grant issuance process using the non... nine offshore converter platforms, which would receive electricity via cable from offshore...

  15. Optimal Selection of AC Cables for Large Scale Offshore Wind Farms

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; Chen, Zhe

    2014-01-01

    platform in Matlab. A real offshore wind farm is chosen as the study case to demonstrate the proposed method. Furthermore, the optimization is also applied to an offshore wind farm under development. It can be observed from the results that the proposed optimal cable selection framework is an efficient and...

  16. China Offshore Oil Logging Technology

    Institute of Scientific and Technical Information of China (English)

    Duan Kang

    1996-01-01

    @@ China offshore oil logging business entered a faster developing stage sin-ce 1982 with the beginning of international cooperation in its offshore oil exploration. Nearly 90% of the logging expertises of China National Offshore Oil Corporation (CNOOC)are in China Offshore Oil Logging Company (COOLC), headquartered in Yanjiao, Hebei Province.

  17. Understanding the geological record of carbonate platform drowning across rifted Tethyan margins: Examples from the Lower Jurassic of the Apennines and Sicily (Italy)

    Science.gov (United States)

    Marino, Maurizio; Santantonio, Massimo

    2010-04-01

    In the geological record a drowning process is documented by various types of shallow water-to-pelagic or shallow water to mixed benthic/pelagic carbonate transitions. Drowning unconformities are paraconformities, to disconformities, to angular unconformities, and their drowning surfaces range from planar to highly irregular morphologies. Drowning successions display a mix of products of both the benthic and pelagic carbonate factories. These successions can be also bounded by unconformities. Drowning unconformities and drowning successions are contrasted through a description and discussion of examples of escarpment-bounded platforms from the Jurassic of the Northern Apennines and, subordinately, from Sicily and other Tethyan sectors. The areal distribution of drowning unconformities and successions is discussed with reference to a complex depositional system whose architecture was the product of the rift-induced fragmentation of a regional Hettangian carbonate megabank. The examples in this study show drowning unconformities to be exclusive to intrabasinal highs, while drowning successions are found both on highs and in hangingwall basins. Drowning unconformities, with their long associated hiatuses, and drowning successions are often seen to merge laterally into one another over very short distances on the same intrabasinal high. The deposits of the drowning succession are sometimes missing on the top of the platform, while they are found forming clinoforms along its flanks, evidence that sediment could be permanently swept from the highs in these depositional systems at this stage.

  18. Import, Offshoring and Wages

    DEFF Research Database (Denmark)

    Fosse, Henrik Barslund; Maitra, Madhura

    ) because all existing workers get higher pay (rent sharing effect). Using Danish worker-firm data we explain how much each channel contributes to higher wages. To estimate the causal effect of offshoring on wages we use China’s accession to the WTO in December 2001 - and the soon after boom in Chinese...... exports - as positive exogenous shocks to the incentive to offshore to China. Both skill composition and rent sharing effects are found to be important in explaining the resultant gain in wages. We also show that the firm’s timing in the offshoring process determines the relative importance of a channel...

  19. Challenges in Simulation of Aerodynamics, Hydrodynamics, and Mooring-Line Dynamics of Floating Offshore Wind Turbines

    Energy Technology Data Exchange (ETDEWEB)

    Matha, D.; Schlipf, M.; Cordle, A.; Pereira, R.; Jonkman, J.

    2011-10-01

    This paper presents the current major modeling challenges for floating offshore wind turbine design tools and describes aerodynamic and hydrodynamic effects due to rotor and platform motions and usage of non-slender support structures.

  20. Loads Analysis of a Floating Offshore Wind Turbine Using Fully Coupled Simulation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Jonkman, J. M.; Buhl, M. L., Jr.

    2007-06-01

    This paper presents the use of fully coupled aero-hydro-servo-elastic simulation tools to perform a loads analysis of a 5-MW offshore wind turbine supported by a barge with moorings, one of many promising floating platform concepts.

  1. 30 CFR 250.910 - Which of my facilities are subject to the Platform Verification Program?

    Science.gov (United States)

    2010-07-01

    ... buoyant offshore facility that does not have a ship-shaped hull The entire platform is subject to the... interfaces; (iii) Foundations, foundation pilings and templates, and anchoring systems; and (iv) Mooring or tethering systems. (2) Your new floating platform is a buoyant offshore facility with a ship-shaped...

  2. Optimisation of electrical system for offshore wind farms via genetic algorithm

    DEFF Research Database (Denmark)

    Chen, Zhe; Zhao, Menghua; Blaabjerg, Frede

    2009-01-01

    An optimisation platform based on genetic algorithm (GA) is presented, where the main components of a wind farm and key technical specifications are used as input parameters and the electrical system design of the wind farm is optimised in terms of both production cost and system reliability. The......, is developed. Different GA techniques are investigated based on a real example offshore wind farm. This optimisation platform has been demonstrated as a powerful tool for offshore wind farm design and evaluation....

  3. Dynamic Analysis of a Braceless Semisubmersible Offshore Wind Turbine in Operational Conditions

    OpenAIRE

    Karimirad, Madjid; Michailidis, Konstantinos

    2015-01-01

    The development of cost effective floating type offshore wind turbines has been desired in deep sea areas. Semisubmersible platform can be considered as a very efficient design configuration among the different type proposed floating platforms. In the present paper, a preliminary assessment of the dynamic behavior of a 5-MW braceless semisubmersible offshore wind turbine with three columns and two fully submerged pontoons is presented for selected environmental operational conditi...

  4. Offshore Wind Power Data

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Litong-Palima, Marisciel; Zeni, Lorenzo;

    2012-01-01

    – Storm management at national and European level. For that, detailed scenarios for offshore wind power development by 2020 and 2030 were required. The aggregation level that is suitable for the analysis to be done is at wind farm level. Therefore, the scenarios for offshore wind power development offer...... details about the wind farms such as: capacity and coordinates. Since the focus is on the impact of storm fronts passage in Northen Europe, the offshore wind power scenarios were estimated only for the countries at North and Baltic Sea. The sources used are public sources, mentioned in the reference list...... this work was to create a dataset containing forecast and realised wind power time series with hourly resolution. The database should cover all Europe, i.e. onshore and offshore and it will be further used in the project for the economic assessment impact, Tasks 16.2.2 and 16.2.3. For the onshore wind...

  5. Offshoring R&D

    DEFF Research Database (Denmark)

    Hansen, Zaza Nadja Lee; Rasmussen, Lauge Baungaard

    2010-01-01

    Companies are increasingly offshoring R&D activities. Many firms, however, experience difficulties related to virtual teamwork across cultures and time zones. The research question is: How does increasing R&D offshoring impact transparency of communication structures and knowledge sharing? Using...... case studies from Danish multinational corporations with R&D activities in China, India or Eastern Europe this paper analyses the impact observed in these companies in regard to communication structures and knowledge sharing in management of offshored R&D activities. The findings show that companies...... complexity of the R&D activity. This paper shows that management of offshored R&D activities touches upon many key management dilemmas like trust, control and knowledge sharing....

  6. Offshore Supply Industry Dynamics

    DEFF Research Database (Denmark)

    Roslyng Olesen, Thomas

    challenges and opportunities for the companies engaged in the different parts of the sector. The report is developed from interviews with top management of key players in the Danish supply industry combined with studies on management literature. The macro- and meso levels of the offshore sector are examined...... at Copenhagen Business School with a focus on value creation in the maritime industries. The project embraces various maritime segments from shipping and offshore to ports and suppliers. The research questions for the individual projects have been formulated by researchers at CBS Maritime in...... cooperation with companies in the maritime sector. This report “Offshore Supply Industry Dynamics – Business strategies in the offshore supply industry” is the second report in mapping project D. It examines the markets and business strategies of various suppliers and furthermore presents an analysis of the...

  7. Offshore production flares: a PETROBRAS review

    Energy Technology Data Exchange (ETDEWEB)

    Pagot, Paulo R.; Burmann, Clovis P.; Araujo, Paulo Bento de; Motomura, Tsukasa [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The purpose of the present work is to briefly present the offshore flare system technological evolution and the main design criteria for flare and its supporting structure. In order to perform the aimed task, this work was divided into two parts: the first part presents the technological evolution of the offshore production flares and the second one discusses the flare system designing criteria. The evolution of the technology associated to the offshore production flares is organized by the authors just dividing the history in four chronological phases. Each phase is defined by the predominant use of the, by the time, most up-to-date technological alternative and it will be described with the help of sketches, drawings, photographs, data and information about the platforms where such technologies were applied. The second part of the present work discusses the dimensional criteria, interesting aspects and flaws of the offshore flare systems in two different fields, which are: definition of the flare system capacity; and flow and thermal design of the flare system. (author)

  8. Ice induced vibrations of offshore structures

    Directory of Open Access Journals (Sweden)

    E.A. Salganik

    2014-06-01

    Full Text Available The aim of the article was to analyze the process of the dynamic interaction between ice and offshore structures and find conditions of vibration beginnings. The problems of creating a full-scale finite element model of ice and offshore structure interaction and comparison of the received results of vibration conditions with the field data were solved. Modeling was realized with the finite element analysis software ANSYS. The problems of modeling cracks formation, checking the multilateral model using basic ice strength tests and finding ice loads level on different types of structures were solved in order to create a destructible ice model. The object of the investigation is the role of elastic and inertial offshore structure parameters and geometrical and dynamical ice field parameters in the process of ice-induced structure vibrations. Molikpaq drilling and oil production platform in Canada and Norströmsgrund lighthouse in Sweden were chosen as objects for modeling. The research contains verification of the results, their comparison to field data, load magnitudes from ISO 19906 «Petroleum and natural gas industries – Arctic offshore structures» algorithm and results of discrete element modeling. The results are acceptable in comparison with the results of other ice-induced vibration research.

  9. Offshoring in Textile Industry

    OpenAIRE

    MONTÓN GARCÍA, JORGE

    2015-01-01

    [ EN] This project is about offshoring in the textile industry, focusing in the rights violated in this process, this concept can be defined as the moving of various operations of a company to another country for reasons such as lower labor costs or more favorable economic conditions in that other country. The project describes the evolution of offshoring, which started in 1960’s and has continued since then; it was characterized primarily by the transferring of factories from the develope...

  10. Offshore Wind Energy

    Energy Technology Data Exchange (ETDEWEB)

    Strach-Sonsalla, Mareike; Stammler, Matthias; Wenske, Jan; Jonkman, Jason; Vorpahl, Fabian

    2016-07-27

    In 1991, the Vindeby Offshore Wind Farm, the first offshore wind farm in the world, started feeding electricity to the grid off the coast of Lolland, Denmark. Since then, offshore wind energy has developed from this early experiment to a multibillion dollar market and an important pillar of worldwide renewable energy production. Unit sizes grew from 450 kW at Vindeby to the 7.5 MW-class offshore wind turbines (OWT ) that are currently (by October 2014) in the prototyping phase. This chapter gives an overview of the state of the art in offshore wind turbine (OWT) technology and introduces the principles of modeling and simulating an OWT. The OWT components -- including the rotor, nacelle, support structure, control system, and power electronics -- are introduced, and current technological challenges are presented. The OWT system dynamics and the environment (wind and ocean waves) are described from the perspective of OWT modelers and designers. Finally, an outlook on future technology is provided. The descriptions in this chapter are focused on a single OWT -- more precisely, a horizontal-axis wind turbine -- as a dynamic system. Offshore wind farms and wind farm effects are not described in detail in this chapter, but an introduction and further references are given.

  11. Industrial opportunities - offshore

    International Nuclear Information System (INIS)

    Industrial opportunities available in the Canadian offshore petroleum industry are discussed. Oil has been produced offshore from Nova Scotia since 1992, and offshore from Newfoundland since 1997. Special needs that must be addressed in offshore operations in eastern Canada such as the cold North Atlantic environment, isolation, logistics, safety, and quality assurance, are examined. The most obvious opportunities lie with the designing, building and installing the facilities needed to extract oil and gas from beneath the sea floor and transport it to market. However, there are also opportunities in designing and fabricating clothing, customized food containers and other equipment for offshore needs. Short term opportunities also exist in the decommissioning of depleted production fields and their facilities. One of the greatest obstacles facing new entrants into the offshore oil and gas industry is the lack of a track record. To meet this challenge, the ability to seek out partners to pursue local and international opportunities through joint ventures, strategic alliances and technology sharing partnering arrangements is of great importance. It may be the difference between success and failure. 6 figs

  12. MMSReefish Study Databases from 1993-1999 field collections (SEC7-95-11 Fish Mortalities From Explosive Removal of Petroleum Platforms)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Impacts of the Explosive Removal of Offshore Oil and Gas Structureson Fish Stocks in the Gulf of MexicoOffshore oil and gas platforms in the Gulf of Mexico (GOM)...

  13. High frequency peritidal cycles of the upper Araras Group: Implications for disappearance of the neoproterozoic carbonate platform in southern Amazon Craton

    Science.gov (United States)

    Rudnitzki, Isaac Daniel; Romero, Guilherme Raffaeli; Hidalgo, Renata; Nogueira, Afonso Cesar Rodrigues

    2016-01-01

    The Araras Group is an extensive carbonate platform developed at the southeastern margin of the Amazon Craton during the Neoproterozoic. The Nobres Formation corresponds to the upper unit of the Neoproterozoic Araras Group. It is exposed in road cuts and quarries in the Northern Paraguay Belt, and is characterized by meter-scale shallowing upward cycles. Forty-four fourth-to fifth-order parasequence cycles are enclosed into three third order sequences/megacycles, unconformably overlain by siliciclastic deposits of the Alto Paraguay Group. The cycles are generally of peritidal type, limited by exposure surfaces composed of asymmetrical tidal flat/sabkha lithofacies in the basal Nobres Formation. They consist of fine dolostone, intraclastic dolostones with megaripples, stromatolites biostrome, sandy dolostone with enterolithic structures and silicified evaporite molds. Upsection, the cycles progressively become symmetrical, comprising arid tidal flat deposits with abundant stromatolite biostrome, fine-grained sandstone and rare evaporitic molds. The stacking patterns for hundreds of meters indicate continuous and recurrent generation of accommodation space, probably triggered by subsidence concomitant with relative sea-level changes. Palynomorphs found in the upper part of Nobres Formation comprehend spheroidal forms, such as Leiospharidia, rare filamentous and acanthomorphous acritarchs, mostly Tanarium correlated to the Ediacaran Complex Acantomorph Palynoflora of ˜580-570 Ma. Previous data of carbon isotopes and paleogeographic reconstructions, and also the presence of evaporites and storm-influenced deposits in the Araras Group, suggest a wet to tropical setting for Amazonia during the Mid-Ediacaran, which is incompatible with previous claims for Gaskiers-related glacial sedimentation in the region. During the final stages of evolution of the Araras carbonate platform, a progressive input of terrigenous has occurred in the peritidal setting likely due tectonic

  14. Technology assessment of offshore industry and its impact on the maritime industry 1976-2000. Executive summary. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Durfee, J.H.

    1977-08-01

    This report contains a 25 year forecast of the offshore industry including offshore petroleum production, offshore power production, offshore mining, offshore service platforms, and commercial ocean fishing. Each segment of the offshore industry is described in terms of the current status of industry, trends that might influence the direction of future development, and forces acting on the industry to impede or encourage growth. The report examines potential areas of impact on the maritime industry, such as financial, manpower, environmental, materials requirements, legislation and regulation, and new technologies, that might result from offshore industry development. Further it discusses changes likely to result in the maritime industry from the various impacts described and suggests planning that will be needed to accommodate to the changes. The report provides a comprehensive analysis of the future of the offshore industry.

  15. Caracterização de tubo e adesivo utilizados em tubulações de plástico reforçado com fibras de vidro aplicados em plataformas marítimas Characterization of pipes and adhesives of glassfiber reinforced plastics used in offshore platforms

    Directory of Open Access Journals (Sweden)

    Maikon C. R. Pessanha

    2008-03-01

    Full Text Available Na indústria de exploração e produção de petróleo, principalmente no setor offshore, os plásticos reforçados por fibras de vidro (PRFV têm apresentado grande destaque. Isso se deve à intrínseca capacidade destes de resistir à corrosão em ambientes salinos, bem como serem materiais que apresentam elevada resistência mecânica específica. O presente trabalho buscou caracterizar tubo e adesivo utilizados em plataformas marítimas. Para tanto, as técnicas utilizadas foram: espectroscopia na região do infravermelho com transformada de Fourier (FTIR, análise termogravimétrica (TGA, análise termodinâmico-mecânica (DMTA e temperatura de amolecimento de Vicat. Amostras do tubo de PRFV e dos componentes do adesivo (denominados de A e B foram estudadas individualmente. Além disso, foram confeccionadas misturas, em massa, nas seguintes proporções: 40%A-60%B, 50%A-50%B e 60%A-40%B. Foi possível determinar a composição e a estrutura química dos materiais, além do comportamento mecânico à degradação térmica. Foi verificado que adesivo e tubo apresentaram desempenho satisfatório à temperatura ambiente quanto à degradação e à rigidez. Por outro lado, quando submetido ao calor, principalmente os adesivos, apresentaram queda brusca de desempenho.Glassfiber reinforced plastics (GFRP have been applied in the offshore industry owing to their high resistance to corrosion and high specific mechanical strength. The present work aimed at characterizing pipes and adhesives used in offshore platforms in order to evaluate the thermo-mechanical performance of these materials. The techniques used were: Fourier transform infrared spectroscopy (FTIR, thermogravimetry analysis (TGA, dynamic mechanical thermal analysis (DMTA and Vicat softening temperature. Specimens of GFRP pipe and adhesive components (referred to as A and B were evaluated individually. The adhesive samples were made in the following ratios (% weight: 40%A-60%B, 50%A-50

  16. The record of the early Toarcian and early Aptian oceanic anoxic events in the Apenninic Carbonate Platform (Southern Italy)

    OpenAIRE

    Trecalli, Alberto

    2011-01-01

    About one third of the carbon dioxide released mainly from burning of fossil fuels is absorbed into the oceans where it reacts to form carbonic acid. As a result the pH of the ocean and the amount of carbonate ions decrease in a process called ocean acidification. Detrimental effects on calcifying organisms, which use carbonate minerals to build their protective shells and skeletons, have been documented in the laboratory and in the field. However, due to the spatio-temporal limits of experim...

  17. Active Vibration Control of a Monopile Offshore Structure

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.; Kirkegaard, Poul Henning

    In the Danish part of the North Sea it has been found that marginal fields can be exploited using monopile offshore platforms which present significant advantages with respect to the costs involved in fabrication and installation and can therefore tip the economic balance favourably. Monopile pla...

  18. Middle Miocene mound-shaped sediment packages on the slope of the Xisha carbonate platforms, South China Sea: Combined result of gravity flow and bottom current

    Science.gov (United States)

    Tian, Jie; Wu, Shiguo; Lv, Fuliang; Wang, Dawei; Wang, Bin; Zhang, Xinyuan; Ma, Benjun

    2015-12-01

    Deep-water mound-shaped sediment packages on the northern slope of the Xisha carbonate platforms in the northern South China Sea were analyzed by integrating high-resolution multi-channel seismic and drilling data. The mounds are distributed in the Beijiao depression of the Qiongdongnan Basin within the T41-T40 seismic horizons, which correspond to the middle Miocene. Mound-shaped reflections were identified both in the NE-SW and NW-SE oriented seismic profiles. The mound shapes are most prominent in the center of the NW-SE oriented seismic profiles, and the undulating tops flatten out towards the NW and SE. Similar reflections are mostly asymmetric, with steeper eastern flanks in the NE-SW oriented seismic profiles, and they are mostly round in shape. The wave impedance from the inversion calculation is 6-8×106 kg/(m2·s). It is much lower than that of the reef reservoir in the LH11-1 Reef Oilfield. Paleogeographic analysis shows that the Xisha uplift was dominated by tropical shallow carbonate platforms, while the Beijiao depression became a bathyal environment in the middle Miocene. Drilling data confirmed that the mound-shaped sediment packages are mainly composed of calcareous mudstone. Therefore, we infer that the mound-shaped sediment packages could be reef complexes or they were presumably built by combined gravity flow and bottom current.

