正态分布法在判别深层低饱和度储层流体性质中的应用

Normal distribution method's application in estimating character of reservoir with low saturation of deep layer

前人利用正态分布法判别储层的流体性质都停留在定性到半定量的标准下,笔者以南八仙气田深层储层流体判别为例,总结了气、水层正态分布的差异性,建立了该气田深层低饱和度气藏流体性质的定量判别标准。主要体现在气层(R_(wa))^(1/2)>0.8,斜率>0.3;气水同层0.6<(R_(wa))^(1/2)<0.8,曲线形态为折线或斜率0.15~0.3;水层或含气水层(Rwa)1/2<0.5,斜率<0.15。在方法实际运用过程中,对该方法进行改进,利用视地层水电阻增大率与声波时差进行交会来建立研究区流体性质判别图版,实现了正态分布法的定量运用,实际应用效果证明,正态分布法在南八仙气田深层低饱和度气藏的流体性质判别上是有效的。

Praeanthropus used normal distribution method to estimate reservoir's fluid character qualitatively or semi-quantitatively, author summarized the characters of Nanbaxian reservoir's normal distribution and established the quantitative criterion of this gasfield.Based on the study of reservoir fluid logging discrimination of gasfield, it reflected in the following aspects, gas layer's value of(R_(wa))^(1/2)>0.8, slope>0.3. Gas and water provided layer's value of(R_(wa))^(1/2) distributes in 0.6~0.8, broken line or 0.15<slope<0.3. Water layer's value of(R_(wa))^(1/2)<0.5, slope<0.15. In the actual use of the method, the method is improved, the fluid properties of the study area were distinguished by using the apparent formation water resistance increasing rate and the porosity. The practical application proved that it was effective on the application of the normal distribution method in discriminating the character of the reservoir.