Journal articles: 'Offshore jacket platform'

1

Shen, Zhao Wei, Wei Liang Jin, and Xiao Hong Wang. "Reliability of the Offshore Jacket Platform Based on Load Combination." Applied Mechanics and Materials 405-408 (September 2013): 1415–19. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.1415.

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Offshore jacket platforms under complicated and changeful ocean environments are subjected to various stochastic actions such as actions of wave, current, wind, ice, earthquake and their combinations. This paper presented the approach to calibrate of the reliability of the offshore jacket platform, and suggested all kinds of associated load cases. The combination of loads were mainly investigated. As an example, the reliability of offshore jacket platform of QK18-1 in Bohai Bay was verified. The result shows that the reliability of the offshore jacket platform related to 25-year reference period is between 2.7 and 3.39, which is close to the conclusion of some existing researches. This method would be used more widely for the design of offshore jacket platforms.

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Yan, Qing Zhi, Zhan Zhang, Liang Cui, and Yan Hua Wang. "Study on Reliability of Jacket Offshore Platform by Seismic Action Based on ANSYS." Advanced Materials Research 163-167 (December 2010): 3023–28. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.3023.

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Jacket Offshore Platform is a complex statically indeterminate structure, reliability of which is impacted by many factors, and the earthquake is a main factor. This paper simplify the significant failure mode of Jacket Offshore Platform by standard. Calculate the reliability of Jacket Offshore Platform under the effect of earthquake with the Monte Carlo method based on ANSYS. The result can provide evidence for safety assessment of Jacket Offshore Platform.

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Yan, Qing Zhi, Zhan Zhang, Liang Cui, and Yan Hua Wang. "Structural Optimization of Offshore Jacket Platform Based on ANSYS." Advanced Materials Research 163-167 (December 2010): 3029–33. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.3029.

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Offshore Jacket Platform is a very important infrastructure in the offshore oil exploration and exploitation. In order to make it more economical, designers should do Structural Optimization to it. This paper do Structural Optimization to Offshore Jacket Platform, and provide reference for the using of ANSYS in the Structural Optimization of Offshore Jacket Platform.

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Sarhan, Osamah, and Mahdy Raslan. "Offshore petroleum rigs/platforms: An overview of analysis, design, construction and installation." International Journal of Advanced Engineering, Sciences and Applications 2, no. 1 (January 31, 2021): 7–12. http://dx.doi.org/10.47346/ijaesa.v2i1.58.

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Jacket platforms are one of the most important and regularly used types of offshore structures for oil and gas extraction that have a big impact on the economy of the countries. In this paper, all aspects including design, analysis, construction and installing of the jacket type offshore structure, are summarized and classified. This type of structure is one of the specified platforms for shallow water, and for long term service, it also has the ability to carry large deck loads. This paper aims to present general guidance about the planning, design and construction of offshore jacket (template) platforms. Jacket platforms are fixed type platforms which are attached to the seabed using piles which provide stability against the wind, wave and current loads. Also, this type of offshore platform has a high initial and maintenance cost because of its exposure to corrosion, and cannot be reused after the end of its service period. Jacket platforms are most suitable for shallow water having no better alternative while it has the cost disadvantage for deep water.

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George, Jerin M., V. John Kurian, and M. M. A. Wahab. "Incorporation of Axial Aging Effects of Pile Foundations into Pushover Analysis of Offshore Jacket Platforms." Applied Mechanics and Materials 877 (February 2018): 270–75. http://dx.doi.org/10.4028/www.scientific.net/amm.877.270.

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The integrity assessment of jacket platforms using non-linear pushover analysis in the past had shown that most of the platform failure occur due to the lack of strength in the pile foundation. When the failure of jacket platforms in extreme weather conditions were studied, it was observed that the foundation was intact while the platform failed. This disagreement between the simulation and the actual condition can be explained by the phenomenon of Aging of pile foundations. Experimentally, the axial capacity of pile foundations have been found to be improving with time due to aging. The rate of improvement of the capacity can be empirically predicted using the properties of the soil in which the pile is installed. An empirical equation namely Skov and Denver equation was utilised to determine the improvement in capacity of offshore jacket piles in this study. This improvement was incorporated into the pile-soil modelling of jacket platforms using a new, yet very simple technique of stepping up the axial soil structure interaction curves. Pushover analysis of two offshore jacket platforms with the modified pile-soil model was done using the software SACS. The RSR (Reserve Strength Ratio) obtained from the pushover analysis showed significant difference due to the incorporation of the axial aging effects of the piles. Jacket A has showed a maximum improvement in RSR of 11% and a maximum reduction of RSR of 11% whereas Jacket B has showed a maximum improvement in RSR of 27% and a maximum reduction of RSR of 17%. The study has given a good insight into the changes in behaviour of a jacket platform due to aging of its pile foundations and is expected to improve the structural integrity assessment techniques of aged offshore jacket platforms.

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Shen, Zhao Wei, Xiao Hong Wang, and Wei Liang Jin. "Reliability of Pile Foundation of Offshore Jacket Platforms Subjected to Seismic Action." Advanced Materials Research 919-921 (April 2014): 1047–51. http://dx.doi.org/10.4028/www.scientific.net/amr.919-921.1047.

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Pile foundation of offshore platform is very important. Earthquake is devastating and unpredictable.It is important to assess the reliability of pile foundation of offshore jacket platforms subjected to seismic action. This paper presents the approach to calibrate of reliability of pile foundation subjected to seismic action. The combination of loads are mainly investigated. The reliability of pile foundation of of QK18-1 in Bohai Bay related to 25-year reference period is3.37, which is close to the conclusion of some existing researches. The results could provide significant reference for the design of offshore jacket platforms.

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Feng, Hua-Nv, Bao-Lin Zhang, Qing Li, and Gong-You Tang. "Delayed Fuzzy Output Feedback H∞ Control for Offshore Structures." Journal of Marine Science and Engineering 8, no. 6 (June 12, 2020): 434. http://dx.doi.org/10.3390/jmse8060434.

