摘要
裂缝带的识别和判断,对于实现中国大陆科学钻探的研究目标,为地学研究提供基础的井中物性参数具有很重要的意义。阵列声波测井的纵波频谱参数为实现这个目标提供了可能。通过对纵波频谱特征的分析得到这样的认识:对于断裂构造,纵波的频谱特征有着明显的变化,如纵波的主频位置向低频偏移,在低频位置上其幅度(能量)急剧地增大,与上下未破碎的岩层有着非常明显的差别。通过这些明显的特征,可以很好地识别和判断构造破碎带。利用主峰位置漂移、主峰幅度、主峰的半幅值高宽、主峰的能量这几个参数,对中国大陆科学钻探主孔的裂缝带进行了识别和判断。
The identification and determination of fractural zone plays an important role in achieving the research targets of the China Continental Scientific Drilling(CCSD) and providing the basic physical parameters in the drilling hole for geological study.The parameters of primary wave frequency spectrum derived from array acoustic logging provided the possibility to achieve this aim.Based on the analysis on primary wave frequency characteristics,some conclusions can be obtained: there were variations obviously for the characteristics of primary wave frequency spectrum in fracture zones,such as the dominant frequency shifted towards the low frequency,at this location the amplitude(energy) increased rapidly,and there were significant differences from the surrounding unbroken rocks.By using these characteri-stics,the structure fractured zones can be identified and determined properly.And also this paper suggested several parameters,such as main peak amplitude,the location drifting of the basic frequency,the width of main peak half-amplitude and the main peak energy of the basic frequency,and had acquired a good result by making use of these parameters to identify and determine the structural zones in CCSD.