冻土区天然气水合物勘查技术研究主要进展与成果

摘要

The permafrost regions of the Tibetan Plateau are distributed in the middle latitudes of China,where the gas hydrate is differ ent from the gas hydrate in sea area and polar permafrost area in existing environment and basic characteristics.The lack of effective exploration technology has become the major technical bottleneck that restricts the investigation and evaluation of natural gas hydrate resources in permafrost regions of China.Supported by National 863 Program,Special Research Project of Ministry of Land and Resources and National Special Project of Gas Hydrate,the authors studied the development of key technologies of natural gas hydrate exploration in the permafrost regions of China.The prorate exploration methods for China's terrestrial gas hydrate exploration in permafrost areas have been initially established,which include the high resolution seismic method,the audio magnetotelluric sounding technology,the ultra-deep ground penetrating radar (GPR) technology,geochemical exploration technology and integrated geophysical logging technology.The seismology and electromagnetism identifications of gas hydrate reservoir have been found,the effective index of hydrate geochemical exploration is optimized,and the logging identification technology and reservoir parameter evaluation technology of gas hydrate reservoir are developed.An effective combination method for geophysical and geochemical exploration and a comprehensive geophysical and geochemical exploration model have been tentatively established in permafrost regions.The favorable area of gas hydrate accumulation is predicted,and several gas hydrate reservoirs have been found in the well suggested by the authors,which shows that the validity of methods proposed by the authors are tentatively tested and applied.The research results have great significance for promoting the progress of gas hydrate exploration and for supporting the exploration and development of natural gas hydrate resources in permafrost regions of China.%青藏高原多年冻土区分布在中纬度地带,天然气水合物赋存环境和基本特征既不同于海域水合物,也不同于极地冻土区水合物,缺少有效的勘探技术成为制约我国陆域天然气水合物资源调查与评价工作的主要技术瓶颈.在国家863计划、国土资源部行业科研专项和水合物国家专项共同支持下,开展了陆域冻土区天然气水合物勘查技术攻关,初步建成了陆域永久冻土区天然气水合物勘查的高精度地震勘探技术、音频大地电磁测深技术、超深探地雷达技术、地球化学勘查技术和综合地球物理测井技术;总结了冻土区天然气水合物地震学和电磁学识别标志,优选出了水合物地球化学勘查的有效指标,研发了水合物储层测井识别技术和储层参数评价技术;初步建立了冻土区天然气水合物物化探有效方法组合和物化探综合勘查模型;预测了水合物成藏有利区,提出的建议并位钻遇天然气水合物,方法有效性得到初步检验和应用.研究成果对推动陆域冻土区天然气水合物勘查技术进步、支撑我国冻土区天然气水合物资源评价与开发工作有重要意义.