溶洞型储层地震采集参数与成像关系研究

The relationship between seismic acquisition parameters and data imaging in areas with cavern reservoirs

覆盖次数、面元尺寸、炮检距、炮排关系等地震采集参数的选择,既决定了野外采集资料的质量,又直接关系到采集成本。根据TH地区地质特点,对溶洞型储层进行了三维正演模拟;结合该区实际地震资料处理,重点探讨和分析了面元、覆盖次数、炮检距对溶洞型储层成像的影响。研究结果表明:1面元尺寸主要影响串珠的横向分辨率,该区面元边长以15m^30m为宜;2覆盖次数主要影响剖面能量强弱及信噪比,对溶洞的成像分辨率影响很小,该区宜选取140~180次(实际采集中的352次覆盖略显偏大);3炮检距越大,速度谱能量团越收敛,综合考虑仪器接收道数和排列长度,该区最大炮检距约为6000m即能满足速度分析和成像要求。

Seismic acquisition parameters such as fold,bin size,offset,source and receiver pattern,determine not only the field seismic data quality but also the acquisition cost.Based on 3Dforward modeling of cavern reservoirs in TH area and with seismic data processing,we analyze in this paper the influences of some acquisition parameters on cavern reservoir imaging.The following observation are obtained:A.The bin size has mainly influence on the lateral resolution of the bead-like reflection,the bin size between 15m×15mto 30m×30mis appropriate;B.Fold mainly influences on signal to noise ratio,and it has little influence on resolution of cave imaging.Fold ranges from 140 to 180can meet production requirements;C.The bigger offset is,the more convergent velocity spectrums energy is.According to the number of channels of the recording system and the spread length,the maximum offset 6000 mcan meet velocity analysis and imaging requirements.