基于叠前波场模拟的火成岩地震反射特征分析

Analysis of reflection characteristics of volcanic rock by using pre-stack wavefield simulation.

(1.中国石油大学(北京)油气资源与探测国家重点实验室,北京102249;2.中国石油大学(北京)中国石油天然气集团公司物探重点实验室,北京102249;3.CNPC东方地球物理公司研究院大港分院,天津300280)

State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum (Beijing),Beijing 102249,China

利用褶积模型得到的地震记录由于没有考虑处理过程以及火成岩上覆地层等因素的影响,不能很好地模拟火成岩在实际地震剖面上的反射特征。因此,设计了一个火成岩地质模型,利用波动方程正演得到其叠前地震波场。分别利用叠后时间偏移、叠前时间偏移和叠前深度偏移对模拟的地震数据进行偏移成像,进而对火成岩地震反射特征进行观察和分析,由此得到对该火成岩模型地震相模式的基本认识。实验结果表明,与传统的褶积模型相比,该方法更真实地模拟了火成岩在实际地震剖面上的反射特征,形成的火成岩地震相模式对于实际火成岩机构的地震识别具有较好的指导意义。

Because the impact of processing procedure and the overlying formations of volcanic rocks hasn′t been considered,the seismic records obtained by convolution model cannot well simulate the reflection characteristics of volcanic rock on actual seismic sections;therefore,we designed a geological model of volcanic rock,and achieved its pre-stack seismic wavefield by wave equation forward simulation.Then post-stack time migration,pre-stack time migration and pre-stack depth migration were carried out on simulated seismic data to discover and analyze the reflection characteristics of volcanic rock.Finally,the seismic facies pattern of volcanic model was basically obtained.Actual application result indicates that the method provides more real simulation on the reflection characteristics of volcanic rock on seismic section,and the obtained seismic facies pattern of volcanic rock has better guidance meaning on seismic identification of actual volcanic apparatus.