自然伽马反褶积法在柴达木盆地的适用性研究

Applicability of Natural Garmma Deconvolution Method in Qaidam Basin

青海柴达木盆地许多油田发育有大量薄层与薄互层,常规测井曲线的纵向分辨率较低,在薄层处常出现曲线畸变现象,不能反映地层真实值。以自然伽马曲线为例,通过傅氏变换求取自然伽马曲线的反褶积校正因子,并且首次设计了岩石物理试验来检验薄层校正效果。通过对柴达木盆地XX地区Y375井岩心进行高密度采样,并作了自然伽马放射性分析,将原始自然伽马曲线与三点、五点、七点自然伽马反褶积曲线进行对比,结果表明无论是在薄层还是在薄互层,七点反褶积后的自然伽马曲线分辨率更高,与实际情况更符合。对柴达木盆地XX地区W106井的薄层测井解释处理表明,以自然伽马七点反褶积法为基础薄层处理技术在柴达木盆地适用性较好。

There were large number of thin beds and thin interbeds developed in oilfields of Qaidam Basin,of which vertical resolution of conventional logs was low.Curve distortion often occurred in the thin beds,therefore the true value of the curves could not be reflected.By taking natural garmma curve for example,Fourier transform was deployed to compute the deconvolution correcting factors for the garmma curve,and compare the correction effect of the curve with the petrophysical experiment for the first time:with high-density core sampling was carried out on Well Y375 in XX Area of Qaidam Basin,and the natural garmma radiation was analyzed,at the same time,the original garmma curve was contrasted with that of three-dot,five-dot and seven-dot deconvolution.The result shows that the garmma curves after seven-dot deconvolution is higher both for thin beds and interbeds and is consistent with that of actual situation.The thin bed logging interpretation of Well W106 in XX Area of Qaidam Basin shows that the seven-dot deconvolution is adaptive in Qaidam Basin.