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

    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...... nutrient input derived from the uplifted mainland, possibly enhanced by deteriorated climatic conditions and rapid sea-level fluctuations promoting platform drowning....

  2. INTERNAL CORROSION MONITORING IN OFFSHORE PLATFORMS

    Directory of Open Access Journals (Sweden)

    Fernando Benedicto Mainier

    2008-08-01

    Full Text Available Corrosion is one of the main causes of failures in equipment and pipes in off-shore oil production. These failures harm the process, slow the production operational chronogram, and generate high costs of maintenance, beyond generation risks to health and environment. Due to the fact that most of the equipment, tubing and pipes of production platforms are made of steel, in general, carbon steel, the industry of petroleum exploration will always coexist with the corrosive process. The use of a Corrosion Monitoring Plan to diagnostic, to control and to manage the evolution of corrosives process in off-shore oil platforms is the strategy proposed in this work to prevent problems as described above. The Internal Corrosion Monitoring Plan (ICMP, is based on lab analysis of the corrosively of fluids and residues showed periodically in off-shore operational platform; in the corrosion rate determined by the periodic use of test bodies installed inside off-shore oil platforms tubing systems, as mass loss coupons and electric resistance probes; and finally, in periodic operational data collect obtained during the off-shore oil platform systems operation. The ICMP will direct and manage the actions to be taken in case of aggravation of a corrosive process, quickly identifying to the corrosive mechanisms and its localization in the various systems of the platforms. The optimized use of the corrosion inhibitor and other chemical products are one of the main advantages of the ICMP.

  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. 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...

  5. Waste heat recovery technologies for offshore platforms

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Benato, Alberto; Scolari, E.;

    2014-01-01

    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-weight power...... 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 organic...

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

    Energy Technology Data Exchange (ETDEWEB)

    Coimbra, Melayne M. E-mail: melayne@onda.com.br; Barbosa, Catia F.; Soares-Gomes, Abilio; Silva, Cleverson G.; Rios-Netto, Aristoteles; Mueller, Ken A

    2000-10-01

    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.

  7. 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.

  8. 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.

  9. Design of Access Platforms for Offshore Windturbines

    DEFF Research Database (Denmark)

    Andersen, Thomas Lykke; Frigaard, Peter

    2007-01-01

    A large number of offshore windmill farms have been constructed, more are currently under construction and much more are planned. Therefore, a lot of research is going on within the design of offshore windmills and their foundation....

  10. 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...

  11. 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.

  12. Load Identification of Offshore Platform for Fatigue Life Estimation

    DEFF Research Database (Denmark)

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

    2014-01-01

    of the structure and the discrete Kalman filter which recursively estimates unknown states of the system in real time. As a test-case, the algorithm is designed to estimate the equivalent total loading forces of the structure. The loads are estimated from noised displacement measurements of a single location......The lifetime of an offshore platform is typically governed by accumulated fatigue damage. Thus, the load time history is an essential parameter for prediction of the lifetime of the structure and its components. Consequently, monitoring of structural loads is of special importance in relation to re......-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...

  13. 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.

  14. 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)

  15. 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.

  16. 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.

  17. 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......, sell or store energy attending to the price in the electricity market....

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

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van

    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...... of oil and gas facilities, (ii) the means to reduce their performance losses, and (iii) the systematic design of future plants. This work builds upon a combination of modelling tools, performance evaluation methods and multi-objective optimisation routines to reproduce the behaviour of five offshore...... 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...

  19. 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....

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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

  8. Calibration of LRFD Format for Steel Jacket Offshore Platforms in China Offshore Area (1):Statistical Parameters of Loads and Resistances

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The statistical characteristics and parameters of loads and resistances are systematically studied for the development of probabilistic limit state design method for steel jacket offshore platforms in the China offshore area. The mean value, standard variance and distribution pattern of resistances and loads in different base periods are presented. The statistical parameters of structural member resistance, self-weight, deck live load, and environmental loads such as wind, wave, current and ice, which are drawn on a large amount of observation data of offshore environmental factors, and the design data of platforms in China Bohai Sea form the data set, providing a necessary basis for the calibration of load and resistance factors to realize the reliability-based design of jacket platform structures.

  9. 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)

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

    Science.gov (United States)

    Roni Sahroni, Taufik

    2015-01-01

    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.

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

    Science.gov (United States)

    Roni Sahroni, Taufik

    2015-01-01

    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. PMID:26550605

  12. 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.

    The safety of an offshore platform depends on the predicting environmental phenomena such as wind, current, wave, seismic loadings and accurate calculation of responses of the structure to these loads and determining the strength of the structure...

  13. 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.

  14. 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.

  15. 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.

  16. Design of self-contained sensor for monitoring of deep-sea offshore platform

    Science.gov (United States)

    Song, Yang; Yu, Yan; Zhang, Chunwei; Dong, Weijie; Ou, Jinping

    2013-04-01

    Offshore platform, which is the base of the production and living in the sea, is the most important infrastructure for developing oil and gas resources. At present, there are almost 6500 offshore platforms servicing in the 53 countries' sea areas around the world, creating great wealth for the world. In general, offshore platforms may work for 20 years, however, offshore platforms are expensive, complex, bulky, and so many of them are on extended active duty. Because of offshore platforms servicing in the harsh marine environment for a long time, the marine environment have a great impact on the offshore platforms. Besides, with the impact and erosion of seawater, and material aging, the offshore platform is possible to be in unexpected situations when a badly sudden situation happens. Therefore, it is of great significance to monitor the marine environment and offshore platforms. The self-contained sensor for deep-sea offshore platform with its unique design, can not only effectively extend the working time of the sensor with the capability of converting vibration energy to electrical energy, but also simultaneously collect the data of acceleration, inclination, temperature and humidity of the deep sea, so that we can achieve the purpose of monitoring offshore platforms through analyzing the collected data. The self-contained sensor for monitoring of deep-sea offshore platform includes sensing unit, data collecting and storage unit, the energy supply unit. The sensing unit with multi-variables, consists of an accelerometer LIS344ALH, an inclinometer SCA103T and a temperature and humidity sensor SHT11; the data collecting and storage unit includes the MSP430 low-power MCU, large capacity memory, clock circuit and the communication interface, the communication interface includes USB interface, serial ports and wireless interface; in addition, the energy supply unit, converting vibration to electrical energy to power the overall system, includes the electromagnetic

  17. 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)

  18. 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.

  19. 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

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

    OpenAIRE

    Lei Wang; Shan Zuo; Y. D. Song; 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...

  1. 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...

  2. 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.

  3. 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.

  4. Nonlinear ultimate strength analysis of fixed offshore platforms for earthquake environments

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S.S. [Hudson Engineering Corp., Houston, TX (United States)

    1995-12-01

    The design of an offshore platform usually requires the use of ASME B31.3 and API (American Petroleum Institute) RP 2A design codes. ASME B31.3 addresses the design of pressure piping systems for offshore facilities while API RP 2A ``Recommended Practice for Planning, Designing and Constructing Fixed Offshore Platforms`` (WSD or LRFD) addresses the structural design. This paper first identifies the difference between the ASME B31.3 and API RP 2A on the earthquake load requirements. Second, the paper presents a nonlinear static pushover analysis of a typical fixed offshore platform subject to a ductility level earthquake in 394 ft (120 m) of water depth. The analysis uses a three-dimensional structural model consisting of STRUT, BEAM-COLUMN and LINEAR BEAM elements to determine the structural response while properly accounting for structure-pile-soil interaction effort. Finally, the status of current on-going efforts to implement the API RP 2A code (LRFD version) to the ISO code (International Organization for Standardization), particularly on the earthquake resistant design aspect of fixed offshore the platforms, is briefly reported.

  5. 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.

  6. Vertical Wave Impacts on Offshore Wind Turbine Inspection Platforms

    DEFF Research Database (Denmark)

    Bredmose, Henrik; Jacobsen, Niels Gjøl

    2011-01-01

    on a horizontal inspection platform is computed for five different platform levels. The computational results show details of monopile impact such as slamming pressures from the overturning wave front and the formation of run-up flow. The results show that vertical platform impacts can occur at 20 m water depth......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....... The dependence of the vertical platform load to the platform level is discussed. Attention is given to the significant downward force that occur after the upward force associated with the vertical impact. The effect of the numerical resolution on the results is assessed. The position of wave overturning is found...

  7. 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.

  8. 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.

  9. 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.

  10. 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...

  11. Finite Element Analysis of Deformed Legs of Offshore Platform Structures

    Institute of Scientific and Technical Information of China (English)

    柳春图; 秦太验; 段梦兰

    2002-01-01

    The element stiffness matrix of the equivalent beam or pipe element of the deformed leg of the platform is derived bythe finite element method. The stresses and displacements of some damaged components are calculated, and the numeri-cal solutions agree well with those obtained by the fine mesh finite element method. Finally, as an application of thismethod, the stresses of some platform structures are calculated and analyzed.

  12. 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

  13. 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.

  14. Development of Jacket Platform Tsunami Risk Rating System in Waters Offshore North Borneo

    Institute of Scientific and Technical Information of China (English)

    HE Lee; MS Liew; NH Mardi; KL Na; Iraj Toloue; SK Wong

    2016-01-01

    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 9.3Mw 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.

  15. 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

  16. 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 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 pile. Hereafter, the run-up generated impact forces were measured on two types of grates and a solid plate. The pressure distribution was also measured for the solid plate. In addition to this the wave generated backfilling of an initial scour hole and the strength of the backfilling soil was studied...

  17. Requalification of offshore structures. Reliability analysis of platform

    Energy Technology Data Exchange (ETDEWEB)

    Bloch, A.; Dalsgaard Soerensen, J. [Aalborg Univ. (Denmark)

    1999-03-01

    A preliminary reliability analysis has been performed for an example platform. In order to model the structural response such that it is possible to calculate reliability indices, approximate quadratic response surfaces have been determined for cross-sectional forces. Based on a deterministic, code-based analysis the elements and joints which can be expected to be the most critical are selected and response surfaces are established for the cross-sectional forces in those. A stochastic model is established for the uncertain variables. The reliability analysis shows that with this stochastic model the smallest reliability indices for elements are about 3.9. The reliability index for collapse (pushover) is estimated to 6.7 and the reliability index for fatigue failure using a crude model is for the expected most critical detail estimated to 3.2, corresponding to the accumulated damage during the design lifetime of the platform. These reliability indices are considered to be reasonable compared with values recommended by e.g. ISO. The most important stochastic variables are found to be the wave height and the drag coefficient (including the model uncertainty related to estimation of wave forces on the platform). (au)

  18. 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.

  19. Bird interactions with offshore oil and gas platforms: review of impacts and monitoring techniques.

    Science.gov (United States)

    Ronconi, Robert A; Allard, Karel A; Taylor, Philip D

    2015-01-01

    Thousands of oil and gas platforms are currently operating in offshore waters globally, and this industry is expected to expand in coming decades. Although the potential environmental impacts of offshore oil and gas activities are widely recognized, there is limited understanding of their impacts on migratory and resident birds. A literature review identified 24 studies and reports of bird-platform interactions, most being qualitative and half having been peer-reviewed. The most frequently observed effect, for seabirds and landbirds, is attraction and sometimes collisions associated with lights and flares; episodic events have caused the deaths of hundreds or even thousands of birds. Though typically unpredictable, anecdotally, it is known that poor weather, such as fog, precipitation and low cloud cover, can exacerbate the effect of nocturnal attraction to lights, especially when coincidental with bird migrations. Other effects include provision of foraging and roosting opportunities, increased exposure to oil and hazardous environments, increased exposure to predators, or repulsion from feeding sites. Current approaches to monitoring birds at offshore platforms have focused on observer-based methods which can offer species-level bird identification, quantify seasonal patterns of relative abundance and distribution, and document avian mortality events and underlying factors. Observer-based monitoring is time-intensive, limited in spatial and temporal coverage, and suffers without clear protocols and when not conducted by trained, independent observers. These difficulties are exacerbated because deleterious bird-platform interaction is episodic and likely requires the coincidence of multiple factors (e.g., darkness, cloud, fog, rain conditions, occurrence of birds in vicinity). Collectively, these considerations suggest a need to implement supplemental systems for monitoring bird activities around offshore platforms. Instrument-based approaches, such as radar

  20. Damage Detection Methods for Offshore Platforms Based on Wavelet Packet Transform

    Institute of Scientific and Technical Information of China (English)

    LI Dong-sheng; ZHANG Zhao-de; WANG De-yu

    2005-01-01

    The wavelet packet transform is used for the damage detection of offshore platforms. When some damage occurs, the dynamic response parameters of the structure will shift subtly. However, in some cases, the dynamic parameters, such as dynamic response, are not sensitive, and it is very difficult to predict the existence of damage. The present paper aims to describe how to find small damage by the use of wavelet packet transform. As the wavelet packet transform can be used to quickly find the singularity of the response signal on different scales, the acceleration signal of a damaged offshore platform in the time domain is transformed through the wavelet packet. Experimental results show that the Daubechies 4 wavelet transform can be used to detect damage.

  1. 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.

  2. 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.

  3. 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....... They include: (i) the installation of multiple pressure levels in production manifolds, (ii) the implementation of multiphaseexpanders, (iii) the promotion of energy and process integration, (iv) the limitation of gas recirculation around the compressors, (v) the exploitation of low-temperature heat from...... the gas cooling steps, (vi) the downsizing or replacement of the existing gas turbines, and (vii) the use of the waste heat from the powerplant. The present study builds on four actual cases located in the North and Norwegian Seas, which differ by the type of oil processed, operating conditions...

  4. An hybrid ensemble based approach for process parameter estimation in offshore oil platforms

    OpenAIRE

    Baraldi, Piero; Zio, Enrico; Mangili, Francesca; Gola, Giulio; Nystad, Bent H.

    2011-01-01

    International audience The valve flow coefficient is commonly used as a parameter to assess the erosion state of choke valves in offshore oil platforms. In particular, the difference between the theoretical value of the valve flow coefficient and its actual value calculated during operation is retained as the valve health indicator. The actual valve flow coefficient is analytically calculated from the oil, water and gas mass flow rates. These quantities, which are allocated on a daily basi...

  5. 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...

  6. Application of intelligent materials to enhance SPAR floating offshore platforms stability

    OpenAIRE

    Rius Planas, Maria

    2010-01-01

    The following thesis presents a stability study of a floating wind turbine platform, composed by two concentric cylinders, for offshore application. The theoretical bases of the linear theory and the derivation of the equation of motion are introduced in the second chapter. The following chapter resumes the results of the research of the optimum dimensions as well as the results of the simulation of the equation of motion of the spar with and without inertial plate. The addition of the ine...

  7. 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...

  8. 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.

  9. Modal Strain Energy Based Structural Damage Localization for Offshore Platform using Simulated and Measured Data

    Institute of Scientific and Technical Information of China (English)

    WANG Shuqing; LIU Fushun; ZHANG Min

    2014-01-01

    Modal strain energy based methods for damage detection have received much attention. However, most of published articles use numerical methods and some studies conduct modal tests with simple 1D or 2D structures to verify the damage detection algorithms. Only a few studies utilize modal testing data from 3D frame structures. Few studies conduct performance comparisons between two different modal strain energy based methods. The objective of this paper is to investigate and compare the effectiveness of a traditional modal strain energy method (Stubbs index) and a recently developed modal strain energy decomposition (MSED) method for damage localization, for such a purpose both simulated and measured data from an offshore platform model being used. Particularly, the mode shapes used in the damage localization are identified and synthesized from only two measurements of one damage scenario because of the limited number of sensors. The two methods were first briefly reviewed. Next, using a 3D offshore platform model, the damage detection algorithms were implemented with different levels of damage severities for both single damage and multiple damage cases. Finally, a physical model of an offshore steel platform was constructed for modal testing and for validat-ing the applicability. Results indicate that the MSED method outperforms the Stubbs index method for structural damage detection.

  10. 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.

  11. Offshore platform of reinforced concrete and a method of producing same

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, O.

    1989-07-11

    This patent describes an offshore platform structure of reinforced concrete for standing on the bottom of a sea as a consequence of its own weight. The structure includes a base supporting a tower for a platform deck. The lower part of the tower includes a cylindrical portion extending downwardly towards and through the base and providing a skirt. A frusto-conical annular wall extends coaxially with the tower between the tower and the top of the base to provide an annular chamber with a triangular cross section. Also, a method of building a platform structure includes building the lower portion of the structure in a dry dock and floating the lower portion out into deeper water for continuing a casting operation for the remainder of the platform structure.

  12. 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.

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    Shan Zuo

    2013-01-01

    Full Text Available 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.

  15. 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.

  16. Experimental study of tsunami-type waves impact on soil at foundations of offshore gravity platforms

    Directory of Open Access Journals (Sweden)

    N.D. Belyaev

    2014-10-01

    Full Text Available Scouring, caused by waves, currents and races of ship propellers, has been a subject of theoretical investigations, physical modeling in hydraulic laboratories and full-scale experiments in several countries. The results reported on these tests usually recommend formulas and diagrams to determine water velocities that can be used to estimate the risk of scouring and design the required protection measures. The results of the physical modeling of interaction of long tsunami-type waves with an offshore gravity platform are presented in this article. The reaction of seabed soil to wave impact at the platform foundation has been studied and the obtained results have been analyzed. Conclusions about changes in the seabed profile, density of the top layers of the seabed soil and their influence on the platform stability have been made.

  17. 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.

  18. 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.

  19. Vertical Structure of the Wind Speed Profile at the North Sea Offshore Measurement Platform FINO1

    Science.gov (United States)

    Kettle, A. J.

    2013-12-01

    The vertical wind speed profile in the lowest 100m of the marine atmospheric boundary layer has been characterized from data collected at the FINO1 offshore research platform in the German North Sea sector for 2005. Located in 30m of water, the platform has a dense vertical array of meteorological instrumentation to measure wind speed, air temperature, relative humidity, and atmospheric turbulence characteristics. Along measurements of the ocean temperature and surface waves, the platform is well-equipped to characterize wind properties in the near-surface boundary layer. Preliminary analysis reveals a high incidence of vertical wind speed profiles that deviate significantly from Monin-Obukhov similarity theory with wind speed inflections that suggest decoupled layers near the surface. The presentation shows how the properties of the vertical wind speed profile change mainly depending on the wind speed, wind direction, and time of year. The results are significant because there are few reports of inflections in the vertical wind speed profile over the ocean and there is an a priori assumption that the vertical wind speed profile varies smoothly according to similarity theory. There are possible consequences for the wind energy development in terms of understanding the forces acting on offshore wind turbines whose rotors sweep across heights 150-200m above the sea surface.

  20. 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

  1. 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...

  2. Modal Identification of Offshore Platforms Using Statistical Method Based on ERA

    Institute of Scientific and Technical Information of China (English)

    WANG Shu-qing; LI Hua-jun; T.Takayama

    2005-01-01

    Identification of modal parameters of a linear structure with output-only measurements has received much attention over the past decades. In the paper, the Natural Excitation Technique (NExT) is used for acquisition of the impulse signals from the structural responses. Then Eigensystem Realization Algorithm (ERA) is utilized for modal identification.(SAMFM), is developed to distinguish the true modes from noise modes, and to improve the precision of the identified modal frequencies of the structure. An offshore platform is modeled with the finite element method. The theoretical modal parameters are obtained for a comparison with the identified values. The dynamic responses of the platform under random wave loading are computed for providing the output signals used for identification with ERA. Results of simulation demonstrate that the proposed method can determine the system modal frequency with high precision.

  3. 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.

  4. Vibration Control of Multi-Tuned Mass Dampers for An Offshore Oil Platform

    Institute of Scientific and Technical Information of China (English)

    陆建辉; 梅宁; 李宇生; 石湘

    2002-01-01

    The purpose of this study is to investigate the effectiveness of multi-tuned mass dampers (MTMD) on mitigating vi-bration of an offshore oil platform subjected to ocean wave loading. An optimal design method is used to determine the op-timal damper parameters under ocean wave loading. The force on the structure is determined by use of the linearizedMorison equation. Investigation on the deck motion with and without MTMD on the structure is made under design condi-tions. The results show that MTMD with the optimized parameters suppress the response of each structural mode. Thesensitivity of optimum values of MTMD to characteristic wave parameters is also analyzed. It is indicated that a singleTMD on the deck of a platform can have the best performance, and the small the damping value of TMD, the better thevibration control.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. A Single Mooring System with Sag-Extensibility and Flexural Rigidity Applied to Offshore Platform

    Institute of Scientific and Technical Information of China (English)

    M.-C.Tsai; Hsien Hua Lee; Jun-Yen Lee; S.-S.Hsiao

    2013-01-01

    Floating platform system has been extensively used in ocean exploitation,particularly for a tension-leg platform (TLP) system in deep water.Most of the TLPs are multi-mooring systems,where multi-joints are connected to the tension-legs so that the platform is not allowed to twist freely and may subject to enormous force induced by large incident waves in the weak-direction of the structure.This study aims to exploit a single moored offshore platform system that may attract less force and can be operated with less effort.In our analysis,in addition to mechanical properties of the tether,two important properties are also taken into consideration for the single mooring tether with expanded cross sectional dimension and utilization of stronger material,namely,the sag-extensibility and the flexural rigidity.Finally,the dynamic structural behavior produced by the mechanical effects on the new system is investigated and compared with that of traditional design while the wave-structure interactions of large body are also accounted for.Our study finds that the neglect of sag-extensibility or the flexural rigidity of large,strong mooring cable may result in a conservative but not necessarily safe design.

