Through fifty years' development and effort, oil and gas pipeline industry in China has created a self-development way under the country's characteristics which relies on scientific and technological innovatio...Through fifty years' development and effort, oil and gas pipeline industry in China has created a self-development way under the country's characteristics which relies on scientific and technological innovation and introduction,展开更多
The restraint intensity （RI） of the pipeline girth welding joint was investigated using finite element method and experimental method to predict the cold cracking susceptibility of pipeline steel. The distribution o...The restraint intensity （RI） of the pipeline girth welding joint was investigated using finite element method and experimental method to predict the cold cracking susceptibility of pipeline steel. The distribution of RI along the girth weld was investigated to study the influence of welding position on the RL Subsequently, the effects of outer diameter （OD） and wall thickness of pipeline on the RI were studied with ABAQUS software. The results show that the RI is almost independent of welding position. The RI increased with the increasing wall thickness but decreased with the increasing OD. A prediction model of Rl was developed based on the effects of the OD and the wall thickness. It has been found that the predicted RIs were in good agreement with the experimental values. The maximum fractional error between the predicted RI and the experimental values was just about 10%. h was indicated that the errors were mainly caused by the heterogeneous of the weld bead.展开更多
Prospect of engineering technologies for pipelines in ChinaIn recent years,China National Petroleum Corporation (CNPC) has made remarkable achievements in the field of oil and gas transmission pipeline engineering.
Nowadays, we are in great lack of the technology theory for the storage and transportation of gas hydrate. Under this condition, after checking out related theory of these, we established the technology roadmap of the...Nowadays, we are in great lack of the technology theory for the storage and transportation of gas hydrate. Under this condition, after checking out related theory of these, we established the technology roadmap of the storage and transportation of gas hydrate by LNG technology. Study has shown that the technology of LNG is more saving than that of pipeline. Then we came out with the new idea of storage and transportation of hydrate by LNG technology.展开更多
The general features of oscillations within a rectangular harbor of exponential bottom are investigated analytically. Based on the linear shallow water approximation, analytical solutions for longitudinal oscillations...The general features of oscillations within a rectangular harbor of exponential bottom are investigated analytically. Based on the linear shallow water approximation, analytical solutions for longitudinal oscillations induced by the incident perpendicular wave are obtained by the method of matched asymptotics. The analytic results show that the resonant frequencies are shifted to larger values as the water depth increases and the oscillation amplitudes are enhanced due to the shoaling effect. Owing to the refraction effect, there could be several transverse oscillation modes existing in when the width of the harbor is on the order of the oscillation wavelength. These transverse oscillations are similar to standing edge waves, and there are m node lines in the longshore direction and n node lines running in the offshore direction corresponding to mode（n, m）. Furthermore, the transverse eigen frequency is not only related to the width of the harbor, but also to the boundary condition at the backwall and the bottom shape.展开更多
The hydrogen permeation behavior and stress corrosion cracking （SCC） susceptibility of precharged 7075-T6 A1 alloy were inves- tigated in this paper. Devanthan-Stachurski （D-S） cell tests were used to measure the ...The hydrogen permeation behavior and stress corrosion cracking （SCC） susceptibility of precharged 7075-T6 A1 alloy were inves- tigated in this paper. Devanthan-Stachurski （D-S） cell tests were used to measure the apparent hydrogen diffusivity and hydrogen permeation current density of specimens immersed in 3.5wt% NaCl solution. Electrochemical experiment results show that the SCC susceptibility is low during anodic polarization. Both corrosion pits and hydrogen-induced cracking are evident in scanning electron microscope images after the specimens have been charging for 24 h.展开更多
