中国含油气盆地富氦资源分布规律及勘探方向OA

The key to solve the shortage of helium resources in China is to discover more helium-rich resources.However,the distribution patterns and exploration directions of helium-rich resources have not yet been sufficiently studied.Based on critical data(e.g.geochemical characteristics,natural gas reserves abundance,and helium content)of main helium-bearing gas fields in China,as well as the regional distribution,horizon characteristics and origin types of helium-rich gas reservoirs,this paper systematically reviews the distribution characteristics and patterns of helium-rich gas reservoirs in China,and points out the exploration directions.The following results are obtained.First,helium resources are widely distributed in China but with low quality overall.There is a significant negative correlation between natural gas reserves abundance and helium content,helium-rich gas reservoirs are small in number and scale,and only a few gas fields have potential for helium extraction.Second,helium-rich gas reservoirs are characterized by scattered horizons,diverse types,and multiple origins of natural gas.The helium is mainly crust derived.Due to tectonic activities,the eastern basins exhibit a mixture of mantle-derived helium to varying extents.The east-west zonation is closely related to the regional geotectonic pattern.Third,helium-rich resources are concentrated in the petroliferous basins of central-western China,which are developed in the active tectonic zones subjected to significant uplift above the ancient basement,and associated with ancient groundwater development areas,with helium and nitrogen showing the characteristic of enriched coupling,and mostly distributed in low to normal pressure zones with relatively weak sealing capacity.In conclusion,the exploration of helium-rich resources in China should focus on the ancient basement development areas of central-western China,with the priority given to normal/negative pressure regions with basement faults,relatively large uplift amplitude due to late tectonic movements,and medium to low abundance of natural gas.Moreover,nitrogen-rich gas reservoirs can be used as an exploration indicator for helium-rich gas reservoirs.