沂沭断裂带深反射地震资料处理

地震时间剖面可以对地质目标进行精细刻画,但由于变质岩、侵入岩地区存在地质体不规则、地质界线间波阻抗差异不明显、断裂构造倾角高陡等特征,导致地震原始资料具有波场复杂、干扰波发育、资料信噪比低等特点。为获得客观反应实际地质情况的沂沭断裂带深反射地震剖面,通过对研究区原始地震资料细致分析,针对各种干扰波的不同特性特征,分别采取针对性压制措施,进行组合去噪,在压制干扰的同时最大限度保护了有效信号。本次地震资料处理以高保真和高信噪比为目标,通过边处理边解释不断优化处理流程和处理参数。在处理过程中对静校正、叠前去噪、速度场建立以及波场空间归位等关键工作进行了重点研究,最终获得了高品质地震叠加和偏移时间剖面。反射剖面首次揭示了沂沭断裂带及其两侧岩石圈精细结构,为研究沂沭断裂带深部结构及对资源、环境的影响提供了可靠的地震学依据。

Data Processing Method of Deep Seismic Reflection Data in Yishu Fault Belt

Seismic time profile can be used to describe geological target precisely. However, due to irregular geological body, insignificant difference of wave impedance between geological boundaries and high and steep dip angle of fault structure in metamorphic rock and intrusive rock area, seismic original data has the characteristics of complex wave field, development of interference wave and low signal-to-noise ratio. In order to obtain the deep reflection seismic profile in Yishu fault belt which objectively reflects the actual geological conditions, through detailed analysis of the characteristics of the original seismic data in the study area, aiming at different characteristics of various interference waves, targeted suppression measures are taken to carry out combined denoising, so as to suppress the interference and protect the effective signal to the maximum extent. This seismic data processing aims at high fidelity and high signal-to-noise ratio, and continuously optimizes the processing flow and processing parameters by processing while interpreting. In the process of processing, static correction, prestack denoising, velocity field establishment and wave field spatial homing are studied in detail, and high quality seismic stack and migration time section has beem obtained. The reflection section reveals the fine structure of the lithosphere along Yishu fault belt and its two sides for the first time. It will provide reliable seismological basis for studying the deep structures and its impact on resources and environment in Yishu fault belt .