裸眼中测封隔器胶筒骨架材质与力学分析及其改进

针对裸眼中途测试封隔器胶筒骨架落井现象,在对压缩式裸眼测试封隔器胶筒骨架材质分析的基础上,运用有限元方法对胶筒骨架应力和变形进行了分析,并以胶筒骨架强度安全为前提提出了裸眼中测允许测试压差的计算方法。分析结果表明,"细脖子"与扣盘结合处应力最大,最易损坏;球墨铸铁虽有较高的强度和韧性,但脆性较大,在较大冲击载荷下易损坏。为此,提出用强度更高且易磨的优质合金结构钢35CrMo取代球墨铸铁作为胶筒骨架材料,并在胶筒骨架与橡胶接触部位加工了特殊形状的容胶槽,从而提高了胶体与胶筒骨架的结合强度。

Mechanics Analysis and Improvement of the Material Property of Skeleton Structure of the Packer Rubber during Drill-Stem Testing in Open Holes

In order to solve the problem of packer rubber skeleton structure falling during drill-stem testing in open holes,the finite element method was used to analyze stress and deformation of the packer rubber skeleton structure based on the material analysis of the compression packer rubber during drill-stem testing in open holes.The allowed testing pressure difference during drill-stem testing in open hole was proposed considering on the strength safety of the packer rubber.The analysis results indicate that the maximum stress exists in the connection part between the bottle neck and gripping plate,which is also easily damageable.Though nodular cast iron with higher strength and toughness has higher brittleness and is easier to be damaged under larger impact loads.Therefore,an alloy named 35CrMo with higher strength was suggested to substitute nodular cast iron for raw material of rubber skeleton structure. In addition,rubber slot with special shape was also added on the interface between the skeleton structure and packer rubber to improve construction strength between the packer rubber and its skeleton structure.