The Experts below are selected from a list of 1662 Experts worldwide ranked by ideXlab platform
Yuanjiang Chang - One of the best experts on this subject based on the ideXlab platform.
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A Bayesian Network model for risk analysis of Deepwater Drilling riser fracture failure
Ocean Engineering, 2019Co-Authors: Yuanjiang Chang, Changshuai Zhang, Xiangfei Wu, Jihua Ye, Guoming Chen, Liangbin XuAbstract:Abstract Drilling risers are crucial connection of subsea wellhead and floating Drilling platform. Fracture failure of Deepwater Drilling risers is the most serious accident in offshore Drilling, which would lead to disastrous consequences. This paper presents a Bayesian Network (BN) model to conduct risk analysis for fracture failure of Deepwater Drilling riser. A Bow-Tie (BT) model is developed to identify the risk factors associated with fracture failure and the potential consequences. Subsequently, evidence theory is used to calculate the prior probability of the input event, and the developed BT model is mapped into BN to carry out risk analysis of fracture failure of Drilling riser. Finally, the probability updating is implemented using forward reasoning in BN model when new evidence is obtained, and a dynamic risk profile of fracture failure and consequence status are performed using probability adaption of BN with the occurrence of the new identified critical factors over a period of time. The application of the developed model is demonstrated through a case study, and some suggestions drawn from the investigation are presented to further mitigate the risk and the severity of accident consequences of Drilling riser fracture failure during Drilling operations.
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comprehensive risk assessment of Deepwater Drilling riser using fuzzy petri net model
Process Safety and Environmental Protection, 2018Co-Authors: Yuanjiang Chang, Xiangfei Wu, Jihua Ye, Liangbin Xu, Guoming Chen, Bin Chen, Jianliang ZhouAbstract:Abstract Drilling risers are the critical connection of subsea wellhead and the floating Drilling unit. With exploration and development of oil and gas resources moving into Deepwater, Drilling riser operations have been characterized with high safety risk and occurrence rate of accidents causing high Drilling downtime and Drilling cost. In the present study, a Fuzzy Petri Net (FPN) methodology is proposed to evaluate the comprehensive risk of Deepwater Drilling risers. A risk index evaluation system was established based on analyses of Drilling riser accidents and identification of risk factors, and the AHP-EM method was used to determine the weights of them. A 9-tuple set was defined to model Drilling riser risks according to the FPN theories, and by using the fuzzy reasoning algorithm, risk values of risk factors at different levels and the integrated system were gained by iteration of state matrix. A specific case study of Deepwater Drilling risers of NANHAI-8 Drilling unit in Liuhua oilfield in South China Sea is presented to illustrate the application of proposed approach, and some suggestions drawn from the investigation are presented to further mitigate the risk of Drilling riser operations. The case study showed that FPN is a practical and reliable method in comprehensive risk evaluation of Deepwater Drilling riser system.
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Analysis on the Operation Fatigue of Deepwater Drilling Riser System
The Open Petroleum Engineering Journal, 2016Co-Authors: Guoming Chen, Jingqi Ji, Jingjie Fu, Qiang Song, Yuanjiang ChangAbstract:Fatigue is one of main failure modes of Deepwater Drilling riser system. Analysis models of wave induced fatigue and vortex induced fatigue of Deepwater Drilling riser are established according to the riser connection, installation and hang-off operations. Characteristics of wave induced fatigue and vortex induced fatigue of riser system in different operation modes are studied. The influence of each operation fatigue on the combined fatigue is also identified. The results show that wave induced fatigue damage and vortex induced fatigue damage of upper riser are large in installation and hard hang-off modes. The fatigue damage of riser system in soft hang-off mode is less than that in hard hang-off mode. The combined fatigue damage of the upper and lower riser is large. The lower riser is under the influence of wave induced fatigue and vortex induced fatigue, while the upper riser is mainly under the influence of wave induced fatigue, especially that in installation and hang-off modes. The fatigue damages of riser in installation and hang-off modes have a great influence on the combined fatigue of riser and cannot be neglected in riser fatigue analysis.