  19. A costing model for offshore decommissioning in California.

    Science.gov (United States)

    Bressler, Andrew; Bernstein, Brock B

    2015-10-01

    California's 27 offshore oil and gas platforms will reach the end of their useful lifetimes sometime in the near future and will require decommissioning. Although existing leases require complete removal of all platforms and associated infrastructure, the underlying laws and regulations have changed in recent years to allow a number of alternative uses after decommissioning. In particular, AB 2503, signed into law in September 2010, provides for a rigs-to-reefs program that allows the state to accept ownership of decommissioned platforms in federal waters. Decisions about whether to remove platforms completely or leave them in place as artificial reefs will depend in part on the relative cost of the 2 options. In this study, we describe the design and use of a mathematical decision model that provides detailed cost estimates of complete and partial removal (to 85 feet below the water line) for California's offshore platforms. The model, PLATFORM, is loaded with Bureau of Safety and Environmental Enforcement (BSEE) and Bureau of Ocean Energy Management (BOEM) costs for complete removal, along with costs for partial removal calculated for this study and estimates of the uncertainty associated with decommissioning cost estimates. PLATFORM allows users to define a wide range of decommissioning and costing scenarios (e.g., number of platforms, choice of heavy lift vessel, shell mound removal, reef enhancement). As a benchmark cost, complete removal of all 27 offshore platforms, grouped into the 7 decommissioning projects defined by the most recent federal cost estimates produced in 2010, would cost an estimated $1.09 billion, whereas partial removal of these platforms, grouped into the same set of projects, would cost $478 million, with avoided costs of $616 million (with minor rounding). PMID:25914378

  20. EPA issues offshore air pollution regulations

    International Nuclear Information System (INIS)

    This paper reports that the Environmental Protection Agency has issued regulations equalizing offshore air pollution rules with onshore standards except in the Gulf of Mexico. The rules hold platforms and drilling rigs within 25 miles of states' seaward boundaries to the same state, local, and federal requirements as if they were located in the corresponding onshore areas. If EPA finds state regulations are adequate, it will delegate to the coastal state the implementation and enforcement authority for the OCS rules. Air emissions sources more than 25 miles offshore will be subject only to federal requirements. EPA said within 2 years the rules will result in significant benefits to certain onshore areas currently violating smog standards

  1. Study on the occupational stress and job satisfaction of oil workers on offshore drilling platforms%某海上石油钻井平台作业工人职业紧张反应与工作满意度调查

    Institute of Scientific and Technical Information of China (English)

    朱陶; 李健; 薄其波; 孙立臣; 兰亚佳

    2013-01-01

    目的 初步探讨海上石油钻井平台作业工人职业紧张反应和工作满意度现况.方法 应用职业紧张量表(OSI-R)的分量表——个体紧张反应问卷(PSQ)和工作满意度问卷进行紧张反应和工作满意度水平的评价.结果 (1)心理紧张反应得分研究组显著高于技术工人常模(P<0.01); (2)25岁~年龄段的紧张水平与< 25岁年龄段及≥35岁年龄段比较,得分有增高的趋势; (3)除躯体紧张反应外,有职业紧张反应组工作满意度评分均显著低于无职业紧张反应组(P<0.05); (4)总紧张反应及各子项与工作满意度间均呈负相关关系(P<0.01).结论 海上石油钻井平台作业工人的心理紧张反应突出,紧张反应越高,其工作满意度越低.%OBJECTIVE To investigate occupational stress and job satisfaction of oil workers on offshore drilling platforms.METHODS According to personal strain questionnaire (PSQ),a sub-scale in OSI-R and job satisfaction survey,the evaluation of the occupational stress and job satisfaction were carried out.RESULTS (1) The scores of psychological strain (PSY) in oil workers were obviously higher than those in norms of technical workers (P < 0.01) ; (2) The scores of occupational stress in 25-age group showed an increasing tendency among various age groups; (3) Except physical strain (PHS),the scores of job satisfaction in strain group were obviously lower than those in non-strain group (P < 0.05); (4)There was a negative correlation between strain and job satisfaction (P< 0.01).CONCLUSION Psychological strain (PSY) of oil workers on offshore drilling platforms is obvious; the higher scores of strain,the lower scores of job satisfaction.

  2. Design and application of hydraulic drive rotary table of modular drilling rig on offshore ifxed platform%液压驱动转盘在海洋固定平台模块钻机上的设计与应用

    Institute of Scientific and Technical Information of China (English)

    罗立臣; 马冬辉; 孟庆元

    2015-01-01

    Owing to small space and compact layout, the modular drilling rig on the offshore ifxed platform has to meet the requirement of small scale, light weight, high integration, operational safety and reliability. However, there are several problems for the traditional motor-driven pattern, such as long transmission chain, many transmission parts, complex transmission devices, large structural dimensions and heave weight, etc. As a result, it is diffcult to be installed and is inconvenient for usage and repair under special requirements, which affects the design of overall layout and structural conifguration. In view of the above situation, it compares the hydraulic drive rotary table with the electrical drive rotary table. It is concluded that the hydraulic drive rotary table can be characterized of small footprint, light weight, easy installation and construction, capability of structural optimization, low cost of operational maintenance, and great safety and reliability. It can provide certain reference for the modular drilling rig with the special space requirements on the offshore ifxed platform.%海洋固定平台模块钻机空间狭小、布局紧凑、要求设备具有尺寸小、质轻、集成度高、运行安全可靠等特点,而传统电机驱动转盘的驱动方式存在传动链长、传动部件多、传动装置复杂、结构尺寸庞大等问题,在模块钻机尺寸有特殊要求的情况下安装难度大、使用和维修不便,影响总体布局和结构形式的设计。针对上述情况,通过液压驱动转盘与电驱动转盘进行对比,总结出液压驱动转盘小巧轻便、易于建造安装、能够优化钻台结构、操作维护费用低、安全可靠等特点,可为空间有特殊要求的海洋固定平台模块钻机提供一定的参考。

  3. Human cytochrome P450 3A4 and a carbon nanofiber modified film electrode as a platform for the simple evaluation of drug metabolism and inhibition reactions.

    Science.gov (United States)

    Xue, Qiang; Kato, Dai; Kamata, Tomoyuki; Guo, Qiaohui; You, Tianyan; Niwa, Osamu

    2013-11-01

    Electrochemical biosensors consisting of cytochrome P450 enzyme modified electrodes have been developed to provide a simple method for screening the metabolism of a drug and its inhibitor. Here, we report a very simple electrochemically driven biosensor for detecting drug metabolism and its inhibition based on cytochrome P450 3A4 (CYP3A4) and a carbon nanofiber (CNF) modified film electrode without any other modified layers such as mediator films. Direct electron transfer (DET) between CYP3A4 and CNFs was observed at a formal potential of -0.302 V. The electrocatalytic reduction current increased with the addition of drugs including testosterone and quinidine. In contrast, the reduction current was greatly suppressed in the presence of ketoconazole, which is a CYP3A4 inhibitor. CNFs with high conductivity, a large surface area and sufficient edge planes provide a suitable microenvironment for achieving excellent DET and biocatalysis properties, which could not be observed when we used other carbon materials such as carbon nanotube (CNT) and carbon black (CB) modified electrodes, indicating that our system is promising as a new bioelectronic platform for electrochemical biosensing. PMID:24027778

  4. Floating Offshore Wind in Hawaii: Potential for Jobs and Economic Impacts from Three Future Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, Tony; Keyser, David; Tegen, Suzanne

    2016-04-18

    Construction of the first offshore wind power plant in the United States began in 2015, off the coast of Rhode Island, using fixed platform structures that are appropriate for shallow seafloors, like those located off the East Coast and mid-Atlantic. However, floating platforms, which have yet to be deployed commercially, will likely need to be anchored to the deeper seafloor if deployed in Hawaiian waters. To analyze the employment and economic potential for floating offshore wind off Hawaii's coasts, the Bureau of Ocean Energy Management commissioned the National Renewable Energy Laboratory (NREL) to analyze two hypothetical deployment scenarios for Hawaii: 400 MW of offshore wind by 2050 and 800 MW of offshore wind by 2050. The results of this analysis can be used to better understand the general scale of economic opportunities that could result from offshore wind development.

  5. The Offshoring Phenomenon

    Directory of Open Access Journals (Sweden)

    Mery Patricia Tamayo Plata

    2014-06-01

    Full Text Available This paper explains some definitions which are necessary in order to understand the offshoring concept, going through the most relevant works about the development of the offshoring phenomenon and its impact on the demand for labor and on the most skilled workers' income. It is evidenced that the offshoring processes not only deal with the purchase and sale of goods anymore, but that the service sector has an increasingly important role, and that the lower cost is not the only aspect that matters when offshoring, but aspects such as the language and culture are also considered. It is also found that technology and research related services flow not only from the parent companies towards its subsidiaries, but from firms in less developed countries to other companies in advanced countries. It concludes with a review of the works that explores the relationship between offshoring, employment and wages, from both, a macro and microeconomic outlook. In the latter case, special consideration is given to the work carried out by Amity and Wei (2006, Crinó (2010, and Geishecker and Görg (2013.

  6. Early diagenetic dolomitization and dedolomitization of Late Jurassic and earliest Cretaceous platform carbonates: A case study from the Jura Mountains (NW Switzerland, E France)

    Science.gov (United States)

    Rameil, Niels

    2008-12-01

    Early diagenetic dolomitization is a common feature in cyclic shallow-water carbonates throughout the geologic record. After their generation, dolomites may be subject to dedolomitization (re-calcification of dolomites), e.g. by contact with meteoric water during emersion. These patterns of dolomitization and subsequent dedolomitization frequently play a key role in unravelling the development and history of a carbonate platform. On the basis of excellent outcrops, detailed logging and sampling and integrating sedimentological work, high-resolution sequence stratigraphic interpretations, and isotope analyses (O, C), conceptual models on early diagenetic dolomitization and dedolomitization and their underlying mechanisms were developed for the Upper Jurassic / Lower Cretaceous Jura platform in north-western Switzerland and eastern France. Three different types of early diagenetic dolomites and two types of dedolomites were observed. Each is defined by a distinct petrographic/isotopic signature and a distinct spatial distribution pattern. Different types of dolomites are interpreted to have been formed by different mechanisms, such as shallow seepage reflux, evaporation on tidal flats, and microbially mediated selective dolomitization of burrows. Depending on the type of dolomite, sea water with normal marine to slightly enhanced salinities is proposed as dolomitizing fluid. Based on the data obtained, the main volume of dolomite was precipitated by a reflux mechanism that was switched on and off by high-frequency sea-level changes. It appears, however, that more than one dolomitization mechanism was active (pene)contemporaneously or several processes alternated in time. During early diagenesis, percolating meteoric waters obviously played an important role in the dedolomitization of carbonate rocks that underlie exposure surfaces. Cyclostratigraphic interpretation of the sedimentary succession allows for estimates on the timing of early diagenetic (de

  7. Offshore Wind Turbines - Estimated Noise from Offshore Wind Turbine, Monhegan Island, Maine: Environmental Effects of Offshore Wind Energy Development

    Energy Technology Data Exchange (ETDEWEB)

    Aker, Pamela M.; Jones, Anthony M.; Copping, Andrea E.

    2010-11-23

    Deep C Wind, a consortium headed by the University of Maine will test the first U.S. offshore wind platforms in 2012. In advance of final siting and permitting of the test turbines off Monhegan Island, residents of the island off Maine require reassurance that the noise levels from the test turbines will not disturb them. Pacific Northwest National Laboratory, at the request of the University of Maine, and with the support of the U.S. Department of Energy Wind Program, modeled the acoustic output of the planned test turbines.

  8. Offshore Wind Farms

    DEFF Research Database (Denmark)

    Lundtang Petersen, Erik; Hasager, Charlotte Bay; Courtney, Michael;

    2015-01-01

    The technology behind constructing wind farms offshore began to develop in 1991 when the Vindeby wind farm was installed off the Danish coast (11 Bonus 450 kW turbines). Resource assessment, grid connection, and wind farm operation are significant challenges for offshore wind power just as it is...... for the more traditional onshore wind power, which has been under development since the 1970s. However, offshore projects face extra technical challenges some of which requires in-depth scientific investigations. This article deals with some of the most outstanding challenges concerning the turbine...... structure: the rotor, the nacelle, the tower, and the foundation. Further the determinations of the essential environmental conditions are treated: the wind field, the wave field, the sea current, and the soil conditions. The various options for grid connections, advantages, and disadvantages are discussed...

  9. Offshore Wind Power

    DEFF Research Database (Denmark)

    Negra, Nicola Barberis

    The aim of the project is to investigate the influence of wind farms on the reliability of power systems. This task is particularly important for large offshore wind farms, because failure of a large wind farm might have significant influence on the balance of the power system, and because offshore...... for the installers, such as the dimension of the wind farm and the difficulty of reaching failed components in case of harsh weather. Each component that affects the assessment must be included and proper models for them are investigated in this thesis. The project provides a survey of available offshore wind farm...... Carlo simulation is used for these calculations: this method, in spite of an extended computation time, has shown flexibility in performing reliability studies, especially in case of wind generation, and a broad range of results which can be evaluated. The modelling is then extended to the entire power...

  10. Scour around Offshore Windturbine Foundations

    DEFF Research Database (Denmark)

    Larsen, Brian Juul; De Vos, Leen; Frigaard, Peter

    For the present report a testprogramme has been performed to determine the scour around offshore windturbine foundations.......For the present report a testprogramme has been performed to determine the scour around offshore windturbine foundations....

  11. Offshore atomic power plants

    International Nuclear Information System (INIS)

    Various merits of offshore atomic power plants are illustrated, and their systems are assessed. The planning of the offshore atomic power plants in USA is reviewed, and the construction costs of the offshore plant in Japan were estimated. Air pollution problem may be solved by the offshore atomic power plants remarkably. Deep water at low temperature may be advantageously used as cooling water for condensers. Marine resources may be bred by building artificial habitats and by providing spring-up equipments. In the case of floating plants, the plant design can be standardized so that the construction costs may be reduced. The offshore plants can be classified into three systems, namely artificial island system, floating system and sea bottom-based system. The island system may be realized with the present level of civil engineering, but requires the development of technology for the resistance of base against earthquake and its calculation means. The floating system may be constructed with conventional power plant engineering and shipbuilding engineering, but the aseismatic stability of breakwater may be a problem to be solved. Deep water floating system and deep water submerging system are conceivable, but its realization may be difficult. The sea bottom-based system with large caissons can be realized by the present civil engineering, but the construction of the caissons, stability against earthquake and resistance to waves may be problems to be solved. The technical prediction and assessment of new plant sites for nuclear power plants have been reported by Science and Technology Agency in 1974. The construction costs of an offshore plant has been estimated by the Ministry of International Trade and Industry to be yen71,026/kW as of 1985. (Iwakiri, K.)

  12. Wave and offshore wind potential for the island of Tenerife

    International Nuclear Information System (INIS)

    Highlights: • The island aims to reduce its carbon footprint by developing renewable energy. • The substantial wave and offshore wind resources around the island are examined. • One area is appropriate for installing a hybrid wave–offshore wind farm. - Abstract: The island of Tenerife, a UNESCO Biosphere Reserve in the Atlantic Ocean, aims to be energy self-sufficient in order to reduce its carbon footprint. To accomplish this goal it should develop the renewable sources, in particular wave and offshore wind energy. The objectives of this work are twofold; (i) to characterize the wave and offshore wind power distribution around the island and (ii) to determine which offshore area is best suited for their exploitation, taking into account the resource and other conditioning factors such as the bathymetry, distance to the coastline and ports, and offshore zoning. To carry out this research, hindcast wave and wind data obtained with numerical models are used alongside observations from meteorological stations. One area, in the vicinity of Puerto de la Cruz, is identified as having great potential for installing a hybrid floating wave–wind farm. Both resources are characterized for the area selected: the wave resource in terms of wave directions, significant wave heights and energy periods; the offshore wind resource in terms of directions and speeds in addition to the seasonality for the both resources. It is found that most of the wave resource is provided by N and NNW waves with significant wave heights between 1.5 m and 3.0 m and energy periods between 10 s and 14 s. It follows that the Wave Energy Converters deployed in the area should have maximum efficiency in those ranges. As for the offshore wind resource, most of the energy corresponds to NNE and NE winds with speeds between 9 and 14 m s−1, which should be taken into account when selecting the offshore wind turbines

  13. Offshoring and financial markets

    Directory of Open Access Journals (Sweden)

    Gianfranco Battisti

    2014-06-01

    Full Text Available The paper analyses the nature and extent of the offshore world, a grey area that is playing a major role in present-day economy. The main institutions moulding this peculiar environment are discussed: preferential tax regimes, tax havens and offshore financial centers. Their role in the globalised world is outlined after a scrutiny of the specialized literature, reports by non-governmental bodies and companies’ advertisings. Finally, we present a tentative reconstruction of its geographical organization, inclusive of cartographic representations of the main international networks.

  14. Organizational Adaptation in Offshoring

    DEFF Research Database (Denmark)

    Geisler Asmussen, Christian; Møller Larsen, Marcus; Pedersen, Torben

    2016-01-01

    of these two strategies depends on nontrivial interactions among the costs of communication, the distance to the offshoring location, and the level of noise in the firm’s performance function. In particular, the difficulties of interpreting performance signals in noisy situations suggest that there......-based learning). Thus, by formalizing these two learning strategies for acquiring architectural knowledge in offshoring, we show that important contingencies can lead to significant performance trade-offs in the search for new organizational configurations that span international borders....

  15. Application of Incentive Mechanism in Schedule Management of Ocean Engineering Construction Project:Taking Land Construction Project of One Offshore Platform%激励机制在海洋工程建造项目进度管理中的应用--以某海洋平台陆地建造项目为例

    Institute of Scientific and Technical Information of China (English)

    赵悦

    2014-01-01

    应用激励机制主要是为了保证项目能够在规定的时间内高质量的完成,这是项目进度管理中经常采用的方法。通过分析项目启动滞后的情况下,某海洋平台陆地建造项目进度管理中运用安全生产激励、时间控制激励、各项目方激励、创新激励等举措,围绕项目目标内在化、激励诱导因素分析、激励制度设计三个方面,构建高效联动的激励机制。%T he application of incentive mechanism is to guarantee that the projects can be finished with high quality within a predetermined period of time ,which is a method often used in project schedule management .In the case of lagging in project initiation ,one offshore platform construction project on land makes use of safe production incentives ,time control incentives ,the project party in-centives and innovation incentives to construct incentives for efficient linkage by project objective in-ternalization ,incentive-induced factor analysis and incentive system design .