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Vibration damping of jacket platforms is among the significant issues in marine science and engineering, and the design of active vibration control schemes is very important to ensure the stability and safety of the jacket platforms against external loadings. This paper provides three fuzzy output feedback H ∞ controllers of the jacket platforms for irregular wave forces. By considering time-varying masses of jacket platforms, a Takagi-Sugeno (T-S) fuzzy dynamic model of the structure is established. Then fuzzy output feedback H ∞ control schemes are developed via using output signals of the platform with current and/or are delayed. Several existence conditions of fuzzy output feedback H ∞ controllers are derived. Simulation results demonstrate that the fuzzy output feedback H ∞ control strategies are remarkable to suppress the vibration of structure. Moreover, by choosing proper delayed output information of the system, the presented delayed fuzzy output feedback H ∞ control schemes outperform the conventional fuzzy output feedback H ∞ control approach.

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Han, Xiaoshuang, Weiliang Qiao, and Bo Zhou. "Frequency Domain Response of Jacket Platforms under Random Wave Loads." Journal of Marine Science and Engineering 7, no. 10 (September 21, 2019): 328. http://dx.doi.org/10.3390/jmse7100328.

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This article presents a procedure that simplifies an offshore jacket platform as a non-uniform cantilever beam subjected to an axial force. A Ritz method combined with a pseudo-excitation method is then used to analyze the responses of the jacket platform under random wave loads with the associated power spectral densities, variances and higher spectral moments. The theoretical basis and pertinent governing equations are derived. The proposed procedure not only eases the process of determining the pseudo wave loads, but also requires only the rudimentary structural details that are typically available at the preliminary design stage. Additionally, the merit of the proposed procedure is that the process does not require one to compute the normal modes, which saves time and is particularly convenient for the dynamic-response analysis of a complex structure (such as an offshore platform). An illustrative example based on a three-deck jacket platform is presented to demonstrate the procedure used to obtain the power spectral densities, variances and second spectral moments of jacket-top displacement and the bending moment of the jacket at the mud line. The results obtained are compared with those obtained using a Finite Element Mothed (FEM) model. Based on the findings of the study and good agreement shown in the comparison of results, it is concluded that the proposed method is effective, simple and convenient, and can be a useful tool for the preliminary design analysis of offshore platforms.

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Silvianita, Andika Trisna Putra, Daniel M. Rosyid, Dirta Marina Chamelia, and Imam Rochani. "Evaluation of Delay Factors in Jacket Structure Project." Applied Mechanics and Materials 836 (June 2016): 317–22. http://dx.doi.org/10.4028/www.scientific.net/amm.836.317.

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Offshore platforms are used worldwide for drrilling, proceesing and even storage purposes. The offshore platforms can be fixed to the seabed, or can be float. The fixed platform namely jacket structure is a complex construction and design. Construction process of the jacket structure sometimes is not in accordance with the time schedule. There are many factors affect them, limited time, equipment, materials required, and cost of human resources. In order to analyze the delay factors of a jacket project requires a systematic approach. This paper will discusses the delay factors of the construction of Jacket Structure using FTA (Fault Tree Analysis). Data is obtained from one fabrication company which involve their experts to identify the contribution of delay project. There are three main factors causing the Jacket project delay namely Long Process of Procurement, Late Schecule of Assembly Structure, and Bad Management.

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Hasanov, F. G. "Technology of steel jackets load-out in deep-water offshore platforms from the barge." Azerbaijan Oil Industry, no. 2 (February 15, 2020): 25–29. http://dx.doi.org/10.37474/0365-8554/2020-2-25-29.

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Currently, great attention is paid to the development issue of the shelf’s fuel and energy resources foremost in the oil-gas fields of the Caspian Sea. The problem solution requires the studying of great majority of scientific-technical issues. One of the significant problems is the lead-out of steel jacket from the offshore platform as a major element of oil-gas field hydro-technical facilities meant for the operation in the deep water. The calculations for the execution of operations with steel jacket of deep stationary platform from the block with the detailed chara- cteristics by the mass and gravity center coordinates alongside line data have been carried out with “SACS” and “STAAD.PRO” software programs. The steel jacket is pushed astern with the push-pull equipment on the barge. Due to the shift of gravity centre the jacket changes the trim in the stern. Through the elevation of trim angle brought in alignment with the friction ration between the jacket and barge, the jacket slides further itself. Herewith, the trim increases until the gravity centre of steel jacket on the barge is not in alignment with rotation centre of the large rocker arms. The studies helped to fix the position of the jacket’s gravity centre from the aft perpendicular, the trim moment, the trim of the barge, the draft with the bow and stern and the trim angle as well.

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Fowai, Issa, Zhang Jianhua, Ke Sun, and Bin Wang. "STRUCTURAL ANALYSIS OF JACKET FOUNDATIONS FOR OFFSHORE WIND TURBINES IN TRANSITIONAL WATER." Brodogradnja 72, no. 1 (January 1, 2021): 109–24. http://dx.doi.org/10.21278/brod72106.

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Most of the offshore wind turbines (OWT) recently installed in Europe, China and North America are in shallow water. However, unlocking the full potential of OWT lies in deeper waters. Jacket substructures have presented themselves as a reliable foundation concept for transitional water depth. This study focuses on the structural static and dynamic analysis of the traditional jacket substructures (with X and K bracing) and the recently patented three-legged twisted jackets (with a twisted angle of 30 and 60 degrees) for deployment in transitional water (beyond 60 m). To facilitate comparison, the dimensions of all the jackets remain the same, while, the geometric configurations are distinct. Static analysis was implemented to better understand the global load bearing behaviour of the jackets. First, the global displacement patterns at the tower top are compared. The individual reactions at mud-line were investigated, followed by the evaluation of the maximum von Mises stress. Subsequently, this research went on to investigate the effect of dynamic loading. In this dynamic analysis, three main critical points were considered, including the wave point (67 m), the platform and the tower top. A modal analysis was performed to compute the mode shapes and natural frequencies for all the jackets. The first five modes of all the jackets were also checked against the results available for the OC4 project. A similar analytical approach was adopted for the structural design of monopile or tripod foundations for offshore wind turbines. The results showed that in the static analysis both the traditional jackets and the twisted jackets were safe under the provided load combination. The twisted jacket proved to possess excellent structural behaviour compared to the traditional four-legged jackets, while maintaining the merits of lower material usage with fewer nodes. Analysing the von Mises stress revealed that the maximum stress occurred at the transition piece and close to the working platform. The modal analysis results of the jackets demonstrated that the twisted jackets (30 and 60 degrees) with the first natural frequency of 0.29 and 0.31 Hz fell under the soft-stiff design category whereas the traditional four-legged jackets were classified as stiff-stiff designs. The discovered structural performance of OWTs equipped with various jacket foundations contributes to the preliminary structural selection and optimal design of foundations of OWTs to be installed in transitional water.

