视地层水电阻率正态分布分析及应用

Analysis and application of characteristic parameters of normal probability frequency distribution map of apparent formation water resistivity

通过多组随机正态分布序列数据正态频率分布绘图分析,指出正态分布序列数据的方差值越大,即储层段的视地层水电阻率分布范围较大时,正态频率分布曲线的斜率就越大;反之,正态分布序列数据的方差值越小,即储层段的视地层水电阻率分布比较集中时,正态频率分布曲线的斜率就越小。实际数据显示P1/2值越大,含气性越好;水层段P1/2值小,斜率小;通过该方法计算的地层水电阻率与水分析资料显示一致。

By means of normal probability frequency distribution mapping of several series of normal distribution data, the rules are found that when the variance of normal distribution data series is great, i.e. the distribution range of reservoir apparent formation water resistivity is large, the line slope of normal probability frequency distribution will be steeper. On the contrary, the variance of normal distribution data series is minor, i.e. the distribution of reservoir apparent formation water resistivity is relatively concentrated, the line slope of normal probability frequency distribution will be flattened. Real data display that the greater the P1/2 value is, the better the gas containing property of reservoir will be. p1/2 value of water pays is little and the line slope of its normal probability frequency distribuion will be flattened. Formation water resistivity from this method is coincident with analytical data of the formation water.