  16. From Basin Black Shales to Platform Carbonate Rocks: A Study on Sequence Stratigraphy for the Lower Cambrian of the Upper-Yangtze Region in South China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In the Upper-Yangtze region, especially in Guizhou Province and its adjacent areas, the Lower Cambrian is well developed and is marked by a succession from black shales of the basin facies to carbonate rocks of the platform facies. The drowning event of the platform occurring at the turn from Sinian to Cambrian resulted in a set of black shales, i.e. the Niutitang Formation, which makes up the bottom part of the Lower Cambrian. With the shoaling of the sedimentary environment, a set of carbonate rocks, i.e. the Qingxudong Formation, was formed in the top part of the Lower Cambrian. Thus, the Lower Cambrian in the study area makes up one second-order sequence that can be further subdivided into five third-order sequences, and forms a regularly cyclic succession of transgression-regression. There is a regularly vertical stacking pattern for the third-order sequences in the second-order sequence. From bottom to top, the succession of the "CS (condensed section)+HST (high-stand system tract)" of the third-order sequences is changed into the succession of the "TST (transgressive system tract)+CS+HST". Correspondingly, the drowning-type sequence boundary is changed into the exposure-type one. Therefore, both the second-order and the third-order sequences have similar sedimentary-facies architectures. A concomitant with these temporal changes,the Lower Cambrian with a thickness of 1000 m that contains five third-order sequences is changed into a condensed succession that cannot identify third-order sequences toward the southeast with the deepening of the sedimentary environment. According to the elementary features of the third-order sequences, i.e. the regularity o sedimentary-facies successions in space and the synchronism of sedimentary-environment changes in time, the detailed division of the third-order sequences at main logged sections in different paleogeographical background becomes the basis to establish the sequence-stratigraphic framework that can demonstrate

  17. Novel Platform Development Using an Assembly of Carbon Nanotube, Nanogold and Immobilized RNA Capture Element towards Rapid, Selective Sensing of Bacteria

    Directory of Open Access Journals (Sweden)

    Elizabeth I. Maurer

    2012-06-01

    Full Text Available This study examines the creation of a nano-featured biosensor platform designed for the rapid and selective detection of the bacterium Escherichia coli. The foundation of this sensor is carbon nanotubes decorated with gold nanoparticles that are modified with a specific, surface adherent ribonucleiuc acid (RNA sequence element. The multi-step sensor assembly was accomplished by growing carbon nanotubes on a graphite substrate, the direct synthesis of gold nanoparticles on the nanotube surface, and the attachment of thiolated RNA to the bound nanoparticles. The application of the compounded nano-materials for sensor development has the distinct advantage of retaining the electrical behavior property of carbon nanotubes and, through the gold nanoparticles, incorporating an increased surface area for additional analyte attachment sites, thus increasing sensitivity. We successfully demonstrated that the coating of gold nanoparticles with a selective RNA sequence increased the capture of E. coli by 189% when compared to uncoated particles. The approach to sensor formation detailed in this study illustrates the great potential of unique composite structures in the development of a multi-array, electrochemical sensor for the fast and sensitive detection of pathogens.

  18. The Economic Geography of Offshoring

    DEFF Research Database (Denmark)

    Ørberg Jensen, Peter D.; Pedersen, Torben

    2011-01-01

    We draw from the literature on economic geography and from the thematic offshoring literature, and propose three hypotheses that rest on the assumption that the choice of offshoring location is based on the fit between the attributes of different destinations and the attributes of the offshored...

  19. Economic Impact of the New England Aqua Ventus (Phases I and II) Offshore Wind Power Program in Maine

    OpenAIRE

    Gabe, Todd

    2013-01-01

    The purpose of this study is to examine the statewide economic impacts of the New England Aqua Ventus offshore wind power program in Maine. Phase I of this program involves the planning and construction, and ongoing operations of a 12 MW pilot project; and Phase II of Aqua Ventus involves a 500 MW offshore wind power installation along with the production of VolturnUS floating platforms and towers that could be used in other offshore wind projects.

  20. Hydrodynamic characteristics of cylindrical semi-submersible offshore oil platform%圆筒形超深海半潜式钻井储油平台运动特性分析

    Institute of Scientific and Technical Information of China (English)

    张永康; 沈翰; 戴峰泽; 倪涛; 庄建军

    2013-01-01

    The models of SEVAN 650 and GVA 7500 were established in Pro/E software. The proposed models were imported into the Hydrodynamic Diffraction module of ANSYS Workbench software to calculate the response amplitude operators of each platform in storm environment of South China Sea. The hydrodynamic character-istics of the two platforms in the storm environment were compared by the characteristic curves of heave, roll and pitch. The results show that SEVAN 650 has better crude oil storage capacity and deck variable load bearing capacity than those of GVA 7500, which indicates that SEVAN 650 has better anti-dumping capacity than that of GVA 7500 in storm environment. However, the heave response amplitude operator of SEVAN 650 in storm environment should be further reduced.%使用Pro/E软件对SEVAN 650平台和GVA 7500平台建模,将模型导入ANSYS Workbench程序的Hydrodynamic Diffraction模块,计算出2座半潜式钻井平台南海海况风暴自存状态下的运动响应幅值算子,得出2座平台各自的垂荡、横摇和纵摇特性曲线,进而对2座平台南海海况风暴自存状态下的运动特性进行对比分析.结果表明:SEVAN 650圆筒形半潜式平台在原油存储性能和甲板承受可变载荷性能优于GVA 7500平台的前提条件下,其在风暴自存状态时具有比GVA 7500更优的抗倾性能,但SEVAN 650平台在风暴情况下的垂荡响应幅值需要进一步减小.

  1. Pricing offshore wind power

    International Nuclear Information System (INIS)

    Offshore wind offers a very large clean power resource, but electricity from the first US offshore wind contracts is costlier than current regional wholesale electricity prices. To better understand the factors that drive these costs, we develop a pro-forma cash flow model to calculate two results: the levelized cost of energy, and the breakeven price required for financial viability. We then determine input values based on our analysis of capital markets and of 35 operating and planned projects in Europe, China, and the United States. The model is run for a range of inputs appropriate to US policies, electricity markets, and capital markets to assess how changes in policy incentives, project inputs, and financial structure affect the breakeven price of offshore wind power. The model and documentation are made publicly available. - Highlights: → We calculate the Breakeven Price (BP) required to deploy offshore wind plants. → We determine values for cost drivers and review incentives structures in the US. → We develop 3 scenarios using today's technology but varying in industry experience. → BP differs widely by Cost Scenario; relative policy effectiveness varies by stage. → The low-range BP is below regional market values in the Northeast United States.

  2. Nearshore versus Offshore

    DEFF Research Database (Denmark)

    Klinge Jacobsen, Henrik; Hevia Koch, Pablo Alejandro; Wolter, Christoph

    Currently there exist high expectations for the development of wind energy, particularly in Europe, out of whichoffshore wind turbine developments will be central as tools to achieve current energy targets. The question betweennearshore and (far)-offshore is particularly relevant, both because of...

  3. Offshore Wind Energy Systems

    Science.gov (United States)

    Musgrove, P.

    1978-01-01

    Explores the possibility of installing offshore windmills to provide electricity and to save fuel for the United Kingdom. Favors their deployment in clusters to facilitate supervision and minimize cost. Discusses the power output and the cost involved and urges their quick development. (GA)

  4. Reconstruction of burial history, temperature, source rock maturity and hydrocarbon generation in the northwestern Dutch offshore

    NARCIS (Netherlands)

    Abdul Fattah, R.; Verweij, J.M.; Witmans, N.; Veen, J.H. ten

    2012-01-01

    3D basin modelling is used to investigate the history of maturation and hydrocarbon generation on the main platforms in the northwestern part of the offshore area of the Netherlands. The study area covers the Cleaverbank and Elbow Spit Platforms. Recently compiled maps and data are used to build the

  5. The chromium isotopic composition of an Early to Middle Ordovician marine carbonate platform, eastern Precordillera, San Juan, Argentina

    DEFF Research Database (Denmark)

    D'Arcy, Joan Mary; Frei, Robert; Gilleaudeau, Geoffrey Jon; Peralta, Silvio; Kah, Linda; Gaucher, Claudio

    A broad suite of redox proxy data suggest that despite ocean and atmosphere oxygenation in the late Neoproterozoic, euxinic conditions persisted in the global deep oceans until the at least Ordovician [1,2,3]. Major changes in the sulphur isotopic composition of carbonate associated sulphate and ...

  6. Specificity of Geotechnical Measurements and Practice of Polish Offshore Operations

    Directory of Open Access Journals (Sweden)

    Bogumil Laczynski

    2015-12-01

    Full Text Available As offshore market in Europe grows faster and faster, new sea areas are being managed and new ideas on how to use the sea potential are being developed. In North Sea, where offshore industry conducts intensive expansion since late 1960s, numerous wind farms, oil and gas platforms and pipelines have been put into operation following extensive research, including geotechnical measurement. Recently, a great number of similar projects is under development in Baltic Sea, inter alia in Polish EEZ, natural conditions of which vary from the North Sea significantly. In this paper, those differences are described together with some solutions to problems thereby arising.

  7. Subsea prizes : companies pushing the envelope offshore

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, R.

    2009-06-15

    In order to make projects economic, companies are going farther offshore and deeper to find oil and gas or to use existing offshore platforms and longer horizontals. Companies such as StatoilHydro are reworking strategies on how to approach future oil finds. This article discussed examples of ultra deep and long horizontal oil finds such as Statoil's complicated but highly successful Gulltopp project. Although drilling ultra-deep wells or long horizontal wells is risky, they can also be very lucrative. The article also discussed McMoRan Exploration Company of New Orleans' high-risk deeper targets in the Gulf of Mexico and its exploration strategy. The longest well in the world, drilled by Maersk Oil Qatar AS was also described. The article noted that the Danish company reported that the entire horizontal section of the well was placed within a reservoir target which was only 20 feet thick. Schlumberger helped Maersk Oil Qatar break several records with extended reach drilling (ERD) offshore well. This well set 10 records, including the longest well ever drilled; longest along-hole departure; longest 8 and a half inch section; highest ERD ratio; highest directional drilling difficulty index; deepest directional control; deepest downlink, MWD transmission and LWD geosteering; deepest battery-less operation; longest reservoir contact; and longest open hole. Last, the article discussed an unsuccessful well drilled by Murphy Oil Corporation known as the Manhattan well. 8 figs.

  8. Current trends in offshore technology

    International Nuclear Information System (INIS)

    Although this is a technical symposium concerning advances in the technology of producing oil and gas offshore, a keynote address would not be complete without mentioning non-technical factors which are extremely important for the business of producing oil and gas offshore. These are political factors and economic factors. Offshore operations are an easy target for political forces that are opposed to marine operations involving the production and transfer of hydrocarbons. For example, the oil pollution act of 1990 was a reaction to the Exxon Valdez grounding in Alaska and this act has added significantly to the risk and cost of operating offshore. Another example of this is that it is becoming more and more difficult to dispose of produced water offshore. Producing oil and gas offshore is a business that competes with other energy sources such as coal and oil and gas from wells on land. The offshore oil can only compete with these other resources by providing the same product at a competitive price. Since offshore operations are inherently more costly than land operations, the offshore oil field or gas field must be significantly larger than a land field in order to be produced. Also the offshore oil field or gas field is more susceptible to environmental risks from weather. On a more positive note, there are technical developments which are taking place and have continuously taken place to make offshore oil and gas both more economic and safer to produce. These developments are briefly discussed

  9. ADVANCES IN UNDERSTANDING THE EVOLUTION OF DIAGENESIS IN CARBONIFEROUS CARBONATE PLATFORMS: INSIGHTS FROM SIMULATIONS OF PALAEOHYDROLOGY, GEOCHEMISTRY, AND STRATIGRAPHIC DEVELOPMENT

    OpenAIRE

    Frazer, Miles

    2014-01-01

    Carbonate diagenesis encapsulates a wide range of water rock interactions that can occur within many environments and act to modify rock properties such as porosity, permeability, and mineralogical composition. These rock modification processes occur by the supply of reactant-laden fluids to areas where geochemical reactions are ther- modynamically and kinetically favoured. As such, understanding the development of diagenesis requires an understanding of both palaeohydrology and geochemistry,...

  10. Effect of carbon source concentration and culture duration on retreivability of bacteria from certain estuarine, coastal and offshore areas around the peninsular India.

    Digital Repository Service at National Institute of Oceanography (India)

    Goltekar, R.C.; Krishnan, K.P.; DeSouza, M.J.B.D.; Paropkari, A.L.; LokaBharathi, P.A.

    which could induce nutritional flexibility, it was observed that lower nutrient strengths yielded higher retrievability. There was a difference of two orders between higher and lower n u trient strengths. This may be due to the heavy organic flux... demonstrated that the nutritional flex i bility of bacteria was more enhanced in oligotrophic co n ditions. The retrievability of bacteria from estuarine sources is not uniformly high across a range of carbon concentrations, as might hav e been expected...

  11. An enhanced electrochemical platform based on graphene oxide and multi-walled carbon nanotubes nanocomposite for sensitive determination of Sunset Yellow and Tartrazine.

    Science.gov (United States)

    Qiu, Xinlan; Lu, Limin; Leng, Jing; Yu, Yongfang; Wang, Wenmin; Jiang, Min; Bai, Ling

    2016-01-01

    A novel electrochemical platform was designed for the simultaneous determination of Sunset Yellow (SY) and Tartrazine (TT), synthetic food dyes, by combining the signal amplification properties of graphene oxide (GO) and the excellent electronic and antifouling properties of multi-walled carbon nanotubes (MWCNTs). Stable dispersion of GO/MWCNTs composite was produced by sonication mixing. Compared with glassy carbon, MWCNTs and GO electrodes, GO/MWCNTs electrode exhibited strong enhancement effect and greatly increased the oxidation signal of SY and TT. Under optimized conditions, the enhanced anodic peak currents represented the excellent analytical performance of simultaneous detection of SY and TT in the range of 0.09-8.0 μM, with a low limit of detection of 0.025 μM for SY and 0.01 μM for TT (S/N = 3), respectively. To further validate its possible application, the proposed method was successfully used for the determination of SY and TT in orange juice with satisfactory results. PMID:26213053

  12. Offshore Supply Industry Dynamics

    DEFF Research Database (Denmark)

    Roslyng Olesen, Thomas

    of services including includes legal advice, financing, insurance etc. The two value chains have a number of activities in common. Both include (1) a tender and concession phase where the energy company obtains the right to explore and produce energy from the authorities. (2) An exploration phase...... at the same level) and vertical cooperation (between suppliers in different layers). Finally the suppliers and the energy companies are supported by a number of companies which are usually not considered as part of the offshore sector but are important none the less. These companies provide a number...... direct investments. At the center of both value chains are the energy companies. The energy companies have a number of suppliers and sub suppliers which provide a range of equipment and services to the offshore operations. The supply industry is characterized by horizontal cooperation (between suppliers...

  13. Offshore seabird monitoring program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-12-15

    Offshore petroleum activities have been ongoing since the 1970s in eastern Canada, a zone which supports a rich and diverse assemblage of seabirds. Seabirds are extremely vulnerable to oiling and in November 2004 an important crude oil spill occurred off the shore of Newfoundland. At that time there was no information on seabird abundance to determine the effects of the spill and a study was funded by the Environmental Studies Research Funds (ESRF) to quantify seabird abundance and distribution in areas of offshore petroleum activities in eastern Canada. A novel protocol was used under this project and over 2500 hours of observation were conducted on 50,000 km of ocean transect over a 3.5 year period. The relationship between survey intensity and the precision of density estimates is presented herein and recommendations are made for increasing the precision of the estimates. This paper recommends continued survey efforts in production areas to maintain data precision.

  14. Offshore Rankine Cycles

    OpenAIRE

    Brandsar, Jo

    2012-01-01

    The title of the thesis - "Offshore Rankine Cycles" - is very general and cover a large range of engineering fields, e.g. thermodynamic cycles (Rankine, ORC, Brayton, Kalina, etc.), mechanical equipment (gas/steam turbine, heat exchangers and additional equipment) and safety concerns (flammable and/or toxic fluids, high temperature and pressures), to name the most important.The thesis try to give a brief overview of all critical points and alternatives, concerning employment of a wa...

  15. Offshore Wind Turbine Design

    DEFF Research Database (Denmark)

    Frandsen, Sten; Hansen, Erik Asp; Ibsen, Lars Bo;

    2006-01-01

    important uncertainty drivers specific for offshore wind turbine design loads is required. Describing the initial efforts in a Danish research project, the paper points to focal points for research and development. These are mainly: soil-structure interaction, improved modelling of wave loads from deep...... to shallow waters, integrated re-sponse modelling, wake effects, response extrapola-tion and clarification of the relevance of deterministic load cases in the operational regime....

  16. On the instability of offshore foundations: theory and mechanism

    Science.gov (United States)

    Gao, FuPing; Li, JinHui; Qi, WenGang; Hu, Cun

    2015-12-01

    As the offshore engineering moving from shallow to deep waters, the foundation types for fixed and floating platforms have been gradually evolving to minimize engineering costs and structural risks in the harsh offshore environments. Particular focus of this paper is on the foundation instability and its failure mechanisms as well as the relevant theory advances for the prevailing foundation types in both shallow and deep water depths. Piles, spudcans, gravity bases, suction caissons, and plate anchors are detailed in this paper. The failure phenomena and mechanisms for each type of foundations are identified and summarized, respectively. The theoretical approaches along with sophisticated empirical solutions for the bearing capacity problems are then presented. The major challenges are from flow-structure-soil coupling processes, rigorous constitutive modeling of cyclic behaviors of marine sediments, and the spatial variability of soil properties for large-spreading structures. Further researches are suggested to reveal the instability mechanisms for underpinning the evolution of offshore foundations.

  17. Outsourcing software development offshore making IT work

    CERN Document Server

    Gold, Tandy

    2004-01-01

    THE OFFSHORE IMPERATIVECrunching the Offshore Numbers: What the Financials PortendWelcome to the Definitive Guide on Offshore OutsourcingSetting the Stage: The Compelling Offshore StoryOffshore Outsourcing versus Traditional IT OutsourcingChallenges of Offshore OutsourcingChapter SummaryGetting Started in OffshoreExecutive Support and Communications: The Key to SuccessA Look at an Example of Enlightened Leadership: Handling Employee Impact at a Northeast Utilities CompanyWell-Planned and Executed Communications: A Critical Success Factor for Offshore Program InitiationEstablishing the Offshore

  18. Optimization of Clamping Force of Wire Saw for Offshore Discarded Platform Plies Removal Based on Particle Swarm%基于粒子群算法的海洋废弃平台桩基拆除绳锯机夹紧力优化

    Institute of Scientific and Technical Information of China (English)

    王海波; 张岚; 孟庆鑫; 王喆

    2013-01-01

      水下绳锯机可以用来完成海洋废弃平台桩基切割。绳锯机切割过程中,当水下环境发生变化时,应能够较迅速地调整夹紧力以适应环境的改变。介绍绳锯机的夹紧数学模型,根据绳锯机的实际设计条件,采用粒子群算法对夹紧力进行快速的优化求解。通过实验表明,此方法获得的夹紧力能够使绳锯机稳定地工作,并且测得了相应的动态参数。研究结果为绳锯机夹紧力的水下环境快速自适应控制提供了一定的基础。%Underwater wire saw can be used to cut offshore discarded platform plies. When the underwater environment changes in cutting process,it should adjust clamping force quickly to adapt to the changes. The wire saw clamp mathematical model was de-scribed. According to wire saw actual design conditions,clamping force was quickly solved using particle swarm algorithm. Experi-ments show that using obtained clamping force,wire saw can work stably. Corresponding dynamic parameters were measured. The re-sults provide a foundation for the wire saw clamping force quickly adaptive control in the underwater environment.

  19. Carbon Flux Estimation in Southeast Asia using a Eulerian-Lagrangian Coupled Inversion System and Observational Data from Multiple Platforms

    Science.gov (United States)

    Ishizawa, M.; Shirai, T.; Terao, Y.; Mukai, H.; Nomura, S.; Mohamad, M.; Jahaya, M. F.; Inoue, M.; Morino, I.; Yoshida, Y.; Uchino, O.; Zhuravlev, R.; Ganshin, A.; Maksyutov, S. S.