  12. Control of Offshore Passive Platform System Voltage and Frequency through Control of Onshore Back-to-Back Voltage Source Converters

    OpenAIRE

    Høvik, Kristin Malene

    2011-01-01

    This thesis work shows implementation and testing of existing control strategies in a novel offshore passive platform configuration. Control of the platform voltage and frequency is done through control of a shore-based B2B-VSC configuration, when the frequency on shore differs from the frequency on the platform. An 80 km HVAC-cable and transformers separates the shore-based B2B-VSCs from the platform installation. The system is modeled and simulated in MATLAB® Simulink™ SimPowerSys...

  13. 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...

  14. Lectotype Optimization of Offshore Platforms by Use of Three-Scale Fuzzy Analytical Hierarchy Process

    Institute of Scientific and Technical Information of China (English)

    王立成; 宋玉普; 封盛

    2001-01-01

    A Three-Scale Fuzzy Analytical Hierarchy Process (T-FAHP) is proposed by introducing the Three-Scale Analyti- cal Hierarchy Process (T-AHP) and the trapezoid fuzzy number. A multi-objective optimization model based on the T-FAHP is presented subsequently, in which many factors influencing the lectotype of offshore platform are taken intoaccount synthetically, such as the original investment, the maintenance cost, the ability of resisting fatigue and corrosion,the construction period, the threat to the environment, and so on. With this method, the experts can give the relatively precise ranking weight of each index and at the same time the requirement of consistence checking can be met. The result of a calculation example shows that the T-FAHP is practical.

  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. 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

  17. 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)

  18. 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

    The oil and gas processing plants of four North Sea offshore platforms are analysed and compared, based on the exergy analysis method. Sources of exergy destruction and losses are identified and the findings for the different platforms are compared. Different platforms have different working...... conditions, which implies that some platforms need less heat and power than others. Reservoir properties and composition vary over the lifetime of an oil field, and therefore maintaining a high efficiency of the processing plant is challenging. The results of the analysis show that 27%-57% of the exergy...... 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...

  19. Semi-Active Control of Wave-Induced Vibration for Offshore Platforms by Use of MR Damper

    Institute of Scientific and Technical Information of China (English)

    李华军; 王树青; 嵇春艳

    2002-01-01

    The objective of the present research is to examine the effectiveness of the lateral vibration control of wave-excited re-sponse of offshore platforms with magneto-rheological (MR) damper. In this study, the offshore platform is simplified to bewave force is determined with a white noise via a designed filter. A semi-active control method based on optimal control the-ory is proposed considering that the yield stress of the MR damper can be varied continuously within a certain range. The dy-namics of SDOF structure coupled with the MR damper is investigated. Numerical simulation demonstrates that the MRdamper with this control strategy can significantly reduce the maximum responses and the root-mean-square (RMS) values.

  20. 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.

  1. Flexible dynamic analysis of an offshore wind turbine installed on a floating spar platform

    Directory of Open Access Journals (Sweden)

    Xiangqian Zhu

    2016-05-01

    Full Text Available Flexible dynamic analysis is a critical process in designing offshore wind turbines that are composed of several huge components. This process was implemented with a hybrid method of finite element multibody system using commercial software in this article. Based on this method, the tower and blades were modeled as flexible components using three-dimensional solid elements. The effect of flexible deformation of the tower and blades on the global motions of the floating wind turbine was investigated by comparing the simulation results from the flexible body modeling with those from the rigid body modeling. The tower, blades, and spar platform were divided into sections according to the geometry configuration of the 5-MW OC3-Hywind floating wind turbine. The time- and position-dependent loads, coming from the wind, wave, and mooring system, were expressed approximately with respect to the divided sections. The relationships between the global motions and the external loads were studied, which indicated that the wind loads had dominant influences on the translational motions and the rotational motions were mainly generated by the propagating waves.

  2. 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.

  3. 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.

  4. 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...

  5. 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....

  6. Design Loads on Platforms on Offshore wind Turbine Foundations with Respect to Vertical Wave Run-up

    DEFF Research Database (Denmark)

    Damsgaard, Mathilde L.; Gravesen, Helge; Andersen, Thomas Lykke

    2007-01-01

    Experiences have shown that the vertical run-up generated by waves meeting the offshore wind turbine foundations, can result in rather vigorous loads on appurtenances and platform structures. This study aims to provide a qualitative method of determining run-up height and the following loads...... depending on the wave parameters in the area in question. This is approached by a three step calculation routine supported by model tests. Supplementary tests have been made to determine the reduction in loads, when grated platforms are used in preference to a closed surface. This leads to an appreciable...

  7. Whole-body concentrations of elements in three fish species from offshore oil platforms and natural areas in the Southern California Bight, USA

    Science.gov (United States)

    Love, Milton S.; Saiki, Michael K.; May, Thomas W.; Yee, Julie L.

    2013-01-01

    There is concern that offshore oil platforms off Southern California may be contributing to environmental contaminants accumulated by marine fishes. To examine this possibility, 18 kelp bass (Paralabrax clathratus Girard, 1854), 80 kelp rockfish (Sebastes atrovirens Jordan and Gilbert, 1880), and 98 Pacific sanddab (Citharichthys sordidus Girard, 1854) were collected from five offshore oil platforms and 10 natural areas during 2005–2006 for whole-body analysis of 63

  8. 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

  9. High-resolution onshore-offshore morpho-bathymetric records of modern chalk and granitic shore platforms in NW France

    Science.gov (United States)

    Duperret, Anne; Raimbault, Céline; Le Gall, Bernard; Authemayou, Christine; van Vliet-Lanoë, Brigitte; Regard, Vincent; Dromelet, Elsa; Vandycke, Sara

    2016-07-01

    Modern shore platforms developed on rocky coasts are key areas for understanding coastal erosion processes during the Holocene. This contribution offers a detailed picture of two contrasted shore-platform systems, based on new high-resolution shallow-water bathymetry, further coupled with aerial LiDAR topography. Merged land-sea digital elevation models were achieved on two distinct types of rocky coasts along the eastern English Channel in France (Picardy and Upper-Normandy: PUN) and in a NE Atlantic area (SW Brittany: SWB) in NW France. About the PUN case, submarine steps, identified as paleo-shorelines, parallel the actual coastline. Coastal erosive processes appear to be continuous and regular through time, since mid-Holocene at least. In SWB, there is a discrepancy between contemporary coastline orientation and a continuous step extending from inland to offshore, identified as a paleo-shoreline. This illustrates a polyphased and inherited shore platform edification, mainly controlled by tectonic processes.

  10. Multi-objective optimization of organic Rankine cycles for waste heat recovery: Application in an offshore platform

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Nguyen, Tuong-Van; Larsen, Ulrik;

    2013-01-01

    . The methodology is applied to recover the waste heat from the SGT-500 gas turbine installed on the Draugen off-shore oil and gas platform in the North Sea. Results suggest two optimal working fluids, i.e. acetone and cyclopentane. Thermal efficiency and net present value are higher for cyclopentane than...... for acetone. Other promising working fluids are cyclohexane, hexane and isohexane. The present methodology can be utilized in waste heat recovery applications where a compromise between performance, compactness and economic revenue is required. © 2013 Elsevier Ltd. All rights reserved....

  11. 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

  12. Method for constructing an offshore platform structure having a plurality of supporting legs inclined inwardly towards each other

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, O.

    1984-04-17

    A method for constructing an offshore platform structure having a plurality of supporting legs inclined inwardly towards each other is disclosed. The entire structure may be constructed in a dry dock, or optionally the lower raft may be constructed in the dry dock and then towed out to a deep water site where the structure is completed. The platform foundation includes a plurality of foundation footings and the lower end of the inclined supporting legs are built in the dry dock. The legs are cast in vertical position using conventional slip forms. Subsequent to the termination of the casting of the inclined legs the supporting legs are tilted towards each other and permanently interconnected at their upper ends. At their lower ends the legs are permanently anchored to the foundation footings. Remaining sections of the legs, if any, may then be cast in any conventional manner, preferably using slip forming.

  13. 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.

  14. 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...

  15. 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.

  16. 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

  17. 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.

  18. 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...

  19. 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.

  20. Authigenic carbonates from active methane seeps offshore southwest Africa

    Science.gov (United States)

    Pierre, Catherine; Blanc-Valleron, Marie-Madeleine; Demange, Jérôme; Boudouma, Omar; Foucher, Jean-Paul; Pape, Thomas; Himmler, Tobias; Fekete, Noemi; Spiess, Volkhard

    2012-12-01

    The southwest African continental margin is well known for occurrences of active methane-rich fluid seeps associated with seafloor pockmarks at water depths ranging broadly from the shelf to the deep basins, as well as with high gas flares in the water column, gas hydrate accumulations, diagenetic carbonate crusts and highly diverse benthic faunal communities. During the M76/3a expedition of R/V METEOR in 2008, gravity cores recovered abundant authigenic carbonate concretions from three known pockmark sites—Hydrate Hole, Worm Hole, the Regab pockmark—and two sites newly discovered during that cruise, the so-called Deep Hole and Baboon Cluster. The carbonate concretions were commonly associated with seep-benthic macrofauna and occurred within sediments bearing shallow gas hydrates. This study presents selected results from a comprehensive analysis of the mineralogy and isotope geochemistry of diagenetic carbonates sampled at these five pockmark sites. The oxygen isotope stratigraphy obtained from three cores of 2-5 m length indicates a maximum age of about 60,000-80,000 years for these sediments. The authigenic carbonates comprise mostly magnesian calcite and aragonite, associated occasionally with dolomite. Their very low carbon isotopic compositions (-61.0 Hole and Worm Hole pockmarks which were interpreted to reflect spatiotemporal variations in AOM related to subsurface gas hydrate formation-decomposition.

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

    Energy Technology Data Exchange (ETDEWEB)

    Reed, M.; Rye, H. [IKU Petroleumsforskning A/S, Trondheim (Norway); Melbye, A.; Johnsen, S.

    1996-12-31

    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.

  2. 海洋平台结构振动控制研究综述%Review on the Study of Structure Vibration Control for Offshore Platforms

    Institute of Scientific and Technical Information of China (English)

    肖宇维; 孙树民

    2012-01-01

    The vibration of offshore platforms will harm staff's physical and mental health, cause fatigue and destruction of the structure, reduce practicality, survivability and maneuverability of offshore platforms and bring a series of threat to oil mining. This paper mainly introduces the study and application status of structure vibration control of offshore platforms and focuses on the passive control, active control and semi-active control technology. Finally some problems on structure vibration control offshore platforms are puts forward.%海洋平台结构的振动将会影响工作人员的身心健康,导致结构疲劳和破坏,降低平台的实用性、生存性以及可操作性,给海上油气顺利开采带来一系列的威胁。本文主要对海洋平台结构振动控制的研究和应用现状做了简要的介绍,并重点介绍了被动控制、主动控制以及半主动控制技术。最后提出了海洋平台结构振动控制存在的一些问题。

  3. A bilevel decomposition technique for the optimal planning of offshore platforms

    Directory of Open Access Journals (Sweden)

    M.C.A. Carvalho

    2006-03-01

    Full Text Available There is a great incentive for developing systematic approaches that effectively identify strategies for planning oilfield complexes. This paper proposes an MILP that relies on a reformulation of the model developed by Tsarbopoulou (UCL M.S. Dissertation, London, 2000. Moreover, a bilevel decomposition technique is applied to the MILP. A master problem determines the assignment of platforms to wells and a planning subproblem calculates the timing for fixed assignments. Furthermore, a heuristic search procedure that relies on the distance between platforms and wells is applied in order to reduce the search region. Results show that the decomposition approach using heuristic generates optimal solutions for instances of up to 500 wells and 25 platforms in 10 discrete time periods that otherwise could not be solved with a full-scale approach. One important feature regarding these instances is that they correspond to problems of real-world dimension.

  4. 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

    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...

  5. 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

  6. 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.

  7. Generation and application of a standardized load-time history to tubular T-joints in offshore platforms

    Science.gov (United States)

    Li, Shan-shan; Cui, Wei-cheng

    2015-10-01

    Marine structures are mostly made of metals and always experience complex random loading during their service periods. The fatigue crack growth behaviors of metal materials have been proved from laboratory tests to be sensitive to the loading sequence encountered. In order to take account of the loading sequence effect, fatigue life prediction should be based on fatigue crack propagation (FCP) theory rather than the currently used cumulative fatigue damage (CFD) theory. A unified fatigue life prediction (UFLP) method for marine structures has been proposed by the authors' group. In order to apply the UFLP method for newly designed structures, authorities such as the classification societies should provide a standardized load-time history (SLH) such as the TWIST and FALSTAFF sequences for transport and fighter aircraft. This paper mainly aims at proposing a procedure to generate the SLHs for marine structures based on a short-term loading sample and to provide an illustration on how to use the presented SLH to a typical tubular T-joint in an offshore platform based on the UFLP method.

  8. 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...

  9. 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.

  10. 海洋平台舱室舾装布置及舾装板隔声%Outfitting Arrangement and Sound Insulation of Offshore Platform

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    By analyzing the structural characteristic and the sound insulation property of the outfitting panel, the sound insulation empirical values of several types of outfitting panels of offshore platform were obtained. The results from the mea-surement in laboratory and the measurement in real offshore platform were compared mutually. It was found that the noise insulation property can be improved by increasing the thickness of the internal cavity of the double-layer outfitting panel. Re-sults of this work provide a reference for design and installation of outfitting panels on offshore platform.%  通过讨论舾装板结构特点及其隔声性能,得到海洋平台常用舾装板结构的隔声经验值,为海洋平台整体噪声预测分析提供一定的参考。比较大量的实验室测量数据和实船测试数据,可通过加厚双层舾装板的空腔夹层以提高其低频隔声性能,大大节约生产成本。可为舾装设计安装提供参考。

  11. Hybrid Carbon-Based Nanostructured Platforms for the Advanced Bioreactors.

    Science.gov (United States)

    Levchenko, I; Mai-Prochnow, A; Yick, S; Bilek, M M M; Kondyurin, A; Han, Z J; Fang, J; Cvelbar, U; Mariotti, D; Ostrikov, K

    2015-12-01

    Mankind faces several global challenges such as chronic and acute hunger, global poverty, energy deficiency and environment conservation. Common biotechnologies based on batch, fluidbed and other similar processes are now extensively used for the production of a wide range of products such as antibiotics, biofuels, cultured and fermented food products. Unfortunately, these processes suffer from low efficiency, high energy demand, low controllability and rapid biocatalyst degradation by microbiological attack, and thus still are not capable of seriously addressing the global hunger and energy deficiency challenges. Moreover, sustainable future technologies require minimizing the environmental impact of toxic by-products by implementing the "life produces organic matter, organic matter sustains life" principle. Nanostructure-based biotechnology is one of the most promising approaches that can help to solve these challenges. In this work we briefly review the unique features of the carbon-based nanostructured platforms, with some attention paid to other nanomaterials. We discuss the main building blocks and processes to design and fabricate novel platforms, with a focus on dense arrays of the vertically-aligned nanostructures, mainly carbon nanotubes and graphene. Advantages and disadvantages of these systems are considered. PMID:26682454

  12. 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.

  13. 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

  14. 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

  15. Measurement and Analysis of Extreme Wave and Ice Actions in the Great Lakes for Offshore Wind Platform Design

    Energy Technology Data Exchange (ETDEWEB)

    England, Tony; van Nieuwstadt, Lin; De Roo, Roger; Karr, Dale; Lozenge, David; Meadows, Guy

    2016-05-31

    This project, funded by the Department of Energy as DE-EE0005376, successfully measured wind-driven lake ice forces on an offshore structure in Lake Superior through one of the coldest winters in recent history. While offshore regions of the Great Lakes offer promising opportunities for harvesting wind energy, these massive bodies of freshwater also offer extreme and unique challenges. Among these challenges is the need to anticipate forces exerted on offshore structures by lake ice. The parameters of interest include the frequency, extent, and movement of lake ice, parameters that are routinely monitored via satellite, and ice thickness, a parameter that has been monitored at discrete locations over many years and is routinely modeled. Essential relationships for these data to be of use in the design of offshore structures and the primary objective of this project are measurements of maximum forces that lake ice of known thicknesses might exert on an offshore structure.

  16. Measurement and Analysis of Extreme Wave and Ice Actions in the Great Lakes for Offshore Wind Platform Design

    Energy Technology Data Exchange (ETDEWEB)

    England, Tony [Univ. of Michigan, Ann Arbor, MI (United States). College of Engineering; van Nieuwstadt, Lin [Univ. of Michigan, Ann Arbor, MI (United States). College of Engineering; De Roo, Roger [Univ. of Michigan, Ann Arbor, MI (United States). College of Engineering; Karr, Dale [Univ. of Michigan, Ann Arbor, MI (United States). College of Engineering; Lozenge, David [Univ. of Michigan, Ann Arbor, MI (United States). College of Engineering; Meadows, Guy [Univ. of Michigan, Ann Arbor, MI (United States). College of Engineering

    2016-05-30

    This project, funded by the Department of Energy as DE-EE0005376, successfully measured wind-driven lake ice forces on an offshore structure in Lake Superior through one of the coldest winters in recent history. While offshore regions of the Great Lakes offer promising opportunities for harvesting wind energy, these massive bodies of freshwater also offer extreme and unique challenges. Among these challenges is the need to anticipate forces exerted on offshore structures by lake ice. The parameters of interest include the frequency, extent, and movement of lake ice, parameters that are routinely monitored via satellite, and ice thickness, a parameter that has been monitored at discrete locations over many years and is routinely modeled. Essential relationships for these data to be of use in the design of offshore structures and the primary objective of this project are measurements of maximum forces that lake ice of known thicknesses might exert on an offshore structure.

  17. 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)

  18. 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...

  19. 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.

  20. Reliability assessment of offshore platforms exposed to wave-in-deck loading. Appendix F: Reliability analysis of offshore jacket structures with wave load on deck using the model correction factor method

    Energy Technology Data Exchange (ETDEWEB)

    Dalsgaard Soerensen, J. [Aalborg Univ., Aalborg (Denmark); Friis-Hansen, P. [Technical Univ. Denmark, Lyngby (Denmark); Bloch, A.; Svejgaard Nielsen, J. [Ramboell, Esbjerg (Denmark)

    2004-08-01

    Different simple stochastic models for failure related to pushover collapse are investigated. Next, a method is proposed to estimate the reliability of real offshore jacket structures. The method is based on the Model Correction Factor Method and can be used to very efficiently to estimate the reliability for total failure/collapse of jacket type platforms with wave in deck loads. A realistic example is evaluated and it is seen that it is possible to perform probabilistic reliability analysis for collapse of a jacket type platform using the model correction factor method. The total number of deterministic, complicated, non-linear (RONJA) analysis is typically as low as 10. Such reliability analyses are recommended to be used in practical applications, especially for cases with wave in deck load, where the traditional RSR analyses give poor measures of the structural reliability. (au)

  1. DEVELOPMENT AND RESEARCH OF H-BEAM USING FOR OFFSHORE OIL DRILLING PLATFORM%海洋石油平台用H型钢的开发研究

    Institute of Scientific and Technical Information of China (English)

    顾建国

    2001-01-01

    简述了国内外海洋石油平台用H型钢的发展概况,介绍了此种H型钢国产化研究进展及达到的实物质量水平,同时对马钢生产的H型钢和国外同类产品的性能作了对比,并给出马钢实际生产经验。%Domestic and abroad development and research of H-beam using for offshore oil driling platform is summarized in the paper. Authors introduce the domestic develoment and research of H-beam using for offshore oil drilling platform and its real product quality level, compare the properties of H-beam produced by Magang with the abroad ones. The metallurgical basis, TMCP process and practical producing experience of the product are analysed and producing experience for higher properties of marine oil drilling platform H-beam is given.

  2. 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.

