基于TK能量的峰值瞬时频率在薄互层预测中的应用

砂泥岩薄互层厚度预测一直是薄互层油气勘探的难点之一。将分析单频信号局部非线性能量密度比较有效的Teager-Kaiser能量算子和具有多尺度分辨属性的连续小波变换相结合, 可以使频谱能量分析结果具有更高的时间聚焦性, 有助于分辨薄互层。在此基础上通过在薄互层的时间窗内求取最大峰值瞬时频率, 继而根据测井目的层段的薄互层厚度和最大瞬时峰值频率拟合关系进行砂泥岩薄互层厚度的定量预测。理论和实际资料分析表明, 该方法可以有效地对薄互层进行定量预测, 最大峰值瞬时频率和实际测井上的薄互层厚度有着很好的对应关系, 预测的薄互层厚度图和测井厚度等值线图基本一致。结合预测的厚度平面图和已有测井资料可以更好地对研究区的沉积特征进行描述。

Thin interbed thickness prediction using peak instantaneous frequency of time-frequency Teager-Kaiser energy

Thin interbed thickness prediction is one of the most difficult problems in petroleum exploration. We use the Teager-Kaiser energy associated with wavelet transform to generate a joint time-frequency representation, which is constructive to detect thin beds. Then we calculate peak instantaneous frequency in a small window around thin bed response. Thin interbed thickness can be predicted by the relation between peak instantaneous frequency and thickness of wells which located in the area. Model and real data examples indicate that the method can well predict thin interbed thickness. The peak instantaneous frequency has a close relationship with the layer thickness measured on logging data, and predicted thin interbed thickness matches very well with its thickness on logging isopach maps.