深源CO_2对沉积盆地油气成藏的影响

INFLUENCES OF ANATECTIC [STH4]CO_2 ON HYDROCARBON RESERVOIRING IN SEDIMENTARY BASINS ~

深部地壳和沉积盆地中已经有大量深部来源的CO2被发现,这些CO2的存在已经对油气的成藏产生了重大影响。研究表明,在地质条件下,CO2不仅能与H2发生费托反应生成烃类物质,还可以被Fe2SiO4还原为CH4;地球深部的这些CO2是以超临界状态存在的,这种状态的CO2可以大量吸附和溶解壳幔中分散的有机质,并促使其运移;CO2还能与盆地流体构成酸性介质,溶解盆地中的碳酸盐矿物和铝硅酸盐矿物,显著改善储层物性。加强这方面研究,不仅对于油气的勘探开发有重大指导作用,而且对于油气资源评价也有深远影响。

Large amount of anatectic CO_2 have been discovered in deep Earth crust and deep sedimentary basins, their occurrence has been great influence upon hydrocarbon reservoiring. In geologic setting, CO_2 not only can generate hydrocarbons through Fischer Tropsch (FT) reaction with H_2, but also can be reduced to CH_4 by Fe_2SiO_4. The CO_2 in the deep of the Earth occur in supercritical state, and can absorb and dissolve large amount of organic matters dispersed in the Earth crust and mantle, and accelerate their migration. Moreover, CO_2 can also convert the basin fluid into acidic medium, and dissolve the carbonate and aluminum silicate minerals in the basin, thus significantly improve the poroperm characteristics of reservoirs. Strengthening researches in these respects can not only guide exploration and development, but also have far-reaching influences on assessment of hydrocarbon resources.