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Tawekal, Ricky L., Faisal D. Purnawarman, and Yati Muliati. "Development of Risk-Reliability Based Underwater Inspection for Fixed Offshore Platforms in Indonesia." MATEC Web of Conferences 147 (2018): 05002. http://dx.doi.org/10.1051/matecconf/201814705002.

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In RBUI method, platform with higher risk level will need inspection done more intensively than those with lower risk level. However, the probability of failure (PoF) evaluation in RBUI method is usually carried out in semi quantitative way by comparing failure parameters associated with the same damage mechanism between a group of platforms located in the same area. Therefore, RBUI will not be effective for platforms spread in distant areas where failure parameter associated with the same damage mechanism may not be the same. The existing standard, American Petroleum Institute, Recommended Practice for Structural Integrity Management of Fixed Offshore Structures (API RP-2SIM), is limited on the general instructions in determining the risk value of a platform, yet it does not provide a detail instruction on how determining the Probability of Failure (PoF) of platform. In this paper, the PoF is determined quantitatively by calculating structural reliability index based on structural collapse failure mode, thus the method in determining the inspection schedule is called Risk-Reliability Based Underwater Inspection (RReBUI). Models of 3-legs jacket fixed offshore platform in Java Sea and 4-legs jacket fixed offshore platform in Natuna Sea are used to study the implementation of RReBUI.

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Zhang, Min, Shu Qing Wang, Jia Li Fu, and Xiao Long Xu. "Model Simplification for Offshore Platforms Using Model Refinement Scheme." Applied Mechanics and Materials 284-287 (January 2013): 1436–40. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.1436.

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Offshore jacket platforms have been widely used in offshore oil and gas exploitation under hostile ocean environments. Finite element models of such structures need to have many degrees of freedom (DOFs) to represent the geometrical detail of complex structures, which leads to more computing power when performing the analysis and what’s more, the incompatibility in the number of degrees of freedom to the experimental models. Therefore, there is a need to simplify the analytical model by reducing the DOFs and in the process, making the essential eigen-properties agree with those of the experimental model is desired. In this paper, a scaled physical experimental model of an offshore jacket platform is simplified using the recently developed model refinement scheme. Mathematically, the procedure to implement the model refinement technique is an application of cross-model cross-mode (CMCM) method for model updating. The master degrees of freedom are chosen according to the placement of accelerometers in the experiment. Upon the completion of the refinement, the improved reduced jacket platform model matches the dynamic characteristics of the experimental model quite well.

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Tabeshpour, Mohammad Reza, and Younes Komachi. "Rehabilitation of jacket offshore platforms using friction damper device and buckling restrained braces under extreme loads." Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 233, no. 1 (September 28, 2017): 209–17. http://dx.doi.org/10.1177/1475090217730944.

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Some existing platforms may have some problems with probable extreme future loads such as earthquake. From economic point of view, it is preferable to retrofit and continue using of existing jackets in many cases, in comparison to a new installation. Two efficient rehabilitation methods of friction damper device and buckling restrained braces are presented and investigated numerically for seismic loads from far-fault and near-fault earthquakes. As an example, an existing four-leg service platform placed in the Persian Gulf (Ressalat) is considered and the results are presented. Because of low redundancy in jacket platforms (after buckling of compression members), it is important to investigate the effect of friction damper device on the structural behavior. Buckling restrained braces solves the law redundancy because of no buckling and no decrease in strength. The results show the high efficiency of both methods in reducing structural responses and increasing seismic performance level. Such studies are very useful for many existing jacket platforms that their lifetime is to be extended.

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Jha, Alok K., Omer K. Kiciman, Joseph M. Gebara, Bernhard Stahl, and Knut H. Dahl-Stamnes. "Assessment of Offshore Platforms Under Subsidence—Part II: Analysis and Results." Journal of Offshore Mechanics and Arctic Engineering 122, no. 4 (April 21, 2000): 267–73. http://dx.doi.org/10.1115/1.1313531.

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An assessment of three offshore platforms in the Valhall field of the North Sea is described in this paper. Ultimate strength and reliability analyses were performed for the jacket-type platforms for four levels of sea floor subsidence. The nonlinear structural models of the platform elements, joints, and associated soil-structure interaction are summarized in a companion paper by Gebara et al., 2000, “Assessment of Offshore Platforms Under Subsidence—Part I: Approach,” ASME J. Offshore Mech. Arct. Eng., 122, pp. 260–266. Similarly, environmental loads and reliability acceptance criteria are presented by Pawsey et al., 1998, “Characterization of Environmental Loads on Subsiding Offshore Platforms,” OMAE98, Lisbon, Portugal, and Stahl et al., 1998, “Acceptance Criteria for Offshore Platforms,” OMAE98, Lisbon, Portugal, respectively. This paper describes the procedures employed and results obtained for ultimate strength and reliability analysis. Ultimate platform strength was calculated using a pushover analysis in which environmental loads for increasingly rare events were applied incrementally until the platform failed. Failure was defined as formation of a limiting mechanism in the platform structure or foundation. Structural reliability analysis was performed to estimate the annual probability of platform failure as a function of subsidence level. The platform structural system was modeled in terms of two major subsystems that were assessed as likely to fail: (i) the platform deck, and (ii) the platform jacket and piles. Uncertainties were included in the loads, structural components, and soil strengths based on industry experience and data. First and second-order reliability methods (FORM/SORM) were used to estimate the annual failure probabilities. Consideration was given to the correlated nature of the failure modes due to the common environmental loads. The reliability results were compared with predefined acceptance criteria to judge the suitability of continued operations. [S0892-7219(00)00304-6]

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Tian, Xiaojie, Qingyang Wang, Guijie Liu, Yunxiang Liu, Yingchun Xie, and Wei Deng. "Topology optimization design for offshore platform jacket structure." Applied Ocean Research 84 (March 2019): 38–50. http://dx.doi.org/10.1016/j.apor.2019.01.003.

