用声波弹性参数确定剩余油饱和度的方法探讨

On the Method to Determine Residual Oil Saturation from Acoustic Compression Coefficient.

基于M.A.Biot理论和J.G.Berryman的自洽理论,考察了饱和泥质砂岩在不同孔隙度和泥质含量条件下,储层岩石的声学弹性中的压缩系数随不同含水饱和度的变化情况。研究结果表明,岩石的声学压缩系数主要受其孔隙度、泥质含量和所饱和流体的性质的影响,孔隙度和泥质含量是影响岩石的声学压缩系数的主要因素,流体饱和度次之。岩石的孔隙度和泥质含量越高,其声学压缩系数越大;随着含水饱和度的升高(含油饱和度的降低),其声学压缩系数越小。用岩石的声学压缩系数确定储层剩余油饱和度值基本可行,如果对储层进行时间连续声波测井,有可能监测到储层剩余油饱和度的变化情况。

On the basis of M. A. Biot's theory and Berryman s self-consistent theory,the author reviews that acoustic compression coefficient of saturated shale sandstones varies with water saturation in the change of porosity or shale content. The result indicates that acoustic compression coefficient of rock is decided by its porosity and shale content and fluid saturation. Porosity , shale content and fluid saturation are factors deciding acoustic compression coefficient of saturated shale sandstones. The higher porosity and shale content, the bigger acoustic compression coefficient is. With water saturation going up (oil saturation going down), acoustic compression coefficient is becoming small. It's OK to determine residual oil saturation from rock acoustic compression coefficient. If successive acoustic logging is made , it is possible to gain changes of residual oil saturation in reservoir.