The suffering force of sheath and casing is analyzed by the elasticity mechanics and finity element.Then the faction mechanism of the high toughness sheath decreasing the damage of casing is analyzed.

• 采用弹性力学和有限元方法分析井下水泥环以及套管的受力情况，尝试分析高韧性水泥环降低套管挤压套损的作用机制。