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Drift-off warning limits for Deepwater Drilling platform/riser coupling system
Petroleum Exploration and Development, 2016Co-Authors: Guoming Chen, Yuanjiang Chang, Jingqi Ji, Jingjie Fu, Qiang SongAbstract:Abstract The drift-off dynamic model of Deepwater Drilling platform and riser coupling system was established. An analysis method on drift-off warning limits of Deepwater Drilling platform and riser coupling system was proposed, and a Deepwater Drilling platform/riser system was taken for case study. The analysis model of Deepwater riser, wellhead and conductor coupling system and the drift-off dynamic model of platform were established respectively. The drift-off dynamic solver of Deepwater platform was developed. The coupling dynamic characteristics and coupling effect of the Deepwater Drilling platform and riser system were analyzed in combination with example, and the analysis method for drift-off warning limits was described. The results show that: the riser load acting on platform plays a driving role in the platform drift-off in the initial drift-off stage, and begins to inhibit the platform drift-off gradually as the drift-off displacement increases; During the platform drift-off, the transient response speed of upper riser parameters is high, while the transient response of lower riser parameters presents an obvious hysteresis effect; As the current speed increases or water depth decreases, the drift-off warning limits of Deepwater Drilling platform/riser coupling system decrease and the Deepwater Drilling riser should be disconnected earlier.
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analyses and countermeasures of Deepwater Drilling riser grounding accidents under typhoon conditions
Petroleum Exploration and Development, 2013Co-Authors: Guoming Chen, Yuanjiang Chang, Lei Zhang, X U LiangbinAbstract:Abstract For Deepwater Drilling riser system facing grounding risk in the South China Sea, a mechanical analysis model of Deepwater Drilling riser grounding accident was established. Focusing on Drilling riser grounding accidents of a Deepwater floating Drilling platform in the South China Sea, mechanical characteristics and grounding accidents of riser were analyzed. And the riser retrieving window was determined. The results showed that the shape of the riser system after riser grounding is catenary. The maximums of bending moment and von Mises stress are located at lower flex joint. Platform moon pool, tensioner and lower flex joint are damaged due to severe bending deformation in the upper and lower Drilling riser system after riser grounding accidents. The riser may fracture if Drilling platform continues to move toward shallow water. Drilling platform displacement and riser lift height must be within the riser operation window during riser retrieving, or else the riser may fracture and the LMRP may suffer further damage. Residual riser and LMRP can be retrieved in a fixed position when the Drilling riser system is separated from seabed.
Guoming Chen - One of the best experts on this subject based on the ideXlab platform.
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A Bayesian Network model for risk analysis of Deepwater Drilling riser fracture failure
Ocean Engineering, 2019Co-Authors: Yuanjiang Chang, Changshuai Zhang, Xiangfei Wu, Jihua Ye, Guoming Chen, Liangbin XuAbstract:Abstract Drilling risers are crucial connection of subsea wellhead and floating Drilling platform. Fracture failure of Deepwater Drilling risers is the most serious accident in offshore Drilling, which would lead to disastrous consequences. This paper presents a Bayesian Network (BN) model to conduct risk analysis for fracture failure of Deepwater Drilling riser. A Bow-Tie (BT) model is developed to identify the risk factors associated with fracture failure and the potential consequences. Subsequently, evidence theory is used to calculate the prior probability of the input event, and the developed BT model is mapped into BN to carry out risk analysis of fracture failure of Drilling riser. Finally, the probability updating is implemented using forward reasoning in BN model when new evidence is obtained, and a dynamic risk profile of fracture failure and consequence status are performed using probability adaption of BN with the occurrence of the new identified critical factors over a period of time. The application of the developed model is demonstrated through a case study, and some suggestions drawn from the investigation are presented to further mitigate the risk and the severity of accident consequences of Drilling riser fracture failure during Drilling operations.
