Abstract: At the base of rejecting normal suppose of impressibility of rubber volume, the packer rubber radial displacement formula were derived from Lame formula and elastic mechanics resolution of spatial axial symmetric problem. The example showed that results we calculated was greater than actual value. According to experiment testing, it was found that the elasticity modulus of packer rubber was ten times as much as value given in the literatures. However, the value we calculated was greater than actual value in the deep well. So it was considered that Lame formula which was widely used in packer design and calculation was only used in shallow well. A kind of method used spatial axial symmetric theory to analyze packer rubber that was constrained in the both ends was referred in shallow well, at the same time, the nonlinear problem should be considered in the deep well, at the base of it, more accurate resolution can be obtained expectively.

Key words: Packer rubber, Radial displacement, Modulus of elasticity, Measured values