关键词: 二氧化碳气藏, 分布特征, 低速异常体, 深断裂, 成藏模式, 阳信-花沟地区

Abstract: The genesis,migration,accumulation and pool-forming models of carbon dioxide gas reservoirs in Yangxin-Huagou area were discussed.The data of geochemistry,deep geological background,deep faults and volcanic rock were analyzed.The results show that carbon dioxide mostly originated from inorganic mantle source and magmatic rock,which were primarily accumulated into low-velocity zones within lithosphere with a net of faults as vertical migration pathway.Two shear zones in the extensional basin and two volcanotectonic rift zones of the Paleogene with different pool-forming models and gas reservoirs are the most favorable factors for release and accumulation of carbon dioxide as well as formation of gas reservoirs.The distribution of the gas reservoirs,volcanic rock of the Cenozoic and helium isotope anomaly from inorganic mantle source showed the string-beads form along the principal faults of shear zones and volcano-tectonic rift zones.A gas reservoir assembly of the deep buried hills and medium-deep anticlines or fault-blocks and shallow draping deformational traps developed in the shear zones,and the gas reservoirs associated with igneous mass existed in the volcano-ectonic rift zones.

Key words: carbon dioxide gas reservoir, distribution characteristics, low-velocity zone, deep fault, pool-forming model, Yanxin-Huagou area