    2015-12-01

    Southeast Asia is rich in tropical forest and biodiversity. Previous inversion studies show large inter-annual variability in the biosphere-atmosphere carbon exchange attributable to climate anomalies. However, the magnitudes of estimated fluxes are significantly different among the inversions. On the other hand, land-use change has been accelerating the anthropogenic emissions. For the sustainable development in Southeast Asia under the on-going climate change, it is important to understand the biosphere-atmosphere carbon exchange and access the regional emissions. One of the reasons for the large uncertainty in flux estimate is a limited coverage of atmospheric observation against the large variety of ecosystems and the geographical complexity. Recently, the number of measurements has been increasing, including ground-based and satellite-based measurements. We estimated the regional CO2fluxes using a Eulerian-Lagrangian inverse modeling system and examined the characteristics of observational constraints and their impacts on the flux estimate in Southeast Asia. The results show that the temporal variations and source/sink strength of estimated regional fluxes are sensitive to the observational constraints. As a control run, we used the Observational Package (ObsPack) data product since 2001 as a global dataset of atmospheric CO2 measurement. In the addition to Bukit, Sumatra Island (BKT) in ObsPack, we included a stationary CO2 data at Danum Valley in Borneo Island (DMV) since late 2009. Compared to BKT, DMV shows a clear seasonal cycle. The inversion including DMV tends to increase the regional carbon sink in the second half of year. Remotely the aircraft measurements over Rarotonga (RTA) in the tropical Pacific Ocean see the signals from Southeast Asia through an atmospheric convection. The sensitivity test shows RTA impacts on the inter-annual variations of estimated flux, which might be associated with ENSO events. Since June 2009, Greenhouse gases Observing

  20. The Hidden Costs of Offshoring

    DEFF Research Database (Denmark)

    Møller Larsen, Marcus; Manning, Stephan; Pedersen, Torben

    2011-01-01

    This study seeks to explain hidden costs of offshoring, i.e. unexpected costs resulting from the relocation of business tasks and activities outside the home country. We develop a model that highlights the role of complexity, design orientation and experience in explaining hidden costs of...... offshoring. Specifically, we propose that hidden costs can be explained by the combination of increasing structural, operational and social complexity of offshoring activities. In addition, we suggest that firm orientation towards organizational design as part of an offshoring strategy and offshoring...... experience moderate the relationship between complexity and hidden costs negatively i.e. reduces the cost generating impact of complexity. We develop three hypotheses and test them on comprehensive data from the Offshoring Research Network (ORN). In general, we find support for our hypotheses. A key result...

  1. Development of small carbonate banks on the south Florida platform margin: Response to sea level and climate change

    Science.gov (United States)

    Mallinson, David J.; Hine, Albert C.; Hallock, Pamela; Locker, Stanley D.; Shinn, Eugene; Naar, David; Donahue, Brian; Weaver, Douglas C.

    2003-01-01

    Geophysical and coring data from the Dry Tortugas, Tortugas Bank, and Riley’s Hump on the southwest Florida margin reveal the stratigraphic framework and growth history of these carbonate banks. The Holocene reefs of the Dry Tortugas and Tortugas Bank are approximately 14 and 10 m thick, respectively, and are situated upon Pleistocene reefal edifices. Tortugas Bank consists of the oldest Holocene corals in the Florida Keys with earliest coral recruitment occurring at ∼9.6 cal ka. Growth curves for the Tortugas Bank reveal slow growth (sea level) reef growth at Tortugas Bank at ∼4.2 cal ka is attributed to paleoclimate change in the North American interior that increased precipitation and fluvial discharge. Reef growth rates and characteristics are related to the rate of sea-level rise relative to the position of the reef on the shelf margin, and are additionally modified by hydrographic conditions related to climate change.

  2. Soil organic carbon and particle sizes mapping using vis–NIR, EC and temperature mobile sensor platform

    DEFF Research Database (Denmark)

    Knadel, Maria; Thomsen, Anton Gårde; Schelde, Kirsten;

    2015-01-01

    Soil organic carbon (SOC) is an important parameter in the climate change mitigation strategies and it is crucial for the function of ecosystems and agriculture. Particle size fractions affect strongly the physical and chemical properties of soil and thus also SOC. Conventional analyses of SOC and...... particle sizes are costly limiting the detailed characterization of soil spatial variability and fine resolution mapping. Mobile sensors provide an alternative approach to soil analysis. They offer densely spaced georeferenced data in a cost-effective manner. In this study, two agricultural fields (Voulund...... the obtained spectra to partition the fields and to select representative samples for calibration purposes. Calibration samples were analyzed for SOC and particle sizes (clay, silt and sand) using conventional wet chemistry analysis. The objectives of this study were to determine whether it is the...

  3. Temporal variability of carbon and nutrient burial, sediment accretion, and mass accumulation over the past century in a carbonate platform mangrove forest of the Florida Everglades

    Science.gov (United States)

    Breithaupt, Joshua L.; Smoak, Joseph M.; Smith, Thomas J.; Sanders, Christian J.

    2014-10-01

    The objective of this research was to measure temporal variability in accretion and mass sedimentation rates (including organic carbon (OC), total nitrogen (TN), and total phosphorous (TP)) from the past century in a mangrove forest on the Shark River in Everglades National Park, USA. The 210Pb Constant Rate of Supply model was applied to six soil cores to calculate annual rates over the most recent 10, 50, and 100 year time spans. Our results show that rates integrated over longer timeframes are lower than those for shorter, recent periods of observation. Additionally, the substantial spatial variability between cores over the 10 year period is diminished over the 100 year record, raising two important implications. First, a multiple-decade assessment of soil accretion and OC burial provides a more conservative estimate and is likely to be most relevant for forecasting these rates relative to long-term processes of sea level rise and climate change mitigation. Second, a small number of sampling locations are better able to account for spatial variability over the longer periods than for the shorter periods. The site average 100 year OC burial rate, 123 ± 19 (standard deviation) g m-2 yr-1, is low compared with global mangrove values. High TN and TP burial rates in recent decades may lead to increased soil carbon remineralization, contributing to the low carbon burial rates. Finally, the strong correlation between OC burial and accretion across this site signals the substantial contribution of OC to soil building in addition to the ecosystem service of CO2 sequestration.

  4. Temporal variability of carbon and nutrient burial, sediment accretion, and mass accumulation over the past century in a carbonate platform mangrove forest of the Florida Everglades.

    Science.gov (United States)

    Breithaupt, Josh L.; Smoak, Joseph M.; Smith, Thomas J., III; Sanders, Christian J.

    2014-01-01

    The objective of this research was to measure temporal variability in accretion and mass sedimentation rates (including organic carbon (OC), total nitrogen (TN), and total phosphorous (TP)) from the past century in a mangrove forest on the Shark River in Everglades National Park, USA. The 210Pb Constant Rate of Supply model was applied to six soil cores to calculate annual rates over the most recent 10, 50, and 100 year time spans. Our results show that rates integrated over longer timeframes are lower than those for shorter, recent periods of observation. Additionally, the substantial spatial variability between cores over the 10 year period is diminished over the 100 year record, raising two important implications. First, a multiple-decade assessment of soil accretion and OC burial provides a more conservative estimate and is likely to be most relevant for forecasting these rates relative to long-term processes of sea level rise and climate change mitigation. Second, a small number of sampling locations are better able to account for spatial variability over the longer periods than for the shorter periods. The site average 100 year OC burial rate, 123 ± 19 (standard deviation) g m-2yr-1, is low compared with global mangrove values. High TN and TP burial rates in recent decades may lead to increased soil carbon remineralization, contributing to the low carbon burial rates. Finally, the strong correlation between OC burial and accretion across this site signals the substantial contribution of OC to soil building in addition to the ecosystem service of CO2 sequestration.

  5. Tailoring the Pore Environment of Metal-Organic and Molecular Materials Decorated with Inorganic Anions: Platforms for Highly Selective Carbon Capture

    Science.gov (United States)

    Nugent, Patrick S.

    Due to their high surface areas and structural tunability, porous metal-organic materials, MOMs, have attracted wide research interest in areas such as carbon capture, as the judicious choice of molecular building block (MBB) and linker facilitates the design of MOMs with myriad topologies and allows for a systematic variation of the pore environment. Families of MOMs with modular components, i.e. MOM platforms, are eminently suitable for targeting the selective adsorption of guest molecules such as CO2 because their pore size and pore functionality can each be tailored independently. MOMs with saturated metal centers (SMCs) that promote strong yet reversible CO2 binding in conjunction with favorable adsorption kinetics are an attractive alternative to MOMs containing unsaturated metal centers (UMCs) or amines. Whereas MOMs with SMCs and exclusively organic linkers typically have poor CO2 selectivity, it has been shown that a versatile, long known platform with SMCs, pillared square grids with inorganic anion pillars and pcu topology, exhibits high and selective CO 2 uptake, a moderate CO2 binding affinity, and good stability under practical conditions. As detailed herein, the tuning of pore size and pore functionality in this platform has modulated the CO2 adsorption properties and revealed variants with unprecedented selectivity towards CO 2 under industrially relevant conditions, even in the presence of moisture. With the aim of tuning pore chemistry while preserving pore size, we initially explored the effect of pillar substitution upon the carbon capture properties of a pillared square grid, [Cu(bipy)2(SiF6)] (SIFSIX-1-Cu). Room temperature CO2, CH4, and N 2 adsorption isotherms revealed that substitution of the SiF6 2- ("SIFSIX") inorganic pillar with TiF6 2- ("TIFSIX") or SnF62- ("SNIFSIX") modulated CO2 uptake, CO2 affinity (heat of adsorption, Qst), and selectivity vs. CH4 and N2. TIFSIX-1-Cu and SNIFSIX-1-Cu were calculated to exhibit the highest CO2/N 2

  6. Experiment study of the motion of the floating offshore turbine

    Science.gov (United States)

    Chuang, Tzu-Ching; Hsu, Wen-Yang; Yang, Ray-Yeng; Chen, Yang-Yi

    2016-04-01

    Recently the wind industry moved to offshore areas. The floating wind turbine combined the platform and the mooring system. This research focuses on studying the motion of the floating offshore turbine with a mooring system. The platform, which was developed by the Ship and Ocean Industries R&D Center, had been test in a wave-wind flume in the Tainan Hydraulics Laboratory by using a 1:50 Froude scaling model. In the experiment, the floating offshore turbine was placed in a water flume and exposed to periodic waves at frequencies ranging from 0.22 rad/s - 0.875 rad/s, the wave amplitude is about 2.5 meter, and with the different pretension of the mooring lines. The experiment includes the measurement of damping coefficient from the free decay test and the dynamic response in a sea state. This research compares the motion of the floating offshore turbine with the different pretension of the mooring lines, and the model provides comprehensive data for the operational, design, and survival seas states, as well as the calibration and improvement of the existing design and performance of numerical models.

  7. Stepwise drowning of the urgonian carbonate platform and the sedimentary regime during the Mid-Cretaceous environmental crisis: new evidence from the Helvetic Alps

    Science.gov (United States)

    Linder, P.; Weissert, H.; Funk, H.; Föllmi, K. B.

    2003-04-01

    In the region of Anzeindaz (Ct. Vaud, Switzerland) the sedimentary succession of the so-called "Urgonian" of the Schrattenkalk Formation (late Barremian to early Aptian in age) and of the Garschella Formation (early Aptian to late Cenomanian in age) is well developed. These outcrops in the helvetic Morcles nappe are particularly appropriate to study the drowning events that lead to the disappearance of the urgonian carbonate platform and the subsequent development towards a sedimentary regime of condensation and authigenesis. Cavities with infillings of Garschella Formation sediments penetrating the Schrattenkalk limestone up to 20 meters deep are interpreted as karstic erosional cavities and/or neptunian dikes. The most interesting finding was the special way in which the drowning of the urgonian carbonate platform is documented. At one outcrop (La Corde) thin relics of a bed interpreted as the Upper Orbitolina Bed seem to be integrated in the Garschella Formation since it separates relics of at least two phosphoritic beds, probably the Luitere Bed but also an older bed that was not described by Föllmi and Ouwehand (1987). In fact a diploma student at the University of Neuchâtel, François Gainon (2001) just recently rediscovered and correctly interpreted a similar but less condensed succession in the nearby Rawil region that was first described (but misinterpreted) by Schaub (1936). Gainon named this older phosphoritic horizon of the Rawil region "Plaine Morte Bed" and he was able to date it with an ammonite of the earliest Aptian Weissi/Tuarkyricus Zones. In both the Rawil and Anzeindaz regions the whole ensemble is deposited over an erosive unconformity cutting off the Schrattenkalk limestone. The sedimentary succession of the Garschella Formation in the Anzeindaz region contains equivalents of nearly all beds described and defined in the type outcrops of eastern Switzerland and Austria (Föllmi &Ouwehand 1987). The study of these sediments revealed new

  8. Stress prevention in the offshore oil and gas exploration and production industry

    OpenAIRE

    Sutherland, Valerie J; Cary L Cooper

    1996-01-01

    This working paper is directed towards the prevention of stress in the offshore exploration and production industries. Many recommendations are given to reduce work stress, but it must be acknowledged that on any mobile drilling rig or fixed production platform there exists a great diversity of occupations and skill levels. This means that a step-by step-guide for stress prevention for each specific occupational offshore group is beyond the scope of this paper. It is suggested that the "Tripl...

  9. Proceedings of the International Workshop on Seismic Design and Reassessment of Offshore Structures

    OpenAIRE

    Iwan, Wilfred D.

    1992-01-01

    This Executive Summary presents the major conclusions and recommendations of the International Workshop on Seismic Design and Reassessment of Offshore Structures. Full versions of the text of all invited lecturers and complete working group reports are contained elsewhere in these Proceedings. Site Seismic Hazard and Ground Motion Continuous improvements have been made in the state-of-the-art of estimation of seismic ground motion for design and reassessment of offshore platforms. C. ...

  10. For the birds : suspected roastings prompt study of offshore flares

    International Nuclear Information System (INIS)

    A recent research project has revealed that offshore flares can pose a hazard to waterfowl. Two academic environmentalists from Memorial University and the Atlantic Co-operation Wildlife Ecology Research are working with Hibernia, PanCanadian Resources, Terra Nova and the Sable gas group to study the possibility of oil platforms having killed great numbers of birds. The objective is to study the potential problem and try to quantify the number of seabirds and what the impacts might be on the birds. The work involves observing waterfowl from oil platforms and supply vessels and taking a census of various species, the number of casualties and how they die. This project did not start because of any hard facts suggesting the offshore oil industry hurts the ecology of the Grand Banks. It stems from public concerns about Terra Nova, the next big project. 1 fig

  11. Spoke Dimension on the Motion Performance of a Floating Wind Turbine with Tension-Leg Platform

    OpenAIRE

    Wang, H. F.; Fan, Y. H.

    2016-01-01

    The tension-leg platform (TLP) supporting structure is a good choice for floating offshore wind turbines because TLP has superior motion dynamics. This study investigates the effects of TLP spoke dimensions on the motion of a floating offshore wind turbine system (FOWT). Spoke dimension and offshore floating TLP were subjected to irregular wave and wind excitation to evaluate the motion of the FOWT. This research has been divided into two parts: (1) Five models were designed based on differen...

  12. Polydopamine Coated Single-Walled Carbon Nanotubes as a Versatile Platform with Radionuclide Labeling for Multimodal Tumor Imaging and Therapy.

    Science.gov (United States)

    Zhao, He; Chao, Yu; Liu, Jingjing; Huang, Jie; Pan, Jian; Guo, Wanliang; Wu, Jizhi; Sheng, Mao; Yang, Kai; Wang, Jian; Liu, Zhuang

    2016-01-01

    Single-walled carbon nanotubes (SWNTs) with various unique properties have attracted great attention in cancer theranostics. Herein, SWNTs are coated with a shell of polydopamine (PDA), which is further modified by polyethylene glycol (PEG). The PDA shell in the obtained SWNT@PDA-PEG could chelate Mn(2+), which together with metallic nanoparticulate impurities anchored on SWNTs offer enhanced both T1 and T2 contrasts under magnetic resonance (MR) imaging. Meanwhile, also utilizing the PDA shell, radionuclide (131)I could be easily labeled onto SWNT@PDA-PEG, enabling nuclear imaging and radioisotope cancer therapy. As revealed by MR & gamma imaging, efficient tumor accumulation of SWNT@PDA-(131)I-PEG is observed after systemic administration into mice. By further utilizing the strong near-infarared (NIR) absorbance of SWNTs, NIR-triggered photothermal therapy in combination with (131)I-based radioisotope therapy is realized in our animal experiments, in which a remarkable synergistic antitumor therapeutic effect is observed compared to monotherapies. Our work not only presents a new type of theranostic nanoplatform based on SWNTs, but also suggests the promise of PDA coating as a general approach to modify nano-agents and endow them with highly integrated functionalities. PMID:27570554

  13. A simple electrochemical platform for detection of nitrobenzene in water samples using an alumina polished glassy carbon electrode.

    Science.gov (United States)

    Thirumalraj, Balamurugan; Palanisamy, Selvakumar; Chen, Shen-Ming; Thangavelu, Kokulnathan; Periakaruppan, Prakash; Liu, Xiao-Heng

    2016-08-01

    In this work, we report a selective electrochemical sensing of nitrobenzene (NB) using an alumina (γ-Al2O3) polished glassy carbon electrode (GCE) for the first time. The scanning electron microscopy studies confirm the presence of alumina particles on the GCE surface. X-ray photoelectron spectroscopy studies reveal that the utilized alumina is γ-Al2O3. The alumina polished GCE shows an enhanced sensitivity and lower overpotential toward the reduction of NB compared to unpolished GCE. The differential pulse voltammetry response was used for the determination of NB and it shows that the reduction peak current of NB is linearly proportional to the concentrations of NB ranging from 0.5 to 145.5μM. The limit of detection is found to be 0.15μM based on 3σ. The fabricated electrode exhibits its appropriate selectivity towards NB in the presence of a range of nitro compounds and metal ions. The good practicality of the sensor in various water samples reveals that it can be a promising electrode material for practical applications. In addition, the proposed NB sensor is simple and cost effective one when compared with previously reported NB sensors in the literature. PMID:27163842

  14. Payment Platform

    DEFF Research Database (Denmark)

    Hjelholt, Morten; Damsgaard, Jan

    2012-01-01

    Payment transactions through the use of physical coins, bank notes or credit cards have for centuries been the standard formats of exchanging money. Recently online and mobile digital payment platforms has entered the stage as contenders to this position and possibly could penetrate societies...... applies a co-evolutionary multilevel perspective to model the interplay and processes between technology and society wherein digital payment platforms potentially will substitute other payment platforms just like the credit card negated the check. On this basis this paper formulate a multilevel conceptual...

  15. Effect of Second-Order Hydrodynamics on a Floating Offshore Wind Turbine

    Energy Technology Data Exchange (ETDEWEB)

    Roald, L.; Jonkman, J.; Robertson, A.

    2014-05-01

    The design of offshore floating wind turbines uses design codes that can simulate the entire coupled system behavior. At the present, most codes include only first-order hydrodynamics, which induce forces and motions varying with the same frequency as the incident waves. Effects due to second- and higher-order hydrodynamics are often ignored in the offshore industry, because the forces induced typically are smaller than the first-order forces. In this report, first- and second-order hydrodynamic analysis used in the offshore oil and gas industry is applied to two different wind turbine concepts--a spar and a tension leg platform.

  16. A planning model for offshore natural gas transmission

    OpenAIRE

    Edson K. Iamashita; Frederico Galaxe; José Arica

    2008-01-01

    This paper aims at new approach to solve complex integrated offshore gas planning problems, defining the best transmission strategy for a system with a large number of platforms interconnected between them and with delivery points through a complex gas pipeline network (which can be cycled). The problem is formulated as a large quadratic mixed-integer problem, where non-convexity and non-differentiability is found. Because the complexity of the problem, it is proposed a heuristic, in the cont...

