伊朗库姆盆地含烃盐水包裹体成分和温度研究

摘要

通过对伊朗库姆盆地Aran2井和FKH1井含烃盐水包裹体成分和均一温度的对比研究,揭示油气充注和成藏过程.含烃盐水流体包裹体成分和均一温度研究表明,Aran2井和FKH1井分别有过3期和4期含烃流体充注;流体体系主要为(CO2-有机)-H2O,(CO-有机)-H2O和(H2S+CO2-有机)-H2O体系.流体包裹体气相部分较液相部分富含有机相、较高的均一温度和缺少液态烃包裹体,表明两口井所充注的并不是与Aran1井类似的液态石油,而是富氮或不含氮的天然气.富氮的天然气可能是来自下伏侏罗系油藏裂解后形成的裂解气,不含氮的天然气可能是下伏Shemshak组烃源岩二次生烃的产物.Aran2井具有相对好的保存条件而使气藏得以保存, FKH1井具有较差的保存条件使气藏被破坏和逸散.%Based on the comparison of the composition and homogeneous temperature of salt-water inclusions with hydrocarbon between Well Aran2 and Well FKH1 in Iran Qom Basin, this paper reveals the process of oil/gas injection and accumulation. Based on the composition and homogeneous temperature of fluid inclusions, three and four stages of hydrocarbon-bearing fluid injection can be identified in Well Aran2 and Well FKH1, respectively. Three kinds of fluid system are suggested. They are (CO2-hydrocarbon) -H2O, (CO-hydrocarbon) -H2O and (H2S+CO2-hydrocarbon) -H2O. The facts, such as more abundant hydrocarbon in gas phase than that in liquid phase, higher homogeneous temperature and absence of liquid hydrocarbon inclusion, suggest that both wells were filled with the gas with abundant or less nitrogen and they are much different from Well Aran1 filled with oil. The gas with abundant nitrogen may be the cracking gas produced by the crack of trapped hydrocarbon in underlying Jurassic;the gas with less nitrogen may be ascribed to the secondary generating hydrocarbon of underlying Shemshak Formation. The preservation condition of the Well Aran2 is better than that of Well FKH1. So the trapped gas in Well Aran2 can be preserved well while that in Well FKH1 was destructed and dissipated.