The Al-alloy arc-welding shaping system based on arc-welding robot is established, and the Al-alloy shaping manufacture is realized with the DC （direct current） gas metal arc welding （GMAW）. The research indicates...The Al-alloy arc-welding shaping system based on arc-welding robot is established, and the Al-alloy shaping manufacture is realized with the DC （direct current） gas metal arc welding （GMAW）. The research indicates that the metal transfer type of DC GMA W, heat input and the initial temperature of the workpiece greatly affect the Al-alloy shaping based on arc welding robot. On the penetration, the weld width and the reinforcement, the influence of welding parameters is analyzed by generalized regression neural network （GRNN） fitting.展开更多
In order to study the arc force distribution of ultrasonic assisted tungsten inert gas （U-TIG） welding and compare it with the conventional tungsten inert gas （TIC） welding, a series of experiments have been carri...In order to study the arc force distribution of ultrasonic assisted tungsten inert gas （U-TIG） welding and compare it with the conventional tungsten inert gas （TIC） welding, a series of experiments have been carried out, using our self- designed welding and testing system. The distribution of arc pressure is studied, under conditions as radiation distance, which is the distance between the ultrasonic horn tip and workpiece, and welding current. The values of arc pressure generally increase as the current increases. Other experimental phenomena are also accounted for in detail in this paper. Welding parameters are thought to be responsible for enhancing the welding efficiency and improving the appearance of weld.展开更多
In order to effectively improve penetration rates and enhance wellbore quality for vertical wells,a new Automatic Vertical Drilling Tool(AVDT)based on Eccentric Braced Structure(EBS)is designed.Applying operating prin...In order to effectively improve penetration rates and enhance wellbore quality for vertical wells,a new Automatic Vertical Drilling Tool(AVDT)based on Eccentric Braced Structure(EBS)is designed.Applying operating principle of rotary steering drilling,AVDT adds offset gravity block automatic induction inclination mechanism.When hole straightening happens,tools take essentric moment to be produced by gravity of offset gravity lock to control the bearing of guide force,so that well straightening is achieved.The normal tool's size of the AVDT is designed as 215.9 mm,other major components'sizes are worked out by the result of theoretical analysis,including the offset angle of EBS.This paper aims to introduce the structure,operating principle,theoretical analysis and describe the key components'parameters setting of the AVDT.展开更多
文摘Through fifty years' development and effort, oil and gas pipeline industry in China has created a self-development way under the country's characteristics which relies on scientific and technological innovation and introduction,
基金financially supported by the Tianjin Natural Science Foundation(No.11JCYBJC06000)the Key Project of Tianjin Municipal Science and Technology Support Program(No.11ZCGYSF00100)the Gansu Province Science and Technology Support Program(No.1204GKCA007)
文摘The restraint intensity （RI） of the pipeline girth welding joint was investigated using finite element method and experimental method to predict the cold cracking susceptibility of pipeline steel. The distribution of RI along the girth weld was investigated to study the influence of welding position on the RL Subsequently, the effects of outer diameter （OD） and wall thickness of pipeline on the RI were studied with ABAQUS software. The results show that the RI is almost independent of welding position. The RI increased with the increasing wall thickness but decreased with the increasing OD. A prediction model of Rl was developed based on the effects of the OD and the wall thickness. It has been found that the predicted RIs were in good agreement with the experimental values. The maximum fractional error between the predicted RI and the experimental values was just about 10%. h was indicated that the errors were mainly caused by the heterogeneous of the weld bead.
文摘Technology progress of oil & gas pipelines transportation project of CNPC since the 11th Five-Year Plan period An introduction to oil & gas pipelines
文摘Prospect of engineering technologies for pipelines in ChinaIn recent years,China National Petroleum Corporation (CNPC) has made remarkable achievements in the field of oil and gas transmission pipeline engineering.
文摘Nowadays, we are in great lack of the technology theory for the storage and transportation of gas hydrate. Under this condition, after checking out related theory of these, we established the technology roadmap of the storage and transportation of gas hydrate by LNG technology. Study has shown that the technology of LNG is more saving than that of pipeline. Then we came out with the new idea of storage and transportation of hydrate by LNG technology.
