低渗透岩石声学特征及在含气性预测中的应用

针对低渗透储层含气性定性识别、定量预测困难等问题，开展了模拟地层条件下的声学岩石物理实验，定量研究了围压、孔隙压力、有效应力和孔隙流体等对纵、横波速度的影响。系统分析了纵横波速度、弹性参数等与含气饱和度的关系，并基于Krief 弹性参数预测方法对实验结果进行了验证分析。实验和数值模拟结果表明，岩石的声学性质受孔隙度、压力、孔隙流体性质等因素的综合影响，纵横波速度比波阻抗交会和纵横波平方交会截距对孔隙流体性质较为敏感，可用于含气储层的识别与评价，对利用声波测井资料进行储层流体性质识别具有重要指导意义。

Acoustic Properties of Low Permeability Cores and its Application to#br#Reservoir Gas Predication

To solve the problem in qualitative identification and quantitative prediction of gas content in low permeabilityreservoir，an acoustic rock physics experiment was carried out which simulates the reservoir conditions and a quantitativeresearch of the influence of confining pressure，pore pressure，effective stress and pore fluid on compression and shear wavevelocity was done. Then the relationship between compression and shear wave velocity，elastic parameters and the gas saturationwas systematically analyzed. And the experimental result was checked with Krief elastic parameters prediction method. Theexperimental results and numerical simulations show that the acoustical properties are affected by combination of factors suchas porosity，pressure，fluid property etc.，and shear wave velocity ratio-wave impedance intersection and compression and shearwave square intercept can be used to identify gas. The ability of using acoustic logging data to identify reservoir fluid can beimproved with the two methods.