液压油管锚锚定机构的设计与研究

Design and Study on Anchoring Mechanism of Hydraulic Tubing Anchor

液压油管锚是一种管柱锚定用井下工具,抽油时使用液压油管锚锚定套管,可以降低冲程损失、油管漏失、提高泵效,改善管柱受力状态,延长管柱寿命。油管锚的关键是起锚定作用的卡瓦,文中设计了一种液压油管锚,对卡瓦进行了详细设计和ANSYS有限元分析。发现锚定时卡瓦最大应力出现在卡瓦牙上,卡瓦牙发生微小屈服,卡瓦牙根部和其余部位应力较小,卡瓦不会发生断裂失效。微小屈服使卡瓦牙与套管内壁的接触由线接触变为面接触,摩擦力更大,锚定更加可靠。

Hydraulic tubing anchor is a kind of downhole tool for anchoring the string. In process of pumping oil, casing can be anchored by using hydraulic tubing anchor, which can reduce the loss of stroke and tubing leakage, and can improve the pump efficiency and decrease the string stress to extend the life of the tubing string. Slip for anchoring is the key to tubing anchor. We design a kind of hydraulic tubing anchor and complete ANSYS finite element analysis for slip. The analysis proves that the slip maximum stress appears on the slip tooth which has tiny yield. The stress is lower in slip tooth root and the rest of the section, and slip fracture failure will not occur. Tiny yield changes the line contact from the slip tooth contact with the inner wall of the casing into the surface contact,which causes the greater friction and more reliable anchoring.