地震频谱分解技术应用中有关问题的讨论

Discussion on the problems in using the technology of seismic spectral decomposition

(中国石油化工股份有限公司西北油田分公司，新疆乌鲁木齐 830000)

Northwest Oilfield Branch Company, SINOPEC, Urumqi 830000, China

薄层反射在频率域会出现陷频现象，其陷频周期的倒数等于薄层的时间厚度。频谱分解技术以此为理论基础对地层厚度进行预测。从此原理出发，阐述了频谱分解技术对原始地震数据体的高保真要求和定义频率范围的原则。实际应用时，利用沿层调谐体，通过求取频率域第一优势频带的频率进行地层厚度预测；利用各单一频率调谐体对薄层进行检测，利用调谐能量的变化对横向不连续的地质异常体空间分布特征进行描述。实际应用结果表明，频谱分解技术比传统的基于时间域地震主频的方法对地质体有更高程度的识别

The reflection of thin layer may lead to frequency notch and the reciprocal of notch cycle is equal to the time thickness of thin layer. The frequency spectrum decomposition technology takes this as the rationale to predict the layer thickness. Starting from this rule, the high fidelity requirement of original seismic data and principles defining frequency range acquired by frequency spectrum decomposition was elaborated. In actual application, tuning cubes along interest horizons was used to predict layer thickness through calculating the first maximum frequency in frequency domain; the single frequency tuning cube was used to detect the thin beds; the changes of tuning energy was used to describe the spatial distribution characteristics of lateral disconnected geologic abnormal bodies. The application results show that the spectral decomposition technology has a greater ability of recognizing geologic bodies than the conventional method which is based on main frequency in time domain.