套管振荡器在振动固井过程中,会对套管产生周期性冲击,可能会引起套管损坏,而螺纹连接是套管柱中最薄弱的环节,有必要进一步对冲击载荷作用下的套管螺纹连接应力场进行研究。以API?139.7 mm×7.72 mm N80钢级的圆螺纹套管的螺纹连...套管振荡器在振动固井过程中,会对套管产生周期性冲击,可能会引起套管损坏,而螺纹连接是套管柱中最薄弱的环节,有必要进一步对冲击载荷作用下的套管螺纹连接应力场进行研究。以API?139.7 mm×7.72 mm N80钢级的圆螺纹套管的螺纹连接部分为研究对象,分析了套管螺纹连接部分的应力强度和在冲击载荷作用下螺纹连接部分的应力分布规律。研究结果表明:在上扣扭矩、轴向拉伸和内压等复合载荷作用下套管内、外螺纹接触应力均出现两头高中间低的分布状态;随着上扣扭矩的增加、轴向拉应力的加大和内压的增高,套管螺纹连接部分整体Von Mises应力均呈现升高的趋势;螺纹牙承载侧的接触压应力要普遍高于导向侧;套管振荡器对套管的周期性冲击不会造成破坏。所得结论可为有冲击载荷作用的振动固井技术提供理论支持。展开更多
燕尾螺纹因独特的结构,具有独特的性能特点。根据燕尾螺纹的不同种类,对其中一种适用于油井管连接的楔形燕尾锥螺纹结构、性能特点、加工和检验方法作了详细的说明,实际设计了一种具有高气密封性能的全啮合楔形燕尾锥螺纹接头,采用有限...燕尾螺纹因独特的结构,具有独特的性能特点。根据燕尾螺纹的不同种类,对其中一种适用于油井管连接的楔形燕尾锥螺纹结构、性能特点、加工和检验方法作了详细的说明,实际设计了一种具有高气密封性能的全啮合楔形燕尾锥螺纹接头,采用有限元分析方法对接头进行了分析。结果显示,接头螺纹应力分布均匀,为验证该接头的实际性能,参照最高等级的ISO 13679:2002 CAL IV油管试验标准,对接头进行上卸扣以及复合加载试验,试验过程中接头无任何黏扣与气密封泄漏,证明了该接头结构设计的合理性。展开更多
The main failure modes of tubing and casing in current service conditions are represented in this study.The progress of the tubing and casing application technology and the problems that should be focused on during ap...The main failure modes of tubing and casing in current service conditions are represented in this study.The progress of the tubing and casing application technology and the problems that should be focused on during application are introduced,with special attention paid to the reliability of the pipe string design and the connection sealing properties.The necessary work that should be undertaken in future research is also summarized.展开更多
The dynamic modal model analysis of the oil casing connection is done by finite element method (FEM), and the first nature frequency, the second nature frequency, the vibration mode shape and the time domain of the no...The dynamic modal model analysis of the oil casing connection is done by finite element method (FEM), and the first nature frequency, the second nature frequency, the vibration mode shape and the time domain of the node displacement and the element stress variation in the thread connection are gotten. The Von.Mises stresses of the connection in the static and dynamic state are also studied. The results of calculation and analysis show: (1) because the maximum of static stress is at the coupling thread end of connection, the connection begins to thread off at the coupling thread end, which is in accord with the results of the thread off experiment in laboratory; (2) because the first nature frequency is very high, the probability of casing connection to be damaged from vibration is little; (3) the shock dynamic load makes casing connection begin to thread off at the tube thread end.展开更多
Dovetail thread has a unique structure and characteristics. This paper describes different dovetail threads,and provides detailed descriptions of structure,performance characteristics,and processing and measurement me...Dovetail thread has a unique structure and characteristics. This paper describes different dovetail threads,and provides detailed descriptions of structure,performance characteristics,and processing and measurement methods of a wedge dovetail tapered thread,which is used in OCTG joints. A full-engagement wedge dovetail tapered thread joint that is highly gas-tight was designed and subjected to finite element method analysis,and the results show an even stress distribution in the joint. To verify the actual performance of these joints,the highest IV tubing test standard,ISO 13679: 2002 CAL,was used in a make-up/break-out test and combined loading test. No galling or gas leakage occurred in these tests,which confirms that the structure of the designed joint demonstrates reasonable and excellent performance.展开更多