  3. 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

  4. COCAP - A compact carbon dioxide analyser for airborne platforms

    Science.gov (United States)

    Kunz, Martin; Lavrič, Jošt V.; Jeschag, Wieland; Bryzgalov, Maksym; Hök, Bertil; Heimann, Martin

    2014-05-01

    Airborne platforms are a valuable tool for atmospheric trace gas measurements due to their capability of movement in three dimensions, covering spatial scales from metres to thousands of kilometres. Although crewed research aircraft are flexible in payload and range, their use is limited by high initial and operating costs. Small unmanned aerial vehicles (UAV) have the potential for substantial cost reduction, but require lightweight, miniaturized and energy-efficient scientific equipment. We are developing a COmpact Carbon dioxide analyser for Airborne Platforms (COCAP). It contains a non-dispersive infrared CO2sensor with a nominal full scale of 3000 μmol/mol. Sampled air is dried with magnesium perchlorate before it enters the sensor. This enables measurement of the dry air mole fraction of CO2, as recommended by the World Meteorological Organization. During post-processing, the CO2 measurement is corrected for temperature and pressure variations in the gas line. Allan variance analysis shows that we achieve a precision of better than 0.4 μmol/mol for 10 s averaging time. We plan to monitor the analyser's stability during flight by measuring reference air from a miniature gas tank in regular intervals. Besides CO2, COCAP measures relative humidity, temperature and pressure of ambient air. An on-board GPS receiver delivers accurate timestamps and allows georeferencing. Data is both stored on a microSD card and simultaneously transferred over a wireless serial interface to a ground station for real-time review. The target weight for COCAP is less than 1 kg. We deploy COCAP on a commercially available fixed-wing UAV (Bormatec Explorer) with a wingspan of 2.2 metres. The UAV has high payload capacity (2.5 kg) as well as sufficient space in the fuselage (80x80x600 mm3). It is built from a shock-resistant foam material, which allows quick repair of minor damages in the field. In case of severe damage spare parts are readily available. Calculations suggest that the

  5. 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.

  6. 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.

  7. 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。

  8. 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.

  9. Noise Occupational Hygiene Assessment of Platform Offshore%某海洋石油平台噪声职业病危害卫生学评价

    Institute of Scientific and Technical Information of China (English)

    宋文青; 邵华; 赵倩

    2011-01-01

    目的 引入结构性声传播噪声影响分析,对某海洋石油作业平台噪声职业病危害进行卫生学评价.方法 对某石油作业平台噪声职业病危害场所及防护措施进行卫生学调查,检测分析噪声强度评价其危害.结果 发电机间噪声检测超标,噪声危害达到Ⅱ级,其他场所均符合卫生学要求.结论 发电机间在做好监测的同时,应加强管理、个体防护等措施,控制噪声危害.%[Objective]To introduce structural sound transmission noise analysis for hygienically evaluation of noise hazards in a offshore oil platform.[Methods]Hygienically evaluation was performed on the workplace with noise hazards and the protective measures in a offshore oil platform.The noise intensity was tested for harm evaluation.[Results]Noise intensity in power room was over standard and up to the hazard grade H, other places met the hygiene requirements.[Conclusion]Generator room should be monitored continually.Administration, personal protection and other means should be strengthened to control noise hazardous.

  10. 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

  11. 海上石油平台电力系统自励磁研究%Study on Generator Self- Excitation in Offshore Oil Platform Power System

    Institute of Scientific and Technical Information of China (English)

    张国民

    2012-01-01

    When the offshore oil platform power system black - start, submarine cables for long - distance need to put in, the self - excitation of generator happen easily, which is bad to generator and other electrical equipments. But analyzing and inhibiting measures of self - excitation for land power system are not fit for island power system. According to the characteristics of offshore oil platform power system, the paper presented a suitable method for the offshore oil platform power system to restrain generator self - excitation. First, the paper introduced the basic principle and criterion of synchronous generator's self - excitation based on armature reaction of synchronous generator. The Louts criterion was used to get judgment basis and conditions of generator parameter in producing synchronous self -excitation. In one offshore oil platform power system, for example, the measures was posed through analysis of self -excitation in the offshore oil platform power system. Then the black - start path was simulated and calculated by PSCAD/EMTDC. The computer simulation result illustrates the effectiveness of the proposed method.%研究海上石油平台的电力系统抑制自励磁优化控制问题,当海上石油平台孤岛电力系统黑启动时,由于海缆距离长、分布电容大,易造成发电机的自励磁现象,对系统的电气设备产生极大危害,影响了系统的安全.而应用在陆地电力系统的抑制自励磁措施并不能在孤岛电力系统中完全有效.针对海上石油平台电力系统的特点,提出三种应用在海上油田群电力系统的抑制自励磁方法,即双机带空载海缆黑启动、防止新接入的海缆长度超过临界长度以及并联电抗器黑启动.首先通过同步发电机电枢反应原理分析了同步发电机产生自励磁现象,以劳斯判据来确定产生同步自励磁时发电机参数的判断依据及条件,对某海上油田群电力系统的自励磁情况提出抑制模型,最

  12. 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.

  13. 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)

  14. Prediction of offshore risks

    Energy Technology Data Exchange (ETDEWEB)

    Castro, J.A.A.

    1979-09-01

    Topographic and geophysical surveys of offshore drilling sites taken prior to platform installation or the commencement of drilling operations can warn operators of the presence of hazardous subsea structures or soil conditions. As illustrated by operations in Campeche Bay, the use of sonar, sidescanners, and shallow and deep profiling systems can produce reliable marine surveys that greatly reduce the risks related to offshore operations.

  15. 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.

  16. Supersequence and composite sequence carbonate platform growth: Permian and Triassic outcrop data of the Arabian platform and Neo-Tethys

    Science.gov (United States)

    Weidlich, O.; Bernecker, M.

    2003-05-01

    Permian and Triassic carbonate platforms of the Arabian Peninsula (Gondwana) and seamounts of the Neo-Tethys (Hawasina and Batain basins) are characterized by distinctive supersequences (second order, duration 5-20 million years, my) and composite sequences (third order, duration 0.5-5 my). The presented sequence stratigraphic framework will be compared with existing sea level curves to discuss the validity of different regional oscillations during the dispersal of Pangea. The carbonate succession of the Haushi and Akhdar Groups of the Arabian platform is composed of four Permian (P1-P4) and four Triassic supersequences (Tr1-Tr4). Isolated platforms of the Hawasina and Batain basins comprise two Permian supersequences and one Triassic supersequence. In contrast to the continuous development of the Arabian shield, carbonate platform growth of the seamounts was restricted to the Guadalupian-Lopingian and to the Middle-Upper Triassic, and ceased after drowning events. Composite sequences exhibit a well-developed stacking pattern during the Guadalupian-Lopingian (Saiq Formation). Lowstand systems tracts (LSTs) occur during the Cisuralian (Gharif Formation, Haushi Group) and Triassic (Mahil Formation, Akhdar Group). Open-marine depositional environments prevail during transgressive systems tracts (TSTs) with diverse biota including rugose and scleractinian corals, chaetetids, bryozoans, and crinoids. Highstand system tracts (HSTs) exhibit a twofold pattern: During the transgressive phase of supersequences, composite sequence highstands are dominated by reef or level-bottom communities with corals. Cyclic platform deposits or monotonous mud- and wackestone accumulated during the turnaround or late second-order highstand of a supersequence. Correlation of maximum flooding surfaces with published data suggests that supersequences P1, P2, and Tr4 can be traced across the Arabian platform into the Neo-Tethys basins, while supersequences P3, P4, and Tr1-Tr3 resulted from

  17. 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)

  18. 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。

  19. 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

  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.

    up to a water depth of 110 m. The inner shelf is a clastic depocentre - the Dahanu depression - in which Narmada and Tapti River-derived sediments have been deposited since the Eocene. The sediments on the platform are largely faecal pellet... of the platform (see Fig. 1). Aragonite faecal pellets, fragments of corals, bivalves and bryozoans compose the coarse fraction of the sediments (Rao et aI., 1994). Dark-grey clayey sands were recovered at 64 ill water depth in a seaward depression of the fringing...

  1. 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

  2. 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.

  3. 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.

  4. P ushover analysis on a jacket offshore platform in the South China Sea%南海某导管架海洋平台倒塌分析

    Institute of Scientific and Technical Information of China (English)

    唐友刚; 朱龙欢; 李焱; 刘成义; 张少洋

    2016-01-01

    Pushover analyses were performed for an aging jacket-type platform to obtain the ultimate capacity and then to evaluate the safety margin. A three-dimensional finite element model of the jacket platform was established using SACS software. Based on the step-by-step loading method, the nonlinear collapse analysis for the jacket offshore platform in the South China Sea was performed, considering the loads of wave and current and the nonlinear interaction between soil and piles. The analysis results show that the ultimate strength of this jacket platform is at a high level, with a large margin of safety. The collapse of the platform is the result of gradual damages. Firstly, the brace begins to yield, causing damages of partial structure. Secondly, the piles start to yield, reducing the capacity. Finally, some joints fail, resulting in the collapse of the whole structure. Overall, the mechanism of the failure and collapse of the jacket platform is revealed, and the feasible analysis method and procedures of collapse analysis are put forward.%针对在役老龄导管架平台进行倒塌计算分析,确定极限承载力进而评估老龄导管架的安全裕度。采用非线性有限元方法,考虑平台的波流载荷及桩-土的非线性相互作用,利用SACS软件建立导管架整体三维有限元计算分析模型,并用逐步加载的方式,对南海某导管架平台进行了全过程非线性倒塌分析。计算分析表明,该导管架平台极限强度很高,具有较大的安全裕度;导管架倒塌过程呈逐步破坏形式,先是撑杆屈服,造成局部结构破坏,然后是钢桩发生屈服,降低结构承载力,最后节点逐步失效,造成结构倒塌。揭示了导管架平台结构失效倒塌的机理,给出了倒塌分析的可行方法和步骤。

  5. Differential severity of Permian Triassic environmental changes on Tethyan shallow-water carbonate platforms

    Science.gov (United States)

    Weidlich, Oliver; Bernecker, Michaela

    2007-01-01

    Significantly different Guadalupian-Late Triassic patterns are observed in the evolution of attached and isolated carbonate platforms of the southwestern Tethys (Oman Mountains). Close to the rim of the attached Arabian platform, carbonates of the Saiq and Mahil Formations reveal an almost complete Permian-Triassic sedimentary record. Guadalupian-Changhsingian 3rd order sequences consist of fossiliferous transgressive systems tracts and monotonous highstand systems tracts with mud/wackestone and coral bafflestone. The youngest Changhsingian beds are bioturbated floatstone with crinoids, sponges and bryozoans. All sediments indicate a healthy, tropical carbonate production. Above, a unique facies change begins with a pyrite-encrusted omission surface. Greenish mudstone rich in authigenic pyrite infills the relief of the unconformity and is overlain by clastic sediment and by laminated, microbialite-bearing carbonate. Unfossiliferous sediments and seafloor cements indicate a change in carbonate production towards abiotic processes. Prevailing anoxic conditions were interrupted by seven oxic event beds, as indicated either by low-diversity and small-sized ichnotaxa or by shell beds with low-diversity bivalve and crinoid assemblages. By comparison with published data, the described sedimentary sequence can be assigned to the Changhsingian-earliest Griesbachian. Beginning probably with the Anisian, bioturbated Griesbachian-Dienerian recovery period and the unconformity below to the latest grain-supported sediment textures mark the return to biogenic tropical carbonate production under oxic conditions. The Middle-Late Triassic carbonate platform consists of stacked high-frequency shallowing upward cycles. By contrast, carbonate production of Neo-Tethyan isolated platforms was discontinuous and interrupted by a large gap. Guadalupian deposits of the Al Jil Formation consist of bioclastic limestone typical of a tropical carbonate production. The uppermost bed, an

  6. 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

  7. "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.

    31 (2004) 791–793 www.elsevier.com/locate/oceaneng Letter to the editor “Nonlinear coupled dynamic response of offshore spar platforms under regular sea waves” By Agarwal, AK and Jain, AK. Ocean Engineering, 2003, 30, 517-555 The authors have shown... 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...

  8. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Sarrafan, Atabak; Zareh, Seiyed Hamid; Khayyat, Amir Ali Akbar; Zabihollah, Abolghassem [Sharif University of Technology, Teheran (Iran, Islamic Republic of)

    2012-04-15

    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.

  11. 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

  12. 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

  13. 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.

  14. 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...

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 海上石油平台液压多功能输送栈桥研制%Manufacture of the Hydraulic Multifunction Transfer Bridge for Offshore Oil Platform

    Institute of Scientific and Technical Information of China (English)

    程龙; 张琳

    2014-01-01

    The technical feature , equipment compositions and working principle of the hydraulic multifunction transfer bridge for an offshore oil platform were introduced .The transfer bridge has advantages of bridging safely and reliably , high degree of mechanizing , convenient operation , which was applied in an offshore oil platform successfully .%介绍海上石油平台液压多功能输送栈桥的技术性能、主要结构及工作原理,该栈桥具有搭接安全可靠、外输管线集成化程度高,机械化程度高、操作方便等优点,已在海洋石油平台上得到成功应用。

  20. 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.;

    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 fr...

  1. 海上平台采油树辅助液压系统研究%Study of the christmas tree auxiliary hydraulic control system on offshore platform

    Institute of Scientific and Technical Information of China (English)

    陈肇日; 苟潮洋

    2011-01-01

    海上平台采油树钢丝作业过程中,为了防止采油树液控主阀意外关闭而切断钢丝,目前采用的是给液控主阀戴帽的方法,此方法存在很大的安全隐患.设计了采油树辅助液压系统,在钢丝作业过程中采用双液压源控制采油树液控主阀,提高了钢丝作业过程的安全性.%At present, the valve cap is used to prevent the wire line from cut off due to unexpected close of hydraulic master valve during the christ-mas tree wire line operation on offshore platform. This method has the potential safety hazard. Therefore,a set of auxiliary hydraulic control system has been designed to keep the master valve o-pening by using double hydraulic source during the wire line operation, so as to improve the safety of wire line operation.

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. Management of Human Performance in Offshore Platform Maintenance Based on Fuzzy Comprehensive Evaluation%海洋钻井平台维修中的人因管理

    Institute of Scientific and Technical Information of China (English)

    余建星; 张贵珍; 柴松; 马维林

    2012-01-01

    Shengli oilfield;horizontal well;screen;long life;intelligentWith higher reliability of the offshore production equipment, human reliability becomes more and more important in determining safety in the gas and oil production industry. As a matter of fact,management of human factor in platform maintenance is a significant aspect of human reliability management. Current methods that are aimed at controlling human error in maintenance have two vital disadvantages. On the one hand, they tend to be reactive rather proactive; on the other hand they are qualitative description rather than quantitative assessment. However, a successful plan to manage human factor should not only be able to find out causes of the past accidents and damages but also be able to detect which issue is most likely to lead to future incidents. Therefore, Fuzzy Comprehensive Evaluation, which is semi-qualitative and semi-quantitative, is used in this article. Through a fuzzy assessment of factors that affect maintenance performance, weaknesses and problems of the organization can be recognized, thus helping preventing human error from happening.%人员可靠性越来越成为制约海样钻井平台生产安全的重要因素,海洋平台维修中的人为因素管理是人因可靠性的一个重要方面.目前国内外控制维修中人为差错方法,一方面趋向于被动反应式而不是主动前瞻式的管理;另一方面属于定性评价而非定量分析.选用定性与定量结合的模糊综合评价法,对维修组织各因素的安全性进行评价,找出弱项,以预防维修中人为差错的产生.

  8. Application of MEG regeneration and reclamation technology on offshore platform%乙二醇再生回收技术在海上平台的应用

    Institute of Scientific and Technical Information of China (English)

    刘飞龙; 倪浩; 曾树兵; 姜振晖

    2014-01-01

    乙二醇(MEG)再生回收装置首次应用于海上平台,其流程包括预处理、再生和脱盐3部分。预处理通过闪蒸脱除MEG富液中的轻烃并加入NaOH,利用化学反应脱除能生成沉淀物的二价盐。再生过程是在低压下利用精馏原理将轻组分(水)与重组分(MEG)分离,获取质量分数高于80%的MEG贫液。MEG贫液脱盐采用负压闪蒸的方法使可溶性一价盐(Na+等)和MEG分离,最终获得合格的MEG贫液。装置性能稳定可靠,MEG损失量少,具有广阔的应用前景。%The MEG regeneration and reclamation technology is successfully applied to off-shore platform .The process includes MEG pre-treatment ,regeneration and desalination .The pre-treatment section is designed to remove hydrocarbon from the rich MEG and divalent metal salts ,which can generate precipitation by reacting with sodium hydroxide .Adopting distillation column ,the MEG regeneration section operates at a pressure slightly above the atmospheric pres-sure ,and the mass concentration of lean MEG solubility should be more than 80% .The key technology of the process is desalination ,w hich uses a vacuum flash separator to crystallize and remove the high soluble one valence salts ,and primarily sodium salts from the lean MEG .The MEG regeneration and reclamation package has good performance and less MEG loss .Therefore , it has a variety of applications in prospect .

  9. 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

  10. 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

  11. Shelf architectures of an isolated Late Cretaceous carbonate platform margin, Galala Mountains (Eastern Desert, Egypt)

    Science.gov (United States)

    Scheibner, C.; Marzouk, A. M.; Kuss, J.

    2001-12-01

    An asymmetrical carbonate platform margin to basin transect has been investigated in the Upper Campanian-Maastrichtian succession of the Galala Mountains, northern Egypt. Identification of systems tracts and their lateral correlation was possible in slope sections only, whereas the monotonous chalk-marl alternations of the basinal sections could not be subdivided with respect to sequence stratigraphic terminology. The platform asymmetry is expressed by varying large-scale depositional architectures exhibiting a rimmed platform with a sigmoidal slope curvature in south-easterly dip-sections and a ramp with a linear slope curvature in south-westerly dip-sections. The rimmed platform is subdivided into a gentle upper slope and a steep lower slope. The platform formed as a result of the initial topography that was controlled by the tectonic uplift of the Northern Galala/Wadi Araba Syrian Arc structure. The calculated angles of the steep lower slope of the rimmed part range from 5 to 8°, whereas the ramp part has an angle of less than 0.1°.

  12. 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...

  13. Carbon isotopes of benthic foraminifera associated with methane seeps in Four-Way Closure Ridge, offshore southwestern Taiwan

    Science.gov (United States)

    Wang, W. R.; Wei, K. Y.; Mii, H. S.; Lin, Y. S.; Huang, J. J.; Wang, P. L.; Lin, A. T.

    2015-12-01

    Release of large amounts of methane from marine gas hydrate reservoirs has been considered as a possible trigger of climate change, which can be recorded by the variation of carbon isotopes (δ13C) of the benthic foraminifera. In modern analogs, previous studies have suggested that δ13C becomes more negative when influenced by methane seeps. However, values of δ13C of benthic foraminifera might vary with different species and sedimentary settings in different regions. Seismic profiles in offshore southwestern Taiwan show the existence of Bottom Simulating Reflector (BSR) in the region, indicative of gas hydrate reservoirs. Various methane seepages have been found, and they are suspected to be related to the gas hydrates buried underneath. A better understanding of the δ13C signals of benthic foraminifera near the methane seepages can further clarify the origin of the methane and to evaluate it as a proxy of methane release for the geologic past. We have analyzed δ13C of benthic foraminifera Uvigerina proboscidea (150-250 mm) in the topmost 15 cm sediments in five marine cores (OR1-1092-WFWC-1, OR1-1092-WFWC-4, OR1-1092-WFWC-6, OR3-1806-C5-2 and OR3-1806-C10) collected from the Four-Way Closure Ridge in offshore southwestern Taiwan (water depth from 1330 to 1580 m). Our results show that δ13C values of U. proboscidea range from -0.98‰ to -6.21‰ (VPDB) for core OR3-1806-C5-2, which is considered as a seeps-influenced site. On the other hand, δ13C values of U. proboscidea from the background sites range from -0.40‰ to -1.00‰. The difference between the methane seep-affected and the background sites is in the range of 0.00‰ to 5.01‰, comparable to those documented in previous studies in other areas. The significant negative excursion in carbon isotopes in the seep site foraminifera is likely caused by incorporation of light inorganic carbon generated by methanotrophy in the system.

  14. Quantification, morphology and source of humic acid, kerogen and black carbon in offshore marine sediments from Xiamen Gulf, China

    Institute of Scientific and Technical Information of China (English)

    Yanting Chen; Jinping Zhao; Li qianYin; Jinsheng Chen; Dongxing Yuan

    2013-01-01

    Three types of macromolecular organic matters (MOMs),i.e.humic acid (HA),kerogen+black carbon (KB),and black carbon (BC)were extracted from marine sediments of Xiamen Gulf,southeast of China.The chemical composition,morphological property and source of the three extractions were characterized by elemental analyzer/isotope ratio mass spectrometry (EA/IRMS) and scanning electron microscope (SEM).The results showed that KB was the predominant fraction in MOMs,which accounted for 61.79%-89.15% of the total organic content (TOC),while HA consisted less than 5%.The relative high contents of kerogen and BC,and low contents of HA in the samples indicated that anthropogenic input might be the major source of organic matter in marine sediments near the industrial regions.The characterization of SEM,not only revealed morphological properties of the three fractions,but also allowed a better understanding of the source of MOMs.The δ13C values of the three fractions suggested that materials from terrestrial C3 plants were predominant.Furthermore,the anthropogenic activities,such as the discharge of sewage,coal and biomass combustion from industry nearby and agricultural practices within drainage basin of the Jiulong River,were remarkably contributed to the variations in δ13C values of MOMs in the offshore marine sediments.

