可控震源非线性扫描参数的定量选取

Quantitative selection of nonlinear sweep parameters of vibroseis

中国石油集团东方地球物理勘探有限责任公司采集技术支持部,河北涿州 072751

Acquisition Technical Support Department, Bureau of Geophysical Prospecting, CNPC, Zhuozhou 072751, China

由于大地滤波作用,地震波的频谱随频率呈指数衰减趋势,为了补偿这种衰减,在可控震源的施工当中往往采取非线性扫描,以达到提高地震分辨率的目的。但传统的非线性扫描参数的选取仅仅根据试验资料凭经验和视觉加以确定,缺少科学依据。通过对实际资料的分析,利用主要目的层的频谱特征,求出地震波的衰减曲线,找出非线性扫描的最佳参数,实现对可控震源非线性扫描参数的定量分析。

Seismic spectrum energy decreases exponentiallywith frequency due to the earth filtering.To com-pensate the attenuation of high frequency energy,nonlinear sweep of signals is usually used in data ac-quisition with vibroseis to acquire high-resolution da-ta. However. the nonlinear sweep parameters arecommonly determined on the test data according tothe appearance of data. In this paper, Ⅰ propose amethod that can determine the parameters quantita-tively. The method requires performing spectrum a-nalysis on real seismic data, and calculating the at-tenuation curve of seismic waves to determine the op-timal sweep parameters.