采用常规打捞方式打捞GS接口井下工具时,不仅操作繁琐、效率低下,而且还容易破坏工具内部结构,不利于井下工具的再次使用。鉴于此,设计了连续管作业用液力释放式打捞器。建立了液力释放式打捞器的关键部件卡爪的有限元模型,采用Ansys对...采用常规打捞方式打捞GS接口井下工具时,不仅操作繁琐、效率低下,而且还容易破坏工具内部结构,不利于井下工具的再次使用。鉴于此,设计了连续管作业用液力释放式打捞器。建立了液力释放式打捞器的关键部件卡爪的有限元模型,采用Ansys对卡爪进行静力学分析,得到合理的卡爪设计参数(爪数8,承载角45°)。通过建立打捞器动力学模型,计算出落鱼抓取推力、落鱼释放提力、缸体受液压力以及弹簧压缩量。室内试验及现场应用结果表明,液力释放式打捞器的承压元件性能、卡爪收缩性能以及在最大打捞力150 k N作用下的整体强度均可靠。展开更多
Micron-scale crack propagation in red-bed soft rocks under hydraulic action is a common cause of engineering disasters due to damage to the hard rockesoft rockewater interface.Previous studies have not provided a theo...Micron-scale crack propagation in red-bed soft rocks under hydraulic action is a common cause of engineering disasters due to damage to the hard rockesoft rockewater interface.Previous studies have not provided a theoretical analysis of the length,inclination angle,and propagation angle of micron-scale cracks,nor have they established appropriate criteria to describe the crack propagation process.The propagation mechanism of micron-scale cracks in red-bed soft rocks under hydraulic action is not yet fully understood,which makes it challenging to prevent engineering disasters in these types of rocks.To address this issue,we have used the existing generalized maximum tangential stress(GMTS)and generalized maximum energy release rate(GMERR)criteria as the basis and introduced parameters related to micron-scale crack propagation and water action.The GMTS and GMERR criteria for micronscale crack propagation in red-bed soft rocks under hydraulic action(abbreviated as the Wmic-GMTS and Wmic-GMERR criteria,respectively)were established to evaluate micron-scale crack propagation in redbed soft rocks under hydraulic action.The influence of the parameters was also described.The process of micron-scale crack propagation under hydraulic action was monitored using uniaxial compression tests(UCTs)based on digital image correlation(DIC)technology.The study analyzed the length,propagation and inclination angles,and mechanical parameters of micron-scale crack propagation to confirm the reliability of the established criteria.The findings suggest that the Wmic-GMTS and Wmic-GMERR criteria are effective in describing the micron-scale crack propagation in red-bed soft rocks under hydraulic action.This study discusses the mechanism of micron-scale crack propagation and its effect on engineering disasters under hydraulic action.It covers topics such as the internal-external weakening of nano-scale particles,lateral propagation of micron-scale cracks,weakening of the mechanical properties of millimeter-scale soft rocks,and resulting int展开更多
文摘采用常规打捞方式打捞GS接口井下工具时,不仅操作繁琐、效率低下,而且还容易破坏工具内部结构,不利于井下工具的再次使用。鉴于此,设计了连续管作业用液力释放式打捞器。建立了液力释放式打捞器的关键部件卡爪的有限元模型,采用Ansys对卡爪进行静力学分析,得到合理的卡爪设计参数(爪数8,承载角45°)。通过建立打捞器动力学模型,计算出落鱼抓取推力、落鱼释放提力、缸体受液压力以及弹簧压缩量。室内试验及现场应用结果表明,液力释放式打捞器的承压元件性能、卡爪收缩性能以及在最大打捞力150 k N作用下的整体强度均可靠。
基金funded by the National Natural Science Foundation of China(NSFC)(Grant Nos.42293354,42293351,and 42277131).
文摘Micron-scale crack propagation in red-bed soft rocks under hydraulic action is a common cause of engineering disasters due to damage to the hard rockesoft rockewater interface.Previous studies have not provided a theoretical analysis of the length,inclination angle,and propagation angle of micron-scale cracks,nor have they established appropriate criteria to describe the crack propagation process.The propagation mechanism of micron-scale cracks in red-bed soft rocks under hydraulic action is not yet fully understood,which makes it challenging to prevent engineering disasters in these types of rocks.To address this issue,we have used the existing generalized maximum tangential stress(GMTS)and generalized maximum energy release rate(GMERR)criteria as the basis and introduced parameters related to micron-scale crack propagation and water action.The GMTS and GMERR criteria for micronscale crack propagation in red-bed soft rocks under hydraulic action(abbreviated as the Wmic-GMTS and Wmic-GMERR criteria,respectively)were established to evaluate micron-scale crack propagation in redbed soft rocks under hydraulic action.The influence of the parameters was also described.The process of micron-scale crack propagation under hydraulic action was monitored using uniaxial compression tests(UCTs)based on digital image correlation(DIC)technology.The study analyzed the length,propagation and inclination angles,and mechanical parameters of micron-scale crack propagation to confirm the reliability of the established criteria.The findings suggest that the Wmic-GMTS and Wmic-GMERR criteria are effective in describing the micron-scale crack propagation in red-bed soft rocks under hydraulic action.This study discusses the mechanism of micron-scale crack propagation and its effect on engineering disasters under hydraulic action.It covers topics such as the internal-external weakening of nano-scale particles,lateral propagation of micron-scale cracks,weakening of the mechanical properties of millimeter-scale soft rocks,and resulting int
