Walsh反演法在提高滩坝砂薄层测井曲线分辨率中的应用——以沾化凹陷为例

Application of Walsh Inversion in Improving Resolution of Logging Curve of Beach-sand Thin Layers ——By Taking Zhanhua Sag for Example

针对沾化凹陷滩坝砂薄互层发育、测井资料纵向分辨率难以满足储层精细评价的问题,根据Walsh函数及地层特性,结合测井原理构建了Walsh反演模型。采用正则化手段和追赶法求解了第一类Fredholm积分方程,得到了地层测井真值,并通过测井、录井、岩心等数据对反演效果进行了综合评价。结果表明,Walsh反演法在沾化凹陷测井资料高分辨率处理中具有明显的效果,经处理后地层界面更加清晰,薄层识别能力明显增强;用处理后的声波测井曲线计算孔隙度,其与岩心分析孔隙度的误差变小,精度明显提高。

Thin beach-sand interlayer was developed in Zhanhua Sag,and its longitudinal resolution of logging data was difficult to meet fine reservoir evaluation.Based on Walsh function and formation characteristics,and combined with logging principles,Walsh inversion model was established.First type of Fredholm integral equation was solved by adopting regularization method and Thomas algorithm,and true logging value was obtained,and integrated evaluation was performed on inversion effects by using well logging,geological log and core data.The result shows that the application effect of Walsh inversion in high resolution logging data processing is obvious.By the method,after it is processed the formation boundary is more clearly,and the ability of identifying thin layer increases apparently.The error between calculated porosity and core porosity decreases,the calculated accuracy is obviously improved.