Abstract: The relation between poroelastic modulus and effective modulus of rock under dry and fluid-saturated conditions was discussed in this paper. The poroelastic modulus could describe pore effect on elastic behavior of porous media such as rocks. From this, Gassmann equation which was widely used in seismic exploration and petroleum logging was deduced. This equation was based on linear elasticity assumption and could be used only within low frequency. The accurate formula of computing effective pressure was pointed out also. The method was proposed to compute the rock modulus when one kind of pore fluid changed to another, and to identify the pore fluids by the use of poroelastic modulus.

Key words: poroelastic modulus, effective pressure, pore fluids type, Gassmann equation, elastic modulus

摘要： 论述了在干燥和饱和两种情况下，岩石的有效体积模量于孔隙弹性模量的关系。孔隙弹性模量描述了孔隙对岩石等多孔材料的弹性性质的影响，利用其可导出在地震勘探和石油测井界应用很广的Gassamann，该方程建立在线性弹性假设之上并仅限于低频范围。还阐述了有效压力的概念和计算方法。提出孔隙流体变化时岩石有效模量的计算，及利用孔隙弹性模量辨别储层中不同流体类型的计算方法。

关键词: 孔隙弹性模量, 有效压力, 流体类型, Gassmann方程, 体积模量