地震资料的双约束频谱补偿方法

Dual constraint frequency spectrum compensation of seismic data

石油大学资源系,东营257062

Department of Resources, University of Petroleum, Dongying 257062

指出了现行的最小熵高频外推方法存在的一些问题,在此基础上首次提出“理论记录+熵”约束的频谱补偿方法,并给予了具体实现。该方法改以往的“最小熵”为“熵约束”,利用对数变换定义的熵模,要求频率补偿后的记录向约束条件靠近的同时,记录的熵模也要向约束条件的熵模靠近,并且保持有效频带内的频率成分不变。这一方法有效地保证了弱小反射不被压制,且同相轴原有的基本特征保持不变。理论模型和实际资料的处理都证明了该方法的正确性。

Some problems existing in the currently used minimal entropy high frequency extrapolation method are pointed out. On the basis of this, a new method of frequency compensation constrained with “synthetic record + limited entropy” is put forward firstly. The method substitutes the minimal entropy for entropy constraint, and uses an entropy norm defined with logarithm transformation. It is demanded that while the record after frequency compensation moves close to the constraint condition, the entropy norm of the record also moves close to the entropy norm of constraint condition, and frequency components in effective frequency band keep unchanged. This can effectively prevent the weak reflections from being suppressed and keep the original basic feature of seismic events. Both theoretical model and real data processing prove the correctness of the method.