This work provides a description of oil leak/spill processes from containment such as pipeline. Understanding of such processes is important in order to adequately estimate oil spills and to justify an appropriate eme...This work provides a description of oil leak/spill processes from containment such as pipeline. Understanding of such processes is important in order to adequately estimate oil spills and to justify an appropriate emergency action for minimizing spills. Internal diameters of pipes used in the study are within 4 inches. Leaks are simulated from plastic pipeline oil containment fitted with valves. The leak response with time when upstream and downstream valves are operated is studied. Within the internal diameters of pipelines considered in the tests, two ranges of leak characteristics are evident;the “holding range” and the “flowing range” characteristics. The consequences of these characteristics in the oil industry operations have been discussed. The work suggests a spill estimation method based on this knowledge. Furthermore, in order to minimise spill in event of pipeline failure, it is observed that the optimum action on pipeline operational valves, is the immediate closure of upstream valve, followed by the downstream valve, nearly simultaneously. Future work will extend the test to larger diameter pipelines to attempt developing a mathematical approach for estimating limits of the “holding range” characteristics of pipelines given appropriate parameters and in-field test.展开更多
Oil spill-induced vapor cloud explosions in a confined space can cause catastrophic consequences.In this work,investigation was conducted on the catastrophic pipeline leak,oil spill,and the resulting vapor cloud explo...Oil spill-induced vapor cloud explosions in a confined space can cause catastrophic consequences.In this work,investigation was conducted on the catastrophic pipeline leak,oil spill,and the resulting vapor cloud explosion accident occurring in China in 2013 by modeling analysis,field surveys,and numerical simulations.The total amount of the spilled oil was up to2044.4 m3 due to improper disposal.The long residence time of the oil remaining in a confined space permitted the formation of explosive mixtures and caused the vapor cloud explosion.A numerical model was developed to estimate the consequence of the explosion based on volatilization testing results.The results show that the death-leading zone and the glass-breaking zone could be 18 m and 92 m,respectively,which are consistent with the field investigation.The severity of the explosion is related to the amount of the oil spill,properties of oil,and volatilization time.It is recommended that a comprehensive risk assessment be conducted to analyze the possible consequences upon oil spilling into a confined space.Prompt collection and ventilation measures should be taken immediately after the spill occurs to reduce the time for oil volatilization and prevent the mixture from reaching its explosive limit.展开更多
A fully distributed optical fiber sensor （DOFS） for monitoring long-distance oil pipeline health is proposed based on optical time domain reflectometry （OTDR）. A smart and sensitive optical fiber cable is installe...A fully distributed optical fiber sensor （DOFS） for monitoring long-distance oil pipeline health is proposed based on optical time domain reflectometry （OTDR）. A smart and sensitive optical fiber cable is installed along the pipeline acting as a sensor, The experiments show that the cable swells when exposed to oil and induced additional bending losses inside the fiber, and the optical attenuation of the fiber coated by a thin skin with periodical hardness is sensitive to deformation and vibration caused by oil leakage, tampering, or mechanical impact. The region where the additional attenuation occurred is detected and located by DOFS based on OTDR, the types of pipeline accidents are identified according to the characteristics of transmitted optical power received by an optical power meter, Another prototype of DOFS based on a forward traveling frequency-modulated continuous-wave （FMCW） is also proposed to monitor pipeline. The advantages and disadvantages of DOFSs based on OTDR and FMCW are discussed. The experiments show that DOFSs are capable of detecting and locating distant oil pipeline leakages and damages in real time with an estimated precision of ten meters over tens of kilometers.展开更多
This paper examines the advances in pipeline third party encroachment alert systems and leak control methods in the oil/gas industry. It also highlights the extent of spill/pollution issues in the Niger Delta region d...This paper examines the advances in pipeline third party encroachment alert systems and leak control methods in the oil/gas industry. It also highlights the extent of spill/pollution issues in the Niger Delta region due to intended/unin- tended damages and suggests a possible method of control. It is believed that the best option to avoid pollution due to pipeline failure is to ensure that hydrocarbon does not exit from the pipeline. With the different methods considered in this review, acoustic monitoring of change in the operational sound generated from a given pipeline section is suggested to be practicable to identifying sound abnormalities of third party encroachments. One established challenge of the acoustic system for buried pipelines protection is attenuation of acoustic transmission. An attempt to check the performance of an acoustic transmission on steel pipelines submerged in water points to a similar research on plastic water pipelines that attenuation is small compared with pipe buried in soil. Fortunately, Niger Delta of Nigeria is made of wetland, swamps and shallow water and could therefore offer an opportunity to deploy acoustic system for the safety of pipelines against third party attacks in this region. However, the numerous configuration and quantity of oil installation in this region imply that cost of application will be enormous. It is therefore suggested that a combination of impressed alternating cycle current (IACC) which traces encroachment on the pipeline coating and an acoustic system be used to manage intended and unintended pipeline potential damages. The IACC should be used for flow lines and other short distance delivery lines within the oilfield, while the relatively large diameter and long length delivery, trunk and transmission lines should be considered for acoustic protection. It is, however, noted that further efforts are required to reduce cost and improve effectiveness of these systems.展开更多
文摘This work provides a description of oil leak/spill processes from containment such as pipeline. Understanding of such processes is important in order to adequately estimate oil spills and to justify an appropriate emergency action for minimizing spills. Internal diameters of pipes used in the study are within 4 inches. Leaks are simulated from plastic pipeline oil containment fitted with valves. The leak response with time when upstream and downstream valves are operated is studied. Within the internal diameters of pipelines considered in the tests, two ranges of leak characteristics are evident;the “holding range” and the “flowing range” characteristics. The consequences of these characteristics in the oil industry operations have been discussed. The work suggests a spill estimation method based on this knowledge. Furthermore, in order to minimise spill in event of pipeline failure, it is observed that the optimum action on pipeline operational valves, is the immediate closure of upstream valve, followed by the downstream valve, nearly simultaneously. Future work will extend the test to larger diameter pipelines to attempt developing a mathematical approach for estimating limits of the “holding range” characteristics of pipelines given appropriate parameters and in-field test.