  15. 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...

  16. Analysis of offshore jacket platform

    Digital Repository Service at National Institute of Oceanography (India)

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

    particle velocities and acceleration. Generally sinusoidal wave theory is suitable for deep water waves. In the present study simple sinusoidal wave theory (Airy wave theory) is used. The ratio of horizontal dimension (D) to wave length (L) is smaller... deflections to calculate the generalized forces for each mode. Working with a mode at a time, and considering the fact that the generalized forces calculated for different time steps represent a periodic function, a Fourier transformation can be applied...

  17. Anti-corrosion Technology for Offshore Drilling Platform Fasteners%海洋平台紧固件防腐工艺探讨

    Institute of Scientific and Technical Information of China (English)

    黄建勋; 徐红九; 刘宏亮; 王明磊

    2013-01-01

    To achieve long and effective anti-corrosion of fasteners and standard parts of offshore drilling platforms and to solve the problem of corrosion caused by severe environment, the anti-corrosion technology of the KK1 # composite coating was proposed. The technology adopts the composite coating of " electrolytic zinc and Xylan paint" . It makes use of the self-lubricating property of the Xylan 1424 water paint dry film and the characteristic of frictional factor between 0. 05 and 0. 10. It has the advanced anti-salt spray corrosion performance and very strong anti-acid rain performance and anti-chemical corrosion performance. Compared with galvanized coating, KK1# composite coating improves anti-corrosion capacity remarkably. As for black oxide fasteners, the torsion has been reduced by 70% . It has anti-seizure and anti-deformation functions. The test findings of the anti-corrosion coating show that after 2 500 hours of salt spray resistance test, the component with KK1# composite coating has 33% of white rust area and less than 1 % of red rust area. The latter goes far beyond and thus desirably satisfies the requirement that red rust area should be less than 15% of the total.%为了实现海洋平台紧固件和标准件的长效防腐,解决恶劣环境带来的腐蚀问题,提出了KK1#复合涂层防腐工艺.该工艺采用“电镀锌+Xylan狮隆涂料”复合涂层,利用了Xylan 1424水性涂料的干膜自润滑性能和摩擦因数在0.05 ~0.10之间的特性,具有优越的防盐雾腐蚀性能,极强的抗酸雨性能以及防化学腐蚀性能.相比镀锌涂层,KK1#复合涂层能大幅提高防腐蚀能力,相对于发黑紧固件,减小扭矩高达70%,具有防咬死、防变形功能.防腐涂层测试结果表明,涂有KK1#复合涂层的构件耐盐雾试验2 500 h后,白锈面积33%,红锈面积小于1%,远超出红锈面积不大于15%的要求.

  18. 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

  19. 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

  20. 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

  1. 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

  2. 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.

  3. 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

  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. Numerical modelling of thermal convection related to fracture permeability in Dinantian carbonate platform, Luttelgeest, the Netherlands

    Science.gov (United States)

    Lipsey, Lindsay; Pluymaekers, Maarten; van Wees, Jan-Diederik; Limberger, Jon; Cloetingh, Sierd

    2016-04-01

    The presence of convective fluid flow in permeable layers can create zones of anomalously high temperature which can be exploited for geothermal energy. Temperature measurements from the Luttelgeest-01 (LTG-01) well in the northern onshore region of the Netherlands indicate variations in the thermal regime that could be indicative of convection. This thermal anomaly coincides with a 600 m interval (4600 - 5200 m) of Dinantian carbonates showing signs of increased fracture permeability of ~60 mD. For the purpose of geothermal energy exploration, it is of interest to know whether or not convection can occur in a particular reservoir, where convection cells are likely to develop and the temperature enhancements in convective upwellings. Three-dimensional numerical simulations provide insight on possible flow and thermal structures within the fractured carbonate interval. The development and number of convection cells is very much a time dependent process. First longitudinal rolls fill the domain, increasing in width until ultimately transforming into a more complex polyhedral structure. The model relaxes into a steady-state five-cell convection pattern. Furthermore, geometric aspects of the carbonate platform itself likely control the shape and location of upwellings. Convective upwellings can create significant temperature enhancements relative to the conductive profile and in agreement with the observations in the Luttelgeest carbonate platform. This enhancement is critically dependent on the aquifer thickness and geothermal gradient. Given a gradient of 39 °C/km and an aquifer thickness of 600 m, a temperature of 203 °C can be obtained at a depth of 4600 m directly above upwelling zones. Contrarily, downwelling zones result in a temperature of 185 °C at the same depth. This demonstrates the strong spatial variability of thermal anomalies in convective fractures aquifers at large depth, which can have a strong effect on exploration opportunity and risk of

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

    Institute of Scientific and Technical Information of China (English)

    贾爱玲; 黄珍

    2014-01-01

    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。%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.

  8. 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。

  9. DCO-VIVO: A Collaborative Data Platform for the Deep Carbon Science Communities

    Science.gov (United States)

    Wang, H.; Chen, Y.; West, P.; Erickson, J. S.; Ma, X.; Fox, P. A.

    2014-12-01

    Deep Carbon Observatory (DCO) is a decade-long scientific endeavor to understand carbon in the complex deep Earth system. Thousands of DCO scientists from institutions across the globe are organized into communities representing four domains of exploration: Extreme Physics and Chemistry, Reservoirs and Fluxes, Deep Energy, and Deep Life. Cross-community and cross-disciplinary collaboration is one of the most distinctive features in DCO's flexible research framework. VIVO is an open-source Semantic Web platform that facilitates cross-institutional researcher and research discovery. it includes a number of standard ontologies that interconnect people, organizations, publications, activities, locations, and other entities of research interest to enable browsing, searching, visualizing, and generating Linked Open (research) Data. The DCO-VIVO solution expedites research collaboration between DCO scientists and communities. Based on DCO's specific requirements, the DCO Data Science team developed a series of extensions to the VIVO platform including extending the VIVO information model, extended query over the semantic information within VIVO, integration with other open source collaborative environments and data management systems, using single sign-on, assigning of unique Handles to DCO objects, and publication and dataset ingesting extensions using existing publication systems. We present here the iterative development of these requirements that are now in daily use by the DCO community of scientists for research reporting, information sharing, and resource discovery in support of research activities and program management.

  10. Offshore Supply Industry Dynamics

    DEFF Research Database (Denmark)

    Roslyng Olesen, Thomas

    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 challenges......This report is part of the research project “The competitive challenges and strategic development possibilities for The Blue Denmark”, which was launched in 2014. The project is funded by the Danish Maritime Fund and carried out by researchers at CBS Maritime which is a Business in Society Platform...... 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...

  11. 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

  12. Corrosion of carbon steel by bacteria from North Sea offshore seawater injection systems: laboratory investigation.

    Science.gov (United States)

    Stipanicev, Marko; Turcu, Florin; Esnault, Loïc; Rosas, Omar; Basseguy, Régine; Sztyler, Magdalena; Beech, Iwona B

    2014-06-01

    Influence of sulfidogenic bacteria, from a North Sea seawater injection system, on the corrosion of S235JR carbon steel was studied in a flow bioreactor; operating anaerobically for 100days with either inoculated or filtrated seawater. Deposits formed on steel placed in reactors contained magnesium and calcium minerals plus iron sulfide. The dominant biofilm-forming organism was an anaerobic bacterium, genus Caminicella, known to produce hydrogen sulfide and carbon dioxide. Open Circuit Potentials (OCP) of steel in the reactors was, for nearly the entire test duration, in the range -800corrosion rate, expressed as 1/(Rp/Ω), was lower in the inoculated seawater though they varied significantly on both reactors. Initial and final corrosion rates were virtually identical, namely initial 1/(Rp/Ω)=2×10(-6)±5×10(-7) and final 1/(Rp/Ω)=1.1×10(-5)±2.5×10(-6). Measured data, including electrochemical noise transients and statistical parameters (0.0545), suggested pitting on steel samples within the inoculated environment. However, the actual degree of corrosion could neither be directly correlated with the electrochemical data and nor with the steel corrosion in the filtrated seawater environment. Further laboratory tests are thought to clarify the noticed apparent discrepancies.

  13. 海上钻井方式的演变与不同类型移动式钻井平台的特点%Evolvement of Offshore Drilling Style and Characteristics of Different Mobile Drilling Platforms

    Institute of Scientific and Technical Information of China (English)

    吴家鸣

    2013-01-01

    目前在海洋油气资源开发中所使用的移动式钻井平台主要包括:坐底式平台、自升式平台、半潜式平台和钻井船四种类型,不同类型的钻井平台在它们进化过程中表现出了一种传承和演变的关系.对不同类型的移动式钻井平台的演变过程与特点进行了综述.%The mobile drilling platforms nowadays applied in offshore oil exploration activities mainly include bottom-supported platform, self-elevating platform, semi-submersible, and drilling ship. Different kinds of mobile drilling platforms manifest their connections of inheriting and evolvement during their development processes. The transfer processes and characteristics of different kinds of modern mobile drilling units are analyzed.

  14. 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

  15. Offshoring Process

    DEFF Research Database (Denmark)

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

    2011-01-01

    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......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...

  16. 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)

  17. 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.

  18. 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)

  19. 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

  20. Depositional ''cyclicity'' on carbonate platforms: Real-world limits on computer-model output

    Energy Technology Data Exchange (ETDEWEB)

    Boss, S.K.; Neumann, A.C. (Univ. of North Carolina, Chapel Hill, NC (United States)); Rasmussen, K.A. (Northern Virginia Community Coll., Annandale, VA (United States))

    1994-03-01

    Computer-models which attempt to define interactions among dynamic parameters believed to influence the development of ''cyclic'' carbonate platform sequences have been popularized over the past few years. These models typically utilize vectors for subsidence (constant) and cyclical (sinusoidal) eustatic sea-level to create accommodation space which is filled by sedimentation (depth-dependent rates) following an appropriate lag time (non-depositional episode during initial platform flooding). Since these models are intended to reflect general principles of cyclic carbonate deposition, it is instructive to test their predictive utility by comparing typical model outputs with an actively evolving depositional cycle on a modern carbonate platform where rates of subsidence, eustatic sea-level and sediment accumulation are known. Holocene carbonate deposits across northern Great Bahama Bank provide such an ideal test-platform for model-data comparisons. On Great Bahama Bank, formation of accommodation space depends on eustatic sea-level rise because tectonic subsidence is very slow. Contrary to typical model input parameters, however, the rate of formation of accommodation space varies irregularly across the bank-top because irregular bank-top topography (produced by subaerial erosion and karstification) results in differential flooding of the platform surface. Results of this comparison indicate that typical computer-model input variables (subsidence, sea-level, sedimentation, lag-time) and output depositional geometries are poorly correlated with real depositional patterns across Great Bahama Bank. Since other modern carbonate platforms and ancient carbonate sequences display similarly complex stratigraphies, it is suggested that present computer-modeling results have little predictive value for stratigraphic interpretation.

  1. 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

  2. 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.

  3. Printable nanoscale metal ring arrays via vertically aligned carbon nanotube platforms.

    Science.gov (United States)

    Lee, Sang Ho; Yoon, Seungha; Jeong, Huisu; Han, Mingu; Choi, Sung Mook; Kim, Jong Guk; Park, Ji-Woong; Jung, Gun Young; Cho, Beong Ki; Kim, Won Bae

    2013-11-01

    This paper reports a novel and efficient strategy for fabricating sub-100 nm metal ring arrays using a simple printing process. Vertically aligned carbon nanotubes that are supported by hexagonally ordered channels of alumina matrices are used as a stamp to print nanoscale ring patterns, which is a very unique stamping platform that has never been reported. Using this strategy, uniform nanoring patterns of various metals can be directly printed onto a wide range of substrate surfaces under ambient conditions. Significantly, the size and interval of the printed nanorings can be systematically tuned by controlling the ring-shaped tip dimensions of the pristine stamps. An advanced example of these printable nanoscale metal ring arrays is explicitly embodied in this work by investigation of the plasmon resonances of metal nanorings with different sizes and intervals.

  4. 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 ...

  5. 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.

  6. 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.

  7. 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。

  8. Dramatic nano-fluidic properties of carbon nanotube membranes as a platform for protein channel mimetics

    Science.gov (United States)

    Hinds, Bruce

    2013-03-01

    Carbon nanotubes have three key attributes that make them of great interest for novel membrane applications: 1) atomically flat graphite surface allows for ideal fluid slip boundary conditions and extremely fast flow rates 2) the cutting process to open CNTs inherently places functional chemistry at CNT core entrance for chemical selectivity and 3) CNT are electrically conductive allowing for electrochemical reactions and application of electric fields gradients at CNT tips. Pressure driven flux of a variety of solvents (H2O, hexane, decane ethanol, methanol) are 4-5 orders of magnitude higher than conventional Newtonian flow [Nature 2005, 438, 44] due to atomically flat graphite planes inducing nearly ideal slip conditions. However this is eliminated with selective chemical functionalization [ACS Nano 2011 5(5) 3867-3877] needed to give chemical selectivity. These unique properties allow us to explore the hypothesis of producing ``Gatekeeper'' membranes that mimic natural protein channels to actively pump through rapid nm-scale channels. With anionic tip functionality strong electroosmotic flow is induced by unimpeded cation flow with similar 10,000 fold enhancements [Nature Nano 2012 7(2) 133-39]. With enhanced power efficiency, carbon nanotube membranes were employed as the active element of a switchable transdermal drug delivery device that can facilitate more effective treatments of drug abuse and addiction. Recently methods to deposit Pt monolayers on CNT surface have been developed making for highly efficient catalytic platforms. Discussed are other applications of CNT protein channel mimetics, for large area robust engineering platforms, including water purification, flow battery energy storage, and biochemical/biomass separations. DOE EPSCoR (DE-FG02-07ER46375) and DARPA, W911NF-09-1-0267

  9. 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)

  10. 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

  11. 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.

  12. 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

  13. Epidemiological investigation of gastroesophageal reflux disease in offshore oil platform workers%海上石油平台作业人员胃食管反流病流行病学调查

    Institute of Scientific and Technical Information of China (English)

    长蒙; 温冰

    2016-01-01

    目的 调查海上石油平台作业人员胃食管反流病(gastroesophageal reflux disease,GERD)的发病率,分析与之相关的危险因素.方法 应用随机整群分层抽样的方法,对518名海上石油平台作业人员(均为男性)进行反流性疾病问卷(reflux disease questionnaire,RDQ)及相关危险因素调查,RDQ评分≥12分提示GRED诊断.调查方式均为面访试.调查资料均输入电脑并建立数据库,采用SPSS13.0软件行卡方检验、Logistic回归分析等.结果 海上石油平台作业人员GERD发病率为5.98%,与北京、上海两地普通人群的5.8%相近,高于广东的2.3%;低于海军官兵的27.1%.常食甜食、常饮浓茶、晕船、精神压力大、噪声环境、高脂饮食、常食辛辣食物、睡眠差可能为GERD的危险因素.结论 海上石油平台作业人员GERD的发病率与国内普通人群相近,但低于海军官兵人群,危险因素较多.%Objective To investigate the incidence of gastroesophageal reflux disease among offshore oil platform workers and analyze related risk factors of the disorder.Methods Reflux disease questionnaire (RDQ) and related risk factor survey were conducted among 518 offshore oil platform male workers by using random stratified cluster sampling method.The questionnaire survey was tarried out by personal interviews,and RDQ scores higher than 12 points indicated GERD diagnosis.SPSS 13.0 software chi-square test and Logistic regression analysis were used in the end results of the study.Results The incidence of gastroesophageal reflux disease among offshore oil platform workers was 5.98%,while that of the general population in Beijing and Shanghai was 5.77%,and it was obviously higher than that of the Guangdong general population (2.3%),but much lower than that of naval officers and enlisted (27.1%).Sweet diet,strong tea,seasickness,mental strain,noise,high-fat diet,spicy food and poor sleep might possibly the risk factors of the

  14. 提高海上平台油田伴生气利用效益的探讨%Improving the Efficiency of Oilfield Associated Gas in the Offshore Platform

    Institute of Scientific and Technical Information of China (English)

    杜佳

    2013-01-01

      When the oilfield associated gas in the offshore platform is serving as fuel gas, according to the project specific conditions, it needs technical and economic argumentation. Combining with the specific case, the article analyzes and discusses every influencing factors of improving the comprehensive benefit of associated gas utilization.%  海上平台的油田伴生气作为燃料气时,需要针对项目具体条件,进行技术、经济上的研究论证。结合具体案例,对提高伴生气利用的综合效益的各方面影响因素做了深入分析探讨。

  15. 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

  16. 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.

  17. Dossier Super Ships. Special on Offshore; Dossier Superschepen. Special Offshore

    Energy Technology Data Exchange (ETDEWEB)

    Van Velzen, T.; Biesboer, F.; Akkermans, J.

    2010-02-26

    In 5 articles attention is paid to the offshore industry focusing on the use of ships (1) capacity of cargo carriers; (2) problems with regard to the Nord Stream pipeline for the transport of natural gas; (3) energy efficient ships; (4) foundations for offshore wind turbines; and (5) on the platform Perdido, the offshoreproject in the Gulf of Mexico. [Dutch] In 5 artikelen wordt aandacht besteed aan de offshore industrie met de nadruk op het gebruik van schepen: (1) capaciteit van containerschepen voor transport; (2) problemen met de aanleg van de Nord Stream aardgaspijpleiding; (3) energie efficiente vaartuigen; (4) funderingspalen voor windturbines op zee; en (5) over het platform Perdido, het offshoreproject in de Golf van Mexico.

  18. 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.

  19. 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...

  20. Optimization of surface network and platform location using a next generation reservoir simulator coupled with an integrated asset optimizer application to an offshore deep water oil field in Brazil; Otimizacao de redes de superficie e locacao da plataforma atraves do acoplamento de um simulador de reservatorios de nova geracao e um otmizador global de ativo: aplicacao em um campo offshore

    Energy Technology Data Exchange (ETDEWEB)

    Campozana, Fernando P.; Almeida, Renato L. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Madeira, Marcelo G.; Sousa, Sergio H.G. de; Spinola, Marcio [Halliburton Servicos Ltda., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    To design, modify, and expand surface facilities is a multidisciplinary task which involves substantial financial resources. It can take months or years to complete, depending on the size and level of detail of the project. Nowadays, the use of Next Generation Reservoir Simulators (NGRS) is the most sophisticated and reliable way of obtaining field performance evaluation since they can couple surface and subsurface equations, thus eliminating the need of lengthy multiphase flow tables. Furthermore, coupling a NGRS with an optimizer is the best way to accomplish a large number of simulation runs on the search for optimized solutions when facilities are being modified and/or expanded. The suggested workflow is applied to a synthetic field which reproduces typical Brazilian offshore deep water scenarios. Hundreds of coupled simulation runs were performed and the results show that it is possible to find optimal diameters for the production lines as well as the ideal location for the production / injection platform. (author)

  1. The fatigue and corrosion fatigue behavior of welded Inconel 625 alloy employed in off-shore platforms; Avaliacao do comportamento a fadiga e a corrosao-fadiga de juntas soldadas da liga Inconel 625 testada para uso em plaaformas off-shore

    Energy Technology Data Exchange (ETDEWEB)

    Pfingstag, M.E.; Schroeder, R.M.; Mueller, I.L. [Universidade Federal do Rio Grande do Sul (LAPEC/UFRGS), Porto Alegre, RS (Brazil). Dept. de Metalurgia. Lab. de Pesquisa em Corrosao], e-mail: maiquel10@walla.com

    2006-07-01

    The fatigue and corrosion fatigue behavior of welded Inconel 625 employed live like risers in off-shore platforms was studied. These risers may be employed integrally of this alloy, or combined with API 52 X60 steel in the form of 'Clads'. One of the most susceptible points in .these structures is the circumferential weld that joint the pipes together. In these regions, stresses and defects are generated by the welding process, and these material remind in contact with aggressive species like, chlorides and Co{sub 2} . Polarization curves, slow strain rate fatigue and corrosion fatigue tests were used to characterize the Inconel alloy behavior. In the welded deposit condition, this alloy shows an excellent resistance corrosion and a good fatigue and corrosion-fatigue behavior.(author)

  2. Assessment of the occupational hazards control in a offshore oil production platform%某海洋石油生产平台职业病危害控制效果评价

    Institute of Scientific and Technical Information of China (English)

    宁宇; 侯旭剑

    2012-01-01

    [Objective] To understand occupational hazards and its control effect in a offshore oil production platform and put forward the key control points of occupational hazard and further betterment measures. [Methods]Occupational investigation was carried out on this project, detection and analysis were made on the occupational hazards in the workplace. [Results] main occupational hazards in this production were methane, non-methane hydrocarbons, benzene, toluene, xylene, hydrogen sulfide, metha-nol, isopropyl alcohol, acetic acid, carbon monoxide, nitrogen oxides, noise, heat, microwave radiation, power frequency electric field, etc. The above-mentioned hazards might existed in each operation post in production. The inspection results showed the concentrations of methane, pentane, hexane, heptane, benzene, toluene, xylene, hydrogen sulfide, methanol, isopropyl alcohol and acetic acid all matched the request of national occupational standards. Two individual noise measurement results (mechanician and electrician) had exceeded the request of national occupation standards, the noise when the emergency generator is on had exceeded the request of nationa standards, the measurement results of microwave radiation and work frequency electric field all met the request of national standards. [ Conclusion]The protective measures, rules and regulations aiming at the generated occupational hazards of this project are effective and feasible, their occupational disease protective facilities can satisfy the requirements of occupational health acceptance.%目的 通过了解海洋石油生产平台存在的职业病危害因素及其控制效果,提出职业病危害的关键控制点和防护的进一步改进措施.方法 对项目进行职业卫生调查,对作业场所中的职业病危害因素进行检测并分析.结果 该项目在正常生产过程中存在的职业病危害因素主要有甲烷、非甲烷总烃、苯、甲苯、二甲苯、硫化氢、甲醇、异丙醇、

  3. 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.

