深拖多道高分辨率地震探测技术综述

随着我国主要海域的天然气水合物勘探逐步进入详查和开采阶段,对深海天然气水合物矿体空间分布的探查精度要求显著提高,而海洋常规多道地震探测系统分辨率不足,难以满足现阶段深海天然气水合物资源详查、勘探和开发的需要.本文详细阐述了深拖多道高分辨率地震探测技术探测方式及其特点,分析对比了深拖多道地震技术与常规海洋多道地震技术、短排列小道距地震技术及OBC地震技术相比的优越性;总结了国外深拖多道高分辨率地震探测装备以及在精细识别BSR、海底冷泉及海底麻坑等的应用效果.因为深拖多道高分辨率地震探测技术是将震源与采集缆拖曳与近海底(约100 m)且震源具有高主频、宽频带的特点,从而降低了勘探海洋噪声对地震信号的影响,缩短了与被探测目标的距离,降低了地震信号在传播过程中海水的吸收衰减,并且能够克服海面拖曳地震勘探中多次波、气泡效应的影响,所以其具有很高的纵向分辨率和横向分辨率以及高信噪比特点,将在天然气水合物勘探以及海洋工程领域具有极大的应用价值.

Review of deep-towed,high resolution multi-channel seismic exploration

As the exploration of gas hydrate in China's major sea areas gradually enters the period of detailed investigation and exploitation,the high accuracy for the exploration of the spatial distribution of gas hydrate in deep sea has been significantly improved.However,the resolution of conventional marine multichannel seismic systems is insufficient to meet the needs of detailed investigation,exploration and development of gas hydrate resources.In this paper,the techniques and characteristics of the high resolution,deep-towed multi-channel seismic technology are described in detail;The advances of deep-towed multi-channel seismic technology is compared with the conventional marine multichannel seismic,small scale multichannel seismic and OBC technology;Its applications of finely identifying BSR,vent and pockmark have been summarized.Obviously,because the highresolution,deep-towed multi-channel seismic technology is towing the source and hydrophone array near the bottom of the sea(about 100 m)and the source has high main frequency and wider band width,the impact of noise and attenuation caused by the ocean on seismic signals is reduced,and it can overcome the effects of multiple waves and bubble effects in towed seismic exploration on the sea surface,so it has high vertical and horizontal resolution and high S/N.The specific characteristics will have great application value in the field of gas hydrate exploration and marine engineering.