测井曲线最优特征值在层序界面识别中的应用

根据测井曲线的特点,提取能够描述测井曲线的5个最优特征值,利用特征分级函数进行层界面的识别和旋回界面的划分;在此基础上,深度从下到上,按照旋回界面所限定的层段,依次进行该段地层测井曲线的拟合,对拟合曲线的数学表达式求取其一阶导数,根据其最高阶自变量的系数的正负情况进行测井曲线形态的判断;在形态判断和旋回界面识别的基础上,结合测井曲线分形特征以及沉积特征的研究,完成层序界面的识别.按照以上步骤,完成了白音查干凹陷达28井腾格尔组层界面、旋回界面、形态的判断以及层序界面的识别,并给出相应的单井层序分析结果.实例表明,利用测井曲线最优特征值能够较好地完成对层序界面的识别,为单井层序地层学的研究打下良好的基础.图2,参8.

The Identify of Sequence Surface Using the Best Eigenvalue from Geophysical Logging Curve

Though picking up the five best eigenvalnes according to the characteristic of geophysical logging curve,layer and cycle surface was identified and recognized using the function of characteristic classification. At the base of that,doing the logging curve simulation,from bottom to top,take turns,at certain section that was defined by cycle surface,finding the first rank derivative of mathematic expression of the simulated curve, getting the coefficient of independent variable in the highest rank,making the judgment of curve shaper from the coefficient. At the results of the judgment of curve shape and cycle surface identify,joining with the study of sediment characteristic and Fractal techniques, sequence stratigraphic surface was recognized. According to this method, the judgment of layer surface, cycle surface, curve shape and sequence surface and analysis result of sequence stratigraphy with single wall is given from the data of Tengge'er group,Da 28 wall,BaiYinChaGan depression. The identify of sequence surface is fully and suitably achieved through the example analysis result using the best eigenvalue, and the results is a good foundation of sequence stratigraphic researchment.2figs.,8refs.