  4. Microbial Mats in the Mesoproterozoic Carbonates of the North China Platform and Their Potential for Hydrocarbon Generation

    Institute of Scientific and Technical Information of China (English)

    Shi Xiaoying; Zhang Chuanheng; Jiang Ganqing; Liu Juan; Wang Yi; Liu Dianbo

    2008-01-01

    The well-preserved Mesoproterozoic succession in the North China platform consists mainly of three llthological associations including peritidal quartz sandstone, shallow marine and lagoonai dark to black shales, and shallow epeiric carbonates, with a total thickness of up to 8 000 m. In addition to well-documented microplants, macroalgae, and microbial buildups, abundant microbially induced sedimentary structures (MISS) and mat-related sediments have been recognized in these rocks. Intensive microbial mat layers and MISS are especially well preserved in the carbonates of the upper Gaoyuzhuang (高于庄) (ca. 1.5 Ga) and lower Wumishan (雾迷山) (ca. 1.45 Ga) formations, Indicating diversified microbial activities and a high organic production. In these petrified blomats, putative microbial fossils (both coccoidal and filamentous) and framboidal pyrites have been identified. The abundance of authigenic carbonate minerals in the host rocks, such as, acicular aragnnites, rosette barites, radial siderites, ankerites, and botryoidai carbonate cements, suggests authigenlc carbonate precipitation from anaerobic oxidation of methane (AOM) under anoxic/euxinic conditions. Warm climate and anoxic/euxinic conditions in the Mesoproterozoic oceans may have facilitated high microbial productivity and organic burial in sediments. Although authigenic carbonate cements may record carbonate precipitation from anaerobic methane oxidation, gas blister (or dome) structures may indicate gas release from active methanogenesls during shallow burial Bituminous fragments in mat-related carbonates also provide evidence for hydrocarbon generation. Under proper conditions, the Mesoproterozoic mat-rich carbonates will have the potential for hydrocarbon generation and serve as source rocks. On the basis of petrified biomats, a rough estimation suggests that the Mesoproterozoic carbonates of the North China platform might have a hydrocarbon production potential in theorder of 10×108t.

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

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Haglind, Fredrik; Kandepu, Rambabu;

    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 bot...

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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;

    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 co......-existing pyrite in the later Middle Ordovician are consistent with oxygen mixing at depth and ventilation of euxinic bottom waters [4]. We measured the Cr isotopic composition of an Early to Middle Ordovician carbonate platform to test whether Cr isotopes record ocean oxygenation. The Cr isotopic composition...

  13. 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.

  14. 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

  15. Offshore Platform Modular Drilling Rig Driller Control Room Layout Based on Humanized Design%基于人性化设计的海洋钻井平台司钻控制房布局

    Institute of Scientific and Technical Information of China (English)

    苏继锋

    2013-01-01

    Based on the survey of driller control room layout of the domestic and international offshore platform modular drilling rig (hereinafter referred to as modular drilling rig).The modular drilling rig driller control room layout problems in our country are pointed out,and the "people-oriented" design concept in industrial design are introduced into the design of offshore platform device.This paper puts forward the specific humanized design method,that is determine the users' cognition for driller operation by full investigation,and establish Chinese digital human model as the design basis to meet the need of human body physiology.And then according to the ergonomics theory and considering the human psychological cognition,determine the humanized operation space by means of computer-aided ergonomics design.This research lays the foundation for establishing the design specification of China-made modular drilling rig driller control room layout.%在对国内外海洋平台模块钻机(以下简称模块钻机)司钻控制房的布局调查基础上,指出我国模块钻机司钻控制房布置存在的问题,将工业设计中“以人为本”的设计理念引入海洋平台设备设计中.本文提出了具体的人性化设计方法,即对用户进行充分的调查以寻找用户对司钻操作的认知,建立中国数字人体模型作为满足人体生理需要的设计依据,根据人机工程学理论并考虑人的心理认知,通过计算机辅助人机设计确定人性化操作空间,为建立国产模块钻机司钻控制房布局设计规范奠定基础.

  16. 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...... that outsourcing can be used proactively to promote expanded international operations....

  17. 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.

  18. 系泊油轮与海上平台的碰撞力分析%Collision Force Between Moored Tanker and Offshore Platform

    Institute of Scientific and Technical Information of China (English)

    唐友刚; 陶海成; 王榕; 曹菡

    2012-01-01

    考虑风、浪、流的联合作用以及平台护舷非线性恢复刚度,研究船舶系泊状态与平台的撞击力及其分布规律.针对不同的风、浪、流的作用方向以及不同的风速、波高及流速,计算波浪和海流的载荷,建立系泊船舶的分析模型,采用频域与时域分析方法,进行系泊船舶运动及其与平台之间碰撞力的仿真,得到系泊船舶与平台的碰撞力时间历程,并分析不同碰撞力发生的概率,确定发生最大碰撞力的风、浪、流方向,比较常量护舷刚度与非线性护舷刚度的计算结果.结果表明,橡胶护舷刚度的选取对于碰撞力的计算结果影响显著,选取非线性护舷刚度计算靠泊碰撞力十分必要,用目前的经验公式计算得到的碰撞力偏差较大.%Collision force and its distribution which acted on the rubber fender of a ship moored to a platform were researched by considering the influence of wind, wave, flow and nonlinear stiffness of the platform fender. According to different angles of wind, wave and flow as well as different wind speed, wave height and flow velocity, the loads of wave and ocean current for mooring system were calculated. And also the analysis model for moored ship was established. Moreover the collision force between the moored ship and a platform were simulated through the method of time domain and frequency domain, and obtained the time history of collision force. Besides, the probability of occurrence of different collision force was analyzed in order to determine the direction of wind, wave and flow which maximum collision force occurred. The results show that the rubber fender stiffness has significant effect on the calculation of collision force, it is essential to choice non-linear fender stiffness when calculating the collision force on the platform. And there are relatively larger deviations by using empirical formula to calculate collision force.

  19. Offshore Space Center (offshore launch site)

    Science.gov (United States)

    Harvey, D. G.

    1980-07-01

    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.

  20. 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

  1. 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.

  2. Effect of wind turbine on TLP flating platform response

    Digital Repository Service at National Institute of Oceanography (India)

    Chodnekar, Y.P.; Mandal, S.; Rao, K.B.

    focuses on the innovative concept of renewable offshore wind energy wherein the hydrodynamic analysis of Tension Leg Platform (TLP) Floating Offshore Wind Turbine (FOWT) which supports 5MW wind turbine tower is carried out using ‘ANSYS Workbench 14...

  3. Persistence of Carbonate Platform Environments in Central Mexico during the Oceanic Anoxic Event 2: impact of the Carribean Plateau?

    Science.gov (United States)

    Bomou, Brahimsamba; Adatte, Thierry; Föllmi, Karl; Arnaud-Vanneau, Annie; Fleitmann, Dominik

    2010-05-01

    The Cenomanian-Turonian Oceanic Anoxic Event 2 is described as an interruption of normal pelagic sediment deposition by several distinct intervals of widespread oceanic anoxia (Schlanger & Jenkyns, 1976; Jenkyns, 1980; Arthur et al., 1990) characterized by black shales deposition coinciding with a positive shift in carbon isotope excursion. Some authors show a relationship between OAEs and massive volcanic events associated with the emplacement of large igneous provinces (LIPs) and sea floor spreading at mid-ocean ridges (Kuroda et al., 2007; Snow et al., 2005). High metal abundance anomalies recorded in pelagic sections (e.g. Pueblo, Colorado) coincide with the massive volcanism that built the Carribean plateau (around 93-94 Ma), associated with the onset of OAE 2 (Snow et al., 2005). Mort et al., (2007) demonstrate that the onset of the OAE 2 was triggered by a short-lived but significant increase in phosphorus burial. The bottom waters became anoxic and switched from being a P sink to a P source, sustaining the productivity in a positive feedback loop. However, the behaviour of phosphorus and trace metals at larger scale, in different paleogeography and paleodepht is still poorly known. The Axaxacualco and Baranca el Cañon sections, located at the Guerrero-Morelos carbonate platform in southern Mexico exhibit a fully correlateable d13C curves. In the distal part of the carbonate platform at Axaxacualco, the maximum d13C positive excursion coincides with oligotrophic carbonate platform environments supported by low concentrations in P and characterized by abundant and diversified benthic microfauna and rudists. The impact of OAE appears may be more significant in the proximal part of the carbonate platform at Barranca, characterized by the deposition of thick laminated microbialites indicative of mesotrophic conditions. The Morelos Carbonate platform with oligotrophic to mesotrophic conditions was persistent throughout the entire OAE2 in Central Mexico despite

  4. Study on Static-recrystallization and Phase Transition under Continuous Cooling of Offshore Platform Steel F550%F550再结晶和连续冷却相变行为研究

    Institute of Scientific and Technical Information of China (English)

    王焕洋

    2013-01-01

    Double-pass compression tests were carried out on the MMS-200 thennomechanical simulator to obtain static-recrystalization curves of offshore platform steel F550.By using a combined method of dilatometry and metallography,dilatometric curves of continuous cooling of F550 were measured,and dynamic CCT curves were obtained.Transformation process of austenite during continuous cooling and microstructure of the transformed products were studied.These tests could provide references for the on-site rolling process of F550.%在MMS-200热模拟试验机上进行双道次压缩试验,测定了F550级海洋平台用钢的静态再结晶曲线;利用膨胀法、结合金相法,测定了F550连续冷却转变的膨胀曲线,获得了动态CCT曲线;研究了F550连续冷却过程的奥氏体转变及转变产物的显微组织,为现场轧制工艺的制定提供了依据.

  5. 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.

  6. 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.

  7. Exergy analysis of conventional and electrified oil and gas platforms

    OpenAIRE

    Panton, Luke Kollerøs

    2014-01-01

    This paper compares the efficiencies of oil and gas producing offshore platforms, at different points in the production lifetime and for different heat and power supply options by means of energy and exergy analysis. Offshore platform electrification is a tool being employed by the Norwegian government in order to meet its emission reduction promises. The electrification of offshore platforms however, may not always lead to a higher overall system efficiency or the reduction of CO2 emissions ...

  8. 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。

  9. 海洋石油平台用E40钢板的高温变形行为%High Temperature Deformation Behavior for E40 Steel Plate Used for Offshore Platform

    Institute of Scientific and Technical Information of China (English)

    狄国标; 刘美艳; 麻庆申; 司良英; 刘振宇

    2013-01-01

    在MMS-200型热模拟试验机上通过单道次压缩试验研究了海洋平台用E40钢板的高温变形行为及动态再结晶行为;确定了该钢理想的加热温度.结果表明:随着变形温度的升高,该钢的动态再结晶临界切应力呈减小的趋势;动态再结晶的开始温度在900~950℃范围内;850℃时真应力-真应变曲线下降的主要原因是应变诱导铁素体相变;900℃以上时真应力-真应变曲线的下降是动态再结晶所致;其理想的变形加热温度为1 200℃.%High temperature deformation behavior and dynamic recrystalization behavior of an E40 steel plate used for offshore platform were studied by single-pass compressive testing on MMS-200 hot simulation tester. A perfect austenization temperature for the tested steel was determined. The results show that critical shear stree for dynamic recrystalization decreased with the increase of deformation temperature. The start temperature for dynamic recrystalization varied in the range of 900-950℃. The true stress-true strain curve declined at 850℃, which could be explained by strain-induced ferrite transformation, and when deformation temperature was above 900 ℃,dynamic recrystalization led to true stress-true strain curve declining. Ideal deformation temperature of the steel was 1 200℃.

  10. 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.

  11. 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。

  12. 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.

  13. Magnetic porous carbon nanocomposites derived from metal-organic frameworks as a sensing platform for DNA fluorescent detection.

    Science.gov (United States)

    Tan, Hongliang; Tang, Gonge; Wang, Zhixiong; Li, Qian; Gao, Jie; Wu, Shimeng

    2016-10-12

    Metal-organic frameworks (MOFs) have emerged as very fascinating functional materials due to their tunable nature and diverse applications. In this work, we prepared a magnetic porous carbon (MPC) nanocomposite by employing iron-containing MOFs (MIL-88A) as precursors through a one-pot thermolysis method. It was found that the MPC can absorb selectively single-stranded DNA (ssDNA) probe to form MPC/ssDNA complex and subsequently quench the labelled fluorescent dye of the ssDNA probe, which is resulted from the synergetic effect of magnetic nanoparticles and carbon matrix. Upon the addition of complementary target DNA, however, the absorbed ssDNA probe could be released from MPC surface by forming double-stranded DNA with target DNA, and accompanied by the recovery of the fluorescence of ssDNA probe. Based on these findings, a sensing platform with low background signal for DNA fluorescent detection was developed. The proposed sensing platform exhibits high sensitivity with detection limit of 1 nM and excellent selectivity to specific target DNA, even single-base mismatched nucleotide can be distinguished. We envision that the presented study would provide a new perspective on the potential applications of MOF-derived nanocomposites in biomedical fields. PMID:27662768

  14. Application of the Cuttings Treatment Device in the DSJ300-1 Offshore Drilling Platform%岩屑处理装置在DSJ300-1海洋钻井平台上的应用

    Institute of Scientific and Technical Information of China (English)

    冯利杰; 张福; 马永新; 杜渊; 蔡胜利

    2013-01-01

    采用油基钻井液钻井产生的岩屑不但会造成钻井液的损失,而且随着井深的加大,大量岩屑若不加处理而直接排放,会破坏海洋生态环境,若直接收集又会给平台的岩屑清理造成很大的工作量.针对该问题,DSJ300-1海洋钻井平台采用了一套岩屑处理装置来处理钻井岩屑.该装置主要由岩屑甩干机、螺旋输送机、钻井液驳运泵、液体收集罐和液位自控控制装置等组成,它与振动筛、一体机、离心机等其他钻井液净化设备相比较,能减小岩屑的含油质量分数约10%,使其不大于5%.该装置具有液位自控控制功能,能有效减少现场操作人员的工作量,延长钻井液驳运泵的使用寿命.%The cuttings produced in the process of drilling which adopts oil-based drilling fluid will cause loss of drilling fluid. Moreover, with the increase in well depth large amounts of cuttings produced in drilling will do harm to the marine ecological environment if they are not treated but discharged directly. The workload of cuttings removal from the platform will increase remarkably if they are gathered directly. In light of the problem the DSJ300 - 1 offshore drilling platform adopted a set of cuttings treatment device to handle drilling cuttings. The device mainly consists of cuttings drying machine, spiral conveyor, drilling fluid transfer pump, liquid gathering tank and liquid level self-control device. Compared with other drilling fluid purification equipments such as shale shaker, all-in-one machine and centrifuge, it can reduce oil content in cuttings by about 10% and make it no more than 5%. It can effectively reduce the workload of field operators and lengthen the service life of drilling fluid transfer pump.

  15. 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.

  16. Relationship between occupational stress and mental health in offshore oil platform workers%海上平台员工职业应激与心理健康的关系

    Institute of Scientific and Technical Information of China (English)

    吴洪涛; 肖太钦; 邹建芳; 单永乐; 李子建

    2014-01-01

    Objective To investigate the relationship between occupational stress and mental health in offshore oil platform workers and to provide a scientific basis for protection of their mental health.Methods A total of 768 workers on offshore oil platform were surveyed with the Occupational Stress Inventory Revised Edition and Symptom Check List-90 (SCL-90).Results The total score of Occupational Role Questionnaire (ORQ) for the workers (160.27±24.63) was significantly lower than the national norm (166.52±27.01) (P< 0.01); the total score of Personal Strain Questionnaire (PSQ) (101.96±19.8) was significantly higher than the national norm (92.45±17.33) (P<0.01).The total score of Personal Resource Questionnaire (PRQ) for the workers was not significantly different from the national norm (P>0.05),but the items of recreation,social support,and rational/cognitive fonnd significant difference (P<0.05).The total score of SCL-90 was positively correlated with all items of ORQ and PSQ (P<0.0l) and negatively correlated with all items of PRQ (P<0.01).The multiple stepwise regression analysis showed that current work seniority,education background,drinking,role overload,role insufficiency,role ambiguity,responsibility,physical environment,and rational/cognitive conduct impacted the score of SCL-90 (P<0.05).Conclusion The mental health of workers on offshore oil platform is related to occupational stress,and role overload,role ambiguity,physical environment,and rational/ cognitive conduct,etc,are closely associated with the workers' mental health.%目的 探讨某油田海上平台员工职业应激、心理健康状况以及两者之间的关系,为提高其心理健康水平提供科学依据.方法 采用职业紧张量表(OSI-R)与症状自评量表(SCL-90)对768名海上平台员工进行问卷调查.结果 海上平台员工的职业任务总分(160.27±24.63)低于常模值(166.52±27.01)、个体紧张反应总分(101.96±19.8)高于常模值(92.45±17

  17. 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

  18. 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......Corp had outsourced part of its software development work to two Ukrainian companies. The case study approach allowed us to explore the dynamic processes in depth. The study shows that involvement in the foreign market generates learning in various forms that provide a foundation for eventual mode...... development or change—beyond outsourcing specific learning. At the same time, restrictions on 3rd parties’, that is, independent vendors’ access to confidential client data, as well as protection of specific investments in human assets, may eventually become a driver for mode change, as in the SimCorp case...

  19. Wave run-up on offshore wind turbine foundations

    DEFF Research Database (Denmark)

    Baden, Elisabeth; Skourup, Jesper; Andersen, Thomas Lykke;

    2012-01-01

    Wave run-up on appurtenances like boat landings, ladders, platforms and J-tubes of Offshore Wind Turbine foundations have in some cases caused severe and costly damage to these installations. A well-known example of large run-up was registered at the foundations of Horns Reef Offshore Wind Farm, ...

  20. Advances in electrospun carbon fiber-based electrochemical sensing platforms for bioanalytical applications.

    Science.gov (United States)

    Mao, Xianwen; Tian, Wenda; Hatton, T Alan; Rutledge, Gregory C

    2016-02-01

    Electrochemical sensing is an efficient and inexpensive method for detection of a range of chemicals of biological, clinical, and environmental interest. Carbon materials-based electrodes are commonly employed for the development of electrochemical sensors because of their low cost, biocompatibility, and facile electron transfer kinetics. Electrospun carbon fibers (ECFs), prepared by electrospinning of a polymeric precursor and subsequent thermal treatment, have emerged as promising carbon systems for biosensing applications since the electrochemical properties of these carbon fibers can be easily modified by processing conditions and post-treatment. This review addresses recent progress in the use of ECFs for sensor fabrication and analyte detection. We focus on the modification strategies of ECFs and identification of the key components that impart the bioelectroanalytical activities, and point out the future challenges that must be addressed in order to advance the fundamental understanding of the ECF electrochemistry and to realize the practical applications of ECF-based sensing devices. PMID:26650731

  1. Advances in electrospun carbon fiber-based electrochemical sensing platforms for bioanalytical applications.

    Science.gov (United States)

    Mao, Xianwen; Tian, Wenda; Hatton, T Alan; Rutledge, Gregory C

    2016-02-01

    Electrochemical sensing is an efficient and inexpensive method for detection of a range of chemicals of biological, clinical, and environmental interest. Carbon materials-based electrodes are commonly employed for the development of electrochemical sensors because of their low cost, biocompatibility, and facile electron transfer kinetics. Electrospun carbon fibers (ECFs), prepared by electrospinning of a polymeric precursor and subsequent thermal treatment, have emerged as promising carbon systems for biosensing applications since the electrochemical properties of these carbon fibers can be easily modified by processing conditions and post-treatment. This review addresses recent progress in the use of ECFs for sensor fabrication and analyte detection. We focus on the modification strategies of ECFs and identification of the key components that impart the bioelectroanalytical activities, and point out the future challenges that must be addressed in order to advance the fundamental understanding of the ECF electrochemistry and to realize the practical applications of ECF-based sensing devices.

