库车坳陷克拉苏构造带有机包裹体特征及对油气成藏的指示意义

储集层有机包裹体测试分析是研究油气运移、成藏时间和期次等问题的一种非常有效的方法。对塔里木盆地库车坳陷克拉苏构造带的克拉 2气田 4口探井和KL3井取心层位岩样进行偏光显微镜和荧光显微镜的镜下观察 ,并采用激光拉曼光谱仪对有机包裹体内含物的成分进行测试 ,进行有机包裹体种类、分布特征的对比研究。结果表明 ,克拉苏构造带曾有两期油气运聚事件 :第一期在构造抬升至现今埋深 ( 350 0～ 4 0 0 0m)之前的成岩早期阶段 ,克拉 2构造和克拉 3构造都是在胶结作用开始时就有油注入 ,并一直存在于地层中 ,有机包裹体丰度低表明并未形成大规模的油藏。第二期在喜马拉雅运动晚期的逆冲推覆构造变形阶段 ,克拉 2构造有大量的天然气向上运移直接进入该构造储集层中 ,但克拉 3构造未见天然气活动 ,仅有这一时期开始时的轻质油运聚和稍后的重质油运聚。照片 9图 1表 1参 4

The characteristics of organic inclusions of Kela 2 and Kela 3 gas fields and their indicative significance to oil and gas pool-forming in Kuqa depression

The test and analysis of fluid inclusions in the reservoirs is a very effective method in studying oil and gas migration and the pool-forming times. The rock samples in Kela 2 gas field and Well KL3 are examined with polarization microscope, fluorescence microscope, the composition of inclusions has been tested with Laser Raman spectrometer, and the type and distribution of organic inclusions have comparatively been studied in this paper. The study results indicate that there are two stages in oil and gas migration-accumulation events in Kelasu trend. The first is early diagenesis stage (before tectonic uplift), during which petroleum charge were starting at the beginning of cement process in Kela 2 and Kela 3 traps, and preserved in the reservoirs since then. The content of organic inclusions is low, which shows that a large oil & gas accumulation has not been formed in this stage. The second is late Himalayas stage. The abundant gas inclusions indicate that the huge amount of gas has charged the reservoirs in Kela 2 trap. But the characteristics of organic inclusions in Kela 3 trap show that there is only the activity of migration-accumulation of light oil in early time and those of heavy oil in late time.