阿尔奇公式中a,m值对饱和度计算结果的影响

应用岩电实验数据确定阿尔奇公式中a,m值时发现地层因素与孔隙度的相关性较差,通过不同的回归处理方法得到的a,m值有时相差较大,甚至出现一些异常的情况。以青海花土沟油田为例,对同一批岩电实验数据进行了不同的处理,得到了几组相关的a,m值。据此利用阿尔奇公式分别计算了取心层段的地层饱含水电阻率值R0和含水饱和度值Sw,并结合试油和压汞资料进行了对比讨论。研究发现,在岩电实验数据准确可靠的前提下,通过不同处理方法得到的关于同一组岩心的不同a,m值,因地层孔隙度的不同而对R0和Sw计算结果的影响也不同。在中等孔隙度情况下,对R0和Sw计算结果的影响不大,可以忽略;在低孔隙度和高孔隙度情况下,不同的a,m值对R0和Sw计算结果的影响较大,此时应优先采用岩电实验结果得出的a,m值。

Effect of different values of a and m in Archie formula on water saturation

If the relativity between formation factor and porosity from rock experimentation is little, the values of a and m calculated by different regression methods using the data from the same experimentation may be different. Three groups of a and m were gotten from the same data of Huatugou Oilfield in Qinghai by different disposing methods. Three groups of resistivity of formation saturated by water and water saturation were given using Archie formula. The data were compared with the data of testing oil and analyzing capillary. The results show that the different values of a and m calculated from the same exact experimentation have different effects on resistivity of formation saturated by water and water saturation because the porosity is different in the formation. The resistivity of formation saturated by water and water saturation computed from three groups of a and m are almost same in the formation when the porosity is middling. There are large differences in resistivity of formation saturated by water and water saturation when the porosity of formation is high or low.