基于测井数据小波变换的准层序自动划分

层序地层分析的关键在于不同级别层序界面的识别，准层序是测井层序地层分析的最小基本单元。准层序地层单元的分界面上物理性质变化明显，测井曲线表现为突变，测井数据小波变换能够表征这种突变。以胜利油田某井沙三上亚段第Ⅲ层序为例，选用二次样条小波，对该井段SP测井数据进行二进小波变换，将一维测井数据拓展为二维深度-尺度空间，得到不同尺度上的小波系数曲线。选定最佳分解尺度后，依据小波系数模极值的位置准确识别出准层序的界面，划分的准层序比人工划分的结果更细。

Parasequence Automatical Partition Based on Wavelet Transform of Logging Data

The key of sequence stratigraphy analysis lies in recognizing sequence boundaries of different levels.Parasequence is the minimum unit of sequence stratigraphy analysis of well-logging.Logging curves changed abruptly due to obvious variation of physical properties at the interface of parasequence unit.The mutation can be revealed clearly by wavelet transform of logging data.Example was taken from the No.3 sequence in the third middle member of Shahejie Formation in a well of Shengli oilfield,the SP data were processed by two-scale wavelet transform using quadric spline wavelet.With this transformation the logging data were expended from one dimensional depth space into two dimensional depth-scale space and wavelet coefficient curves on different scales were obtained.When the optimum decomposed-scale was determined,the interface of parasequence unit can be recognized correctly according to the position of wavelet modulus and the result was finer than that of manual recognition.The research was of important significance in quantitative sequence demarcation at different levels.