利用地震数据分频相干技术检测火山岩裂缝

Fracture detection in volcanic rocks using discrete frequency coherency cubes on full-azimuth seismic data

针对在全频带地震剖面上小断层特征不明显,而在单频地震剖面上断层特征非常明显的特点,本文采用分频相干数据体分析技术,基于单频相干解释,借鉴信号重构的部分思路,提出了地震数据分频相干技术。主要内容包括:分频数据的处理、解释,分频相干数据的处理、解释,分频相干数据的融合、重构。利用地震数据分频相干技术对XS井区火成岩储层裂缝进行了检测。结果表明,利用分频相干数据体的多尺度分辨率特性可以识别一些常规数据难以发现的小断裂和裂缝发育带,且高频相干数据体对裂缝的反映更为清晰、准确,相干融合数据反映了更丰富的裂缝发育带信息,且与HTI各向异性裂缝检测结果相吻合。

Tiny fault is not obvious in full-frequency seismic sections,but rather clear in single-frequency seismic sections.So it is necessary to adopt the discrete frequency coherency cube technique for tiny fault interpretation.Based on the combination mono-frequency data interpretation and signal reconstruction technique,this work provides a discrete frequency coherency cube technique.The fractures in volcanic rock reservoir of XS well-block is detected by this method.The result shows that some unrecognized tiny faults and fracture zones in conventional seismic data are identified on discrete frequency coherency cube.The fractures detected by high-frequency coherency cube are more obvious and accurate.Reconstructed coherency cube shows more information about fractures than conventional cube,and is consistent with the results of HTI anisotropy fracture detection.