漠河冻土带天然气水合物地震采集关键技术

Key technology of seismic acquisition of gas hydrate in Mohe permafrost area

由于陆域常年冻土带天然气水合物巨大的潜在资源价值,冻土带天然气水合物的勘探研究引起了人们的极大关注。不同于海域天然气水合物地震勘探技术渐趋于成熟,陆域冻土带天然气水合物地震勘探技术仍处于研究阶段,其在数据采集、处理、解释等各方面仍存在许多问题。文中针对中国陆域冻土带天然气水合物开展地震勘探采集技术研究;结合漠河冻土带特征,建立研究区地质模型,针对冻土层较薄以及区内深部构造复杂等勘探难点,利用基于波动方程的正演模拟方法进行观测系统参数论证,并通过对采集数据分析对比,提出了小道距、小炮距以及浅井炮、小炮、中炮交替激发以实现同时获取浅中深部信息的数据采集技术,并取得了进行储层预测和构造探测的高信噪比地震反射数据。

The exploration research on gas hydrate resources in permafrost areas has aroused much attention due to its huge potential resource value.Although the seismic exploration technology of marine gas hydrates is almost m ature,the seismic exploration technologyof gas hydrate in terrestrial permafrost area is still in the research phase,and there are still many problems in data acquisition,processing and interpretation.In this paper,the authors carried out the research on the seismic acquisition technology of gas hydrate in terrestrial permafrost area in China,conducted a comprehensive analysis and established a geological model of the study area on the basis of geological and geophysical data obtained in Mohe permafrost area.To tackle the exploration difficulties of the thin permafrost layer and deep complex structures,the authors conducted forward modeling based on the wave equation.Meanw-hile,through a comparative analysis of the collected data,the authors put forward the data acquisition method of alternate blasting of small interval and shallow,shots,small shots and moderate shots,which will acquire shallow-,middle-level and deep high SNR data for reservoir prediction and structure detection.