  17. Ultrasensitive Nanoimmunosensor by coupling non-covalent functionalized graphene oxide platform and numerous ferritin labels on carbon nanotubes.

    Science.gov (United States)

    Akter, Rashida; Jeong, Bongjin; Choi, Jong-Soon; Rahman, Md Aminur

    2016-06-15

    An ultrasensitive electrochemical nanostructured immunosensor for a breast cancer biomarker carbohydrate antigen 15-3 (CA 15-3) was fabricated using non-covalent functionalized graphene oxides (GO/Py-COOH) as sensor probe and multiwalled carbon nanotube (MWCNTs)-supported numerous ferritin as labels. The immunosensor was constructed by immobilizing a monoclonal anti-CA 15-3 antibody on the GO modified cysteamine (Cys) self-assembled monolayer (SAM) on an Au electrode (Au/Cys) through the amide bond formation between the carboxylic acid groups of GO/Py-COOH and amine groups of anti-CA 15-3. Secondary antibody conjugated MWCNT-supported ferritin labels (Ab2-MWCNT-Ferritin) were prepared through the amide bond formation between amine groups of Ab2 and ferritin and carboxylic acid groups of MWCNTs. The detection of CA 15-3 was based on the enhanced bioelectrocatalytic reduction of hydrogen peroxide mediated by hydroquinone (HQ) at the GO/Py-COOH-based sensor probe. The GO/Py-COOH-based sensor probe and Ab2-MWCNT-Ferritin labels were characterized using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), transmission electron microscope (TEM), and x-ray photoelectron spectroscopy (XPS) techniques. Using differential pulse voltammetry (DPV) technique, CA 15-3 can be selectively detected as low as 0.01 ± 0.07 U/mL in human serum samples. Additionally, the proposed CA 15-3 immunosensor showed excellent selectivity and better stability in human serum samples, which demonstrated that the proposed immunosensor has potentials in proteomic researches and diagnostics. PMID:26820360

  18. Landmark Report Analyzes Current State of U.S. Offshore Wind Industry (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2011-09-01

    New report assesses offshore wind industry, offshore wind resource, technology challenges, economics, permitting procedures, and potential risks and benefits. The National Renewable Energy Laboratory (NREL) recently published a new report that analyzes the current state of the offshore wind energy industry, Large-Scale Offshore Wind Power in the United States. It provides a broad understanding of the offshore wind resource, and details the associated technology challenges, economics, permitting procedures, and potential risks and benefits of developing this clean, domestic, renewable resource. The United States possesses large and accessible offshore wind energy resources. The availability of these strong offshore winds close to major U.S. coastal cities significantly reduces power transmission issues. The report estimates that U.S. offshore winds have a gross potential generating capacity four times greater than the nation's present electric capacity. According to the report, developing the offshore wind resource along U.S. coastlines and in the Great Lakes would help the nation: (1) Achieve 20% of its electricity from wind by 2030 - Offshore wind could supply 54 gigawatts of wind capacity to the nation's electrical grid, increasing energy security, reducing air and water pollution, and stimulating the domestic economy. (2) Provide clean power to its coastal demand centers - Wind power emits no carbon dioxide (CO2) and there are plentiful winds off the coasts of 26 states. (3) Revitalize its manufacturing sector - Building 54 GW of offshore wind energy facilities would generate an estimated $200 billion in new economic activity, and create more than 43,000 permanent, well-paid technical jobs in manufacturing, construction, engineering, operations and maintenance. NREL's report concludes that the development of the nation's offshore wind resources can provide many potential benefits, and with effective research, policies, and commitment

  19. Offshore Wind Payload Transfer Using Flexible Mobile Crane

    OpenAIRE

    Magnus B. Kjelland; Hansen, Michael R.

    2015-01-01

    This article presents an offshore-simulated loading and unloading of a payload from a floating platform to a fixed structure. The experiments are performed in a dry-lab, where a Stewart platform is used to simulate the motion of the vessel. A hydraulically actuated vehicle loader crane is used to perform the tasks of payload transfer. The crane includes a hydraulic winch where the wire force is measured by a load cell. A mathematical model of the winch is derived and is experimentally verifie...

  20. Immobilized organoruthenium(II) complexes onto polyethyleneimine-wrapped carbon nanotubes/in situ formed gold nanoparticles as a novel electrochemical sensing platform

    Energy Technology Data Exchange (ETDEWEB)

    Azadbakht, Azadeh, E-mail: Azadbakht.a@gmail.com; Abbasi, Amir Reza; Derikvand, Zohreh; Amraei, Shiba

    2015-03-01

    The polyethyleneimine (PEI) wrapped multi-walled carbon nanotubes functionalized with a carboxylic acid group (CNTs–COOH) gold nanoparticle (AuNP)-modified gold (Au) electrode has been utilized as a platform to immobilize organoruthenium(II) complexes (ORC). The surface structure and composition of the sensor were characterized by scanning electron microscopy (SEM). Electrocatalytic reduction of iodate and nitrite on the surface of modified electrode was investigated with cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and hydrodynamic voltammetry methods. The cyclic voltammetric results indicated the ability of AuNPs/PEI/CNT–COOH/ORC modified Au electrode to catalyze the reduction of this compound. AuNPs/PEI/CNTs–COOH nanocomposite combined the advantages of PEI-well dispersed CNTs–COOH and in situ formed AuNPs. - Highlights: • We prepared composite containing polyethyleneimine (PEI), CNTs and AuNPs. • AuNPs were in situ formed on the surface of CNTs–PEI. • When the AuNPs were in situ formed the stability would be improved. • Nanocomposite combined the advantages of PEI–CNTs and in situ formed AuNPs. • Modified nanocomposite Au electrode catalyzes the reduction of iodate and nitrite.

  1. Immobilized organoruthenium(II) complexes onto polyethyleneimine-wrapped carbon nanotubes/in situ formed gold nanoparticles as a novel electrochemical sensing platform

    International Nuclear Information System (INIS)

    The polyethyleneimine (PEI) wrapped multi-walled carbon nanotubes functionalized with a carboxylic acid group (CNTs–COOH) gold nanoparticle (AuNP)-modified gold (Au) electrode has been utilized as a platform to immobilize organoruthenium(II) complexes (ORC). The surface structure and composition of the sensor were characterized by scanning electron microscopy (SEM). Electrocatalytic reduction of iodate and nitrite on the surface of modified electrode was investigated with cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and hydrodynamic voltammetry methods. The cyclic voltammetric results indicated the ability of AuNPs/PEI/CNT–COOH/ORC modified Au electrode to catalyze the reduction of this compound. AuNPs/PEI/CNTs–COOH nanocomposite combined the advantages of PEI-well dispersed CNTs–COOH and in situ formed AuNPs. - Highlights: • We prepared composite containing polyethyleneimine (PEI), CNTs and AuNPs. • AuNPs were in situ formed on the surface of CNTs–PEI. • When the AuNPs were in situ formed the stability would be improved. • Nanocomposite combined the advantages of PEI–CNTs and in situ formed AuNPs. • Modified nanocomposite Au electrode catalyzes the reduction of iodate and nitrite

  2. APPLICATION OF ALTERNATIVE ENERGIES IN THE AUSTRALIAN OFFSHORE SECTOR

    Directory of Open Access Journals (Sweden)

    M. F. HJ. MOHD AMIN

    2016-09-01

    Full Text Available Fossil fuel is not practically renewable and therefore the world is at risk of fossil fuel depletion. This gives urgency to investigate alternative energies, especially for industries that rely entirely on energies for operations, such as offshore industry. The use of alternative energies in this industry has been in place for a while now. This paper discusses the application of various alternative energy sources to assist powering the Goodwyn Alpha (A Platform, located on the North West Shelf (NWS of Australia. The three alternative energy sources under discussion are: wind, wave and solar. The extraction devices used are the Horizontal and Vertical-Axis Wind Turbines - for wind; Pelamis, PowerBuoy and Wave Dragon - for wave; and the solar parabolic dish of SunBeam and Photovoltaic (PV cells of SunPower - for solar. These types of devices are installed within the same offshore platform area. Technical, environmental and economic aspects are taken into consideration before the best selection is made. The results showed that PowerBuoy used for wave energy, is the best device to be used on offshore platforms where operators could save up to 9% of power; $603,083 of natural gas; and 10,848 tonnes of CO2 per year.

  3. Deepwater fixed platforms now aimed at future optimization

    International Nuclear Information System (INIS)

    This paper reviews the trend of optimization methods of designing offshore oil and gas platforms to consider the long-term operation for maximum economic benefit. While oil and gas platforms are normally designed for the field specifications, there is now a trend toward joint-development where adjacent oil and gas wells could ultimately be produced in the future when declining production from the developed field starts to lag. It also addresses the potential for attracting production or refining services for nearby product pipelines from other offshore developments that are already in-service. The overall thrust of the paper is the design of offshore platforms to maintain optimal production and operation throughout the entire life of operation to maximize the financial return

  4. Product Implications of Design Offshoring

    DEFF Research Database (Denmark)

    Hansen, Zaza Nadja Lee; Ahmed-Kristensen, Saeema

    2011-01-01

    This paper investigates the impact offshoring of product development has on the product and suggest possible ways the negative impacts can be avoided.......This paper investigates the impact offshoring of product development has on the product and suggest possible ways the negative impacts can be avoided....

  5. 基于OGC WPS的碳循环模型服务平台的设计与实现%Designing and Implementing an Online Carbon Cycle Model Service Platform Based on OGC Web Processing Service

    Institute of Scientific and Technical Information of China (English)

    吴楠; 何洪林; 张黎; 任小丽; 周园春; 于贵瑞; 王晓峰

    2012-01-01

    Carbon cycle model is an effective tool in terrestrial ecosystem carbon cycle research, through which people can study the key process mechanism of terrestrial ecosystem carbon cycle and gain more knowledge about its temporal and spatial variation. However, there exist many problems in the application of traditional carbon cycle models, such as vast amounts of data processing, complex calculations, poor interoperability, and difficult to make it more widespread, etc. Using Web Processing Service standard which is established by Open Geospatial Consortium to publish and share carbon cycle models, realize cross-platform invocation, reuse and compose carbon cycle model service, can promote the development and application of carbon cycle models. In this paper, we followed Web Processing Service standard, designed the overall, architecture of the online carbon cycle model service platform, and implemented the service platform through a series of processes: service interface designing, models and spatial analysis algorithm developing, Web Processing Service encapsulating and publishing, user interface based on browser client designing and programming, and so on. The online carbon cycle model service platform provided an amount of functions, including carbon cycle data and model service publication, service management, service invocation, service composition, asynchronous interaction between users and background processes, calculation status monitoring, model result visualization, etc. With a Vegetation Photosynthesis Model chain as an application instance, we demonstrated in detail the means to develop, encapsulate, in-vocate and compose carbon cycle model service found on Web Processing Service standard, meanwhile displayed functions and browser interface of the online carbon cycle model service platform. This platform can be applied to the field of scientific research, decision support, etc. , to promote the use of carbon cycle models, thereby make them get rapid

  6. Decommissioning of offshore installations

    Energy Technology Data Exchange (ETDEWEB)

    Oeen, Sigrun; Iversen, Per Erik; Stokke, Reidunn; Nielsen, Frantz; Henriksen, Thor; Natvig, Henning; Dretvik, Oeystein; Martinsen, Finn; Bakke, Gunnstein

    2010-07-01

    New legislation on the handling and storage of radioactive substances came into force 1 January 2011. This version of the report is updated to reflect this new regulation and will therefore in some chapters differ from the Norwegian version (see NEI-NO--1660). The Ministry of the Environment commissioned the Climate and Pollution Agency to examine the environmental impacts associated with the decommissioning of offshore installations (demolition and recycling). This has involved an assessment of the volumes and types of waste material and of decommissioning capacity in Norway now and in the future. This report also presents proposals for measures and instruments to address environmental and other concerns that arise in connection with the decommissioning of offshore installations. At present, Norway has four decommissioning facilities for offshore installations, three of which are currently involved in decommissioning projects. Waste treatment plants of this kind are required to hold permits under the Pollution Control Act. The permit system allows the pollution control authority to tailor the requirements in a specific permit by evaluating conditions and limits for releases of pollutants on a case-to-case basis, and the Act also provides for requirements to be tightened up in line with the development of best available techniques (BAT). The environmental risks posed by decommissioning facilities are much the same as those from process industries and other waste treatment plants that are regulated by means of individual permits. Strict requirements are intended to ensure that environmental and health concerns are taken into account. The review of the four Norwegian decommissioning facilities in connection with this report shows that the degree to which requirements need to be tightened up varies from one facility to another. The permit for the Vats yard is newest and contains the strictest conditions. The Climate and Pollution Agency recommends a number of measures

  7. Offshore 2010. Final report

    International Nuclear Information System (INIS)

    An overview of the accomplishments of the various projects that have received support from the Norwegian Research Council's program 'Offshore 2010'. The following projects are presented, some have English and some Norwegian project names: 'Critical parameters influencing inhibitor performance in multiphase flow', 'Development of the drilling optimization simulator (DDS) and a totally integrated drilling optimization system', 'Produksjonsoptimalisering og automatisk styring av broenner og roerledninger (PETRONICS)', 'Termisk isolerte undervannsroer for sikring av broenntransport over store avstander', 'Utvikling av magnetisk frekvensformer for styring av store subsea pumper paa havdyp ned mot 4000 meter', 'Flerfase stroemningsmaaler for permanent nedihulls installasjon', 'Hastighetsmaaling i flerfase stroemning ved passiv akustikk', 'Oil/water seperation offshore: optimized flow- and seperation behavior', 'Stroemningshastighet', 'A rock mechanics based reservoir simulation', 'MultiTool fase 2 - et flerbruksverktoey for nedihulls applikasjoner', 'Utvikling av undervanns olje-i-vann monitor for kontinuerlig maaling av lave oljekonsentrasjoner basert paa TR-LIFS', 'Subsea multipath ultrasonic liquid flow meter', 'Fluid characterization at elevated pressures and temperatures (Flucha II)'. The two main goals for the research program are 1. The development of new technology and competency in the field of downhole- and subsea processing and multiphase transportation, and 2. Innovation and commercialisation in small and medium sized companies (less than 100 employees). Some details on the financing and results are included (ml)

  8. Offshoring White-Collar Work

    DEFF Research Database (Denmark)

    Slepniov, Dmitrij; M. Larsen, Marcus; Wæhrens, Brian Vejrum;

    2013-01-01

    The purpose of this chapter is twofold: to explain why white-collar service work in manufacturing firms is increasingly subject to offshoring and to understand the effects of this process on work integration mechanisms. The empirical part of the study is based on two case studies of Danish...... manufacturers. First, the chapter finds that drivers of white-collar work offshoring in many respects are parallel to those of the earlier wave of blue-collar work offshoring, that is, cost minimisation and resource seeking. Second, due to the interdependence of white-collar tasks with the rest of the...... organisation, our results suggest that white-collar offshoring in manufacturing firms poses higher requirements to the organisational configuration and capabilities compared with blue-collar work. We conceptualise the effects of white-collar work offshoring in a framework relating white-collar work to...

  9. OFFSHORING FOR SUSTAINABLE VALUE MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Thaddeus Oforegbunam Ebiringa

    2014-05-01

    Full Text Available This paper evaluates offshoring as a strategic value management initiative using Cadbury Nigeria Plc as a case study. Through offshoring risks associated with inventory holding are hedged. A comparative analysis of in-house and offshored cost profiles as well as critical risk factors that affect firm value are evaluated. The result shows that offshoring led to immediate costs saving, freeing of funds previously held in inventory for other working capital investments as well as profitability for vendors. However, aside financial benefits to partners, it leads to increased stakeholders awareness, shared values, partnerships, teamwork and risk mitigation. It therefore follows that for sustainability of financial benefits of offshoring, concerted effort must be made by partners to ensure that critical drivers of value management are not compromised.

  10. Requalification of offshore structures. Summaries of 9{sup TH} semester and M.SC projects on offshore structural reliability

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This project discusses the determination of the structural safety of an existing and reinforced offshore structure in the North Sea. As subject the example platform used in EFP-97 project 'Requalification of Offshore Structures' is chosen. A reliability analysis of the platform is performed; the reliability analysis includes an extreme-, fatigue- and system analysis. The reliability analysis is based on a stochastic model including both loading and structural strength. The platform is modeled in a 3D non-linear finite element program RONJA. These models are used to determine the structural safety by approximating the failure function with a quadretic response surface. The safety of the platform is evaluated for different levels of subsidence, and a critical subsidence level is determined. Given the subsidence level different methods of reinforcement is analyzed. The reinforcement methods includes insertion of new members and grouting. A fatigue analysis is performed for two critical joints. A 3D finite element model is constructed in ABAQUS and used to determine the stress concentration factors in the joints. The fatigue lives of the two joints are estimated by use of a deterministic and a probabilistic approach. The overall safety of the reinforced platform is determined by a systems reliability analysis including both fatique and extreme analyses. All analyses indicate an improvement of the structural safety after reinforcement of the structure. (au)

  11. Hybrid AC-DC offshore wind power plant topology: optimal design

    OpenAIRE

    Prada Gil, Mikel de; Igualada González, Lucía; Corchero García, Cristina; Gomis Bellmunt, Oriol; Sumper, Andreas

    2015-01-01

    The aim of this paper is to present a hybrid AC-DC offshore wind power plant (OWPP) topology and to optimize its design in order to minimize the OWPP's total cost. This hybrid concept is based on clustering wind turbines and connecting each group to an AC/DC power converter installed on a collector platform which is located between the AC wind turbine array and the HVDC offshore platform. Thereby, individual power converters of each wind turbine are not required, since such AC/DC converters c...

  12. Vertical Wave Impacts on Offshore Wind Turbine Inspection Platforms

    DEFF Research Database (Denmark)

    Bredmose, Henrik; Jacobsen, Niels Gjøl

    2011-01-01

    Breaking wave impacts on a monopile at 20 m depth are computed with a VOF (Volume Of Fluid) method. The impacting waves are generated by the second-order focused wave group technique, to obtain waves that break at the position of the monopile. The subsequent impact from the vertical run-up flow on...

  13. Biofouling of an offshore oil platform: faunal composition and biomass

    Digital Repository Service at National Institute of Oceanography (India)

    Venugopalan, V.P.; Wagh, A.B.

    stream_size 4 stream_content_type text/plain stream_name Indian_J_Mar_Sci_19_53.pdf.txt stream_source_info Indian_J_Mar_Sci_19_53.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  14. PROPOSED PROCEDURE FOR ASSESSMENT OF EXISTING PLATFORMS IN INDONESIA

    OpenAIRE

    Ricky L. Tawekal

    2005-01-01

    Off-shore platforms were built since the 1970âs in Indonesia, but there is no local code or recommended practice for their design or assessment procedure. The common practice is to use the recommended practice issued by the American Petroleum Institute, API RP2A. The off-shore platforms built in the 1970âs must be re-qualified due to exceedance of the design life. This paper discuss the assessment procedure given in the API RP2A WSD 21th edition, API RP2A LRFD, dan ISO 19902 (draft E â 2001)....

  15. Tailoring the Pore Environment of Metal-Organic and Molecular Materials Decorated with Inorganic Anions: Platforms for Highly Selective Carbon Capture

    Science.gov (United States)

    Nugent, Patrick S.