基金financially supported by the National Natural Science Foundation of China(Grant No.51209081)NSFC-RS Joint Projects(Grant No.51411130125)+1 种基金Open Foundation of State Key Laboratory of Coastal and Offshore Engineering(Grant No.LP1405)the Fundamental Research Funds for the Central Universities(Grant No.2015B15714)
文摘The general features of oscillations within a rectangular harbor of exponential bottom are investigated analytically. Based on the linear shallow water approximation, analytical solutions for longitudinal oscillations induced by the incident perpendicular wave are obtained by the method of matched asymptotics. The analytic results show that the resonant frequencies are shifted to larger values as the water depth increases and the oscillation amplitudes are enhanced due to the shoaling effect. Owing to the refraction effect, there could be several transverse oscillation modes existing in when the width of the harbor is on the order of the oscillation wavelength. These transverse oscillations are similar to standing edge waves, and there are m node lines in the longshore direction and n node lines running in the offshore direction corresponding to mode（n, m）. Furthermore, the transverse eigen frequency is not only related to the width of the harbor, but also to the boundary condition at the backwall and the bottom shape.
基金financially supported by the Natural Science Foundation of Jiangsu Province, China (No. BK20141292)the Foundation of Key Laboratory of Marine Environmental Corrosion and Bio-fouling, Institute of Oceanology, Chinese Academy of Sciences (No. MCKF201412)
文摘The hydrogen permeation behavior and stress corrosion cracking （SCC） susceptibility of precharged 7075-T6 A1 alloy were inves- tigated in this paper. Devanthan-Stachurski （D-S） cell tests were used to measure the apparent hydrogen diffusivity and hydrogen permeation current density of specimens immersed in 3.5wt% NaCl solution. Electrochemical experiment results show that the SCC susceptibility is low during anodic polarization. Both corrosion pits and hydrogen-induced cracking are evident in scanning electron microscope images after the specimens have been charging for 24 h.
文摘The Al-alloy arc-welding shaping system based on arc-welding robot is established, and the Al-alloy shaping manufacture is realized with the DC （direct current） gas metal arc welding （GMAW）. The research indicates that the metal transfer type of DC GMA W, heat input and the initial temperature of the workpiece greatly affect the Al-alloy shaping based on arc welding robot. On the penetration, the weld width and the reinforcement, the influence of welding parameters is analyzed by generalized regression neural network （GRNN） fitting.
基金This study was supported by National Natural Science Foundation of China （51105109）, the Major State Basic Research Development Program of China （973Program） （No. 2013CB035500）and Natural Scientific Research Innovation Foundation in Harbin Institute of Technology （ HIT. NSRIF. 201006）.
文摘In order to study the arc force distribution of ultrasonic assisted tungsten inert gas （U-TIG） welding and compare it with the conventional tungsten inert gas （TIC） welding, a series of experiments have been carried out, using our self- designed welding and testing system. The distribution of arc pressure is studied, under conditions as radiation distance, which is the distance between the ultrasonic horn tip and workpiece, and welding current. The values of arc pressure generally increase as the current increases. Other experimental phenomena are also accounted for in detail in this paper. Welding parameters are thought to be responsible for enhancing the welding efficiency and improving the appearance of weld.
基金We thank Prof. Mingbo Wu （State Key Laboratory of Heavy Oil Processing, China University of Petroleum） for his help in experiments. This work was finandally supported by the Key Joint Foundation of PetroChina, the National Natural Science Foundation of China （Nos. 51271215, U1362202, and 21106185） and the PetroChina Key Programs on Oil Refinery Catalysts （No. 2010E-1908 and 2010E-1903）.
文摘In order to effectively improve penetration rates and enhance wellbore quality for vertical wells,a new Automatic Vertical Drilling Tool(AVDT)based on Eccentric Braced Structure(EBS)is designed.Applying operating principle of rotary steering drilling,AVDT adds offset gravity block automatic induction inclination mechanism.When hole straightening happens,tools take essentric moment to be produced by gravity of offset gravity lock to control the bearing of guide force,so that well straightening is achieved.The normal tool's size of the AVDT is designed as 215.9 mm,other major components'sizes are worked out by the result of theoretical analysis,including the offset angle of EBS.This paper aims to introduce the structure,operating principle,theoretical analysis and describe the key components'parameters setting of the AVDT.