  2. 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.

  3. 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

  4. 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.

  5. 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...

  6. 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

  7. 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

  8. 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

  9. 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...

  10. 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.

  11. 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

  12. Relation between stratigraphic architecture and multi-scale heterogeneities in carbonate platforms: The Barremian-lower Aptian of the Monts de Vaucluse, SE France

    Science.gov (United States)

    Leonide, Philippe; Borgomano, Jean; Masse, Jean-Pierre; Doublet, Stefan

    2012-07-01

    Understanding the relationship between multi-scale sedimentary heterogeneities and the stratigraphic architectures of carbonate platforms improves the interpretation of paleoenvironmental evolution in time and space. Such an approach improves the prediction of the spatial distribution of reservoir properties within carbonate stratigraphic units. The reservoir-scale stratigraphic anatomy and the growth history of a Barremian-Aptian carbonate platform (Monts de Vaucluse, SE France) was based on 1) high-resolution measured sections on outcrops, 2) detailed microfacies analyses, 3) paleoenvironmental interpretations, 4) biostratigraphy using rudist bivalves, foraminifera, calcareous algae, and locally echinoderm and ammonites, and 5) sequence stratigraphic interpretations with a special focus on the identification of discontinuity surfaces with a significant stratigraphic correlation potential and critical environmental meaning. The platform succession consists of subtidal (mainly infralittoral) with rare inter- to supratidal deposits. Thirty types of elementary facies, grouped in 12 facies associations, have been defined. The vertical and lateral changes in paleoenvironments together with the development of remarkable stratigraphic surfaces, such as subaerial exposures, marine erosional surfaces, and drowning surfaces, allow the definition of five stratigraphic sequences ranging from the late Barremian to the earliest Aptian. These depositional sequences can be grouped into two distinct carbonate sedimentary systems characterized by specific sedimentary profiles and skeletal and non-skeletal components: 1) a carbonate platform with stronger hydrodynamic gradients, rimmed by a narrow belt of high energy deposits with corals and rudistid rudstone facies and 2) a carbonate ramp dominated by orbitolinids fine-grained facies, including an elongated high energy oolitic shoal. The two-dimension architecture of the depositional sequences (dimensioned geometries, thickness and

  13. Carbon Nanotube-Based Permeable Membranes: A Platform for Studying Nanofluidics

    Energy Technology Data Exchange (ETDEWEB)

    Holt, J K; Park, H G; Noy, A; Huser, T; Eaglesham, D; Bakajin, O

    2004-05-25

    A membrane of multiwalled carbon nanotubes embedded in a silicon nitride matrix was fabricated for use in studying fluid mechanics on the nanometer scale. Characterization by fluorescent tracer diffusion and scanning electron microscopy suggests that the membrane is void-free near the silicon substrate on which it rests, implying that the hollow core of the nanotube is the only conduction path for molecular transport. Nitrogen flow measurements of a nanoporous silicon nitride membrane, fabricated by sacrificial removal of carbon, give a flow rate of 0.086 cc/sec. Calculations of water flow across a nanotube membrane give a rate of 2.1x10{sup -6} cc/sec (0.12 {micro}L/min).

  14. 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...

  15. 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

  16. 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.

  17. 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

  18. Offshoring and International Competitiveness

    DEFF Research Database (Denmark)

    Ørberg Jensen, Peter D.; Pedersen, Torben

    2012-01-01

    of 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....

  19. Platform margins, reef facies, and microbial carbonates; a comparison of Devonian reef complexes in the Canning Basin, Western Australia, and the Guilin region, South China

    Science.gov (United States)

    Shen, Jian-Wei; Webb, Gregory E.; Jell, John S.

    2008-05-01

    Devonian reef complexes were well developed in Western Australia and South China, but no detailed direct comparison has been made between reef building in the two regions. The regions differ in several respects, including tectonic, stratigraphic and palaeoceanographic-palaeogeographic settings, and the reef building styles reflect minor differences in reef builders and reef facies. Similarities and differences between the two reef complexes provide insights into the characteristics of platform margins, reef facies and microbial carbonates of both regions. Here we present a comparison of platform margin types from different stratigraphic positions in the Late Devonian reef complex of the Canning Basin, Western Australia and Middle and Late Devonian margin to marginal slope successions in Guilin, South China. Comparisons are integrated into a review of the reefal stratigraphy of both regions. Reef facies, reef complex architecture, temporal reef builder associations, 2nd order stratigraphy and platform cyclicity in the two regions were generally similar where the successions overlap temporally. However, carbonate deposition began earlier in South China. Carbonate complexes were also more widespread in South China and represent a thicker succession overall. Platforms in the Canning Basin grew directly on Precambrian crystalline basement or early Palaeozoic sedimentary rocks, but in South China, carbonate complexes developed conformably on older Devonian siliciclastic strata. Pre-Frasnian reef facies in South China had more abundant skeletal frameworks than in Canning Basin reefs of equivalent age, and Famennian shoaling margins containing various microbial reefs may have been more common and probably more diverse in South China. However, Late Devonian platform margin types have been documented more completely in the Canning Basin. Deep intra-platform troughs (deep depressions containing non-carbonate pelagic sediments — Nandan-type successions) that developed along

  20. 海上采油平台人员心理健康状况及影响因素%Mental health and related factors in workers on offshore oil recovery platform

    Institute of Scientific and Technical Information of China (English)

    卢士军; 蒋与刚; 庞伟; 杨红澎; 卢豪; 李静; 彭守文

    2011-01-01

    Objective To investigate the status of mental health and its influence factors among the workers on offshore oil recovery platform. Methods Totally 196 works were recruited. Symptom Checklist-90 ( SCL-90), Self-Rating Anxiety Scale ( SAS), Self-Rating Depression Scale ( SDS ), Knowledge, Attitude, Practice (KAP) Scale, Stress Questionnaire, International Physical Activity Questionnaire (IPAQ) Short Forms and the essential information questionnaire were applied to evaluate the status of mental henalth of the workers. Physical examination and biochemical evaluation were conducted simultaneously. Results The results of SCL-90 test showed that the total score,depression score,anxiety score,and psychosis score of the workers were 130. 72 ±37. 37,1.63 ±0. 50,1.53 ±0. 57,and 1.45 ±0. 49,respectirely,and were significantly higher than those in Chinese adult norm( P < 0. 05 ). The number of workers with anxiety and depression were 76 and 57,with the prevalences of 38. 8 % and 29. 1%, respectively. The results of multivariate logistic regression analysis showed that the influence factors of mental health were occupational stress, adaption of special condition and life plumpness. Adaption of special conditions,nutritional and healthy awareness,physical acticities and life plumpness were main influence factors of anxiety scales. While the main influence factors of depression scales included physical activity, life plumpness ,nutrition-related chronic disease, and shift of life rhythm. Conclusion The workers on offshore oil recovery platform have some mental health problems and the comprehensive intervention including psychology ,nutrition and exercise should be developed.%目的 了解中国近海采油平台人员心理健康状况及相关影响因素.方法 以中海油某采油平台员工196人为研究对象,采用症状自评量表(SCL-90)、焦虑自评量表(SAS)、抑郁自评量表(SDS)、营养知识-态度-行为量表(KAP)、应激量表、体力活动

  1. 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

  2. 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...

  3. Subaerial exposure and drowning processes in a carbonate platform during the Mesozoic Tethyan rifting: The case of the Jurassic succession of Western Sicily (central Mediterranean)

    Science.gov (United States)

    Sulli, A.; Interbartolo, F.

    2016-01-01

    The Liassic carbonate platform succession outcropping at Monte Maranfusa (central Western Sicily) consists of a shallowing-upward sequence of peritidal carbonates, with Jurassic to Paleogene pelagic limestone and siliciclastic Tertiary covers above. The cyclic sequences of subtidal wackestones/packstones, intertidal microcrystalline carbonates with bird's-eye pores, and supratidal bioclastic grainstones are interbedded with dark layers of the following composition: 1) dark-gray, compact, and well-cemented limestone with blackish clasts, interpreted as calcretes (a type of carbonate soil) and 2) reddish calcite laminae, deformed by elongated cavities, filled with vadose silt, interpreted as paleokarst. This succession is crossed by almost vertical faults, of the Late Liassic to Miocene, which often coincides with neptunian dykes, filled by several generations of Toarcian-Early Miocene pelagic sediments. Another system of dykes, known as neptunian sills, filled by injected Upper Lias-Dogger pelagic sediments, lies parallel to the stratification. The parallel dykes were caused by the flexure of the platform during the Jurassic and presumably by a planar slip in the carbonate rocks, whereas neptunian dykes are caused by faulting episodes. Here, we present evidence that the dark layers in the Liassic succession of Monte Maranfusa, previously described by many authors only as parallel dykes, can actually be interpreted as a) neptunian sills, b) pedogenic calcretes, and c) paleospeleothems. Therefore, we found evidence of exposure/flooding intervals in the evolution of the carbonate platform during the Liassic, linked to different pulses in both the subsidence/tectonic activity and the sea-level oscillations. At the top, Fe-Mn crusts (hardgrounds) seal the carbonate platform succession, which is in turn overlain by condensed pelagic deposits, confirming its drowning during rifting processes.

  4. 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...

  5. 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.

  6. 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....

  7. 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

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. From Offshoring to Backshoring

    DEFF Research Database (Denmark)

    Slepniov, Dmitrij; Madsen, Erik Skov

    2015-01-01

    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 change in the course of the life cycle of offshored tasks. The findings of the paper advance our understanding about how and why geography and mode of offshored tasks may change over time. The main emphasis is given to the concepts of backshoring and repatriation of activities that increasingly attract...

  16. Inspector shortage in the offshore oil industry

    Energy Technology Data Exchange (ETDEWEB)

    Varcoe, David

    2002-07-01

    According to an article published by the Scotsman Online, a critical shortage of offshore safety inspectors is placing the lives of thousands of North Sea oil men at risk. Key improvements in the offshore safety regime, which followed the Piper Alpha disaster, are being compromised by the inability of front-line inspectors from the UK government's Health and Safety Executive to police platforms in the UK sector of the North Sea. The present article discusses the safety situation in the petroleum industry of the North Sea.

  17. 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.

  18. Telecommunications in connection with the offshore petroleum activity. Telekommunikasjon i forbindelse med petroleumsvirksomhet til havs

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    The conference proceedings contain 19 papers. The topics covered are: Telecommunications in the North Sea; Who has the telecommunications engineering capacity. Concession obligation, obligatory equipment and technical requirements - the regulations of the Norwegian Telecommunications Administration; Loudspeaker and alarm installations on offshore platforms; Telephone systems and networks for offshore platforms; Satelitte communications to platforms - present day and in the future; The use of offshore microwave communications; Power supply plants for communications systems; Radio/TV entertainment installations; Telecommunication cables for offshore applications; Electric installations in areas with a danger of explosion; Fiber optics applications and possibilities offshore; Telecommunications net for STATPIPE; Data communications; New communications systems offshore. Separate abstracts were prepared for none of the papers of the proceedings.

  19. Surface analysis and electrochemistry of a robust carbon-nanofiber-based electrode platform H2O2 sensor

    Science.gov (United States)

    Suazo-Dávila, D.; Rivera-Meléndez, J.; Koehne, J.; Meyyappan, M.; Cabrera, C. R.

    2016-10-01

    A vertically aligned carbon nanofiber-based (VACNF) electrode platform was developed for an enzymeless hydrogen peroxide sensor. Vertical nanofibers have heights on the order of 2-3 μm, and diameters that vary from 50 to 100 nm as seen by atomic force microscopy. The VACNF was grown as individual, vertically, and freestanding structures using plasma-enhanced chemical vapor deposition. The electrochemical sensor, for the hydrogen peroxide measurement in solution, showed stability and reproducibility in five consecutive calibration curves with different hydrogen peroxide concentrations over a period of 3 days. The detection limit was 66 μM. The sensitivity for hydrogen peroxide electrochemical detection was 0.0906 mA cm-2 mM-1, respectively. The sensor was also used for the measurement of hydrogen peroxide as the by-product of the reaction of cholesterol with cholesterol oxidase as a biosensor application. The sensor exhibits linear behavior in the range of 50 μM-1 mM in cholesterol concentrations. The surface analysis and electrochemistry characterization is presented.

  20. 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.

  1. 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

  2. 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)

  3. 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.

  4. 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.

  5. 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

  6. 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....

  7. 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)

  8. 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.

  9. 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)

  10. 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

  11. Waste heat recovery for offshore applications

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Kandepu, Rambabu; Haglind, Fredrik

    2012-01-01

    production, due to low gas turbine outlet temperature, space and weight restrictions and the need for make-up water. A more promising option for use offshore is organic Rankine cycles (ORC). Moreover, several oil and gas platforms are equipped with waste heat recovery units to recover a part of the thermal...... 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...... energy in the gas turbine off-gas using heat exchangers, and the recovered thermal energy acts as heat source for some of the heat loads on the platform. The amount of the recovered thermal energy depends on the heat loads and thus the full potential of waste heat recovery units may not be utilized...

  12. 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。

  13. 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

  14. 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....

  15. Dynamic Modeling and Simulation of Jacking System in Jack-up Offshore Platform Based on Virtual Prototyping%基于数字样机技术的自升式海洋平台升降系统动力学建模及仿真

    Institute of Scientific and Technical Information of China (English)

    陈刚; 何斌

    2012-01-01

    在分析了自升式海洋平台升降系统结构与原理的基础上,利用三维建模软件对升降系统进行三维建模和虚拟装配,然后将其导入动力学分析软件形成数字样机.通过引入齿轮与齿条接触力对整套升降系统力学性能的影响分析,并参照实际的几何参数、物理特性、约束等信息完成动力学分析,最后以曲线图反映升降系统在给定条件下的动力学特性.结果表明考虑齿轮与齿条接触力使得仿真结果更加准确,验证了海洋平台升降系统设计的合理性.%Based on the analysis of the structure and principle of the jacking system in jack-up offshore platform, the 3D modeling and virtual prototyping of the system are done by 3D modeling software, which are then imported into the dynamic analysis software to form the numeral prototype. With reference to the actual geometric parameters, physical characteristics, constraints and other information, on the research of the gear and rack contact force on the mechanical properties of the full set of lifting system, the dynamics analysis is present with the simulation results, which demonstrates that the method is obviously helpful to get more accurate simulation results considering gear and rack contact force and verify the rationality of jacking system in jack-up offshore platform.

  16. 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

  17. 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...

  18. 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 are benefits of making changes to the configuration after the offshoring implementation (host-based learning). In contrast, when coordination costs and distance dominate, the strategy of gearing the organization for offshoring prior to separating them across country borders prevails (home-based learning). Thus......Offshoring offers managers the promise of substantial economic benefits, but also comes with the risk of increased complexity and coordination challenges. We argue that offshoring firms must accumulate architectural knowledge to keep the cost of coordination of the geographically separated...

  19. 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.

  20. Energy Usage of Residents on Offshore Islands in Taiwan

    Directory of Open Access Journals (Sweden)

    Szu-Cheng Lu

    2015-05-01

    Full Text Available A field study was conducted through interviews on offshore islands in Taiwan to investigate the energy usage of local residents. A comparison of household appliance usage in mainland Taiwan with that on the offshore islands revealed that, overall, the most commonly used household appliances are steam cookers/rice cookers, water dispensers, and washing machines. For other household appliances, Levels 2 and 3 offshore isles have lower use penetration rates compared with those in mainland Taiwan and on Level 1 offshore isles, particularly for the use of computers. By contrast, the use penetration rate for chest freezers on Levels 2 and 3 offshore isles is high, and each household has one or more freezers on average. This appliance is not a commonly observed household product in mainland Taiwan or on Level 1 offshore isles. Furthermore, because of the government policy, every household on parts of Level 2 offshore isles and on all Level 3 offshore isles has a fixed monthly charge of electricity. The transportation of liquefied petroleum gas is also inconvenient, and the gas price is slightly higher, leading to the tendency of residents to consume excessive amounts of electrical energy, which does not correspond with the aim of the government to conserve energy and reduce carbon emissions; thus, the relevant authorities’ review and improvement on energy consumption on Levels 2 and 3 offshore isles are required.

  1. 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.

  2. Extensive occurrence and genesis of authigenic carbonates from Krishna-Godavari offshore basin (Bay of Bengal): Possible influence of methane hydrates occurrences.

    Digital Repository Service at National Institute of Oceanography (India)

    Kocherla, M.; Pillai, S.; Patil, D.J.

    that the carbon source for the formation of authigenic carbonates were gas hydrates below, and the carbonates were formed from the flow of methane-enriched fluids through fracture network formed because of shale diapirism. The detailed genetic framework is under...

  3. 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...

  4. Model Predictive Control of Offshore Power Stations With Waste Heat Recovery

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Chan, Richard; Li, Xiangan;

    2016-01-01

    The implementation of waste heat recovery units on oil and gas offshore platforms demands advances in both design methods and control systems. Model-based control algorithms can play an important role in the operation of offshore power stations. A novel regulator based on a linear model predictive...

  5. Fatigue Reliability and Calibration of Fatigue Design Factors for Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Dominguez, Sergio Marquez; Sørensen, John Dalsgaard

    2012-01-01

    Consequences of failure of offshore wind turbines (OWTs) are in general lower than consequences of failure of, e.g., oil & gas platforms. It is reasonable that lower fatigue design factors can be applied for fatigue design of OWTs when compared to other fixed offshore structures. Calibration...

  6. 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...

  7. 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.

  8. 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

  9. 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...

  10. Whether and What to Offshore?

    DEFF Research Database (Denmark)

    Jensen, Peter Ørberg; Pedersen, Torben

    that incorporates two different aspects of the process of offshoring. First, we approach the question of whether to offshore and establish a baseline that investigates the determinants of firms’ participation—or lack thereof—in offshoring. Secondly, we approach the question of what to offshore and the subsequent......, while rather different determinants matter for the subsequent process of offshoring of advanced activities. Although the model portrays a simplified expression of the offshoring process with two stages, the findings underpin our view that a process perspective on offshoring is a useful analytical...

  11. 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.

  12. 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.

  13. 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......, 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....

  14. Offshore Q & A

    Institute of Scientific and Technical Information of China (English)

    AmberStohr

    2003-01-01

    Equity International, Asia, is a leading financial service provider in China, offering planning expertise for expatriates on investing their income and savings. I recently sat down with four senior wealth managers in Shanghai to discuss Equity's approach to offshore investing.

  15. 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.

  16. 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)

  17. Offshore Wind Data Integration

    OpenAIRE

    Nguyen, Trinh Hoang

    2014-01-01

    Using renewable energy to meet the future electricity consumption and to reduce environmental impact is a significant target of many countries around the world. Wind power is one of the most promising renewable energy technologies. In particular, the development of offshore wind power is increasing rapidly due to large areas of wind resources. However, offshore wind is encountering big challenges such as effective use of wind power plants, reduced cost of installation as well a...

  18. 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

  19. 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...

  20. 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.

  1. 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)...

  2. 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.

  3. 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

  4. Reliability Analysis of Tubular Joints in Offshore Structures

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Sørensen, John Dalsgaard

    1987-01-01

    Reliability analysis of single tubular joints and offshore platforms with tubular joints is" presented. The failure modes considered are yielding, punching, buckling and fatigue failure. Element reliability as well as systems reliability approaches are used and illustrated by several examples....... Finally, optimal design of tubular.joints with reliability constraints is discussed and illustrated by an example....

  5. 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...

  6. Ultimate strength performance of offshore structural framing

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This review of the use of nonlinear ultimate strength (pushover) analyses in determining performance measures of tubular framed structures has been prepared for the Health and Safety Executive (HSE) by BOMEL Limited. An in-house state-of-the-art package (SAFJAC), developed over the last decade in parallel with experimental investigations, was used to analyse a variety of frames representative of platforms in the UK Sector of the North Sea. Ultimate strength analysis of offshore structures has increasingly become used to assess the integrity of various design configurations against extreme and accidental loading. It has also been used to determine the safety of existing offshore structures in view of updated environmental and structural data or changing operational requirements. It is now also being adopted to determine the criticality of members within the structural system and to assess various inspection and repair schemes. (author)

  7. 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

  8. 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。

  9. 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.

  10. 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.

  11. A silk derived carbon fiber mat modified with Au@Pt urchilike nanoparticles: A new platform as electrochemical microbial biosensor.