基金supported by China Scholarship Council(201809110035)the State Key Research and Development Plan Project of China(2016YFC0801500).
文摘Oil spill-induced vapor cloud explosions in a confined space can cause catastrophic consequences.In this work,investigation was conducted on the catastrophic pipeline leak,oil spill,and the resulting vapor cloud explosion accident occurring in China in 2013 by modeling analysis,field surveys,and numerical simulations.The total amount of the spilled oil was up to2044.4 m3 due to improper disposal.The long residence time of the oil remaining in a confined space permitted the formation of explosive mixtures and caused the vapor cloud explosion.A numerical model was developed to estimate the consequence of the explosion based on volatilization testing results.The results show that the death-leading zone and the glass-breaking zone could be 18 m and 92 m,respectively,which are consistent with the field investigation.The severity of the explosion is related to the amount of the oil spill,properties of oil,and volatilization time.It is recommended that a comprehensive risk assessment be conducted to analyze the possible consequences upon oil spilling into a confined space.Prompt collection and ventilation measures should be taken immediately after the spill occurs to reduce the time for oil volatilization and prevent the mixture from reaching its explosive limit.
基金This project is supported by R&D Foundation of National Petroleum Corporation (CNPC) of China(No.2001411-4).
文摘A fully distributed optical fiber sensor （DOFS） for monitoring long-distance oil pipeline health is proposed based on optical time domain reflectometry （OTDR）. A smart and sensitive optical fiber cable is installed along the pipeline acting as a sensor, The experiments show that the cable swells when exposed to oil and induced additional bending losses inside the fiber, and the optical attenuation of the fiber coated by a thin skin with periodical hardness is sensitive to deformation and vibration caused by oil leakage, tampering, or mechanical impact. The region where the additional attenuation occurred is detected and located by DOFS based on OTDR, the types of pipeline accidents are identified according to the characteristics of transmitted optical power received by an optical power meter, Another prototype of DOFS based on a forward traveling frequency-modulated continuous-wave （FMCW） is also proposed to monitor pipeline. The advantages and disadvantages of DOFSs based on OTDR and FMCW are discussed. The experiments show that DOFSs are capable of detecting and locating distant oil pipeline leakages and damages in real time with an estimated precision of ten meters over tens of kilometers.
文摘This paper examines the advances in pipeline third party encroachment alert systems and leak control methods in the oil/gas industry. It also highlights the extent of spill/pollution issues in the Niger Delta region due to intended/unin- tended damages and suggests a possible method of control. It is believed that the best option to avoid pollution due to pipeline failure is to ensure that hydrocarbon does not exit from the pipeline. With the different methods considered in this review, acoustic monitoring of change in the operational sound generated from a given pipeline section is suggested to be practicable to identifying sound abnormalities of third party encroachments. One established challenge of the acoustic system for buried pipelines protection is attenuation of acoustic transmission. An attempt to check the performance of an acoustic transmission on steel pipelines submerged in water points to a similar research on plastic water pipelines that attenuation is small compared with pipe buried in soil. Fortunately, Niger Delta of Nigeria is made of wetland, swamps and shallow water and could therefore offer an opportunity to deploy acoustic system for the safety of pipelines against third party attacks in this region. However, the numerous configuration and quantity of oil installation in this region imply that cost of application will be enormous. It is therefore suggested that a combination of impressed alternating cycle current (IACC) which traces encroachment on the pipeline coating and an acoustic system be used to manage intended and unintended pipeline potential damages. The IACC should be used for flow lines and other short distance delivery lines within the oilfield, while the relatively large diameter and long length delivery, trunk and transmission lines should be considered for acoustic protection. It is, however, noted that further efforts are required to reduce cost and improve effectiveness of these systems.