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comprehensive risk assessment of Deepwater Drilling riser using fuzzy petri net model
Process Safety and Environmental Protection, 2018Co-Authors: Yuanjiang Chang, Xiangfei Wu, Jihua Ye, Liangbin Xu, Guoming Chen, Bin Chen, Jianliang ZhouAbstract:Abstract Drilling risers are the critical connection of subsea wellhead and the floating Drilling unit. With exploration and development of oil and gas resources moving into Deepwater, Drilling riser operations have been characterized with high safety risk and occurrence rate of accidents causing high Drilling downtime and Drilling cost. In the present study, a Fuzzy Petri Net (FPN) methodology is proposed to evaluate the comprehensive risk of Deepwater Drilling risers. A risk index evaluation system was established based on analyses of Drilling riser accidents and identification of risk factors, and the AHP-EM method was used to determine the weights of them. A 9-tuple set was defined to model Drilling riser risks according to the FPN theories, and by using the fuzzy reasoning algorithm, risk values of risk factors at different levels and the integrated system were gained by iteration of state matrix. A specific case study of Deepwater Drilling risers of NANHAI-8 Drilling unit in Liuhua oilfield in South China Sea is presented to illustrate the application of proposed approach, and some suggestions drawn from the investigation are presented to further mitigate the risk of Drilling riser operations. The case study showed that FPN is a practical and reliable method in comprehensive risk evaluation of Deepwater Drilling riser system.
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Analysis on the Operation Fatigue of Deepwater Drilling Riser System
The Open Petroleum Engineering Journal, 2016Co-Authors: Guoming Chen, Jingqi Ji, Jingjie Fu, Qiang Song, Yuanjiang ChangAbstract:Fatigue is one of main failure modes of Deepwater Drilling riser system. Analysis models of wave induced fatigue and vortex induced fatigue of Deepwater Drilling riser are established according to the riser connection, installation and hang-off operations. Characteristics of wave induced fatigue and vortex induced fatigue of riser system in different operation modes are studied. The influence of each operation fatigue on the combined fatigue is also identified. The results show that wave induced fatigue damage and vortex induced fatigue damage of upper riser are large in installation and hard hang-off modes. The fatigue damage of riser system in soft hang-off mode is less than that in hard hang-off mode. The combined fatigue damage of the upper and lower riser is large. The lower riser is under the influence of wave induced fatigue and vortex induced fatigue, while the upper riser is mainly under the influence of wave induced fatigue, especially that in installation and hang-off modes. The fatigue damages of riser in installation and hang-off modes have a great influence on the combined fatigue of riser and cannot be neglected in riser fatigue analysis.
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Drift-off warning limits for Deepwater Drilling platform/riser coupling system
Petroleum Exploration and Development, 2016Co-Authors: Guoming Chen, Yuanjiang Chang, Jingqi Ji, Jingjie Fu, Qiang SongAbstract:Abstract The drift-off dynamic model of Deepwater Drilling platform and riser coupling system was established. An analysis method on drift-off warning limits of Deepwater Drilling platform and riser coupling system was proposed, and a Deepwater Drilling platform/riser system was taken for case study. The analysis model of Deepwater riser, wellhead and conductor coupling system and the drift-off dynamic model of platform were established respectively. The drift-off dynamic solver of Deepwater platform was developed. The coupling dynamic characteristics and coupling effect of the Deepwater Drilling platform and riser system were analyzed in combination with example, and the analysis method for drift-off warning limits was described. The results show that: the riser load acting on platform plays a driving role in the platform drift-off in the initial drift-off stage, and begins to inhibit the platform drift-off gradually as the drift-off displacement increases; During the platform drift-off, the transient response speed of upper riser parameters is high, while the transient response of lower riser parameters presents an obvious hysteresis effect; As the current speed increases or water depth decreases, the drift-off warning limits of Deepwater Drilling platform/riser coupling system decrease and the Deepwater Drilling riser should be disconnected earlier.
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analyses and countermeasures of Deepwater Drilling riser grounding accidents under typhoon conditions
Petroleum Exploration and Development, 2013Co-Authors: Guoming Chen, Yuanjiang Chang, Lei Zhang, X U LiangbinAbstract:Abstract For Deepwater Drilling riser system facing grounding risk in the South China Sea, a mechanical analysis model of Deepwater Drilling riser grounding accident was established. Focusing on Drilling riser grounding accidents of a Deepwater floating Drilling platform in the South China Sea, mechanical characteristics and grounding accidents of riser were analyzed. And the riser retrieving window was determined. The results showed that the shape of the riser system after riser grounding is catenary. The maximums of bending moment and von Mises stress are located at lower flex joint. Platform moon pool, tensioner and lower flex joint are damaged due to severe bending deformation in the upper and lower Drilling riser system after riser grounding accidents. The riser may fracture if Drilling platform continues to move toward shallow water. Drilling platform displacement and riser lift height must be within the riser operation window during riser retrieving, or else the riser may fracture and the LMRP may suffer further damage. Residual riser and LMRP can be retrieved in a fixed position when the Drilling riser system is separated from seabed.