    Science.gov (United States)

    Deng, Liu; Guo, Shaojun; Zhou, Ming; Liu, Ling; Liu, Chang; Dong, Shaojun

    2010-06-15

    We present here a facile and efficient route to prepare silk derived carbon mat modified with Au@Pt urchilike nanoparticles (Au@Pt NPs) and develop an Escherichia coli (E. coli)-based electrochemical sensor using this material. Silk is a natural protein fiber, and it is abundant with kinds of functionalities which are important in the development of the derived material. The S-derived carbon fiber mat have amino, pyridine and carbonyl functional groups, these natural existent functionalities allow the Au@Pt NPs to self-assemble on the carbon fiber surface and provide a biocompatible microenvironment for bacteria. The Au@Pt NPs modified S-derived carbon fiber is sensitive to detect the E. coli activities with a low detection limit, where glucose is used as a prelimiltary substrate to evaluate them. The performance of Au@Pt/carbon fiber mat based biosensor is much better than that of commercial carbon paper based biosensor. The high sensitivity of this biosensor stems from the unique electrocatalytic properties of Au@Pt urchilike NPs and quinone groups presented in S-derived carbon fiber. This biosensor is also tested for detection of organophosphate pesticides, fenamiphos. The relative inhibition of E. coli activity is linear with -log[fenamiphos] at the concentration range from 0.5mg/L to 36.6 mg/L with lowest observable effect concentration (LOEC) of 0.09 mg/L. The Au@Pt NPs modified S-derived carbon fiber mat possesses high conductivity, biocompatibility and high electrocatalytic activity and be can used as advanced electrode materials for microbial biosensor improvement. The microbial biosensor based on this material shows potential applications in environmental monitoring.

  12. 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.

  13. 基于FDS的海洋平台油气处理系统火灾危险分析%Fire hazard analysis on oil & gas processing system on the offshore platform based on FDS

    Institute of Scientific and Technical Information of China (English)

    郭杰; 朱渊; 陈国明

    2011-01-01

    以某海洋平台下层甲板油气处理系统为研究对象,针对油气处理系统原油泄漏引发的火灾事故,以计算流体力学为理论基础,采用FDS软件建立油气处理系统火灾动力学模型,选取温度、热辐射强度、烟气层高度(厚度)和能见度等4个火灾危险性评价指标,对火灾影响后果进行了评价.油气处理系统一旦发生火灾将导致严重后果,人员需立即疏散并采取控制措施;通过对比不同脱险梯道受火灾影响程度,确定出了最有利于人员疏散的路径;设备泄漏孔径越大,火灾危险性越大,不利于人员疏散.%To study the fire accidents happened in the oil & gas processing system of offshore plat form due to oil discharge, a fire dynamic model is built by using FDS software, which is based on computational fluid dynamics. Four criteria including temperature, radiation intensity, smoke layer height (thickness) and visibility are used to assess the consequences of the fire. It is shown that the fire resulting from the oil &. gas processing system is so dangerous that people should be evacuated and control measured should he taken immediately. The prime escape route is determined by comparing the damages to the escape routs caused by the fire. And with the growth of the lesk aperture, the fire is more danger ous and people's evacuation is more difficult.

  14. Authigenic minerals related to carbon and sulfur biogeochemical cycling from deep-sea active methane seeps offshore South-West Africa

    Science.gov (United States)

    Pierre, C.; Blanc-Valleron, M.; Demange, J.; Boudouma, O.; Pape, T.; Himmler, T.; Fekete, N.; Spiess, V.

    2011-12-01

    The South-West African continental margin is well known for occurrences of active methane-rich fluid seeps that are associated with seafloor pockmarks in a broad range of water depths, from the shelf to the deep basins. High gas flares in the water column, luxurious oases of benthic fauna, gas hydrate accumulations and diagenetic carbonate crusts have been observed at these seeps. During the M76/3a expedition of R/V METEOR (summer 2008) gravity cores recovered abundant authigenic carbonate concretions from five pockmarks of the South-West African margin including previously studied sites (Hydrate Hole, Worm Hole, Regab Pockmark) and two sites (Deep Hole, Baboon Cluster) newly discovered during the cruise. Carbonate concretions were mostly associated to sediments settled by seep-associated benthic macrofauna and bearing shallow gas hydrates. We present new results of the comprehensive analysis of the mineralogy and isotope geochemistry of the diagenetic carbonates sampled in the five pockmarks. The mineralogy of authigenic carbonates is dominated by magnesian calcite and aragonite, associated occasionally with dolomite. The oxygen and carbon isotopic compositions of authigenic carbonates (+2.4 < δ18O % V-PDB < +6.2 ; -61.0 < δ13C % V-PDB < -40.1) indicate that microbial anaerobic oxidation of methane (AOM) was the main process controling carbonate precipitation within sub-seafloor sediments deposited from the glacial-time up to the present. The frequent occurrence of diagenetic gypsum crystals within the sediments demonstrates that bio-irrigation with oxygenated bottom water by the burrowing activity of benthic fauna caused the secondary oxidation of reduced sulfur (hydrogen sulfide and pyrite) that was produced by sulfate reducting bacteria as a by-product of AOM; during the sulfide oxidation process, the released acidity induced the partial dissolution of carbonates. Our results demonstrate also the strong link that existed between the carbon and sulfur cycles

  15. Offshore Wind Power Data

    DEFF Research Database (Denmark)

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

    2012-01-01

    Wind power development scenarios are critical when trying to assess the impact of the demonstration at national and European level. The work described in this report had several objectives. The main objective was to prepare and deliver the proper input necessary for assessing the impact of Demo 4...... – 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...

  16. Offshore Wind Farms

    DEFF Research Database (Denmark)

    Lundtang Petersen, Erik; Hasager, Charlotte Bay; Courtney, Michael;

    2015-01-01

    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 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......: 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. Of special...

  17. Import, Offshoring and Wages

    DEFF Research Database (Denmark)

    Fosse, Henrik Barslund; Maitra, Madhura

    Offshoring firms are found to pay higher average wages than purely domestic firms. We provide a unifying empirical approach by capturing the different channels through which offshoring may explain this wage difference: (i) due to change in the composition of workers (skill composition effect) (ii......) 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...... of skill composition and rent sharing available in typical firm level datasets - like ratio of educated to uneducated workers and sales per employee....

  18. On outsourcing and offshoring

    DEFF Research Database (Denmark)

    Hansen, Zaza Nadja Lee

    This study investigates the challenges engineering companies face when globalising the product development process through offshoring and outsourcing. Furthermore, to investigate the solutions the companies took to address these and the impact these had on the organisation, the engineering...... models like the stage gate model and outsourcing/offshoring literature concerning how to conduct the globalisation process had not been followed, in particular in the early phases as these called for extensive preparation. iii Knowledge management showed a lack of knowledge sharing initiatives within...... of engineering projects when engineering companies offshore or outsource product development process activities.  Analysing these challenges and impacts using different theoretical tools from organisational studies and operations research.  Demonstrating the disconnection between operational and strategic...

  19. 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....

  20. 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

  1. 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.

  2. 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.

  3. 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 .

  4. 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...

  5. Hurricane damaged fixed platforms and wellhead structures

    Energy Technology Data Exchange (ETDEWEB)

    Shuttleworth, E.P.; Frieze, P.A.

    1998-03-01

    The objective of this study was to review data on damages to offshore platforms with a view to determining their suitability for further exploitation and analysis through a preliminary assessment of trends in the data when viewed from a risk standpoint. To realise this objective, a database on hurricane and other storm related damages was generated and past design practice, particularly concerning environmental load levels, was established. Information was gathered on extreme wave heights, damages, platform details, pushover analyses and structural frame load tests. The information was obtained through: a literature survey of journals, conference proceedings, design codes and guidelines; approaches to organisations in the offshore industry with significant experience of hurricanes, storm-damaged structures and pushover analyses; and interrogation of three major databases on offshore storm and other damages - PMB, MMS and WOAD. (author)

  6. 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...

  7. Floating offshore turbines

    DEFF Research Database (Denmark)

    Tande, John Olav Giæver; Merz, Karl; Schmidt Paulsen, Uwe;

    2014-01-01

    metric of energy production per unit steel mass. Floating offshore wind turbines represent a promising technology. The successful operation of HyWind and WindFloat in full scale demonstrates a well advanced technology readiness level, where further development will go into refining the concepts, cost...

  8. 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

  9. 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.

  10. A self-contained culture platform using carbon dioxide produced from a chemical reaction supports mouse blastocyst development in vitro.

    Science.gov (United States)

    Swain, Jason E

    2011-09-01

    Elevated CO(2) is required for in vitro embryo culture to maintain proper media pH and to supply embryo metabolic pathways. As an alternative to current approaches using gas cylinders, we examined use of a chemical reaction to supply CO(2). A closed culture system was constructed and chemicals added to generate CO(2), which was then supplied to developing embryos. This system was shown to provide a stable pH (7.2-7.4) over 4 days of use. One-cell mouse embryos were cultured in the device and no difference in blastocyst formation or cell number was apparent between embryos grown in a closed system with CO(2) supplied by a chemical reaction or positive controls grown in a an open system in a CO(2) incubator. This approach provides a highly purified, inexpensive, and easily obtainable gas source and offers potential for development of new, self-contained culture platforms. PMID:21532256

  11. 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.

  12. Evolution and hydrocarbon potential of offshore Pinar Del Rio area, Southern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Tenreyro-Perez, R.; Lopez-Rivera, J.G.; Fernandez-Carmona, J.; Lopez-Quintero, J.O.

    1996-09-01

    The evolution of Southeast Gulf of Mexico comprises three main periods: pre-orogenic, syn-orogenic and post-orogenic. During pre-orogenic time, from Lower Jurassic to Campanian, the stages are the rift of Pangaea and the thermal subsidence (or drift). In drift stage two domains interacted in the space; the carbonate platforms (Bahamas, Yucatan, Organos and others), and the deepwater basins. These fluctuations were dictated by the differential subsidence and horizontal displacements of basement blocks as well as by the eustatic movements of the ocean. The Organos platform, for example, was entirely drowned since Upper Jurassic and the sedimentation continued in deepwater environment. The collision between Great Antilles Volcanic Arc and the continental margins since Upper Cretaceous modeled the Cuban orogen. Here, the southern facies thrusted over the northern section with simultaneous strike-slip movements. The interaction suddenly ceased in Eocene. The source rock levels are considerably more frequent in the deepwater domain than in the platforms. The Lower and Upper Jurassic as well as Lower and Middle Cretaceous horizons contain very high levels of organic matter. The offshore seismic shows the transition from the thrusted belt to the foreland basin with a typical triangle zone configuration. Reservoirs are expected in the Cretaceous section covered by seals conformed by early foreland basin sediments of Upper Cretaceous-Paleocene age. Foothill structures has a great potential for hydrocarbon exploration.

  13. 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.

  14. The Numerical Simulation on Diffusion of Flammable Gas from Offshore Platform Vent System%海上平台冷放空可燃气体扩散的数值模拟研究

    Institute of Scientific and Technical Information of China (English)

    张明; 王春升; 衣华磊; 陈绍凯; 钱惠增

    2011-01-01

    为研究烃类物质大气排放所引起的潜在危险,针对某海上平台建立模型,并应用FLUENT软件对平台冷放空泄放气体扩散过程进行了数值模拟研究.研究了可燃气体扩散的基本规律,分析了不同风向、风速、泄放量、冷放空管径、以及泄放口朝向对可燃气体扩散的影响,并将数值模拟结果与规范中的推荐值作了比较,并依据计算结果对冷放空管的设计提出了建议.%To study the potential hazards of flammable mixtures that result from atmospheric discharge of hydrocarbons, the numerical simulation on diffusion of flammable mixtures is carried out using FLUENT software. According to the dimensions of platform, the model is founded. The effect of wind direction, wind speed, discharge capacity, diameter of vent pipe and orientation of vent nozzle to the diffusion of flammable mixtures are analyzed in this paper. At last some proposals about the design of discharge system are made in this paper.

  15. 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,...

  16. A fluorescence-Raman dual-imaging platform based on complexes of conjugated polymers and carbon nanotubes.

    Science.gov (United States)

    Liu, Yun; Huang, Jun; Sun, Min-Jie; Yu, Ji-Cheng; Chen, Yu-Lei; Zhang, Yu-Qi; Jiang, Shao-Jun; Shen, Qun-Dong

    2014-01-01

    The present study describes a flexible nanoplatform based on electrostatic assembly of conjugated polyelectrolytes (CPEs) and carboxylated multi-walled carbon nanotubes (cMWNTs). It is demonstrated that the obtained nanocomposites inherit intrinsic optical properties of CPEs and characteristic Raman vibration modes of MWNTs, providing a fluorescence-Raman dual-imaging method for intracellular tracking and locating of MWNTs. We suggest that the cellular internalization of the CPE-cMWNT nanocomposites is a surface charge-dependent process. The strengths of this nanoplatform include satisfying biocompatibility, enhanced protein-repellent property, and ease of implementation, making it available for both in vitro and in vivo applications.

  17. Electrochemical functionalization of carbon surfaces by aromatic azide or alkyne molecules: a versatile platform for click chemistry.

    Science.gov (United States)

    Evrard, David; Lambert, François; Policar, Clotilde; Balland, Véronique; Limoges, Benoît

    2008-01-01

    The electrochemical reduction of phenylazide or phenylacetylene diazonium salts leads to the grafting of azido or ethynyl groups onto the surface of carbon electrodes. In the presence of copper(I) catalyst, these azide- or alkyne-modified surfaces react efficiently and rapidly with compounds bearing an acetylene or azide function, thus forming a covalent 1,2,3-triazole linkage by means of click chemistry. This was illustrated with the surface coupling of ferrocenes functionalized with an ethynyl or azido group and the biomolecule biotin terminated by an acetylene group.

  18. 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...... 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...... system considering conventional power plants, distributed generation based on wind energy and CHP technology as well as the load and transmission facilities. In particular, the different models are used to represent two well-known test systems, the RBTS and the IEEE-RTS, and to calculate...

  19. Platform Constellations

    DEFF Research Database (Denmark)

    Staykova, Kalina Stefanova; Damsgaard, Jan

    2016-01-01

    This research paper presents an initial attempt to introduce and explain the emergence of new phenomenon, which we refer to as platform constellations. Functioning as highly modular systems, the platform constellations are collections of highly connected platforms which co-exist in parallel and a......’ acquisition and users’ engagement rates as well as unlock new sources of value creation and diversify revenue streams....

  20. Offshore Wind Turbine Design

    DEFF Research Database (Denmark)

    Frandsen, Sten; Hansen, Erik Asp; Ibsen, Lars Bo;

    2006-01-01

    Current offshore wind turbine design methods have matured to a 1st generation state, manifested in the draft of a possible standard, IEC 61400-3 (2005). It is now time to investigate the possibilities of improving existing methods. To do so in an efficient manner a clear identification of the mos...... 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....

  1. 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

  2. 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.

  3. 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

  4. Experimental Study on a Tuned-Mass Damper of Offshore for Vibration Reduction

    Science.gov (United States)

    Wu, Qiong; Zhao, Xilu; Zheng, Rencheng

    2016-09-01

    With the development of industry, oceanic oil production is one of the most important energy resources. Normally, offshore platform, located in the hostile environment, is easily subjected to unstable environmental loading, such as wind, wave, ice, and earthquake, and it becomes a critical problem to ensure the stability of offshore platform for safely engineering operations. In recent years, tuned-mass damper (TMD) technology has been adopted to reduce vibrations from wind and earthquake influences. Due to the complexity of earthquake excitations, most of researchers were focused on controlling response of structures under wind loads; however, less attention has been put on controlling earthquake response. Therefore, this study concentrates on the seismic reduction of offshore platform by application of a TMD system, and a comprehensively experimental study was processed to validate its effectiveness exposed to different earthquake. A 4-column offshore platform was built according to the actual size of approximately 1:200 ratios, and a TMD system was prepared for the experiment. By the different performance analyses, experimental results indicated that the proposed TMD system can effectively suppress the earthquake stimulus and keep the stability of offshore platform.

  5. 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...... sensors or the fusion of sensor data that provides the best predictive ability of the soil properties in question. Using partial least Square regression (PLS) excellent calibration results were generated for all soil properties with a ratio of performance to deviation (RPD) values above 2. The best...

  6. 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.

  7. 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.

  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 proceed with three illustrative case studies and discussion, proposing that the decision to outsource has implications over and beyond the intended strategies. The paper approaches these issues from a strategy-as-practice perspective, and particularly addresses its concern for how micro-level activities...

  9. The Effects of Anthropogenic Structures on Habitat Connectivity and the Potential Spread of Non-Native Invertebrate Species in the Offshore Environment.

    Science.gov (United States)

    Simons, Rachel D; Page, Henry M; Zaleski, Susan; Miller, Robert; Dugan, Jenifer E; Schroeder, Donna M; Doheny, Brandon

    2016-01-01

    Offshore structures provide habitat that could facilitate species range expansions and the introduction of non-native species into new geographic areas. Surveys of assemblages of seven offshore oil and gas platforms in the Santa Barbara Channel revealed a change in distribution of the non-native sessile invertebrate Watersipora subtorquata, a bryozoan with a planktonic larval duration (PLD) of 24 hours or less, from one platform in 2001 to four platforms in 2013. We use a three-dimensional biophysical model to assess whether larval dispersal via currents from harbors to platforms and among platforms is a plausible mechanism to explain the change in distribution of Watersipora and to predict potential spread to other platforms in the future. Hull fouling is another possible mechanism to explain the change in distribution of Watersipora. We find that larval dispersal via currents could account for the increase in distribution of Watersipora from one to four platforms and that Watersipora is unlikely to spread from these four platforms to additional platforms through larval dispersal. Our results also suggest that larvae with PLDs of 24 hours or less released from offshore platforms can attain much greater dispersal distances than larvae with PLDs of 24 hours or less released from nearshore habitat. We hypothesize that the enhanced dispersal distance of larvae released from offshore platforms is driven by a combination of the offshore hydrodynamic environment, larval behavior, and larval release above the seafloor.

  10. 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.

  11. 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...

  12. 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

  13. Lysimeter Platform

    Science.gov (United States)

    Klammler, Gernot; Murer, Erwin; Plieschnegger, Markus

    2014-05-01

    The existing European Lysimeter Platform (www.lysimeter.at/HP_EuLP) provides an overview of lysimeter types used in Europe and show details on equipment, research results and future perspectives of lysimeter facilities. However, this platform is not user-editable and has not been updated since 2008. Thus, the Lysimeter Research Group (www.lysimeter.at) intends to serve a new database based website called Lysimeter Platform, where existing information of the former European Lysimeter Platform will be transferred to the new Lysimeter Platform and, furthermore, registered users are able to create and edit sites where lysimeters, soil water samplers and soil hydrologic measuring profiles are operated. The Lysimeter Research Group is a scientific association and, therefore, the membership is free of charge. The new Lysimeter Platform contains general information of lysimeter sites worldwide (e.g., what is measured at which site) in a standardized form to get a quick but informative overview of the sites and can be linked to more detailed, already existing information provided by the site operators. Due to the standardized information in the database the Lysimeter Platform serves also as search-engine for soil water measurements and helps to find sites of interest and corresponding contact information worldwide. The Session "Estimation of soil-atmosphere and vadose zone water fluxes by use of precision lysimeter measurements" at the EGU General Assembly 2014 would be an excellent chance to present the idea and the concept of this new Lysimeter Platform to international site operators and scientists.

  14. 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

  15. 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.

  16. Bifunctional catalysts based on m-phenylene-bridged porphyrin dimer and trimer platforms: synthesis of cyclic carbonates from carbon dioxide and epoxides.

    Science.gov (United States)

    Maeda, Chihiro; Taniguchi, Tomoya; Ogawa, Kanae; Ema, Tadashi

    2015-01-01

    Highly active bifunctional diporphyrin and triporphyrin catalysts were synthesized through Stille coupling reactions. As compared with a porphyrin monomer, both exhibited improved catalytic activities for the reaction of CO2 with epoxides to form cyclic carbonates, because of the multiple catalytic sites which cooperatively activate the epoxide. Catalytic activities were carefully investigated by controlling temperature, reaction time, and catalyst loading, and very high turnover number and turnover frequency were obtained: 220 000 and 46 000 h(-1) , respectively, for the magnesium catalyst, and 310 000 and 40 000 h(-1) , respectively, for the zinc catalyst. Results obtained with a zinc/free-base hybrid diporphyrin catalyst demonstrated that the Br(-) ions on the adjacent porphyrin moiety also function as nucleophiles.

  17. 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. ...

  18. 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

  19. Pemex increasing offshore activity

    Energy Technology Data Exchange (ETDEWEB)

    Beachy, D.