    Due to their high surface areas and structural tunability, porous metal-organic materials, MOMs, have attracted wide research interest in areas such as carbon capture, as the judicious choice of molecular building block (MBB) and linker facilitates the design of MOMs with myriad topologies and allows for a systematic variation of the pore environment. Families of MOMs with modular components, i.e. MOM platforms, are eminently suitable for targeting the selective adsorption of guest molecules such as CO2 because their pore size and pore functionality can each be tailored independently. MOMs with saturated metal centers (SMCs) that promote strong yet reversible CO2 binding in conjunction with favorable adsorption kinetics are an attractive alternative to MOMs containing unsaturated metal centers (UMCs) or amines. Whereas MOMs with SMCs and exclusively organic linkers typically have poor CO2 selectivity, it has been shown that a versatile, long known platform with SMCs, pillared square grids with inorganic anion pillars and pcu topology, exhibits high and selective CO 2 uptake, a moderate CO2 binding affinity, and good stability under practical conditions. As detailed herein, the tuning of pore size and pore functionality in this platform has modulated the CO2 adsorption properties and revealed variants with unprecedented selectivity towards CO 2 under industrially relevant conditions, even in the presence of moisture. With the aim of tuning pore chemistry while preserving pore size, we initially explored the effect of pillar substitution upon the carbon capture properties of a pillared square grid, [Cu(bipy)2(SiF6)] (SIFSIX-1-Cu). Room temperature CO2, CH4, and N 2 adsorption isotherms revealed that substitution of the SiF6 2- ("SIFSIX") inorganic pillar with TiF6 2- ("TIFSIX") or SnF62- ("SNIFSIX") modulated CO2 uptake, CO2 affinity (heat of adsorption, Qst), and selectivity vs. CH4 and N2. TIFSIX-1-Cu and SNIFSIX-1-Cu were calculated to exhibit the highest CO2/N 2

  16. Model establishment for wire saw cutting kinetics of offshore discarded platform piles removal basing on GTM%基于图形法的海洋废弃平台桩基拆除绳锯机切割动力学模型的建立

    Institute of Scientific and Technical Information of China (English)

    王海波; 张岚; 孟庆鑫; 王喆

    2011-01-01

    Underwater wire saw is a safe environmental protection equipment applied widely underwater.The wire saw shall be applied to cut-off piles during removing the offshore discarded platform.To cortrol cutting motion of the string bead wire steadily is an important factor that ensures wire saw to work steadily,efficiently with long life.The main structure and working principle of wire saw is introduced here.The principles and steps of GMT are described as well as the single sheave GMT modeling is analyzed According to the Features of string bead wire and the structure of cutting frame the translational line graph and the rotational line graph for the string bead wire of wire saw cut frame are obtained.Thus the dynamic nodel of string bead wire cutting process is established,which lay a theoretical foundation for motion parameters control of string bead wire cutting process.%水下绳锯机是一种安全、环保和适用范围广的水下作业机具,海洋废弃平台拆除时,可以采用绳锯机切断桩基.较好的串珠绳切割运动控制是绳锯机能稳定、高效和长寿命工作的一个重要因素.介绍了绳锯机的主要结构及工作原理.简述了图形理论建模法原理和步骤,分析了单个绳轮的图形理论建模过程,根据绳锯机串珠绳的特性及切割框架的结构特点,得到了绳锯机l切割框架串珠绳的平移线图和转动线图,建立了串珠绳切割过程的动力学模型.为串珠绳切割过程中的运动参数控制打下了一定的理论基础.

  17. Peregrino : a heavy oil development offshore Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Eliassen, H. [StatoilHydro, Trondheim (Norway)

    2009-07-01

    This paper discussed a commercial development plan for an offshore oil field located off the coast of Brazil. A 3-D reservoir flow model was combined with an integrated production system model in order to model water-flooding and water injection strategies as well as to determine optimal water handling capacity. Flow assurance modelling was also conducted. A 3-D geological model was developed using data from wells drilled on the field as well as data from a regional sedimentological model. Reservoir penetration will be approximately 40,500 meters. Multilateral wells will be used to increase reservoir penetration in the future. The first phase of the development will consist of a floating production, storage and offloading unit as well as 2 wellhead platforms. A combined power and heating system will be used to provide power for pumps and to heat water. It was concluded that a high recovery factor is needed to ensure the economic viability of the project. 5 figs.

  18. Offshore but on track?

    DEFF Research Database (Denmark)

    Nielsen, Helene Pristed

    2016-01-01

    In the spring 2011, and again during summer 2012, the small coastal town of Hirtshals (approx. 6000 inhabitants) on the north-western shore of Denmark was home to two spectacular symbols of the success of an emergent offshore sector in the region, namely the upgrading and overhauling of two...... indirectly affected by these events. As the interviews illuminate, respondents are often extremely mobile and flexible in terms of their jobs, in some cases ‘bungy jumping’ through working life in an apparent effort to retain local ties while pursuing global opportunities. The paper contributes to qualifying...... more general sociological discussions about the push for increased mobility and flexibility in a presumably increasingly globalising labour market reality. Ultimately, it seems that the multiple ways in which Hirtshals is marked as marginal – in terms of geography, socio-economic profile and discourse...

  19. Analysis of a intra-Carixian clay horizon into carbonate platform of the Ouarsenis (Algeria): composition, dynamic and paleo-climatic implication

    International Nuclear Information System (INIS)

    During the Late Sinemurian a carbonate platform has developed on the Ouarsenis area (external Tell o f the Algerian Alpine belt) with setting deposits of the Kef Sidi Amar Carbonate Formation. A first maximum flooding materialized by a brachiopods (Zeilleriids) layer, is occurring during the Late Carixian. The Late Carixian deepening has been followed by a sea-level fall documented by several meters incisions filled by transgressive breccia and conglomerates. After this episode, this material was sealed by a pedogenic bed (0,05 to 0,20 m) which corresponds to a yellow clay deposit containing well rounded particles interpreted as pedo-genetic globules. These corpuscles are composed of reddish and hardened clay, corroded quartz grains, rhombic and zoned dolomite crystals and ankerite, monocrystalline and xeno-morphous detrital quartz grains (1-2 mm). The observed characteristics allow to recognize a typical calcrete. They are the result of pedo-genetic diagenesis developed inside the phreatic water-table near the surface: this is an alteration profile. The mineralogic fraction has been analyzed by X-Ray which show results of association clay mineral as a predominance of illite (85%) and mixed-layer illite-montmorillonite (I-M, 10%) associated with a low ration of chlorite (5%) and kaolinite trace (1%). This mineralogic clay association indicates a shallow water (hydro-morphic zone). Among these clay minerals, the illite reveals the precious indications in a source area. In this case, it comes from the decomposition of the schist paleo-relief located in the internal domain. This rock was transformed by acid leaching (action of the sour humus) into kaolinite with the presence of the quartzification. The origin of the mixed-layer clay I-M (10%) is the result of the active pedogenesis. The simultaneous presence of the illite, chlorite, kaolinite and the mixed-layer clay I-M seems to be result from the erosion exercised on the alteration product or arenitisation of the

  20. Analysis of a intra-Carixian clay horizon into carbonate platform of the Ouarsenis (Algeria): composition, dynamic and paleo-climatic implication

    Energy Technology Data Exchange (ETDEWEB)

    Benhamou, M.; Salhi, A. [Oran Univ., Faculte des Sciences de la Terre et de l' Amenagement du Territoire, Dpt. de Geologie (Algeria)

    2005-07-01

    During the Late Sinemurian a carbonate platform has developed on the Ouarsenis area (external Tell o f the Algerian Alpine belt) with setting deposits of the Kef Sidi Amar Carbonate Formation. A first maximum flooding materialized by a brachiopods (Zeilleriids) layer, is occurring during the Late Carixian. The Late Carixian deepening has been followed by a sea-level fall documented by several meters incisions filled by transgressive breccia and conglomerates. After this episode, this material was sealed by a pedogenic bed (0,05 to 0,20 m) which corresponds to a yellow clay deposit containing well rounded particles interpreted as pedo-genetic globules. These corpuscles are composed of reddish and hardened clay, corroded quartz grains, rhombic and zoned dolomite crystals and ankerite, monocrystalline and xeno-morphous detrital quartz grains (1-2 mm). The observed characteristics allow to recognize a typical calcrete. They are the result of pedo-genetic diagenesis developed inside the phreatic water-table near the surface: this is an alteration profile. The mineralogic fraction has been analyzed by X-Ray which show results of association clay mineral as a predominance of illite (85%) and mixed-layer illite-montmorillonite (I-M, 10%) associated with a low ration of chlorite (5%) and kaolinite trace (1%). This mineralogic clay association indicates a shallow water (hydro-morphic zone). Among these clay minerals, the illite reveals the precious indications in a source area. In this case, it comes from the decomposition of the schist paleo-relief located in the internal domain. This rock was transformed by acid leaching (action of the sour humus) into kaolinite with the presence of the quartzification. The origin of the mixed-layer clay I-M (10%) is the result of the active pedogenesis. The simultaneous presence of the illite, chlorite, kaolinite and the mixed-layer clay I-M seems to be result from the erosion exercised on the alteration product or arenitisation of the

  1. Review of technology for Arctic offshore oil and gas recovery

    Energy Technology Data Exchange (ETDEWEB)

    Sackinger, W. M.

    1980-08-01

    The technical background briefing report is the first step in the preparation of a plan for engineering research oriented toward Arctic offshore oil and gas recovery. A five-year leasing schedule for the ice-prone waters of the Arctic offshore is presented, which also shows the projected dates of the lease sale for each area. The estimated peak production rates for these areas are given. There is considerable uncertainty for all these production estimates, since no exploratory drilling has yet taken place. A flow chart is presented which relates the special Arctic factors, such as ice and permafrost, to the normal petroleum production sequence. Some highlights from the chart and from the technical review are: (1) in many Arctic offshore locations the movement of sea ice causes major lateral forces on offshore structures, which are much greater than wave forces; (2) spray ice buildup on structures, ships and aircraft will be considerable, and must be prevented or accommodated with special designs; (3) the time available for summer exploratory drilling, and for deployment of permanent production structures, is limited by the return of the pack ice. This time may be extended by ice-breaking vessels in some cases; (4) during production, icebreaking workboats will service the offshore platforms in most areas throughout the year; (5) transportation of petroleum by icebreaking tankers from offshore tanker loading points is a highly probable situation, except in the Alaskan Beaufort; and (6) Arctic pipelines must contend with permafrost, making instrumentation necessary to detect subtle changes of the pipe before rupture occurs.

  2. L-tyrosine immobilized on multiwalled carbon nanotubes: a new substrate for thallium separation and speciation using stabilized temperature platform furnace-electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Pacheco, Pablo H; Gil, Raúl A; Smichowski, Patricia; Polla, Griselda; Martinez, Luis D

    2009-12-10

    An approach for the separation and determination of inorganic thallium species is described. A new sorbent, L-tyrosine-carbon nanotubes (L-tyr-CNTs), was used and applied to the analysis of tap water samples. At pH 5.0, L-tyr was selective only towards Tl(III), while total thallium was determined directly by stabilized temperature platform furnace-electrothermal atomic absorption spectrometry (STPF-ETAAS). The Tl(III) specie, which was retained by L-tyrosine, was quantitatively eluted from the column with 10% of nitric acid. An on-line breakthrough curve was used to determine the column capacity, which resulted to be 9.00 micromol of Tl(III) g(-1) of L-tyr-CNTs with a molar ratio of 0.14 (moles of Tl bound to moles of L-tyr at pH 5). Transient peak areas revealed that Tl stripping from the column occurred instantaneously. Effects of sample flow rate, concentration and flow rate of the eluent, and interfering ions on the recovery of the analyte were systematically investigated. The detection limit for the determination of total thallium (3sigma) by STPF-ETAAS was 150 ng L(-1). The detection limit (3sigma) for Tl(III) employing the separation system was 3 ng L(-1), with an enrichment factor of 40. The precision of the method expressed as the relative standard deviation (RSD) resulted to be 3.4%. The proposed method was applied to the speciation and determination of inorganic thallium in tap water samples. The found concentrations were in the range of 0.88-0.91 microg L(-1) of Tl(III), and 3.69-3.91 microg L(-1) of total thallium. PMID:19932812

  3. Synsedimentary tectonics, mud-mounds and sea-level changes on a Palaeozoic carbonate platform margin: a Devonian Montagne Noire example (France)

    Science.gov (United States)

    Bourrouilh, Robert; Bourque, Pierre-André; Dansereau, Pauline; Bourrouilh-Le Jan, Françoise; Weyant, Pierre

    1998-06-01

    The Devonian sedimentary succession of the southern flank of the Montagne Noire (France) was deposited along a divergent margin. This paper is a contribution to describe and evaluate biogenic, sedimentary, geochemical and micropalaeontological features as indicators of sea-level changes and global history of the Devonian in this area. Following transgression and shallow-water environments during Early Devonian time (Lochkovian to early Emsian), biogenic mud-rich mounds with stromatactis developed during latest Emsian at the platform margin. The depth of the Devonian sea was increasing and the seafloor passed below the photic zone and the lower limit of storm wave base during the Emsian. Growth and seismic faults affected the mounds and created Neptunian cracks and crevices, quickly filled with sedimentary material (pisoids) and cements (Neptunian dykes and veins). Light and CL-microscopy, and stable isotope geochemistry show that stromatactis, cements of Neptunian dykes, veins and pisoid cortices are early marine, whereas the red finely crystalline material that forms the bulk of the mound has been cemented in the near-surface diagenetic environment, after the early marine cementation of stromatactis and Neptunian dykes and veins, by meteoric or hydrothermal fluids. The sedimentary rocks overlying the stromatactis mounds exhibit regularly condensed iron and manganese-rich layers, interrupted by the Kellwasser hypoxic horizon. These condensed deposits developed up to the Famennian in a context of carbonate gravity sedimentation and became more and more rhythmic and frequent up section. The occurrence and irregular distribution of large-scale submarine mass flows during Frasnian and Famennian times can be related to block faulting on which Lower Devonian stromatactis mounds could have been uplifted by this block faulting to form seamounts. The sea-level fluctuations detected in the southern flank of Montagne Noire are compared to the Devonian eustatic sea-level curve

  4. Fabrication of multiwalled carbon nanotubes-magnetite nanocomposite as an effective ultra-sensing platform for the early screening of nasopharyngeal carcinoma by luminescence immunoassay.

    Science.gov (United States)

    Liu, Chia-Ching; Sadhasivam, S; Savitha, S; Lin, Feng-Huei

    2014-05-01

    The hybrid nanocomposite that consists of multiwalled carbon nanotubes (MWCNTs) and magnetite (Fe₃O4) was fabricated by chemical co-precipitation method. Briefly, CNTs were oxidized with acids to form carboxylic group and then co-precipitated with Fe₃O4 to form CNT-Fe₃O4 nanocomposites. The nanocomposites were characterized by SEM, HRTEM, XRD, FTIR X-ray photoelectron spectrometry (XPS) and SQUID. The XRD results indicated the high crystallinity of Fe₃O₄ nanoparticles with spinel structure and the transmission electron microscope images depicted the intercalated iron oxide magnetic particles on the surface of CNTs. The MWCNTs-Fe₃O₄ was applied as a sensing interface to perform luminescence enzyme immunoassays. Firstly, EBNA-1 antigen was immobilized onto the carboxyl group functionalized MWCNTs-Fe₃O₄, followed by binding with anti-EBNA-1 IgA antibodies. The diluted secondary antibodies (anti-human IgA-HRP) were then added to the CNTs/Fe₃O₄-PEG-EBNA-1-anti-EBV IgA ab complex and act as a catalyst to produce a visible light upon reaction with the substrate luminol. The formed RLU is proportional to the amount of IgA anti-EBV antiobodies on the MWCNTs. The detection limit of proposed CNTs/Fe₃O₄ based luminescence enzyme immunoassay was in the order of 0.00128 EU/mL (1:100,000 fold dilution) for the detection of anti-EBV IgA antibodies, whereas the commercial ELISA and magnetic beads' assay was accounted for up to the dilution fold of 1000 (i.e., 0.128 EU/mL). The initial findings showed that CNTs/Fe₃O₄ nanocomposites have a great potential in luminescent enzyme immunoassays and could be used as a sensing platform for the early screening of nasopharyngeal carcinoma. PMID:24720983

  5. Facile and ultrasensitive fluorescence sensor platform for tumor invasive biomaker β-glucuronidase detection and inhibitor evaluation with carbon quantum dots based on inner-filter effect.

    Science.gov (United States)

    Lu, Shuaimin; Li, Guoliang; Lv, Zhengxian; Qiu, Nannan; Kong, Weiheng; Gong, Peiwei; Chen, Guang; Xia, Lian; Guo, Xiaoxi; You, Jinmao; Wu, Yongning

    2016-11-15

    Early detection and diagnosis have great practical significances for the effective prevention and treatment of cancer. In this study, we developed a novel, facile and ultra-sensitive fluorescence assay for the determination of tumor invasive biomarker β-glucuronidase (GLU) based on the inner-filter effect (IFE). The nitrogen-doped carbon quantum dots (N-CQDs) with green photoluminescence were employed as the fluorophore in IFE, and 4-nitrophenyl-β-D-glucuronide (PNPG) was used to act as GLU substrate, and GLU catalytic product (p-nitrophenol (PNP)) was capable of acting as the robust absorber in IFE to turn off the fluorescence of N-CQDs due to the complementary overlap between the absorption of PNP and the excitation of N-CQDs. Thus, signal of GLU activity could be recorded by the fluorescence intensity of N-CQDs. Unlike other fluorescence sensing mechanism such as fluorescence resonance energy transfer (FRET) or photoinduced electron transfer (PET), IFE has no requirement for electron or energy transfer process or any chemical modification of fluorophore, which makes our assay more flexible and simple. The proposed method exhibited a good linear relationship from 1UL(-1) to 60UL(-1) (R(2)=0.9967) with a low detection limit of 0.3UL(-1). This method was also successfully applied to the analysis of serum samples and the inhibitor screening from natural product. The developed sensor platform was proven to be reliable, facile, sensitive, and selective, making it promising as a candidate for GLU activity detection in clinic tumor diagnose and anti-tumor drug screening. PMID:27196253

  6. Reservoir-scale stratigraphic controls on the distribution of vertical fractures: insights from a 200-m thick carbonate platform exposure (Sorrento peninsula, Italy)

    Science.gov (United States)

    Corradetti, Amerigo; Tavani, Stefano; Iannace, Alessandro; Vinci, Francesco; Pirmez, Carlos; Torrieri, Stefano; Giorgioni, Maurizio; Strauss, Christoph; Pignalosa, Antonio; Mazzoli, Stefano

    2016-04-01

    Through-going fractures cutting across numerous beds are often invoked to match large-scale permeability patterns in tight carbonate reservoirs. Despite the importance of these structures for fluid flow simulations, there are only few field analogues allowing estimating many of their parameters, including spacing and vertical extent, which are instead required to populate reservoir models. This is mostly due to the fact that the study of these reservoir-scale fractures requires very wide outcrops that for several reasons, including logistics, are rarely analysed. Nevertheless, recent improvements in the construction of digital models of outcrops can greatly help to overcome many logistic issues. In this work, we present the results obtained from combined field and remote sensing observations of a 300-meters wide and 200-meters high carbonate platform reservoir analogue in the Sorrento peninsula (Italy). The outcrop consists of a nearly vertical cliff exposing alternating gently-dipping shallow-water limestones and dolomites characterized by the presence of several vertical fractures of different size and hence with different vertical connectivity. In order to gather both stratigraphic and structural (i.e. fracture) data, we integrated field measurements and stratigraphic logs with a remote sensing study carried out on a digital model of the cliff, made by means of multi-view stereo-photogrammetry. This combined field and remote sensing study has allowed us to recognize that major bed-perpendicular through-going fractures are vertically discontinuous due to variable segmentation and fracture distribution within the country rock. In particular, we observed that large (i.e. tens of meters in height) fractures pass across medium to thick beds (bed thickness > 30 cm), while they arrest against packages made of thinly stratified layers of dolomites. In essence, through-going fractures arrest on weak levels, consisting of thinly bedded layers interposed between packages

  7. An assessment of the environmental effects of offshore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This report focuses on the development of an approach to the formal environmental assessment of large-scale offshore wind farms around the UK coast which will be required by EU Directives. The legislative background and policy framework are outlined, and key issues to be addressed in the environmental assessment are highlighted. Available information on the manufacture and transportation of wind farm equipment, turbine and cable installation, operation of an offshore wind farm, and wind farm decommissioning is reviewed and recommendations are given. The role of offshore wind power in meeting the UK's commitment to reducing emissions of carbon dioxide and other greenhouse gases and its targets for generating 10% of the UK's electricity from renewable energy sources is discussed.

