青海木里三露天天然气水合物野外现场识别方法研究

摘要

The identification of gas hydrates is the foundation for its exploration and research.The exploration level of gas hydrate in permafrost areas in China is low,and it is different from marine gas hydrate in existing environment and occurrence shape and accumulation mechanism.Therefore,it is urgent to find a new identifi-cation method for gas hydrate in permafrost areas.A continuous research was undertaken to identify gas hydrates in 14 drill holes located in Sanlutian of Muli,Qinghai which were carried out by Qinghai No.105 Coal Geolog-ical Exploration Team.Based on this research this paper builds a real-time identification method for gas hy-drates,namely recognizing the obvious sign of ice-shape gas hydrates and boiling water and water seep age de-tected by gas logging and core analysis.After further verification,this new real-time identification method which is supported by physical and chemical characteristics of gas hydrates is proved to be more reliable and applica-tive.Finally,it summarizes the abnormal symbol and obvious sign and recognizing method for gas hydrates'identification.%天然气水合物的野外识别是其勘查工作和分析研究的工作基础。我国陆域冻土区天然气水合物勘查工作程度低，且其赋存环境、产出形态和成藏机理等特征与海域天然气水合物存在显著差异，由此也决定并急需寻找一套新的、系统的陆域冻土区天然气水合物的野外识别方法。通过对近两年青海煤炭地质局一0五勘探队在青海木里三露天地区实施系列钻井中天然气水合物识别方法的不断分析和总结，建立了以天然气水合物冰状、沸腾、渗水现象为直接识别标志和以气测录井、岩心解析为有效鉴别方法等为主的天然气水合物野外现场识别方法。经过进一步验证表明，以天然气水合物典型物理化学特征为支撑，以研究区零星、分散产出和连续性、对比性差等对识别水合物不利特征为客观前提建立的天然气水合物野外现场系统识别方法可靠性高、适用性更强更广。最后，对诸多围绕天然气水合物的异常标识、直接标志和技术方法以流程的方式梳理和总结了其识别工作方法。