临汾-运城盆地氦气富集要素及成藏条件

Analysis of Helium Enrichment Factors and Reservoir Forming Conditions in Linfen-Yuncheng Basin

为认识临汾-运城盆地氦气资源前景,促进氦气勘查工作,笔者根据地球物理资料、元素地球化学实验及构造资料,分析了临汾-运城盆地氦源岩分布和氦气运移通道条件;在收集和整理临汾-运城盆地前新生界地热、气测录井及物探资料的基础上,开展了以地热和煤系气为主的氦载体特征研究。研究发现:①临汾-运城盆地具备地幔物质上涌和本溪组铝土岩系2种氦源条件。②控制盆地和凹陷的深大断裂贯通了深部氦源与前新生代地层,盆地内发育的正断层在很大程度上可提高前新生界各地层间的连通性,有良好的运移通道。③临汾-洪洞地区石炭系—二叠系具有优越的煤系气成藏条件。综合氦源岩分布、氦气运移通道、氦载体和保存等氦气成藏条件,认为临汾-运城盆地中奥陶统马家沟组为主要富氦地热储层,且临汾-洪洞地区太原组和山西组具备富氦煤系气的找矿前景。

In order to promote the helium exploration and deepen the understanding of helium accumulation theory,the distribution of helium source rocks and the conditions of helium migration channels in Linfen-Yuncheng basin has been analyzed with regional aeromagnetic interpretation data,element geochemical experiments and tectonic evolution data.Then,the study on the characteristics of helium carrier reservoir dominated by geothermal and resources has been carried out by collecting geothermal,gas survey and geophysical exploration data.The main results are as follows:①There are two Helium source conditions,which are mantle upwelling and bauxite series in Benxi Formation.②The deep faults controlling the basin and depression have connected the deep helium source and the pre-Cenozoic strata.The normal faults developed in the basin have greatly improved the connectivity between the pre-Cenozoic strata.They provide good channels for helium migration.③The geological conditions of hydrocarbon generation and accumulation of coal measure gas in the Permo-carboniferous system in Linfen and Hongdong areas are superior.Based on helium source,transportation,carrier and other enrichment factors,it is considered that Majiagou Formation of Middle Ordovician in Linfen-Yuncheng Basin is a main helium rich geothermal reservoir.In addition,the prospecting prospect of helium rich coal measure gas of Shanxi Formaion and Taiyuan Formation in Linfen and Hongdong areas is broad.