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Zhao, Yuliang, Sheng Dong, Fengyuan Jiang, and Carlos Guedes Soares. "System Reliability Analysis of an Offshore Jacket Platform." Journal of Ocean University of China 19, no. 1 (January 16, 2020): 47–59. http://dx.doi.org/10.1007/s11802-020-4181-2.

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Rubin, S., and R. N. Coppolino. "Sensitivity of Flexibility Monitoring of Offshore Jacket Platforms." Journal of Energy Resources Technology 108, no. 1 (March 1, 1986): 72–76. http://dx.doi.org/10.1115/1.3231244.

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Flexibility monitoring is a vibration-based method for simplifying the detection of major underwater damage on offshore jacket platforms. Ambient vibrations are detected at each of the underwater framing levels relative to abovewater vibration in the fundamental sway and torsional modes. Derived are flexibility parameters which relate to the shear flexibilities of each framing bay and of the foundation. Great promise has been shown by laboratory and field testing. This paper presents a comprehensive sensitivity assessment for severance of diagonal members over a wide range of structural redundancy for generic platform configurations.

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ZHANG, B. L., and Y. M. XU. "DELAYED FUZZY CONTROL OF OFFSHORE STEEL JACKET PLATFORMS." ANZIAM Journal 58, no. 3-4 (April 2017): 446–54. http://dx.doi.org/10.1017/s1446181117000128.

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We study a delayed fuzzy $H_{\infty }$ control problem for an offshore platform under external wave forces. First, by considering perturbations of the masses of the platform and an active mass damper, a Takagi–Sugeno fuzzy model is established. Then, by introducing time delays into the control channel, a delayed fuzzy state feedback $H_{\infty }$ controller is designed. Simulation results show that the delayed fuzzy state feedback $H_{\infty }$ controller can reduce vibration amplitudes of the offshore platform and can save control cost significantly.

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Sharifian, Hesam, Khosro Bargi, and Mohamad Zarrin. "Ultimate Strength of Fixed Offshore Platforms Subjected to Near-Fault Earthquake Ground Vibration." Shock and Vibration 2015 (2015): 1–19. http://dx.doi.org/10.1155/2015/841870.

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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.

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Yazici, Hakan, and Mert Sever. "Design of an optimal state derivative feedback LQR controller and its application to an offshore steel jacket platform." An International Journal of Optimization and Control: Theories & Applications (IJOCTA) 8, no. 1 (December 25, 2017): 84–91. http://dx.doi.org/10.11121/ijocta.01.2018.00468.

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This paper concerns with the optimal state derivative feedback LQR controller design for vibration control of an offshore steel jacket platform having active tuned mass damper against the wave induced disturbances. Considering that the state derivative signals such as acceleration and velocity are easier to measure rather than the state variables such as displacement, state derivative feedback control strategy is proposed to obtain practically applicable and easily realizable synthesis method. On the basis of convex optimization approach, state derivative feedback LQR controller design is formulated in Linear Matrix Inequalities (LMIs) form to get an optimal feasible solution set. Finally, an offshore steel jacket platform subject to nonlinear self excited wave force is used to illustrate the effectiveness of the proposed approach through simulations. The results show that proposed state derivative LQR controller is very effective in reducing vibration amplitudes of each floor of modeled offshore steel jacket platform and achieves compitable control performance to classical LQR controller design.

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Liu, Gui Jie, Basit Farooq, Jian Bo Jiao, Li Hua Wang, and Yu Zhang. "Research on the Effect of Seasonal Environmental Loads on Bohai Bay Offshore Platform." Advanced Materials Research 1006-1007 (August 2014): 18–25. http://dx.doi.org/10.4028/www.scientific.net/amr.1006-1007.18.

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In recent decades jacket platforms are widely used for facilitating the offshore oil industries in order to reach their demands of producing oils. In this regard given analyses shows the influence of seasonally based environmental loads acting on the offshore platform structure situated at Bohai Bay northeast of China. This paper studies and summarizes the structure reliability theory with jacket platform as the research object; it is the first time to aim and finds the most dangerous season effecting Bohai Bay offshore platforms by considering seasonal environmental loads. Finite element analysis ANSYS software is used for model analyses and optimisation of the structure spatial correlation seasonal loads. Environmental design data is extracted according to its geographical conditions in the form of wave, wind and current forces. Since most of the control management nodes work below the surface of the water so the distribution of stress and fatigue life of the pipe node under multi-axial loading is in different forms. The analysis mainly focuses on the stress and fatigue life appropriate characteristics to the actual situation of multi-axial loading case of the K-joint welding location and mainly environmental effect on the platform.

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Wang, Yi Tao, Hui Long Ren, Jia Ju Yu, and Bing Bing Cui. "Risk-Based Inspection Analysis of Jacket Platform." Applied Mechanics and Materials 623 (August 2014): 18–27. http://dx.doi.org/10.4028/www.scientific.net/amm.623.18.

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Risk-based inspection analysis is a key part of structure integrity management (SIM) process for ensuring the fitness-for-purpose of offshore jacket platforms. For the platforms locates in the South China Sea which often suffer severe sea condition, it is essential to employ an appropriate assessment method to determine the structure strength and increase the platforms’ safety. This paper presents a comprehensive risk-based inspection method for in-service jacket platform structure. Nonlinear pushover analysis is used to carry out the ultimate bearing capacity and failure consequence of the structure, in which the platform ultimate bearing capacity is characterized in terms of the Reserve Strength Ratio (RSR) and Residual Capacity Ratio (RCR). Taking the four limit state equations of structure member and limit state judgment criteria of structure system into consideration, the structure reliability analysis is proposed with the combination of extreme probability model of environment loads. On this basis, a risk matrix will be formed and a risk-based inspection plan can be developed. A case study of jacket platform located in the South China Sea is used to illustrate the application of the structure assessment approach.