Using premium casing connections instead of API ones is one of the mosteffective technique to prevent casing failure. The factors contribute to the strength of premiumcasing connections are studied with FEA and full-s...Using premium casing connections instead of API ones is one of the mosteffective technique to prevent casing failure. The factors contribute to the strength of premiumcasing connections are studied with FEA and full-scale test. The criterions are presented thatensure the connection's strength higher than the pipe. At the same time, the method is given todecrease the peak stress of the connection so as to improve its anticorruption property. At last,full-scale tests are done to test the strength of the connections designed with the methoddescribed, the results show that the connection's strength is higher than the pipe. This indicatedthat the method described is effective in designing premium casing connection.展开更多
文摘套管振荡器在振动固井过程中,会对套管产生周期性冲击,可能会引起套管损坏,而螺纹连接是套管柱中最薄弱的环节,有必要进一步对冲击载荷作用下的套管螺纹连接应力场进行研究。以API?139.7 mm×7.72 mm N80钢级的圆螺纹套管的螺纹连接部分为研究对象,分析了套管螺纹连接部分的应力强度和在冲击载荷作用下螺纹连接部分的应力分布规律。研究结果表明:在上扣扭矩、轴向拉伸和内压等复合载荷作用下套管内、外螺纹接触应力均出现两头高中间低的分布状态;随着上扣扭矩的增加、轴向拉应力的加大和内压的增高,套管螺纹连接部分整体Von Mises应力均呈现升高的趋势;螺纹牙承载侧的接触压应力要普遍高于导向侧;套管振荡器对套管的周期性冲击不会造成破坏。所得结论可为有冲击载荷作用的振动固井技术提供理论支持。
文摘燕尾螺纹因独特的结构,具有独特的性能特点。根据燕尾螺纹的不同种类,对其中一种适用于油井管连接的楔形燕尾锥螺纹结构、性能特点、加工和检验方法作了详细的说明,实际设计了一种具有高气密封性能的全啮合楔形燕尾锥螺纹接头,采用有限元分析方法对接头进行了分析。结果显示,接头螺纹应力分布均匀,为验证该接头的实际性能,参照最高等级的ISO 13679:2002 CAL IV油管试验标准,对接头进行上卸扣以及复合加载试验,试验过程中接头无任何黏扣与气密封泄漏,证明了该接头结构设计的合理性。
文摘The main failure modes of tubing and casing in current service conditions are represented in this study.The progress of the tubing and casing application technology and the problems that should be focused on during application are introduced,with special attention paid to the reliability of the pipe string design and the connection sealing properties.The necessary work that should be undertaken in future research is also summarized.
文摘The dynamic modal model analysis of the oil casing connection is done by finite element method (FEM), and the first nature frequency, the second nature frequency, the vibration mode shape and the time domain of the node displacement and the element stress variation in the thread connection are gotten. The Von.Mises stresses of the connection in the static and dynamic state are also studied. The results of calculation and analysis show: (1) because the maximum of static stress is at the coupling thread end of connection, the connection begins to thread off at the coupling thread end, which is in accord with the results of the thread off experiment in laboratory; (2) because the first nature frequency is very high, the probability of casing connection to be damaged from vibration is little; (3) the shock dynamic load makes casing connection begin to thread off at the tube thread end.
文摘Dovetail thread has a unique structure and characteristics. This paper describes different dovetail threads,and provides detailed descriptions of structure,performance characteristics,and processing and measurement methods of a wedge dovetail tapered thread,which is used in OCTG joints. A full-engagement wedge dovetail tapered thread joint that is highly gas-tight was designed and subjected to finite element method analysis,and the results show an even stress distribution in the joint. To verify the actual performance of these joints,the highest IV tubing test standard,ISO 13679: 2002 CAL,was used in a make-up/break-out test and combined loading test. No galling or gas leakage occurred in these tests,which confirms that the structure of the designed joint demonstrates reasonable and excellent performance.
文摘Using premium casing connections instead of API ones is one of the mosteffective technique to prevent casing failure. The factors contribute to the strength of premiumcasing connections are studied with FEA and full-scale test. The criterions are presented thatensure the connection's strength higher than the pipe. At the same time, the method is given todecrease the peak stress of the connection so as to improve its anticorruption property. At last,full-scale tests are done to test the strength of the connections designed with the methoddescribed, the results show that the connection's strength is higher than the pipe. This indicatedthat the method described is effective in designing premium casing connection.
