在高温高压条件下,对岩电参数受CO_2与CH_4混合气体影响规律认识不清,导致该类气层含水饱和度计算精度偏低。为此,通过模拟储层温压条件下(温度150℃、围压70MPa、孔隙压力50MPa)的岩电实验,分别利用不同含量CO_2与CH_4混合气体进行岩心驱替,以测定岩心的岩性系数b值、饱和度指数n值与胶结指数m值,基于实验数据研究分析了CO_2与CH_4混合气体对岩电参数的影响规律。不同CO_2含量混合气体溶解于地层水时候,测定得到的岩性系数a值、胶结指数m值基本没有差异;随着CO_2含量升高,岩性系数b值增大,饱和度指数n值降低,并建立了岩性系数b值与饱和度指数n值随CO_2含量变化的预测模型。利用该方法确定的岩电参数计算得到的含水饱和度与岩心分析结果吻合较好,证实了方法的可靠性。 Under the condition of high temperature and high pressure, the law of rock electric parameters affected by mixed gas of CO_2 and CH_4 is unclear, resulting in low accuracy of calculating the water saturation of such gas layers. For this reason, the core flooding was carried out by simulating the temperature and pressure conditions of the reservoir (temperature 150 ℃, confining pressure 70MPa, pore pressure 50MPa), respectively, using different mixed gas of CO_2 and CH_4 to determine the lithology coefficient b value, saturation index n value and cementing index value m, and studied the influence law of mixed gas of CO_2 and CH_4 on the parameters of rock electricity based on the experimental data. When the mixed gas with different CO 2 content is dissolved in formation water, the lithology coefficient a and cementation index m are basically the same. With the increase of CO 2 content, the value of lithology coefficient b increases and the saturation index n decreases, The prediction model of the change of b value and saturation index n value with the content of CO_2 was established. The calculated water saturation of the rock electrical parameters determined by the method is in good agreement with the core analysis results, which proves the reliability of the method.