Safety assessment of offshore platforms is an urgent task. Such assessments are now focusing on the structure, maintenance, and retirement of a platform. Some methods employed have many shortcomings. For example, they...Safety assessment of offshore platforms is an urgent task. Such assessments are now focusing on the structure, maintenance, and retirement of a platform. Some methods employed have many shortcomings. For example, they cannot make the reliability adequately explicable. Therefore, a mathematical tool, the unascertained measure, was introduced. First, the basic knowledge of the unascertained sets was introduced briefly. Second, the unascertained measure was defined and credible identification was set up. The method has been introduced into the fields for safety assessment of a jacket loadout procedure. Engineering practices showed that it can complete the safety assessment systematically and scientifically without any assumption. The work should have significance in theory and practice for offshore engineering.展开更多
A typhoon-induced storm surge simulation system was developed for the Qingdao area, including a typhoon diagnostic model for the generation of wind and pressure fields and a 2D Advanced Circulation(ADCIRC) model for s...A typhoon-induced storm surge simulation system was developed for the Qingdao area, including a typhoon diagnostic model for the generation of wind and pressure fields and a 2D Advanced Circulation(ADCIRC) model for simulating the associated storm surge with a 200 m resolution along the Qingdao coastline. The system was validated by an extreme surge event Typhoon Mamie(8509) and the parameters of Typhoon Mamie were used to investigate the sensitivity of typhoon paths to Qingdao storm surges with four selected paths: the paths of Typhoons Mamie(8509), Opal, 3921 and 2413, the selection being made according to their relative position to Qingdao. Experiments based on the Typhoon Mamie(8509) storm surge were also conducted to study the possible influences of future climate changes, including the sea level rise and sea surface temperature(SST) rise, on storm surges along the Qingdao coast. Storm surge conditions under both present day and future(the end of the 21 st century) climate scenarios associated with the four selected paths were simulated. The results show that with the same intensity, when typhoons follow the paths of 3921 and 2413, they would lead to the most serious disasters in different areas of Qingdao. Sea level and SST affect storm surges in different ways: sea level rise affects storm surge mainly through its influence on the tide amplitude, while the increased SST has direct impact on the intensity of the surges. The possible maximum risk of storm surges in 2100 in the Qingdao area caused by typhoons like Mamie(8509) was also estimated in this study.展开更多
Some important questions for new energy development were discussed, such as the prediction and calculation of sea surface temperature, ocean wave, offshore platform price, typhoon track, fire status, vibration due to ...Some important questions for new energy development were discussed, such as the prediction and calculation of sea surface temperature, ocean wave, offshore platform price, typhoon track, fire status, vibration due to earthquake, energy price, stock market’s trend and so on with the fractal methods (including the four ones of constant dimension fractal, variable dimension fractal, complex number dimension fractal and fractal series) and the improved rescaled range analysis (R/S analysis).展开更多
Wave steepness is an important characteristic of a high sea state, and is widely applied on wave propagations at ports, ships, offshore platforms, and CO2 circulation in the ocean. Obtaining wave steepness is a diffic...Wave steepness is an important characteristic of a high sea state, and is widely applied on wave propagations at ports, ships, offshore platforms, and CO2 circulation in the ocean. Obtaining wave steepness is a difficult task that depends heavily on theoretical research on wavelength distribution and direct observations. Development of remote-sensing techniques provides new opportunities to study wave steepness. At present, two formulas are proposed to estimate wave steepness from QuikSCAT and ERS-1/2 scatterometer data. We found that wave steepness retrieving is not affected by radar band, and polarization method, and that relationship of wave steepness with radar backscattering cross section is similar to that with wind. Therefore, we adopted and modified a genetic algorithm for relating wave steepness with radar backscattering cross section. Results show that the root-mean-square error of the wave steepness retrieved is 0.005 in two cases from ERS-1/2 scatterometer data and from QuikSCAT scatterometer data.展开更多
Using data from tens of measured and observed outcrop successions,thin rock slices and sample analyses,we comprehensively studied the Cambrian sedimentary environments and evolutionary characteristics in the north mar...Using data from tens of measured and observed outcrop successions,thin rock slices and sample analyses,we comprehensively studied the Cambrian sedimentary environments and evolutionary characteristics in the north margin of the Middle-Upper Yangtze Plate.During the Cambrian,platform,slope,and deep sea basin environments were developed in the study area.On the platform,both clastic rocks and carbonate rocks were deposited.Clastic rocks mainly occur in the Lower Cambrian,and were deposited in marine shore and shelf environments.Carbonate rocks are dominant in the Middle and Upper Cambrian,and were deposited in the open platform,restricted platform,tidal flat,beach,and reef environments.Carbonate gravity flow deposits were developed on the slope.In the basin,mainly black shales and chert beds were deposited.The Cambrian represents one large transgression-regression cycle,and maximum transgression occurred in the Qiongzhusi Age of the Early Cambrian.Tectonics and sea level fluctuations had important impacts on sedimentary environments.The Chengkou-Fangxian-Xiangfan Fracture controlled the position of the platform,slope and basin,as well as the silica supply for chert deposition in basin.Sea level fluctuations controlled types of sediments and sedimentary facies on the platform.In the study area,there are good reservoir rocks,including dolomites,grainstones,debris flow deposits,sandstones,and conglomerates;there are good source rocks,including black shales,dark micrites,and chert beds;and there are also good reservoir-source rock assemblages.The hydrocarbon potential of the study area is great.展开更多
基金the National Natural Science Foundation of China (505079047)
文摘Safety assessment of offshore platforms is an urgent task. Such assessments are now focusing on the structure, maintenance, and retirement of a platform. Some methods employed have many shortcomings. For example, they cannot make the reliability adequately explicable. Therefore, a mathematical tool, the unascertained measure, was introduced. First, the basic knowledge of the unascertained sets was introduced briefly. Second, the unascertained measure was defined and credible identification was set up. The method has been introduced into the fields for safety assessment of a jacket loadout procedure. Engineering practices showed that it can complete the safety assessment systematically and scientifically without any assumption. The work should have significance in theory and practice for offshore engineering.