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Gong, Hai Xia, Lin Peng, Pei Ran Jiang, and Li Quan Wang. "Mechanics Analysis on Leveling Tool of Offshore Jacket Platform." Applied Mechanics and Materials 44-47 (December 2010): 1223–28. http://dx.doi.org/10.4028/www.scientific.net/amm.44-47.1223.

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The paper aimed to leveling operation of offshore jacket platform, studied mechanics principle of the leveling tool. When the clamp blocks inserted into the pile wall in leveling operation, the pile’s surface presented some indentations of elastic-plastic deformation, which can increase the cross-lifting force but the clamp is susceptible to be damaged certainly. So, special clamping block was designed including its material and mechanical structure, and force analysis of the pile under the action of the clamping blocks was finished, and dynamics simulation of contact process between the clamping block and the pile was finished too. An experimental prototype was developed to verify the clamping principle. Experimental results show that the clamping principle is correct and the leveling tool can meet actual needs.

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Elsayed, T., M. El-Shaib, and K. Gbr. "Reliability of fixed offshore jacket platform against earthquake collapse." Ships and Offshore Structures 11, no. 2 (October 21, 2014): 167–81. http://dx.doi.org/10.1080/17445302.2014.969473.

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Alie, Muhammad Zubair Muis, Y. R. Palentek, and D. G. Sesa. "Buckling Analysis on Pechiko Field of Fixed Offshore Platform in Makassar Strait." Applied Mechanics and Materials 776 (July 2015): 313–18. http://dx.doi.org/10.4028/www.scientific.net/amm.776.313.

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One of the most important criterion in the design of fixed offshore platform is to have strength from applied loads which is acting perpendicular to jacket leg section such as axial compression.The axial compressive load acts vertically downward to jacket legs and the deformation on the jacket legs in horizontal direction due to this load is called buckling. In the present study, buckling analysis on pechiko field of fixed offshore platform is performed using Finite Element Analysis (FEA). The fixed jacket platform namely tripod and tetrapod are taken as the object of the analysis. Only the axial compressive load is used in the analysis and the boundary conditions are assumed to be fixed both tripod and tetrapod at the bottom seabed. As a fundamental case, buckling analysis is carried out in plane-section (2D analysis), then the result obtained by FE analysis is compared with the analytical solution.It is found that the result obtained by FE analysis for the critical buckling load is in good agreement with the analytical solution, and the applicability of FE analysis is further used to investigate the deformation of 3D model.

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Reghu, Swethima, and Sruthy S. "A Comparison of Fatigue Life Improvement Methods for an Existing Offshore Jacket Platform Structure." International Journal of Engineering & Technology 7, no. 4.5 (September 22, 2018): 333. http://dx.doi.org/10.14419/ijet.v7i4.5.20102.

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Most offshore Jacket platforms are installed in shallow water, less than 300 meters for drilling and production of oil or gas. They are normally fixed to seabed and constructed as three dimensional frameworks with tubular members as structural elements. The surrounding environment around offshore platform is affected by various environmental loads that comprise of wind, waves, currents and earthquake. The major load in such structures is wave loading, repetitive in nature which causes time varying stresses that results global and or local fatigue damage on the offshore steel structure. This study includes fatigue assessment of a selected jacket structure using ANSYS software. This study concentrates mainly on the stress reduction at joints by various methods under the applied cyclic loading. The various methods considered in this study are providing: joint cans with branch stubs, grouted connections, FRP wrappings, stiffeners at the joint section. A comparison of various methods for reducing the hotspot stresses which increases fatigue life are studied and the most effective one is recommended.

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Meyer-Gutbrod, Erin L., Li Kui, Mary M. Nishimoto, Milton S. Love, Donna M. Schroeder, and Robert J. Miller. "Fish densities associated with structural elements of oil and gas platforms in southern California." Bulletin of Marine Science 95, no. 4 (October 1, 2019): 639–56. http://dx.doi.org/10.5343/bms.2018.0078.

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There are thousands of offshore oil and gas platforms worldwide that will eventually become obsolete, and one popular decommissioning alternative is the "rigs to reefs" conversion that designates all or a portion of the underwater infrastructure as an artificial reef, thereby reducing the burden of infrastructure removal. The unique architecture of each platform may influence the size and structure of the associated fish assemblage if different structural elements form distinct habitats for fishes. Using scuba survey data from 11 southern California platforms from 1995 to 2000, we examined fish assemblages associated with structural elements of the structure, including the major horizontal crossbeams outside of the jacket, vertical jacket legs, and horizontal crossbeams that span the jacket interior. Patterns of habitat association were examined among three depth zones: shallow (<16.8 m), midwater (16.8–26 m), and deep (>26 m); and between two life stages: young- of-the-year and non-young-of-the-year. Fish densities tended to be greatest along horizontal beams spanning the jacket interior, relative to either horizontal or vertical beams along the jacket exterior, indicating that the position of the habitat within the overall structure is an important characteristic affecting fish habitat use. Fish densities were also higher in transects centered directly over a vertical or horizontal beam relative to transects that did not contain a structural element. These results contribute to the understanding of fish habitat use on existing artificial reefs, and can inform platform decommissioning decisions as well as the design of new offshore structures intended to increase fish production.

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Zhang, Ji Gang, and Zhi Wei Jiang. "Study on Seismic Performance of Offshore Platform with Rocking Wall - TMD System." Applied Mechanics and Materials 610 (August 2014): 78–83. http://dx.doi.org/10.4028/www.scientific.net/amm.610.78.

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Offshore platform rocking wall system and tuned mass damper are briefly introduced, and the paper integrates the advantages of these two kinds of seismic method, and the TMD is attached to the jacket offshore platform - rocking wall system, using the ANSYS for finite element analysis, and the analysis results are optimized. The results show that compared with the offshore platform - rocking wall system, additional TMD can give full play to the performances of the two kinds of seismic methods, which is remarkable.

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Chen, Xiang Yu, Sha Sha Dong, and Fu Shun Liu. "A Multi-Hierarchical Damage Identification Method for Jacket Platform Using BP Neural Network." Applied Mechanics and Materials 166-169 (May 2012): 1170–75. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.1170.

