陆域冻土区地震探测信号提取技术——以青海哈拉湖地区为例

青海哈拉湖地区的陆域冻土区天然气水合物,其埋藏深度较浅,地震有效信号往往被干扰波淹没,如何从复杂的地震波场里有效提取出与地层、水合物有关的地震反射信号是开展地震资料精细解释和天然气水合物预测工作的前提.为此,详细分析青海哈拉湖地区地震探测原始数据,总结该地区干扰噪声的类型及特点,制定地震信号提取流程,并在叠前道集上逐步采用有针对性的噪声衰减、振幅补偿、反褶积以及叠加等处理技术,压制各类干扰信息,最大程度地保留有效反射信号,提高地震资料的分辨率、信噪比和保真度,更好地为地震资料解释和有利储层预测服务.

Extraction technology of seismic detection signal in land permafrost area: A case study of Halahu area in Qinghai

The natural gas hydrate in land permafrost of Halahu area in Qinghai is shallowly buried,and seismic effective signal is often submerged by the noise.Reflection signal related to the formation and hydrate can be effectively separated from the complex seismic wave,which is the foundation of seismic detailed interpretation and gas hydrate prediction.In this paper,the field data in Hahahu area are firstly analyzed,and the type and characteristics of the noise are summarized.Then,signal extraction flow is made.Some targeted technologies,such as noise attenuation,amplitude compensation,deconvolution and stack,are used for the pre-stack gathers so as to effectively suppress all kinds of noise and keep the reflected signal to the greatest extent.Seismic resolution,S/N ratio and fidelity of the results are enhanced,which help a lot for the seismic interpretation and gas hydratc prediction.