高保真高信噪比地震资料的获取方法

Seismic data acquisition method with high fidelity and high signal to noise ratio

以检波器组合为例,通过射线追踪模拟,揭示了组合基距和炮检距变化与反射波波形特征和信号频谱的关系,讨论了组合基距变化对信号保真度和分辨率的影响。利用波动方程正演,对比分析了组合基距变化对小断层和砂岩尖灭的成像结果,说明常规检波器组合对小尺度地质目标存在平均效应,会降低横向分辨率。结合实际资料分析,进一步说明常规检波器组合方法获得的地震记录是非保真的,对有效信号造成极大的伤害,地震分辨率降低明显。因此常规的组合压噪方法是不科学的,应该先保真原始地震道信号并保证适度能量,然后在数据处理中去噪、提高信噪比。由此提出的一点法地震技术获取的地震资料具有高保真、高信噪比、高分辨率的特点,在苏里格气田开发的多个区块中取得了很好的应用效果。

Based on geophone array,we discuss in this paper the relationship among reflection waveform characteristics,signal frequency spectrum,array length and offsets by ray tracing simulation.We also discuss influence of array length on signal fidelity and data resolution.Using wave equation forward modeling,we analyze influence of array length on imaging of small faults and sandstone pinchouts.It is found that geophone arrays have average effect on small scale geological target imaging, which leads lateral resolution decrease.Based on real data analysis,geophone arrays cannot acquire fidelity seismic data.Signals are damaged and data resolution is reduced.We believe that noise removal by geophone arrays is not scientific.In data acquisition stage in the field,we should first ensure data fidelity and signal energy,and noise removal will be carried out in the data processing stage to improve signal-to-noise ratio.Thus we put forward point-receiver approach which can acquire seismic data with high fidelity,high signal-to-noise ratio and high resolution.The proposed approach has been used in several blocks of Sulige Gas field and achieved very good results.