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Jacket-type platforms may be the most common type of offshore structures, and damage localization and severity estimation is important for these structures. This paper employs a multi-hierarchical damage identification method based on BP neural network to detect damages in jacket platforms. Firstly, the damaged storey of the jacket is detected, and the numbers of the elements among the detected storey are then detected. According to this method, the learning samples can be more targeted and the number can be reduced largely. In the end, a jacket model is used to investigate the performance of this method, and the results indicate that this approach is more effective and has higher accuracy than direct diagnosis method.

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Wang, Long, Guoan Yang, Le Le Jia, and Guang Jia. "The Effect of Welding Angle for Acoustic Emission Propagation in Offshore Jacket Platform." Applied Mechanics and Materials 330 (June 2013): 299–303. http://dx.doi.org/10.4028/www.scientific.net/amm.330.299.

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Considering the requirement of NDT for offshore jacket platform, the effection of welding angle to the propagation characteristic of acoustic emission (AE) is studied. Amplitude and energy are the main analysis parameters for the experiment. As used wildly in jacket structure, the 90 and 45 degrees welding angle are discussed. The research result can provide references for engineering application of AE technique to locate the damage source and analyse the failure feature.

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Abdel Raheem, Shehata E., and Elsayed M. A. Abdel Aal. "Finite Element Analysis for Structural Performance of Offshore Platforms under Environmental Loads." Key Engineering Materials 569-570 (July 2013): 159–66. http://dx.doi.org/10.4028/www.scientific.net/kem.569-570.159.

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Offshore structures for oil and gas exploitation are subjected to various ocean environmental phenomena which can cause highly nonlinear action effects. Offshore structures should be designed for severe environmental loads and strict requirements should set for the optimum performance. The structural design requirements of an offshore platform subjected to wave induced forces and moments in the jacket can play a major role in the design of the offshore structures. For an economic and reliable design; good estimation of wave loadings are essential. The structure is discretized using the finite element method, wave force is determined according to linearized Morison equation. Hydrodynamic loading on horizontal and vertical tubular members and the dynamic response of fixed offshore structure together with the distribution of displacement, axial force and bending moment along the leg are investigated for regular and extreme conditions, where the structure should keep production capability in conditions of the one year return period wave and must be able to survive the 100 year return period storm conditions. The results show that the nonlinear response analysis is quite crucial for safe design and operation of offshore platform. Fixed Jacket type offshore platforms under extreme wave loading conditions may exhibit significant nonlinear behavior. The effect of current with different angles when hitting the offshore structure with the wave and wind forces, is very important for calculate the stress, the response displacement and deformation shapes. As the current increase or decrease the effect of wave force according to the hitting angle of current.

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33

Travanca, Joao, and Hong Hao. "Energy dissipation in high-energy ship-offshore jacket platform collisions." Marine Structures 40 (January 2015): 1–37. http://dx.doi.org/10.1016/j.marstruc.2014.10.008.

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34

Bhat‎, Praveen, and S. Karunanithi. "Relocation of existing jacket platform in western offshore of india ‎." Procedia Structural Integrity 14 (2019): 656–63. http://dx.doi.org/10.1016/j.prostr.2019.05.081.

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35

Sun, Jian Mei, and Hao Cui. "The Seismic Response Analysis Method of the Jacket under Multiple Support Excitation." Applied Mechanics and Materials 256-259 (December 2012): 2051–55. http://dx.doi.org/10.4028/www.scientific.net/amm.256-259.2051.

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With the development of demand of exploiting offshore oil reserves, the Jacket platform structure’ span and depth is more and more large, so the seismic analysis of the jacket structure will become more and more complicated. In the dynamic analysis of long-span structures, multiple support excitation may be accounted is necessary. For big jacket structure, it is more accurate and reasonable by multiple support excitation than by uniform excitation. The objective of the research described herein is to develop a simplified method to investigate the effect of multiple support excitation on the jacket structure.

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36

Bayazitoglu, Yildirim O. "Assessment and Repair of Offshore Platform Applications to Bay of Campeche Facilities." Journal of Offshore Mechanics and Arctic Engineering 122, no. 2 (November 18, 1999): 81–92. http://dx.doi.org/10.1115/1.533737.

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In 1995 hurricanes Opal and Roxanne passed through Bay of Campeche (BOC). Opal did not cause any noticeable damage. Roxanne, on the other hand, was the most severe hurricane recorded in the Bay of Campeche in this century. Its anomalous behavior and the resulting extreme environmental conditions did considerable damage. PEMEX implemented a rapid repair program and was able to bring tile production back to its normal levels within two months. Subsequently, PEMEX, jointly with Instituto Mexicano del Petro´leo (IMP), launched an extensive program to inspect, assess, and repair the facilities. Results of the initial assessments indicated that the assessment parameters, as well as the metocean criteria utilized, were not suitable for Bay of Campeche. A detailed risk study considering the site-specific conditions and requirements was performed. Utilizing probability-based risk assessment techniques, a new criteria, known as the “transitory criteria,” was developed. The transitory criteria was then used to reassess the platforms and pipelines in the southwest marine region of BOC. Critically damaged platforms were identified for repair. The scope of repairs included jacket structural members and support framing for deck facilities. An overview of various techniques used for repairs of the underwater jacket structural members and joints is given. Different underwater repair methods are discussed. Repairs of both jacket and deck damages caused by hurricane Roxanne are presented as examples. The repair methods used are based on currently available technology and they will provide practical examples for economical platform repair in shallow, warm water environments. [S0892-7219(00)01101-8]

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37

Sabu, Stephy, and T. P. Somasundaran. "Analysis of Bombay High Jacket during Load out and Transportation." Applied Mechanics and Materials 857 (November 2016): 41–46. http://dx.doi.org/10.4028/www.scientific.net/amm.857.41.