    1985-05-01

    Although austere by boom-year standards, Mexico's National Energy Program for 1984-1988 calls for forty wildcats and 90 to 144 development wells off the coast, primarily in the prolific Campeche Bay area. Platform additions will include nine drilling platforms, each for twelve wells, and eight eight platforms to drill injection wells. Additionally, 7 production, 6 accomodation, 6 linkage and 8 compression platforms and 13 tetrapods will be installed. The main objectives of the plan are energy self-sufficiency through the turn of the century, and energy diversification, savings and productivity. The most controversial portion of Mexico's energy program is that calling for nuclear energy development. The energy program lists three basic goals in hydrocarbon production: continuing research on better techniques of secondary recovery; increasing capacity for refining primary and secondary crude products and improving production of heavy crudes; and increasing storage capacity and installing pipelines capable of carrying a greater volume of crude.

  20. 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.

  1. 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

  2. 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...

  3. 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.

  4. Offshore Supply Industry Dynamics

    DEFF Research Database (Denmark)

    Roslyng Olesen, Thomas

    and 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...... the physical location is examined and the installation is planned. (3) An installation phase where the equipment is produced and transported to the site where it is installed. (4) An operation phase where the energy is produced or the energy source is extracted and (5) a decommissioning phase where the field...

  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. 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.

  7. Offshore Fish Community: Ecological Interactions

    Science.gov (United States)

    The offshore (>80 m) fish community of Lake Superior is made up of predominately native species. The most prominent species are deepwater sculpin, kiyi, cisco, siscowet lake trout, burbot, and the exotic sea lamprey. Bloater and shortjaw cisco are also found in the offshore zone...

  8. 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....

  9. 30 CFR 250.900 - What general requirements apply to all platforms?

    Science.gov (United States)

    2010-07-01

    ... approval will be cancelled (if installation has not occurred) during the application and approval process... OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Platforms and Structures...

  10. Platform contents

    OpenAIRE

    Renault, Régis

    2014-01-01

    A monopoly platform hosts advertisers who compete on a market for horizontally differentiated products. These products may be either mass market products that appeal broadly to the entire consumer population or niche products that are tailored to the tastes of some particular group. Consumers search sequentially through ads incurring a surfing cost of moving to the next ad. They may click on an ad at some cost, which provides all relevant information and the opportunity to buy. The platform c...

  11. 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.

  12. 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

  13. 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)

  14. 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

  15. Dynamic performance of a novel offshore power system integrated with a wind farm

    DEFF Research Database (Denmark)

    Orlandini, Valentina; Pierobon, Leonardo; Schløer, Signe;

    2016-01-01

    Offshore wind technology is rapidly developing and a wind farm can be integrated with offshore power stations. This paper considers as case study a futuristic platform powered by a wind farm and three combined cycle units consisting of a gas turbine and an ORC (organic Rankine cycle) module...... of the system is compared with a simplified plant consisting of three gas turbines and a wind farm, in order to identify benefits of the installation of the ORC system. The maximum allowable wind power is 10 MW for a nominal platform load of 30 MW. The results show that the presence of the ORC system allows...

  16. Fatigue reliability analysis of fixed offshore structures:A first passage problem approach

    Institute of Scientific and Technical Information of China (English)

    MADHAVAN PILLAI T.M.; VEENA G.

    2006-01-01

    This paper describes a methodology for computation of reliability of members of fixed offshore platform structures,with respect to fatigue. Failure criteria were formulated using fracture mechanics principle. The problem is coined as a "first passage problem". The method was illustrated through application to a typical plane frame structure. The fatigue reliability degradation curve established can be used for planning in-service inspection of offshore platforms. A very limited parametric study was carried out to obtain insight into the effect of important variables on the fatigue reliability.

  17. 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...

  18. Offshore Platform Hydrocarbon Risk Assessment – OPHRA: Feasibility

    DEFF Research Database (Denmark)

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

    and fire; • Detection, shut down and alarm; • Escape and evacuation; • Exposure and impact on people and equipment This method leads to a transparent framework for modelling, which helps to demonstrate the correctness and appropriateness of models and assumptions. The report lists the (type of) models...... 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....... Finally, further work is identified in order to develop an operational risk assessment tool....

  19. 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 ...

  20. 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)....

  1. 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

  2. Preliminary results in larger benthic foraminifera assemblage in a mixed siliciclastic-carbonate platform from the Upper Cretaceous of the External Prebetic Domain (Valencia province, SE Spain)

    Science.gov (United States)

    Robles-Salcedo, Raquel; Vicedo, Vicent

    2016-04-01

    In the External Prebetic Domain (Betic Mountain Range, Valencia province, SE Spain) it is difficult to find good outcrops to study larger benthic foraminifera (LBF), particularly in the Upper Cretaceous deposits, because of three main reasons. During the Upper Cretaceous, the complex paleogeography in the northern Prebetic Domain developed a complex system of shallow-water platforms. This is directly linked to the complexity in the distribution of the facies observed nowadays, which may change drastically in lateral, closely related outcrops having a special negative impact in the lateral extension of stratigraphical levels containing LBF. The second reason is the nature of the shallow water environments in which the larger foraminifera lived. The local continental influence derived in the establishment of very complex mixed platforms. Thus, there is not a complete register through carbonate rocks, but an alternation of microconglomerates, sandstones, calcarenites and carbonates that can be observed in the stratigraphic series of the Upper Cretaceous. This affects negatively in observing changes in the evolutionary trends of taxa. The third reason difficulting the study of LBF in northern localities of the Prebetic Domain is diagenetic. Dolomitization affects a huge part of the Mesozoic rocks deleting all fossil microfauna in the affected rocks. Such three reasons are behind the difficulty in developing correlations and having a comprehensive understanding of the biostratigraphy and phylogeny of the taxa involved. However, after several field trips developed in the northern Prebetic area, an excellent reference section for the study of the LBF in the Prebetic Domain has been identified in the surroundings of the Pinet village (Valencia province). Here, a relatively continuous section with scarce dolomitization and good conditions of accessibility exists. The larger foraminifera assemblages appering in the Pinet section will be compared with other paleobiogeographic

  3. 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.

  4. 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.

  5. Water and carbon stable isotope records from natural archives: a new database and interactive online platform for data browsing, visualizing and downloading

    Science.gov (United States)

    Bolliet, Timothé; Brockmann, Patrick; Masson-Delmotte, Valérie; Bassinot, Franck; Daux, Valérie; Genty, Dominique; Landais, Amaelle; Lavrieux, Marlène; Michel, Elisabeth; Ortega, Pablo; Risi, Camille; Roche, Didier M.; Vimeux, Françoise; Waelbroeck, Claire

    2016-08-01

    Past climate is an important benchmark to assess the ability of climate models to simulate key processes and feedbacks. Numerous proxy records exist for stable isotopes of water and/or carbon, which are also implemented inside the components of a growing number of Earth system model. Model-data comparisons can help to constrain the uncertainties associated with transfer functions. This motivates the need of producing a comprehensive compilation of different proxy sources. We have put together a global database of proxy records of oxygen (δ18O), hydrogen (δD) and carbon (δ13C) stable isotopes from different archives: ocean and lake sediments, corals, ice cores, speleothems and tree-ring cellulose. Source records were obtained from the georeferenced open access PANGAEA and NOAA libraries, complemented by additional data obtained from a literature survey. About 3000 source records were screened for chronological information and temporal resolution of proxy records. Altogether, this database consists of hundreds of dated δ18O, δ13C and δD records in a standardized simple text format, complemented with a metadata Excel catalog. A quality control flag was implemented to describe age markers and inform on chronological uncertainty. This compilation effort highlights the need to homogenize and structure the format of datasets and chronological information as well as enhance the distribution of published datasets that are currently highly fragmented and scattered. We also provide an online portal based on the records included in this database with an intuitive and interactive platform (http://climateproxiesfinder.ipsl.fr/), allowing one to easily select, visualize and download subsets of the homogeneously formatted records that constitute this database, following a choice of search criteria, and to upload new datasets. In the last part, we illustrate the type of application allowed by our database by comparing several key periods highly investigated by the

  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. 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

  8. 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

  9. 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.

  10. Integration of Wave and Offshore Wind Energy in a European Offshore Grid

    DEFF Research Database (Denmark)

    Chozas, Julia Fernandez; Sørensen, H. C.; Korpås, M.

    2010-01-01

    of offshore renewable energy sources. According to this, the paper covers i) public and private initiatives for offshore transmission networks, ii) the synergies between the wave and the offshore wind energy sector within an offshore grid, iii) power transmission options for offshore generation and iv...

  11. 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.

  12. Risk-based process safety assessment and control measures design for offshore process facilities.

    Science.gov (United States)

    Khan, Faisal I; Sadiq, Rehan; Husain, Tahir

    2002-09-01

    Process operation is the most hazardous activity next to the transportation and drilling operation on an offshore oil and gas (OOG) platform. Past experiences of onshore and offshore oil and gas activities have revealed that a small mis-happening in the process operation might escalate to a catastrophe. This is of especial concern in the OOG platform due to the limited space and compact geometry of the process area, less ventilation, and difficult escape routes. On an OOG platform, each extra control measure, which is implemented, not only occupies space on the platform and increases congestion but also adds extra load to the platform. Eventualities in the OOG platform process operation can be avoided through incorporating the appropriate control measures at the early design stage. In this paper, the authors describe a methodology for risk-based process safety decision making for OOG activities. The methodology is applied to various offshore process units, that is, the compressor, separators, flash drum and driers of an OOG platform. Based on the risk potential, appropriate safety measures are designed for each unit. This paper also illustrates that implementation of the designed safety measures reduces the high Fatal accident rate (FAR) values to an acceptable level. PMID:12141993

  13. 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.)

  14. 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...... 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...

  15. 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

  16. 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).

  17. 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) .

  18. 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...

  19. 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...

  20. Observations of offshore bar decay

    DEFF Research Database (Denmark)

    Aagaard, Troels; Kroon, Aart; Greenwood, Brian;

    2010-01-01

    Long-term, net offshore bar migration is a common occurrence on many multiple-barred beaches. The first stage of the process involves the generation of a longshore bar close to the shoreline that oscillates about a mean position for some time, followed by a stage of net offshore migration across...... 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...

  1. 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...

  2. 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...

  3. 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)

  4. 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...

  5. 林业碳汇交易平台的法律定位及其完善%The Legal Position and Perfection of Forestry Carbon Sequestration Transaction Platform

    Institute of Scientific and Technical Information of China (English)

    邓雅芬

    2016-01-01

    Forestry carbon sequestration transaction platform acts as independent third parties of the forestry carbon sequestration transaction contains technical ,contractual ,fusion and neutral characteristics . Through the provision of services ,facilities and sites for forestry carbon sequestration transaction ,and the formulation and implementation of supporting business rules ,forestry carbon sequestration transaction platform in fact transactions centralized control .On forestry carbon sequestration trading platform and trading legal theory of the legal relationship between the two sides should not be confined to the traditional definition of the comprehensive consideration ,should be combined with practice .The unity of forestry car‐bon sequestration transaction platform ,and the payment and settlement of forestry carbon sequestration transaction ,supervision and management and other aspects into the orbit of the legal system ,play a decis‐ive role for the maintenance of trading activities .%林业碳汇交易平台作为林业碳汇交易中独立的第三方主体,兼具技术性、契约性、融合性、中立性四大特征。通过为林业碳汇交易提供服务、设施和场所,制定和实施配套的交易规则,林业碳汇交易平台获得了事实上的交易活动集中管理权。对林业碳汇交易平台与买卖双方之间法律关系的界定,不应局限于传统的法律理论,而应结合实践综合考量。统一林业碳汇交易平台,将林业碳汇交易的支付结算、监督管理纳入法制化轨道,对保障交易活动的顺利开展有着举足轻重的作用。

  6. 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

  7. Burgeoning China Offshore Oil Industry

    Institute of Scientific and Technical Information of China (English)

    Luo Ming; Hou Xiaoying; Xiao Yang

    1996-01-01

    @@ Despite its late inception, China's offshore oil industry has been growing rapidly over the past ten years and has become a new division of the energy sector boasting constant, swift and highly-effective development. Before foreign cooperation was introduced, offshore crude production was only about 100 000 tons per year. In 1996,the total production will surpass 10 million tons, indicating promising prospects for further progress in the future.

  8. Offshore northern Europe, the challenges

    Energy Technology Data Exchange (ETDEWEB)

    Bergseth, S. [Statoil, Stavenger (Norway)

    1996-12-31

    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

  9. 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....

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

    Science.gov (United States)

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

    2015-02-28

    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 provided, with a focus on their ability to accommodate the coupled dynamic behaviour of floating offshore wind systems. The exemplary design and testing methodology for a monolithic concrete spar platform as performed within the European KIC AFOSP project is presented. Results from the experimental tests compared to numerical simulations are presented and analysed and show very good agreement for relevant basic dynamic platform properties. Extreme and fatigue loads and cost analysis of the AFOSP system confirm the viability of the presented design process. In summary, the exemplary application of the reduced design and testing methodology for AFOSP confirms that it represents a viable procedure during pre-design of floating offshore wind turbine platforms. PMID:25583870

  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. 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

  13. 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...

  14. 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....

  15. On the definition of exergy efficiencies for petroleum systems: Application to offshore oil and gas processing

    DEFF Research Database (Denmark)

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

    2014-01-01

    ) the differences in operating conditions between facilities. This work focuses on offshore processing plants, considering four oil platforms that differ by their working conditions and designs. Several approaches from the scientific literature for similar processes are presented and applied to the four cases...

  16. 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.

  17. 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)

  18. 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.

  19. 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.

  20. OTEC Cold Water Pipe-Platform Subsystem Dynamic Interaction Validation

    Energy Technology Data Exchange (ETDEWEB)

    Varley, Robert [Lockheed Martin Corporation, Manassas, VA (United States); Halkyard, John [John Halkyard and Associates, Houston, TX (United States); Johnson, Peter [BMT Scientific Marine Services, Inc., Houston, TX (United States); Shi, Shan [Houston Offshore Engineering, Houston, TX (United States); Marinho, Thiago [Federal Univ. of Rio de Janeiro (Brazil). LabOceano

    2014-05-09

    A commercial floating 100-megawatt (MW) ocean thermal energy conversion (OTEC) power plant will require a cold water pipe (CWP) with a diameter of 10-meter (m) and length of up to 1,000 m. The mass of the cold water pipe, including entrained water, can exceed the mass of the platform supporting it. The offshore industry uses software-modeling tools to develop platform and riser (pipe) designs to survive the offshore environment. These tools are typically validated by scale model tests in facilities able to replicate real at-sea meteorological and ocean (metocean) conditions to provide the understanding and confidence to proceed to final design and full-scale fabrication. However, today’s offshore platforms (similar to and usually larger than those needed for OTEC applications) incorporate risers (or pipes) with diameters well under one meter. Secondly, the preferred construction method for large diameter OTEC CWPs is the use of composite materials, primarily a form of fiber-reinforced plastic (FRP). The use of these material results in relatively low pipe stiffness and large strains compared to steel construction. These factors suggest the need for further validation of offshore industry software tools. The purpose of this project was to validate the ability to model numerically the dynamic interaction between a large cold water-filled fiberglass pipe and a floating OTEC platform excited by metocean weather conditions using measurements from a scale model tested in an ocean basin test facility.

  1. 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

  2. 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...... 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 assisted...

  3. 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...

  4. 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....

  5. Aeroelastic Instabilities of Large Offshore and Onshore Wind Turbines

    Science.gov (United States)

    Bir, Gunjit; Jonkman, Jason

    2007-07-01

    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.

  6. 塔中隆起带断裂系统及其对碳酸盐岩台地的控制%Fault system and its control of carbonate platform in Tazhong uplift area, Tarim basin

    Institute of Scientific and Technical Information of China (English)

    任建业; 胡德胜; 阳怀忠; 尹新义; 李朋

    2011-01-01

    The construction and reformation of carbonate platform are controlled by many factors. This paper has mainly discussed?the development and destruction of the carbonate platform under the control of fault activities. There are mainly two types of fault systems developed in Tazhong area, namely the NW-trending basement-involved fault system and the NE- trending cap rock decollement fault system. The former was mainly developed during Caledonian I episode tectonic movement in Late Early Ordovician, and it controlled the tectonic framework which had been formed when the Tazhong uplift started its formation and changed the carbonate platform from the early ramp-ramp-edge type to the isolated reef type. The latter was mainly formed during Mid-Caledonian II episode tectonic movement in Late Ordovician, and its strong activity led to the tilting movement of Tazhong area and, as a result, the eastern uplift started its reformation, which seriously destroyed the carbonate platform formed earlier.%碳酸盐岩台地的建造与改造受多种因素的控制,本文主要探讨以断裂活动为代表的构造运动对碳酸盐岩台地发育和破坏的控制作用.塔中地区主要发育NW向基底卷入式断裂系统和NE向盖层滑脱式逆冲断裂系统两大类,前者主要形成于早奥陶世末的中加里东Ⅰ幕构造运动,该断裂控制了塔中隆起开始形成时的构造格局,从而使塔中隆起带碳酸盐岩台地由早期的缓坡一镶边缓坡型的台地结构演化为礁滩型孤立台地,而后者主要形成于晚奥陶世末中加里东Ⅱ幕构造运动,该断裂的强烈活动,使得塔中地区发生东西翘倾运动,东部隆起接受改造,早期的碳酸盐岩台地遭受严重破坏.

  7. 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)

  8. Managing Hidden Costs of Offshoring

    DEFF Research Database (Denmark)

    Larsen, Marcus M.; Pedersen, Torben

    2014-01-01

    . In 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 learning......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......-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....

  9. Offshore Wind Turbine Foundation Design

    DEFF Research Database (Denmark)

    Passon, Patrik; Hvenekær Rasmussen, Jørgen

    continued into 2015 it is even more important to drive down the costs of energy for renewable energy sources such as offshore wind energy in order to arrive at a sustainable future on a global level.Cost of energy reductions for offshore wind turbines (OWTs) can be achieved by optimizations on different......-wave correlations are typically subjected to sequential load calculation approaches in an iterative and collaborative process between foundation designer and wind turbine manufacturer. Involvement of these different design parties may be motivated by various aspects such as introduction of state-of-the-art design...... in the specific context of OWTs and individual foundation type characteristics. For example, modelling and load calculation approaches for jacket type foundations of OWTs are often inherited from existing experiences of monopile type foundations or from their counterparts in the offshore oil & gas industry...

  10. 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)

  11. 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.

  12. 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.

  13. 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....

  14. 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...

  15. 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,"...

  16. Offshoring and the Elasticity of Labour Demand

    OpenAIRE

    Neil Foster-McGregor; Johannes Pöschl; Robert Stehrer

    2012-01-01

    This paper examines the impact of offshoring on labour elasticities for a sample of 40 countries over the period 1995-2009 using the recently compiled World Input-Output Database (WIOD). Including measures of narrow and broad offshoring, as well as indicators of manufacturing and services offshoring, in conditional and unconditional labour demand equations we find that offshoring has an overall neutral or slightly positive effect on employment. This result hides differences across industry ty...

  17. Offshore wind energy: full speed ahead

    International Nuclear Information System (INIS)

    More than 4,000 MW of wind power may be installed offshore in Denmark in the course of the next 30 years. Large wind turbines, cheaper foundations and new knowledge about offshore wind conditions are improving the economics of offshore wind power. Two pilot offshore wind farms of 5 MW each have been built by electric utilities in Denmark using conventional wind turbines: Vindeby in 1991 and Tuno Knob in 1995. (author)

  18. NEW OFFSHORE LOCATIONS IN THE EUROPEAN UNION

    Directory of Open Access Journals (Sweden)

    RADULESCU IRINA GABRIELA

    2014-05-01

    Full Text Available The offshore activity provides benefits for the host market and has positive effects on services, and on producers that use intermediate services. FDI in services has an important impact on the offshore activity, especially through transfer of technology. Many transnational companies have recognized the advantages of offshoring and the fact that it becomes a key globalization force. Recently, the Central European countries have become popular destinations among offshoring

  19. Introduction to Norwegian Offshore and Marine Operations

    OpenAIRE

    Ikonen, Pekko-Aleksi

    2013-01-01

    Despite the fact that offshore business does not confine to maritime industry, it is a significant sector of the world merchant shipping. It entails the use of specialized vessels in various operations. In Finland, the offshore business has remained insignificant due to lack of natural oil and gas resources. The situation is altogether different in neighbouring Norway. Its maritime and offshore businesses are very important industries to the society and major employers. Offshore operation...

  20. Multiterminal HVDC transmissions systems for offshore wind

    OpenAIRE

    Egea Àlvarez, Agustí

    2014-01-01

    Offshore wind is emerging as one of the future energy vectors. Offshore wind power plants locations provide more strong and constant wind speed that allows to extract more power compared to onshore locations. In addition, as wind turbine components transportation is less restricted to terrestrial infrastructure, bigger and more powerful wind turbines can be installed offshore. In Europe, 1,567 MW of offshore wind power was installed in 2013. It represents the 14\\% of the total wind power inst...