  8. Wind energy in offshore grids

    OpenAIRE

    Schröder, Sascha Thorsten; Morthorst, Poul Erik; Pade, Lise-Lotte; Meibom, Peter; Hindrichsen, Henriette; Sundahl, Lasse

    2013-01-01

    Denne PhD-afhandling beskæftiger sig med integration af vindenergi i offshore grids fra et økonomisk perspektiv. Afhandlingen består af en generisk del samt otte selvstændige publikationer. Som en af første publikationer behandler den markeds- og driftsspørgsmål og de deraf følgende investeringseffekter under forskellige reguleringsregimer.Offshore grids mellem flere lande kombinerer integration af vindenergi og international el-handel. Derudover påvirker inkluderingen i et offshore grid økon...

  9. Offshore wind power in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Holttinen, H. [VTT Energy, Espoo (Finland)

    1998-12-31

    The objectives of the project were to estimate the technical offshore wind power potential of the Gulf of Bothnia, with cost assessments, to study icing conditions and ice loads, and to design a foundation suitable for the environmental conditions. The technical offshore potential from Vaasa to Tornio is huge, more than 40 TWh/a, although the cost of offshore wind power is still higher than on land. Wind turbines have not previously been designed for the icing conditions found in Gulf of Bothnia and the recommendations for load cases and siting of megawatt-class turbines are an important result of the project. (orig.)

  10. Platform computing

    CERN Multimedia

    2002-01-01

    "Platform Computing releases first grid-enabled workload management solution for IBM eServer Intel and UNIX high performance computing clusters. This Out-of-the-box solution maximizes the performance and capability of applications on IBM HPC clusters" (1/2 page) .

  11. Floating Offshore Wind in Oregon: Potential for Jobs and Economic Impacts from Two Future Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, Tony [National Renewable Energy Lab. (NREL), Golden, CO (United States); Keyser, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tegen, Suzanne [National Renewable Energy Lab. (NREL), Golden, CO (United States); Speer, Bethany [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-05-01

    Construction of the first offshore wind power plant in the United States began in 2015, off the coast of Rhode Island, using fixed platform structures that are appropriate for shallow seafloors, like those located off of the East Coast and mid-Atlantic. However, floating platforms, which have yet to be deployed commercially, will likely need to anchor to the deeper seafloor if deployed off of the West Coast. To analyze the employment and economic potential for floating offshore wind along the West Coast, the Bureau of Ocean Energy Management (BOEM) commissioned the National Renewable Energy Laboratory (NREL) to analyze two hypothetical, large-scale deployment scenarios for Oregon: 5,500 megawatts (MW) of offshore wind deployment in Oregon by 2050 (Scenario A), and 2,900 MW of offshore wind by 2050 (Scenario B). These levels of deployment could power approximately 1,600,000 homes (Scenario A) or 870,000 homes (Scenario B). Offshore wind would contribute to economic development in Oregon in the near future, and more substantially in the long term, especially if equipment and labor are sourced from within the state. According to the analysis, over the 2020-2050 period, Oregon floating offshore wind facilities could support 65,000-97,000 job-years and add $6.8 billion-$9.9 billion to the state GDP (Scenario A).

  12. Habitat--Offshore Monterey, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the habitat map of the seafloor of the Offshore of Monterey map area, California. The vector data file is included in...

  13. The Organizational Design of Offshoring

    DEFF Research Database (Denmark)

    Larsen, Marcus M.

    2014-01-01

    . In this respect, a number of questions arise. For example, how does the added distance between the organizational activities signified by offshoring impact task interdependencies and performance? How do bounded rational decision makers account for and plan the organizational change from co......The general research question guiding this thesis is: What are the organizational consequences of offshoring? Increasingly firms are becoming caught up by the “harsh realities of offshoring” (Aron and Singh, 2005: 135). Many firms have begun to realize that managing an increasingly globally....... Accordingly, the overall purpose of this thesis is to investigate why some firms fail when offshoring and others do not. To accomplish this, offshoring is conceptualized as an organizational reconfiguration which requires firms to coordinate and integrate geographically dispersed activities across distances...

  14. Bathymetry--Offshore Bolinas, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetry and shaded-relief maps of the Offshore of Bolinas, California (raster data file is included in...

  15. Bathymetry--Offshore Pacifica, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetry and shaded-relief maps of Offshore Pacifica, California. The raster data file is included in...

  16. The economics of offshore wind

    Energy Technology Data Exchange (ETDEWEB)

    Green, Richard; Vasilakos, Nicholas [Department of Economics, University of Birmingham, Birmingham B15 2TT (United Kingdom)

    2011-02-15

    This paper presents an overview of the main issues associated with the economics of offshore wind. Investment in offshore wind systems has been growing rapidly throughout Europe, and the technology will be essential in meeting EU targets for renewable energy in 2020. Offshore wind suffers from high installation and connection costs, however, making government support essential. We review various support policies used in Europe, concluding that tender-based feed-in tariff schemes, as used in Denmark, may be best for providing adequate support while minimising developers' rents. It may prove economic to build an international offshore grid connecting wind farms belonging to different countries that are sited close to each other. (author)

  17. Wind energy in offshore grids

    DEFF Research Database (Denmark)

    Schröder, Sascha Thorsten

    and investment implications under different regulatory frameworks are a hitherto underrepresented research field. They are addressed by this thesis. Offshore grids between several countries combine the absorption of wind energy with international power trading. However, the inclusion into an offshore...... correcting its wind forecast errors in a specific onshore balancing group. An analytical approach with a transmission system operator and a wind farm as stakeholders illustrates resulting incentives for strategic behaviour. Depending on the regulatory regime, they may be inclined to announce more or less...... special characteristics of offshore grids. With an operational real options approach, it is furthermore illustrated how different support schemes and connections to additional countries affect the investment case of an offshore wind farm and the income of the transmission system operator. The investment...

  18. Contours--Offshore Aptos, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore of Aptos map area, California. The vector data file is...

  19. Dolomitization of carbonated reservoirs of platforms. From geologic data to modeling. Example of the great Bahama bank; La dolomitisation des reservoirs carbonates de plate-forme. Des donnees geologiques a la modelisation. Exemple du Grand Banc des Bahamas

    Energy Technology Data Exchange (ETDEWEB)

    Caspard, E.

    2002-09-01

    Dolomitization has long been one of the most studied geological processes because of its economic interest (dolomitic rocks form a significant share of hydrocarbon reservoirs) as well as its academic interest, based on the fact that dolomite scarcely forms in current and recent marine environments whereas seawater is highly over-saturated; and that it is still not possible to synthesize it in laboratory under the same conditions. We used data collected by the University of Miami (Bahamas Drilling Project, ODP Leg 166) to understand the geological context of complete dolomitization of a Messinian 60 m thick reef unit. Classical methods of petrographic analysis of thin sections (optical microscopy, cathodoluminescence, scanning electron microscopy, in situ isotopic analyze using ionic microprobe) showed that the intensity of dolomitization is not controlled by the initial texture of the sediment, that the key parameter for dolomitization is the conservation of the initial mineralogy of magnesian bio-clasts, and that redox conditions, salinity and/or temperature of the precipitation fluid varied significantly during the process. Hydrodynamic modelling showed that during periods of high sea-level, Kohout thermal convection is a viable mechanism for driving marine fluids through the sediments. The key parameter for fluid circulations is the permeability anisotropy on the platform scale. Geochemical modelling showed that seawater is able to induce a complete dolomitization over durations of around one million years. Sensitivity tests showed that the critical parameter (as well as one of the less well-known) to describe diagenetic processes in carbonates is the water/rock reactions kinetics and in particular the precipitation kinetics of carbonate minerals. We finally propose that the dolomitization of the reef unit of the Unda well took place during the high sea-level period which extended over 1,1 My in the early Pliocene, according to the Kohout thermal convection

  20. WRF Model Methodology for Offshore Wind Energy Applications

    Directory of Open Access Journals (Sweden)

    Evangelia-Maria Giannakopoulou

    2014-01-01

    Full Text Available Among the parameters that must be considered for an offshore wind farm development, the stability conditions of the marine atmospheric boundary layer (MABL are of significant importance. Atmospheric stability is a vital parameter in wind resource assessment (WRA due to its direct relation to wind and turbulence profiles. A better understanding of the stability conditions occurring offshore and of the interaction between MABL and wind turbines is needed. Accurate simulations of the offshore wind and stability conditions using mesoscale modelling techniques can lead to a more precise WRA. However, the use of any mesoscale model for wind energy applications requires a proper validation process to understand the accuracy and limitations of the model. For this validation process, the weather research and forecasting (WRF model has been applied over the North Sea during March 2005. The sensitivity of the WRF model performance to the use of different horizontal resolutions, input datasets, PBL parameterisations, and nesting options was examined. Comparison of the model results with other modelling studies and with high quality observations recorded at the offshore measurement platform FINO1 showed that the ERA-Interim reanalysis data in combination with the 2.5-level MYNN PBL scheme satisfactorily simulate the MABL over the North Sea.

  1. Offshore northern Europe, the challenges

    International Nuclear Information System (INIS)

    This paper relates to challenges of the offshore activity in the North Sea. It is appropriate to address these challenges in the context of generating values through efficient management of resources, markets, safety and technology, as the challenges lie therein. The petroleum industry is built to turn natural resources into market value, assuring broad benefits to stake holders and shareholders. In the following, the challenges facing the industry the industry offshore Northern Europe is examined on this background

  2. The Organizational Design of Offshoring

    DEFF Research Database (Denmark)

    Ørberg Jensen, Peter D.; Larsen, Marcus M.; Pedersen, Torben

    2013-01-01

    Offshoring can be defined as the relocation of organizational tasks and services to foreign locations. At the same time as the scale and scope of offshoring have reached unprecedented levels in recent years, firms have increasingly been exposed to the challenges relating to managing an organizati...... implies an organizational reconfiguration consisting of three stages: disintegration, relocation and reintegration. We discuss the implications of this perspective and outline a research agenda....

  3. Swedish wind energy goes offshore

    International Nuclear Information System (INIS)

    This article highlights the increase in the use of wind energy in Sweden with one offshore wind power plant already in operation, and more under development, and considers the nontechnical barriers which include the process of obtaining building permission and financing. The contribution of the wind power to Sweden's power capacity, and future plans are discussed, and information on offshore wind energy projects in Sweden is tabulated. (UK)

  4. Nova Scotia's offshore royalty regime

    International Nuclear Information System (INIS)

    Oil production from the Hibernia project in Newfoundland's offshore began in December 1997. It is estimated that by 2010 some 30 per cent of Canada's light oil production and as much as 5-10 per cent of its natural gas production will originate from offshore Newfoundland and Nova Scotia. The current level of investment in east coast offshore petroleum developments is the result of the magnitude of discovered and undiscovered petroleum resources in the region. Advances in offshore petroleum technology also contributed to lower development costs. Another reason for increased investment has been an efficient and predictable regulatory environment and government policies. Nova Scotia's royalty regimes and the evolution of royalty regimes for the Sable Offshore Energy project were discussed. The Offshore Petroleum Royalty Act gives Nova Scotia the ability to establish a royalty regime through regulations, or to enter into royalty agreements on a project by project basis, or to use a mix of both agreement and regulation. The philosophy underlying Nova Scotia's royalty regime is to find the right balance between industry and government's share of project revenues

  5. Twin screw multiphase pumps for Bohai Bay offshore applications; Multiphase pumps

    Energy Technology Data Exchange (ETDEWEB)

    Schroener, Hans Juergen

    2010-07-01

    Twin screw multiphase pumps have been installed on offshore platforms in Bohai Bay since 1997. Compared to the operation of a conventional system, the twin screw multiphase pumps offer several advantages, such as: transfer pump and natural gas compressor as well as separate flow lines were eliminated; only one subsea pipeline was used to boost the multiphase fluid to the well head platform; reduced investment because a gas dewatering facility was not required. (AG)

  6. Analysis of the Induction and Wake Evolution of an Offshore Floating Wind Turbine

    OpenAIRE

    Matthew Lackner; Thomas Sebastian

    2012-01-01

    The degrees-of-freedom associated with offshore floating wind turbines (OFWTs) result in a more dynamic flow field. The resulting aerodynamic loads may be significantly influenced by these motions via perturbations in the evolving wake. This is of great interest in terms of OFWT design, placement and simulation. This study presents free vortex wake method (FVM) simulations of the NREL 5-MW wind turbine of a variety of platforms, operating in a range of wind speeds synthesized platform motion ...

  7. Modeling Dynamic Stall for a Free Vortex Wake Model of Floating Offshore Wind Turbines

    OpenAIRE

    Gaertner, Evan

    2015-01-01

    Floating offshore wind turbines in deep waters offer significant advantages to onshore and near-shore wind turbines. However, due to the motion of floating platforms in response to wind and wave loading, the aerodynamics are substantially more complex. Traditional aerodynamic models and design codes do not adequately account for the floating platform dynamics. Turbines must therefore be over designed due to loading uncertainty and are not fully optimized for their operating conditions. Previo...

  8. Offshore Wind Payload Transfer Using Flexible Mobile Crane

    Directory of Open Access Journals (Sweden)

    Magnus B. Kjelland

    2015-01-01

    Full Text Available This article presents an offshore-simulated loading and unloading of a payload from a floating platform to a fixed structure. The experiments are performed in a dry-lab, where a Stewart platform is used to simulate the motion of the vessel. A hydraulically actuated vehicle loader crane is used to perform the tasks of payload transfer. The crane includes a hydraulic winch where the wire force is measured by a load cell. A mathematical model of the winch is derived and is experimentally verified. The control strategies include a heave compensation and a constant tension mode. A motion reference unit is used to generate the reference motion of the moving platform. Experimental results show the wire force while performing the load cases. This paper shows the advantage of using a reference motion as a feed forward control reference, instead of only relying on the constant tension.

  9. ITS Platform

    DEFF Research Database (Denmark)

    Tøfting, Svend; Lahrmann, Harry; Agerholm, Niels;

    2014-01-01

    Aalborg University and two local companies have over the past four years developed and tested an ITS Platform, which can be used for communication with cars and for providing a number of services to the drivers. The purpose has been to perform a technological test of the possible use of a hidden...... GPS box with data connection to a backend server. The ITS Platform project has had a budget of DKK 33 million (app € 4.4) and it has demonstrated that boxes which register the position of the cars can be helpful to drivers in many ways. Establishing dynamic traffic information and support systems for...... safer and more economic driving is technologically possible. Big Data from the system can provide traffic authorities with a better basis for decision for their traffic planning. Last, but not least, it is possible to establish payment systems. The project has also shown that the boxes in the cars do...

  10. Nighttime approaches to offshore installations in Brazil: Safety shortcomings experienced by helicopter pilots.

    Science.gov (United States)

    Nascimento, Felipe A C; Majumdar, Arnab; Jarvis, Steve

    2012-07-01

    Accident rates for night sorties by helicopters traveling to offshore oil and gas platforms are at least five times higher than those during the daytime. Because pilots need to transition from automated flight to a manually flown night visual segment during arrival, the approach and landing phases cause great concern. Despite this, in Brazil, regulatory changes have been sought to allow for the execution of offshore night flights because of the rapid expansion of the petroleum industry. This study explores the factors that affect safety during night visual segments in Brazil using 28 semi-structured interviews with offshore helicopter pilots, followed by a template analysis of the narratives. The relationships among the factors suggest that flawed safety oversights, caused by a combination of lack of infrastructure for night flights offshore and declining training, currently favor spatial disorientation on the approach and near misses when close to the destination. Safety initiatives can be derived on the basis of these results. PMID:22405240

  11. Human factors, shift work, and alertness in the offshore oil industry

    Energy Technology Data Exchange (ETDEWEB)

    Parkes, K.R.

    1993-12-31

    This report describes a two-part study of human factors, shift work and alertness in the oil industry, with particular reference to control-room personnel working offshore. Part I reports a questionnaire survey of 172 control-room operators, employed either on North Sea platforms or at onshore terminals. The main aim of the study was to compare the onshore and offshore work environments, and assess their implications for employees` physical and mental health, work satisfaction, and sleep patterns. Age and personality factors were also examined in relation to these outcomes. Part II reports a smaller-scale, but more intensive, study of alertness among offshore operators in which subjective mood, and objective reasoning, memory, and reaction-time performance, were assessed repeatedly over the two-week offshore period, with particular reference to the effects of shift patterns and work hours. (author)

  12. Offshore industry executives meet

    International Nuclear Information System (INIS)

    The future of the Gulf of Mexico is tied to the overall future of oil/gas on the international market as it relates to the US. Conquering this last frontier, possibly only through development of technology, was one of the themes covered in the 21st Annual Meeting of the National Ocean Industries Association held in early April, 1993 in Washington, D.C. Oil is the major source for foreign exchange but there are major uncertainties in predicting the future. The swing (imports vs. exports) is two million barrels per day. The big oil users (heavy industry) have reduced consumption. The last big uncertainty is the environmental policies of the West. Development of resources in the Gulf was the third record year in a row in 1992. The potential for hydrocarbon discoveries is significant, a substantial number of new fields have been made and significant discoveries are likely to continue. More than 100 trillion cubic feet of natural gas lies undiscovered offshore - 35% of undiscovered domestic resources. The oil potential exceeds nine billion barrels, more than any other basin except Alaska

  13. Earthquake hazards: nuclear power stations and offshore structures in the UK

    International Nuclear Information System (INIS)

    A brief summary is presented of contributions to an informal discussion on earthquake hazards held by the Society of Earthquake and Civil Engineers, and the British Nuclear Energy Society. The distribution of UK earthquakes and the assessment of seismic hazards, including those to offshore platforms in the UK were amongst the topics discussed. (U.K.)

  14. A review of epidemiological injury studies in the oil- and gas offshore industry

    DEFF Research Database (Denmark)

    Jensen, Olaf; Laursen, Lise Hedegaard

    2014-01-01

    Safety and health in offshore oil and gas production has always been important. With the aim to evaluate the preventive program effect, a literature review was done based on epidemiological occupational injuries and musculoskeletal disorders. Methods: A literature review was performed by examining...... fatal occupational injury risk in the oil- and gas platforms calls for more attention....

  15. Thermodynamic Performance Indicators for Offshore Oil and Gas Processing: Application to Four North Sea Facilities

    DEFF Research Database (Denmark)

    Voldsund, Mari; Nguyen, Tuong-Van; Elmegaard, Brian;

    2014-01-01

    Well-defined performance indicators can motivate optimal operation of offshore oil and gas platforms. We evaluate several thermodynamic performance indicators presented in the literature according to three criteria: Thermodynamic performance indicators should evaluate the use of technically...... oil and gas platforms—the best-available-technology efficiency on an exergy basis, a task exergy efficiency, and the specific exergy destruction....