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Marine and offshore structures are constructed worldwide for various functions in a variety of water depths and environmental conditions like deep sea oil drilling, marine excavations etc. The offshore structures built onshore in “fabrication yards” have to be loaded out and transported offshore to the final assembly site, onboard a barge. Hence the design and analysis of an offshore structure must include load out and transportation calculations. The aim of the present work is to conduct load out and transportation analysis of a real time jacket platform installed in 78m water depth in the Mumbai High Basin. The platform was loaded onto a launch barge by lifting. The lift analysis was performed in SACS (Structural Analysis Computer System), to assure no overstressing of the jacket components during load out operations. The analysis was also used to compare the predicted and allowable values of the jacket/barge deflections. The motion analysis was performed in SACS, to determine the Response Amplitude Operators, from which, maximum values for the relevant degrees of freedom were predicted. The obtained data was used to compute the inertia forces and a deterministic structural analysis for the barge was performed. The predicted values obtained were well within the allowable values rendering the design safe. The jacket was also analyzed to determine the significance of water entry forces on its horizontal members during transportation. The predicted stresses were well within the allowable stresses; hence the transportation of the structure from the fabrication site to the Mumbai High Basin is safe.

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Love, Milton S., Mary M. Nishimoto, Scott Clark, Li Kui, Azivy Aziz, and David Palandro. "A comparison of two remotely operated vehicle (ROV) survey methods used to estimate fish assemblages and densities around a California oil platform." PLOS ONE 15, no. 11 (November 10, 2020): e0242017. http://dx.doi.org/10.1371/journal.pone.0242017.

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Offshore oil and gas platforms have a finite life of production operations. Once production ceases, decommissioning options for the platform are assessed. The role that a platform’s jacket plays as fish habitat can inform the decommissioning decision. In this study, conducted along the crossbeams of a California platform jacket and using an ROV, we compared estimates of fish diversity and densities determined from a targeted “biological” survey with those from a replicated “structural” survey. We found that the water column fish species assemblages characterized by the two methods were similar. By contrast, the two survey methods yielded different species assemblages inhabiting the crossbeam at the platform jacket base. This difference occurred because, at least off California, the platform jacket base species diversity tends to be highest where the bottom crossbeam is undercut, creating sheltering sites for many species. Because the structural method inadequately imaged the seafloor-crossbeam interface, particularly where a gap occurred between crossbeam and seafloor, substantial numbers of fishes were not visible. While we cannot extrapolate from this study to all platforms’ worldwide, it is clear that routine platform structural integrity surveys may be a valuable source for opportunistic marine community surveys. Intentional planning of the structural survey to incorporate relatively minor variations (e.g., maintaining fixed ROV distance from the infrastructure and consistent 90° camera angle) coupled with a deliberate consideration of the platform ecology (e.g., positioning the ROV to capture the seafloor-crossbeam interface) can substantially improve the effects on fish assemblage assessments from routine structural surveys without compromising the integrity assessment. We suggest that these biases should be both acknowledged and, understood when using routine structural surveys to inform platform ecology assessment. Additional consideration may be given to structural surveys that incorporate incremental adjustments to provide better data applicability to biological assessments.

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39

Lotfollahi-Yaghin, Mohammad Ali, and Roghayeh Rezaei. "Time-History Response Analysis of Jacket Offshore Platform due to Water Level Variation and Safety of Structural Members." Advanced Materials Research 601 (December 2012): 280–88. http://dx.doi.org/10.4028/www.scientific.net/amr.601.280.

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Jacket structures are designed for a specific water level (LAT). One of the important issues about these structures is the water level rise. For example, the level of water in the Caspian Sea has risen by 2.5m in the last fifteen years and is continuing to rise. The aim of this study is to investigate the behavior of one typical shallow or medium water jacket platform (a four-leg steel jacket platform in 55m water depth) under water level rise and to evaluate utilization factor of different element at different elevations. In this paper the finite element method (ANSYS) was used for the purpose of modeling of the structure. This paper discusses the effect of water level variation acting on the jacket structure and illustrates subsequent results of the stress utilization within the structure elements. The results of time history analysis show that the initial design water depth (before water level rise) has a basic role on the subsequent behavior of structural elements.

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40

Chen, Yu Jing, Min Zhang, Yuan Dong Meng, Qiang Zhao, and Jie Wen Nie. "Modal Parameter Identification of Jacket-Type Platforms Using Vibration Testing Data." Applied Mechanics and Materials 170-173 (May 2012): 2243–47. http://dx.doi.org/10.4028/www.scientific.net/amm.170-173.2243.

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How to estimate the modal parameters (including natural frequencies and mode shapes) of an offshore platform accurately is crucial for the health monitoring problems. The purpose of this paper is to identify the modal parameters of a physical jacket-type platform model from measured modal testing data using Prony’s method. In the modal testing, the identified false modes are unavoidable and bring much difficulty to determine the accurate modal parameters. To solve these problems, in this paper, the Modal Phase Collinearity (MPC) and Modal Assurance Criterion (MAC) are applied to distinguish the true and false modal. The measured data are extracted from a physical model of a realistic offshore platform. And the results demonstrate that the modal parameters of the first two modes of each direction can be accurately estimated by using the proposed method.

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41

Murotsu, Y., M. Kishi, H. Okada, Y. Ikeda, and S. Matsuzaki. "Probabilistic Collapse Analysis of Offshore Structure." Journal of Offshore Mechanics and Arctic Engineering 109, no. 3 (August 1, 1987): 270–77. http://dx.doi.org/10.1115/1.3257020.

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This paper proposes a method for probabilistic collapse analysis of an offshore structure. Wave loads are estimated by using Stokes third-order theory and Morison’s formula. Plastic collapsing is evaluated by taking account of the combined load effect to generate the safety margins, using a matrix method. Probabilistically dominant collapse modes are selected through a branch-and-bound method. The proposed method is successfully applied to a jacket-type offshore platform.

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42

Cabrera, Jairo H., and Jair Macía Ávilar. "Structural Design of a Jacket Platform to the Colombian Caribbean Sea." Ciencia y tecnología de buques 10, no. 19 (July 21, 2016): 61. http://dx.doi.org/10.25043/19098642.141.

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This research paper summarizes the study of the requirements and basic theoretical foundation for the development of structural design of fixed platform type Jacket, resulting in the proposal for a analysis model for this type of offshore structure. Aspects related with cinematics evaluation, selecting of wave theory and hydrodynamic proper formula are also considered in the calculation of acting forces and the need for local metocean data in the analysis. A case study of application of the model for a new type structure jacket RC-5 Block of the Colombian Caribbean is also presented including its geometry proposed and some results of the numerical model procedures.