基金supported by the Marine Industry Research Special Funds for Public Welfare Projects (No. 200905013)
文摘A typhoon-induced storm surge simulation system was developed for the Qingdao area, including a typhoon diagnostic model for the generation of wind and pressure fields and a 2D Advanced Circulation(ADCIRC) model for simulating the associated storm surge with a 200 m resolution along the Qingdao coastline. The system was validated by an extreme surge event Typhoon Mamie(8509) and the parameters of Typhoon Mamie were used to investigate the sensitivity of typhoon paths to Qingdao storm surges with four selected paths: the paths of Typhoons Mamie(8509), Opal, 3921 and 2413, the selection being made according to their relative position to Qingdao. Experiments based on the Typhoon Mamie(8509) storm surge were also conducted to study the possible influences of future climate changes, including the sea level rise and sea surface temperature(SST) rise, on storm surges along the Qingdao coast. Storm surge conditions under both present day and future(the end of the 21 st century) climate scenarios associated with the four selected paths were simulated. The results show that with the same intensity, when typhoons follow the paths of 3921 and 2413, they would lead to the most serious disasters in different areas of Qingdao. Sea level and SST affect storm surges in different ways: sea level rise affects storm surge mainly through its influence on the tide amplitude, while the increased SST has direct impact on the intensity of the surges. The possible maximum risk of storm surges in 2100 in the Qingdao area caused by typhoons like Mamie(8509) was also estimated in this study.
文摘Some important questions for new energy development were discussed, such as the prediction and calculation of sea surface temperature, ocean wave, offshore platform price, typhoon track, fire status, vibration due to earthquake, energy price, stock market’s trend and so on with the fractal methods (including the four ones of constant dimension fractal, variable dimension fractal, complex number dimension fractal and fractal series) and the improved rescaled range analysis (R/S analysis).
基金Supported by the National High Technology Research and Development Program of China(863Program)(No.2008AA09Z102)Data were provided by the European Space Agency
文摘Wave steepness is an important characteristic of a high sea state, and is widely applied on wave propagations at ports, ships, offshore platforms, and CO2 circulation in the ocean. Obtaining wave steepness is a difficult task that depends heavily on theoretical research on wavelength distribution and direct observations. Development of remote-sensing techniques provides new opportunities to study wave steepness. At present, two formulas are proposed to estimate wave steepness from QuikSCAT and ERS-1/2 scatterometer data. We found that wave steepness retrieving is not affected by radar band, and polarization method, and that relationship of wave steepness with radar backscattering cross section is similar to that with wind. Therefore, we adopted and modified a genetic algorithm for relating wave steepness with radar backscattering cross section. Results show that the root-mean-square error of the wave steepness retrieved is 0.005 in two cases from ERS-1/2 scatterometer data and from QuikSCAT scatterometer data.
基金supported by China Petroleum Chemical Industry Co.,LTD (Grant No.YPH08015)
文摘Using data from tens of measured and observed outcrop successions,thin rock slices and sample analyses,we comprehensively studied the Cambrian sedimentary environments and evolutionary characteristics in the north margin of the Middle-Upper Yangtze Plate.During the Cambrian,platform,slope,and deep sea basin environments were developed in the study area.On the platform,both clastic rocks and carbonate rocks were deposited.Clastic rocks mainly occur in the Lower Cambrian,and were deposited in marine shore and shelf environments.Carbonate rocks are dominant in the Middle and Upper Cambrian,and were deposited in the open platform,restricted platform,tidal flat,beach,and reef environments.Carbonate gravity flow deposits were developed on the slope.In the basin,mainly black shales and chert beds were deposited.The Cambrian represents one large transgression-regression cycle,and maximum transgression occurred in the Qiongzhusi Age of the Early Cambrian.Tectonics and sea level fluctuations had important impacts on sedimentary environments.The Chengkou-Fangxian-Xiangfan Fracture controlled the position of the platform,slope and basin,as well as the silica supply for chert deposition in basin.Sea level fluctuations controlled types of sediments and sedimentary facies on the platform.In the study area,there are good reservoir rocks,including dolomites,grainstones,debris flow deposits,sandstones,and conglomerates;there are good source rocks,including black shales,dark micrites,and chert beds;and there are also good reservoir-source rock assemblages.The hydrocarbon potential of the study area is great.