  16. Late Aptian palaeoclimatic turnovers and volcanism: Insights from a shallow-marine and continental succession of the Apennine carbonate platform, southern Italy

    Science.gov (United States)

    Graziano, Roberto; Raspini, Arturo; Bartiromo, Antonello

    2016-06-01

    This study reports an integrated facies analysis carried out on a new section from the Upper Aptian of the SE Matese Mts. (Civitella Licinio, northern Campania, S. Italy), which includes several decimeter-to-meter scale lacustrine intervals straddling a meter-scale plant-rich Plattenkalk. These intervals are assigned to the late Gargasian-early Clansayesian by their stratigraphic relationship with the upper Salpingoporella dinarica acme as well as lithologic and biostratigraphic supra-regional key-markers found in the Apennine Carbonate Platform (ApCP), including the Orbitolina Level. We infer that the monogeneric parautochthonous plant remains (Frenelopsis sp.) were deposited in a supratidal-to-paralic coastal mudflat close to a restricted, shallow-marine lagoon, at the verge of an arid-semiarid climatic phase. The Plattenkalk was rapidly replaced by persistent lacustrine lithofacies at the onset of a major climatic turnover (Glacial Trigger). The overlying shallow-marine deposits are capped by a deeply incised palaeokarstic surface and, in turn, by unconformable middle Clansayesian transgressive shallow-marine deposits. Interlayering of reliable lithologic indicators of palaeoclimate and High-Resolution Event Stratigraphic (HIRES) correlation of the Civitella Licinio succession with the astrochronologically tuned Mt. Faito reference section of the ApCP bring evidence of rapidly fluctuating hydroclimatic conditions (wet and arid phases) in the short (100 ky) and long (400 ky) eccentricity time band. HIRES and astrochronological age assignment to crucial key markers and humid/arid phases at Civitella Licinio permit to further refine the detailed stratigraphy of the Mt. Faito reference section and to assign the upper S. dinarica acme of the ApCP to a numerical age of 118.55-118.50 My. SEM and EDS analyses document common to abundant windblown volcanic particles (glass shards and sanidine crystals) throughout the Frenelopsis-rich Plattenkalk (~ 118.3 to ~ 118.2 My

  17. Development of an oil spill forecast system for offshore China

    Science.gov (United States)

    Wang, Yonggang; Wei, Zexun; An, Wei

    2016-07-01

    An oil spill forecast system for offshore China was developed based on Visual C++. The oil spill forecast system includes an ocean environmental forecast model and an oil spill model. The ocean environmental forecast model was designed to include timesaving methods, and comprised a parametrical wind wave forecast model and a sea surface current forecast model. The oil spill model was based on the "particle method" and fulfills the prediction of oil particle behavior by considering the drifting, evaporation and emulsification processes. A specific database was embedded into the oil spill forecast system, which contained fundamental information, such as the properties of oil, reserve of emergency equipment and distribution of marine petroleum platform. The oil spill forecast system was successfully applied as part of an oil spill emergency exercise, and provides an operational service in the Research and Development Center for Offshore Oil Safety and Environmental Technology.

  18. Offshore wind farm with a series multiterminal CSI HVDC

    Energy Technology Data Exchange (ETDEWEB)

    Jovcic, Dragan [Department of Engineering, King' s College, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom)

    2008-04-15

    This paper presents an integrated design of an offshore wind farm and an interconnection circuit based on a series multiterminal HVDC link with current source inverters (CSI). The transmission converters are used to achieve variable speed operation for a group of generators, and this enables use of very simple generators. The series converter connection eliminates offshore transformers. The paper discusses the control systems for both, generator side and grid side converters. A 200 MW wind farm is simulated on PSCAD/EMTDC platform and the responses confirm satisfactory operation for a range of wind speed changes. It is shown that each generator group can operate with a different and optimal frequency and that wind variations on individual units cannot jeopardize system stability. The main challenges for the proposed topology are system insulation and management of transmission line losses, and the paper studies some possible solutions. (author)

  19. Combatting operational pollution from offshore petroleum activities: international legal regime

    International Nuclear Information System (INIS)

    Existing global and regional rules and regulations, and regulatory trends, aimed at curbing pollution associated with the normal operation of offshore oil and gas installations are assessed. The designation 'operational pollution' is used to cover a variety of discharges including: oil produced in water; contaminated drill cuttings and muds; sewage; garbage; deck drainage; naturally occurring materials such as radionuclides, heavy metals and aromatics; atmospheric emissions, principally CO2, SOx, NOx, CH4 and volatile organic compounds. The main focus of regulatory attention at present is platform drainage, offshore processing drainage, production water discharge, and displacement discharge. The legal framework considered extends to the appropriate global and regional treaties, ''soft law'' instruments and recommendations. (UK)

  20. Development of an oil spill forecast system for offshore China

    Science.gov (United States)

    Wang, Yonggang; Wei, Zexun; An, Wei

    2015-12-01

    An oil spill forecast system for offshore China was developed based on Visual C++. The oil spill forecast system includes an ocean environmental forecast model and an oil spill model. The ocean environmental forecast model was designed to include timesaving methods, and comprised a parametrical wind wave forecast model and a sea surface current forecast model. The oil spill model was based on the "particle method" and fulfills the prediction of oil particle behavior by considering the drifting, evaporation and emulsification processes. A specific database was embedded into the oil spill forecast system, which contained fundamental information, such as the properties of oil, reserve of emergency equipment and distribution of marine petroleum platform. The oil spill forecast system was successfully applied as part of an oil spill emergency exercise, and provides an operational service in the Research and Development Center for Offshore Oil Safety and Environmental Technology.

  1. IS OFFSHORING AN INTERNATIONAL PROCESS

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Gião

    2012-01-01

    Full Text Available This article proposes to analyze the applicability of transaction cost economics - TCE (Coase, 1937; Williamson, 1975, 1979 through its characteristic make-or-buy expression, considering the offshoring pace and emerging economy firms. The make-or-buy decision must be flexible enough to explain offshoring characteristics and developed and emerging economy firms scenarios. As secondary objectives, and to show the trail to the main purpose, two research questions were identified and discussed during the paper: Is offshoring process an international movement only from developed countries to emerging economies? Is the main reason of offshoring the looking for low-cost work / activities? To achieve the proposed objectives, the structure of this paper begins with a reasonable or acceptable definition of offshoring. Some reasons (or “the reason” for the process are also another important starting point. The majority of articles referee the idea that low-cost is the main reason for offshoring, and if it is correct, transaction cost economics seems to be a good basis for our analysis purpose and integrative intention. Also some literature connections between offshoring and TCE are presented and, naturally TCE is presented in highlights for understanding these connections. Ending this section, some different arguments based on newer researches are presented by some authors presenting another perspective as the main reason. After this theoretical approach, a scenario analysis and some discussions are presented based on all possible interactions among firm from developed (DC and emerging economies (EE and examples of international corporations are presented to clarify and improve the understanding of our research questions and to build new contributions to international business theory.

  2. Offshore Wind Energy Market Overview (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Baring-Gould, I.

    2013-07-01

    This presentation describes the current international market conditions regarding offshore wind, including the breakdown of installation costs, how to reduce costs, and the physical siting considerations considered when planning offshore wind construction. The presentation offers several examples of international existing and planned offshore wind farm sites and compares existing international offshore resources with U.S. resources. The presentation covers future offshore wind trends and cites some challenges that the United States must overcome before it will be able to fully develop offshore wind sites.

  3. Offshore investments: Denmark shows the way

    International Nuclear Information System (INIS)

    This article presents an overview of the use of wind power in Denmark and discusses the tremendous growth in the manufacture of wind turbines since 1981 with Denmark holding some 60% of the worlds' wind turbine market. The move to offshore wind farms is explained in terms of the shortage of land and the quality of the offshore wind, and details of the Tuno Knob pilot offshore wind farm are given. Offshore wind power in Europe, the challenges to offshore operations, the costs involved, environmental effects of the use of offshore wind, and the growing amount of wind power capacity are discussed

  4. Wind and Wave Disturbances Compensation to Floating Offshore Wind Turbine Using Improved Individual Pitch Control Based on Fuzzy Control Strategy

    OpenAIRE

    Feng Yang; Qing-wang Song; Lei Wang; Shan Zuo; Sheng-shan Li

    2014-01-01

    Due to the rich and high quality of offshore wind resources, floating offshore wind turbine (FOWT) arouses the attentions of many researchers. But on a floating platform, the wave and wind induced loads can significantly affect power regulation and vibration of the structure. Therefore, reducing these loads becomes a challenging part of the design of the floating system. To better alleviate these fatigue loads, a control system making compensations to these disturbances is proposed. In this p...

  5. 直升机海上运行平台起降阶段风险模型构建的应用研究%Applied study on the construction of risk model of helicopters’ takeoffs and landings on offshore operating platform

    Institute of Scientific and Technical Information of China (English)

    孙佳; 吴乔; 盖文妹; 隋佳

    2015-01-01

    Taking helicopters ’ takeoffs and landings on offshore operating platform as the research object , and combining the modeling principles of SHELL model , TEM model and HFACS model , a three -dimensional risk analysis model is constructed.Taking people , software, hardware and environment as the key factors , threats, errors and unsafe state as the key points , event, premise, monitoring and organizational level as the key links, the risk of takeoffs and landings is analyzed thoroughly and systematically , a summary of 29, 14, 12, 6 and 4 risk factors indicators are made on the individual , team, enforcement department , supervision de-partment and the company respectively.Based on a sample application , the specific weight and quantitative analysis of 29 indicators on the individual level is identified by means of Analytic Hierarchy Process ( AHP).With the relationship between the other four aspects and the individual aspect , the qualitative analysis of the risk factors on team , enforcement department , supervision department and the corporate level is made , and appropriate control measures are developed.The results show that the proposed model and method of risk anal-ysis is feasible and effective.%以直升机海上运行平台起降为研究对象,结合SHELL模型、TEM模型、HFACS模型的建模原理,构建了三维立体的风险分析模型,以人、软件、硬件、环境为关键因素,以威胁、差错、不安全状态为关键点,以事件、前提、监督、组织层面为关键环节,对起降风险进行全面立体系统地分析,汇总了个人、班组、执管部门、监察部门、公司五大层面29个、14个、12个、6个和4个风险因素指标。基于实例应用,运用层次分析法确定了29个个人因素指标的具体权重并进行了定量分析,通过其他四大方面与个人方面的关系,分别对班组、执管部门、监察部门、公司层面的风险因素进行定性分析,并制

  6. Experimental and Theoretical Analysis of a Combined Floating Wave and Wind Energy Conversion Platform

    DEFF Research Database (Denmark)

    Yde, Anders; Pedersen, Mads Mølgaard; Bellew, Sarah Bellew;

    novel, floating, wave- and wind-energy hybrid device. To test the technology they have scaled the design to P37, a 37 m wide test platform that has been undergoing offshore testing for four complete test phases (totaling more than 2 years). The test platform provides electricity to the grid from both...

  7. 33 CFR 149.535 - What are the requirements for rotating beacons on platforms?

    Science.gov (United States)

    2010-07-01

    ... rotating beacons on platforms? 149.535 Section 149.535 Navigation and Navigable Waters COAST GUARD... EQUIPMENT Aids to Navigation Lights on Platforms § 149.535 What are the requirements for rotating beacons on... rotating beacon that distinguishes the deepwater port from other surrounding offshore structures....

  8. Numerical Study of Piping Limits for Suction Installation of Offshore Skirted Foundations an Anchors in Layered Sand

    DEFF Research Database (Denmark)

    Ibsen, Lars Bo; Thilsted, C. L.

    2010-01-01

    Skirted foundations and anchors have proved to be competitive solutions for various types of fixed offshore platforms, subsea systems and an attractive foundation alternative for offshore wind turbines. One main design challenge for skirted structures in sand is to penetrate the skirted deep enough...... evaluation of suction thresholds against piping. These closed form solutions are compared with large scale tests, performed in a natural seabed at a test site in Frederikshavn, Denmark. These solutions are also valid for penetration studies of other offshore skirted foundations and anchors using suction...

  9. Aeroelastic Instabilities of Large Offshore and Onshore Wind Turbines

    International Nuclear Information System (INIS)

    Offshore turbines are gaining attention as means to capture the immense and relatively calm wind resources available over deep waters. This paper examines the aeroelastic stability of a three-bladed 5MW conceptual wind turbine mounted atop a floating barge with catenary moorings. The barge platform was chosen from the possible floating platform concepts, because it is simple in design and easy to deploy. Aeroelastic instabilities are distinct from resonances and vibrations and are potentially more destructive. Future turbine designs will likely be stability-driven in contrast to the current loads-driven designs. Reasons include more flexible designs, especially the torsionally-flexible rotor blades, material and geometric couplings associated with smart structures, and hydrodynamic interactions brought on by the ocean currents and surface waves. Following a brief description of the stability concept and stability analysis approach, this paper presents results for both onshore and offshore configurations over a range of operating conditions. Results show that, unless special attention is paid, parked (idling) conditions can lead to instabilities involving side-to-side motion of the tower, edgewise motion of the rotor blades, and yawing of the platform

  10. About offshore resource assessment with floating lidars with special respect to turbulence and extreme events

    International Nuclear Information System (INIS)

    Offshore resource assessment with lidars on floating platforms is a flexible and particularly cost-effective alternative to the conventional meteorological mast solution, that is considered as onshore state-of-the-art transferred to offshore sites, and may enable better and more complete wind resource assessments for the growing offshore wind sector. Wind lidar technology, and remote sensing in general, has already been proven to be a very promising technology for resource assessment and power performance testing onshore. For offshore applications and on floating platforms in particular, the motions from the floating base have to be considered in addition, affecting the wind measurements significantly and causing systematic measurement errors. We have studied the motions and the corresponding influences on lidar measurements generated by different possible offshore platforms – vessels or buoys – both in detailed simulations as well as first validation experiments. In addition to this, we have developed motion compensation algorithms that allow to correct the affected measurements and retrieve the undisturbed wind data. The motions considered and studied comprise rotations as well as translations in all six degrees of freedom. For the evaluation of the motion-affected and corrected wind data in this paper, special attention is paid to the measurement of turbulence as well as extreme wind events. The research question to be answered is if a lidar device placed on a floating platform is capable of measuring more or less the same statistics of extreme wind events as a fixed lidar device. Quantities to be investigated are: the turbulence intensity as well as the statistics of maximum wind speed values within a 10-min period, but also wind speed increments on different time scales. At this, obviously two issues are to be discussed – the influence of the lidar measurement principle on the recording of extreme wind events, and the additional impact of the

  11. Reverse logistic applied to offshore operations; A logistica reversa aplicada as operacoes offshore

    Energy Technology Data Exchange (ETDEWEB)

    Castro Neto, Jorge Raimundo de Almeida [Universidade Salvador (UNIFACS), BA (Brazil)

    2010-07-01

    Mass production development has brought as consequence the necessity of more complexes distributions ways to come to multiple final consumers a big products quantity. Additionally, these same products has support necessities as well, substitution or product residue during or on the end of yours life. From the initial necessity, have the logistic concept and from the additional necessity, have the reverse logistic concept. Oil offshore operations are applying the reverse logistic concept through the residues returning by support vessels that attends Oil platforms and workers through helicopters to work turns. However, the relative cost to this residue destination is lower in comparative to the operation total costs, decreasing the interest by remanufacture and reapplication during planning stage. Adding to this reason, the fact that this kind of operation occurs during a shorts time periods. (author)

  12. Managing Hidden Costs of Offshoring

    DEFF Research Database (Denmark)

    Larsen, Marcus M.; Pedersen, Torben

    2014-01-01

    This chapter investigates the concept of the ‘hidden costs’ of offshoring, i.e. unexpected offshoring costs exceeding the initially expected costs. Due to the highly undefined nature of these costs, we position our analysis towards the strategic responses of firms’ realisation of hidden costs. In...... learning-by-doing process, where hidden costs motivate firms and their employees to search for new and better knowledge on how to successfully manage the organisation. We illustrate this thesis based on the case of the LEGO Group....... this regard, we argue that a major response to the hidden costs of offshoring is the identification and utilisation of strategic mechanisms in the organisational design to eventually achieving system integration in a globally dispersed and disaggregated organisation. This is heavily moderated by a...

  13. Offshore Wind Energy in Denmark

    DEFF Research Database (Denmark)

    Möller, Bernd; Hong, Lixuan; Hvelplund, Frede;

    Offshore wind energy has developed in terms of turbine and project size, and currently undergoes a significant up-scaling to turbines and parks at greater distance to shore and deeper waters. Expectations to the positive effect of economies of scale on power production costs, however, have not...... can be explained by deeper water, higher distance to shore, bottlenecks in supply or higher raw material costs. This paper will attempt to explain the paradox of increasing costs of offshore wind energy despite larger scales and technological development by looking at other factors: The limited...... availability of locations, driven by accelerating requirements of environmental concern, park size and public acceptance, is one important driver. Mounting risk of mega-projects and the infinite demand for renewable energy is another likely cause. The present paper addresses the scale of offshore wind parks...

  14. Observations of offshore bar decay

    DEFF Research Database (Denmark)

    Aagaard, Troels; Kroon, Aart; Greenwood, Brian; Hughes, Michael G

    2010-01-01

    the upper shoreface, and finally a stage of decaying bar form through loss of sediment volume at the outer boundary of the upper shoreface. The phenomenon has been previously documented in the Netherlands, the USA, the Canadian Great Lakes, and in New Zealand, but our present understanding of the...... morphodynamic processes and sediment transport pathways involved in bar decay is limited. In this paper, long-term, net offshore bar migration is investigated at Vejers Beach, located on the North Sea coast of Denmark where offshore bar migration rates are of the order of 45–55 m a-1. A wave height...... transformation model confirmed that the decay of the outer bar results in increased wave heights and undertow speeds at the more landward bar potentially causing this bar to speed up its offshore migration. The causes for outer bar decay were investigated through field measurements of sediment transport at the...

  15. Major hazards onshore and offshore

    International Nuclear Information System (INIS)

    This symposium continues the tradition of bringing together papers on a topic of current interest and importance in terms of process safety - in this case, Major Hazards Onshore and Offshore. Lord Cullen in his report on the Piper Alpha disaster has, in effect, suggested that the experience gained in the control of major hazards onshore during the 1980s should be applied to improve safety offshore during the 1990s. This major three-day symposium reviews what has been learned so far with regard to major hazards and considers its present and future applications both onshore and offshore. The topics covered in the programme are wide ranging and deal with all aspects of legislation, the application of regulations, techniques for evaluating hazards and prescribing safety measures in design, construction and operation, the importance of the human factors, and recent technical developments in protective measures, relief venting and predicting the consequences of fires and explosions. (author)

  16. OFFSHORE OIL OUTPUT MORE THAN SCHEDULED

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    @@ China Offshore Oil Nan Hai East Corp (CONHE) is one of four subsidiaries of the China National Offshore Oil Corp.The first-quarter output was an encouraging 220 000 tons more than the planned goal for that period.

  17. Offshore Energy Knowledge Exchange Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2012-04-12

    A report detailing the presentations and topics discussed at the Offshore Energy Knowledge Exchange Workshop, an event designed to bring together offshore energy industry representatives to share information, best practices, and lessons learned.

  18. Seafloor character--Offshore of Pacifica, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents the seafloor-character map Offshore of Pacifica, California. The raster data file is included in "SFC_OffshorePacifica.zip," which is...

  19. Seafloor character--Offshore of Bolinas, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents the seafloor-character map Offshore of Bolinas, California (raster data file is included in "SeafloorCharacter_OffshoreBolinas.zip,"...

  20. Run-up on Offshore Windturbine Foundations

    DEFF Research Database (Denmark)

    De Vos, Leen; Larsen, Brian Juul; Frigaard, Peter

    For the present report a testprogramme has been performed to determine the run-up on offshore windturbine foundations.......For the present report a testprogramme has been performed to determine the run-up on offshore windturbine foundations....