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43

BAIG, MIRZA AAMIR, and UMER MAQBOOL. "IN-PLACE ANALYSIS OF OFFSHORE JACKET PLATFORM FOR DIFFERENT WAVE DIRECTIONS." International Journal of Engineering Science Technologies 4, no. 5 (September 23, 2020): 16–25. http://dx.doi.org/10.29121/ijoest.v4.i5.2020.108.

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Offshore jacket platforms are subjected to variety of forces during their life period. To resists all kinds of forces, the structural elements should be designed properly to have safety and economy. In order to fulfil this purpose, the structure should be analyzed with great care. As the improvement of oil and gas moves into more profound water, in any case, taller stages with longer periods are fabricated that react all the more powerfully to extraordinary waves. Expectation of the dynamic reaction of such structures in extraordinary ocean states is in this way an essential plan thought. Standard waves have all their vitality lumped at a couple of particular frequencies and can, in this manner, cause wrong powerful enhancements, particularly if these frequencies happen to be near the regular frequencies of the structure. In any case, waves in the ocean are exceptionally sporadic and can be best depicted as directional range, which indicates the appropriation of wave vitality as for recurrence and heading, and is most appropriate for the examination of structure in recurrence space technique. For this situation the nonlinear drag is linearized and utilized in the Morison's condition. This guess is proper for the littler, operational sort waves considered in weariness counts, in light of the fact that the powers because of these waves are overwhelmed by the direct idleness part. Various kinds of investigations related with the coat stage ought to be performed to figure the reaction of the structure and measurement the components of the structure. Here an endeavor has been made to complete various examinations to comprehend the dynamic conduct of coat stages subject to different stacking conditions in various ecological conditions. Coat set up investigation was performed, both static and dynamic hypothetically fixed base stage. With the ongoing imaginative thoughts of investigation utilizing programming, it is presently simpler for the seaward architects to do disentangled and sensible assessment of the static operational and extreme point of confinement state qualities of format or coat stages, which are exposed to different ecological conditions. The essential auxiliary parts of coat type seaward structures including topsides, coat, heaps and the encompassing soil are viewed as utilizing SACS programming various types of investigations identified with coat stage according to API code prerequisite.

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44

Sudip, Paul, and Datta TK. "Semiactive control of a fixed offshore jacket platform using LQR algorithm." Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 227, no. 4 (November 19, 2012): 367–80. http://dx.doi.org/10.1177/1475090212459848.

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45

El-Din, Mohamed Nour, and Jinkoo Kim. "Seismic Performance Evaluation and Retrofit of Fixed Jacket Offshore Platform Structures." Journal of Performance of Constructed Facilities 29, no. 4 (August 2015): 04014099. http://dx.doi.org/10.1061/(asce)cf.1943-5509.0000576.

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46

Zhang, Bo, Zhuo Wang, and Tao Wang. "Hydrodynamic Load and Parametric Design of Grouted Clamp Used on Offshore Jacket." Polish Maritime Research 25, s3 (December 1, 2018): 154–65. http://dx.doi.org/10.2478/pomr-2018-0125.

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Abstract The reliability and safety of offshore platform are an important research aspect in marine engineering. The jacket platform is mainly used for oil development and submarine drilling, and the long-term work in the marine environment will be subjected to different loads, which will lead to the damage of the structure part of the offshore platform. It affects the structural strength of the platform. For the repair of jacket damage, grouted reinforcement technology is adopted, which has the advantages of simple underwater installation and low cost. The reinforcement technology of the grout hoop has been applied to the engineering projects abroad, but the stress and serialization design of the hoop in the marine environment need further study. This paper will combine the ocean current and wave force to carry out the research of underwater work and prevent loosening, and put forward the parametric design method for the specific size of the hoop. Two types of experimental models are designed: short bolt form clamp and long bolt form clamp. The mechanical experiment of the long bolt clamp is carried out, and the relationship between the slipping force and the bolt preload is analyzed, so as to verify the theoretical analysis.

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47

Mojtahedi, Alireza, and Farhad Hosseinlou. "An Iterative Method for Structural Health Monitoring in a Jacket Type Offshore Platform Based on Mode Reduction." International Journal of Engineering and Technology 8, no. 5 (May 2016): 315–22. http://dx.doi.org/10.7763/ijet.2016.v8.905.

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48

Riyanto, R. D., I. H. Helvacioglu, M. Murdjito, E. B. Djatmiko, K. Sambodho, N. Syahroni, W. Wardhana, Y. Mulyadi, Handayanu, and R. W. Prastianto. "Risk assessment of aging offshore jacket platform group: a case study on “B” Field platforms." IOP Conference Series: Earth and Environmental Science 649, no. 1 (February 1, 2021): 012068. http://dx.doi.org/10.1088/1755-1315/649/1/012068.

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49

Zhang, Bo, Zhi-quan Shang, Tao Wang, and Zhuo Wang. "Hydrodynamic Load Analysis and Experimental Study of Grouting Clamp under Wave and Ocean Current." Journal of Marine Science and Engineering 8, no. 7 (July 13, 2020): 512. http://dx.doi.org/10.3390/jmse8070512.

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The repair of offshore platform jackets is an important research direction in marine engineering, among which the grouting clamp reinforcement is the most widely used. In order to solve the hydrodynamic force of the grouting hoop under the joint action of wave and current in the complex sea condition, the Morison formula is used to analyze the linear wave load on the grouting hoop; then, based on the Morison formula, load force under the combined action of the wave and the ocean current on the clamps in different installation states was determined; finally, the screw jack and car jack were used to carry out the experiment of preventing the clamp from falling off. The mechanical grouting clamp experiment and the wedge tooth experiment were carried out at the same time. The innovative design of the mechanical grouting clamp, analyzed analogously through relevant experimental results and numerical analysis results confirmed that the reinforcement and repair method of the designed grouting clamp is of great help to the safety and reliability of the offshore platform jacket.

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50

Mao, Dongfeng, Chao Zhong, Laibin Zhang, and Gui Chu. "Dynamic response of offshore jacket platform including foundation degradation under cyclic loadings." Ocean Engineering 100 (May 2015): 35–45. http://dx.doi.org/10.1016/j.oceaneng.2015.03.012.

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Journal articles on the topic 'Offshore jacket platform'

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