液压封隔器胶筒座封过程数值分析

NUMERICAL ANALYSIS ON SETTLEMENT OF RUBBERS IN HYDRAULIC PACKER

液压封隔器是通过水力作用使胶筒在套管环空内鼓胀 ,而与套管内壁接触并产生一定接触压力 ,克服了封隔器上、下套管环空液流产生的压差 ,达到分层目的。在座封过程中 ,胶筒产生较大的几何变形 ,此时橡胶材料特性是非线性的 ,胶筒与套管内壁的接触过程也是一个状态非线性问题 ,即封隔器胶筒的座封过程是一个兼有状态、几何和材料的三重非线性问题。采用数值模拟方法 ,对封隔器胶筒压缩过程、座封后胶筒与套管的接触压力分布规律及胶筒与套管内壁之间摩擦系数对接触压力分布规律的影响进行了分析。研究结果表明 ,封隔器座封完成以后 ,上胶筒与套管的接触压力最小 ,中胶筒和下胶筒的接触压力依次增大 ,整体分布呈二次曲线形式。从单个胶筒来看 ,3个胶筒与套管接触面上的压力分布规律并不相同。上胶筒表面的接触压力呈拱形分布 ,而中间胶筒和下胶筒的接触压力呈鞍形分布。随着摩擦系数的增加 ,3个胶筒的接触压力都将降低 ,同时摩擦系数的变化也改变了 3个胶筒与套管接触压力的整体分布格局。当摩擦系数为 0 .3时 ,3个胶筒与套管接触压力最大值的变化梯度基本相等 ;当摩擦系数大于 0 .5时 ,只有下胶筒维持较高的接触压力。利用数值模拟方法 。

The rubbers in hydraulic packer can swell up and contact with the casing wall under hydraulic action. In this way, the annular layers can be separated. The process of compressing distortion and contact with casing wall belongs to a ternary nonlinear problem. The pressure distribution rules of rubbers in contact with casing wall were analyzed using the numerical simulation method, and the effects of friction coefficient between rubbers and casing wall on the contact pressure distribution were analyzed. The results show that the contact pressure on the top of rubber is the lowest, and the contact pressure at the bottom of rubber is the highest. The friction coefficient has a great influence on the contact pressure distribution on the surface of rubber. The contact pressure of rubber will fall down with the friction coefficient increasing.