Matthew J Stahl - One of the best experts on this subject based on the ideXlab platform.
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operation integrity evaluations for Deepwater Drilling riser system
29th International Conference on Ocean Offshore and Arctic Engineering: Volume 5 Parts A and B, 2010Co-Authors: Long Ge, Kenneth Bhalla, Matthew J StahlAbstract:This paper highlights concerns and operating issues for Deepwater Drilling risers operated from dynamically positioned or moored rigs, and discusses proper approaches and criteria to evaluate and ensure the operational integrity of Drilling riser systems. As Drilling water depths go deeper, more operation issues need to be considered. Major operating concerns of Deepwater riser systems include: • collapse pressure rating, • handling and lift capacity, • deployment and retrieval, • planned or emergency riser disconnect, • connected operations, • drift-off or drive-off, • hangoff during storms, • fatigue due to vortex-induced-vibration or wave loads. In Deepwater Drilling, longer and heavier riser equipment, rig motions, weight mass ratio, hydrostatic pressure, mud flow, stiffness, drag, wave, and current all play important roles on riser system integrity, from well head to rig equipment. This paper provides general guidelines to evaluate the Drilling riser system of various rigs under normal and extreme operational conditions. Issues for different major operations will be introduced, evaluation methods and associated criteria will be discussed, typical findings and remedial solutions will be presented.Copyright © 2010 by ASME
Jianliang Zhou - One of the best experts on this subject based on the ideXlab platform.
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comprehensive risk assessment of Deepwater Drilling riser using fuzzy petri net model
Process Safety and Environmental Protection, 2018Co-Authors: Yuanjiang Chang, Xiangfei Wu, Jihua Ye, Liangbin Xu, Guoming Chen, Bin Chen, Jianliang ZhouAbstract:Abstract Drilling risers are the critical connection of subsea wellhead and the floating Drilling unit. With exploration and development of oil and gas resources moving into Deepwater, Drilling riser operations have been characterized with high safety risk and occurrence rate of accidents causing high Drilling downtime and Drilling cost. In the present study, a Fuzzy Petri Net (FPN) methodology is proposed to evaluate the comprehensive risk of Deepwater Drilling risers. A risk index evaluation system was established based on analyses of Drilling riser accidents and identification of risk factors, and the AHP-EM method was used to determine the weights of them. A 9-tuple set was defined to model Drilling riser risks according to the FPN theories, and by using the fuzzy reasoning algorithm, risk values of risk factors at different levels and the integrated system were gained by iteration of state matrix. A specific case study of Deepwater Drilling risers of NANHAI-8 Drilling unit in Liuhua oilfield in South China Sea is presented to illustrate the application of proposed approach, and some suggestions drawn from the investigation are presented to further mitigate the risk of Drilling riser operations. The case study showed that FPN is a practical and reliable method in comprehensive risk evaluation of Deepwater Drilling riser system.
Zhichuan Guan - One of the best experts on this subject based on the ideXlab platform.
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Real-time quantitative description of gas invasion in Deepwater Drilling
The Journal of Engineering Research, 2018Co-Authors: Xiaohui Wang, Zhichuan Guan, Yanan Sheng, Yang TianAbstract:With the increase of global Deepwater Drilling, the scale of the Deepwater Drilling contract market continues to expand, and the depth of the Drilling operations constantly refresh the record. At the same time, the Drilling environment and related geological conditions become more and more complex, which leads to the increase of the risk in the operation of Deepwater Drilling. After the happening of “Deepwater Horizon ” in the Gulf of Mexico, the prevention and control of blowout has become an urgent problem to be solved in the development of offshore oil and gas. Dealing with the problem of overflow and blowout in Deepwater Drilling, the most effective technical measures are early detection and identification of gas influx. The research on the degree of gas invasion is the basis of the formulation and implementation of well control measures. In this paper, a simulation model of gas-liquid twophase flow after the happening of gas influx is established to calculate the cross section gas content, mud tank overflow and bottom-hole pressure. Through the calculation, the real-time quantitative relationship between the characterization of the gas content and the bottomhole pressure and the increment of the mud pool was established and then the realtime quantitative degree of gas invasion is analyzed.
