一种新型不压井作业自动卡瓦设计与分析

DESIGN AND ANALYSIS OF A KIND OF AUTOMATIC SLIPS IN SNUBBING OPERATION

卡瓦是不压井作业装置的核心设备,不压井作业要求卡瓦具有管柱处于"管重"或"管轻"状况下快速、可靠的卡紧和松开管柱的功能。论文为满足不压井作业对卡瓦的要求,提出了新型不压井作业自动卡瓦结构。文中详细地介绍了新型不压井作业自动卡瓦的结构和工作原理。新型不压井作业自动卡瓦由上下两组卡瓦组件对称安装,采用液压缸做动力,实现了管柱在"管重"或"管轻"状况下自动卡紧、松开管柱,在起下管柱作业过程中将大大减轻井口操作工人的劳动强度,且具有起下管柱速度快、作业效率高的优点。论文通过卡瓦力学模型建立和受力分析得出了卡瓦牙均布力计算公式,依据美国API工程实用算法的卡瓦卡紧管柱力学分析模型得出了卡瓦高度计算公式,为进一步设计出可靠的不压井作业自动卡瓦提供了设计理论依据。

Slip is a core equipment of snubbing device.The downhole operation with pressure requires that the slips can fast,reliably clamp and release the string in 'weight pipe' or 'light pipe' situation.To meet the requirement of snubbing operation to slip,a new automatic slip structure was developed.The structure and working principle of the new automatic slip were presented in detail.The upper and lower two slip components were symmetrically installed in new automatic slip and adopting hydraulic cylinder power achieve automatically clamp and release the string.The new automatic slip unit has the advantages of fast tripping the string and high operation efficiency.The uniform power formula of slip insert was derived by establishing slip mechanical model and stress analysis of slip.Based on the mechanical analysis model of slip used in U.S.API the engineering practical algorithms,the calculation formula of slip height was obtained,and it provided a theoretical basis for further design of a reliable automatic slip of snubbing.