地质成因的甲烷释放对大气的影响

地质成因自然源的甲烷释放在整个大气甲烷估算中起着非常重要的作用,它既是不含放射性14C甲烷源(死碳源)缺失部分的重要代表,也是甲烷重碳源的重要部分.概述了国内外关于地质成因甲烷释放对大气甲烷源与汇影响的研究进展,详述了来自地质成因化石燃料泄漏的人为甲烷释放以及来自沉积盆地(含油气盆地)、泥火山、地热区、海洋和甲烷水合物的地质自然源甲烷释放对大气甲烷源与汇的贡献及其影响因素;说明由于地质成因甲烷分布的区域性、不均匀性和时空的高度变化性,以及目前地质成因甲烷的通量估算仅建立在区域性的少量甲烷通量测试基础上,造成了地质成因甲烷释放通量估算的高度不确定性;指出研究中国西北地区油气田集聚区的甲烷释放通量,对油气田地质成因甲烷释放通量的估算具有重要意义.

Effect of Geogenic Emission of Methane on the Atmosphere

Natural geologic emissions of methane are very important in the atmospheric methane budget.They are not only important parts of radio-carbon-free(dead carbon),but also heavier methane sources.The paper systematically summarized advances in the researches on geogenic emissions of methane to sources and sinks of atmospheric methane and dealt with in detail the contribution of geogenic emission of methane(e.g.fossil fuel from anthropogenic activities or deposit basins,volcanoes,geothermal areas,submarine seepage and hydrate from natural sources)to sources and sinks of atmospheric methane and the influential factors.The budgets of geogegnic methane fluxes are highly constrained and therefore provisional,since they are based on a dataset of very few flux measurements that also have short-distance spatial variability,and short-term temporal variability.It is significant to study the methane emission and to evaluate its flux in oil/gas fields in Northwest China.