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Risk Assessment Method of Subsea Wellhead Instability in Consideration of Uncertain Factors in Deepwater Drilling
Arabian Journal for Science and Engineering, 2017Co-Authors: Yuqiang Xu, Zhichuan Guan, Bo Zhang, Yanan ShengAbstract:In Deepwater Drilling, the subsea wellhead is in a complicated stress state and carries the risk of instability. The mechanical stability of subsea wellhead has gradually become one of the key factors in the design and construction of Deepwater Drilling. In this paper, through the analysis of stress and deformation of subsea wellhead system in Deepwater Drilling, the characteristic parameters that characterize the mechanical stability of subsea wellhead were determined. On this basis, the influence of different factors on characteristic parameters was analyzed based on dimensionless processing and sensitivity analysis. Factors that were more sensitive and had greater impact on the wellhead mechanical stability of the instance well were screened. Aiming at the problem of greater uncertainty of resistance coefficient, the risk assessment method of subsea wellhead instability considering of uncertain factors was established. Using this method, the wellhead instability risks could be quantitatively evaluated in the Drilling process, construction parameters and monitoring values of environmental loads which meet the wellhead safety requirements that could also be proposed. Example shows that: according to the selected parameters such as center value of drag coefficient \(\mu = 0.8\), fluctuation coefficient of drag coefficient \(\sigma = 0.05\), safety limit of subsea wellhead displacement \(S_{\mathrm{wm}} = 0.37\,\hbox {m}\), and safety limit of subsea wellhead deflection angle \(\theta _{\mathrm{wm}} = 3.1{^{\circ }}\), there was 24% probability of occurrence of wellhead instability for the target well. Meanwhile, the platform drift \(S_{\mathrm{w}}\) should be < 43 m, and the maximum marine current velocity \(u_{\mathrm{w}}\) should be < 1.188 m s\(^{-1}\).
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the quantitative description of gas cut degree in Deepwater Drilling
Petroleum Exploration and Development, 2016Co-Authors: X U Yuqiang, Zhichuan Guan, Huizeng Zhang, Hongning ZhangAbstract:Abstract Through the analysis of gas-cut features in Deepwater Drilling and shortages of existing gas-cut detection methods, the feasibility of early detection of gas cut at the bottom of riser was demonstrated, and a method was proposed for quantitative description of gas-cut degree in Deepwater Drilling based on ultrasonic monitoring at the bottom of riser. The problems of Doppler ultrasound gas-cut detection method was analyzed and the experimental device of gas-cut monitoring at the bottom of riser based on the ultrasonic transmission was built, which was used to analyze the sound attenuation characteristics under different conditions of void fraction. The solutions for using ultrasound to monitor gas-cut situation at the bottom of riser was proposed. Combined with the gas-liquid two-phase model of wellbore annulus in Deepwater Drilling and the formation pressure prediction method with credibility, the inverse calculation method of gas-cut degree in wellbore was established, which was based on the monitoring data of gas cut at the bottom section of riser. This method could detect the gas cut about four minutes in advance compared with conventional methods, and the gas cut occurring moment, the time left for gas to reach the wellhead, the total overflow rate at any moment, and the void fraction in different depth could be accurately determined based on the acoustic response data of the bottom of riser.
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Dynamic Response of the Casing String in Seabed Soil for Deepwater Drilling
Applied Mechanics and Materials, 2012Co-Authors: Kan Hua Su, Zhichuan GuanAbstract:The marine riser has transfer dynamic cyclic load to the top of casing string when Deepwater Drilling operating. Considering with the nonlinear characteristics of seabed soil, the variable string cross section, and the axial load on the top of string, a dynamic differential equation of casing string below mud line and its numerical solution were established. Results illustrate that, the lateral displacement, the bending moment, and the shear of the casing string are not equal when lateral dynamic cyclic loading achieves amplitude due to the soil hysteresis effect. The diameter and wall thickness of conductor have less affect to string vibration frequency, cannot adjust the string natural frequency by adjusting these parameters. The natural frequency of casing string in sand is bigger than it in clay. The undrained shear strength of soil has great effect on the natural frequency of casing string in clay. The lateral displacement amplitude is highest when the vibration frequency of casing string at its natural frequency.
