【摘要】 过去的研究认为,塔里木盆地塔东地区中—上奥陶统却尔却克组不发育烃源岩,但近期通过钻井系统取样分析,在该组泥岩中发现了烃源岩,有机质含量高达8.59%,厚度达200 m,值得高度关注。为此,通过近年探井的系统取样分析,结合地震追踪与沉积相研究,探讨了该组烃源岩发育特征及其勘探潜力。沉积相分析表明,浊流发育的探井缺乏烃源岩,而盆地相泥岩发育区有烃源岩分布;井震标定发现,浊积岩发育井区通常表现为杂乱反射,而烃源岩发育区多呈中强振幅连续—较连续地震相;根据区域地震追踪结果,认为却尔却克组烃源岩有利分布面积达5×104km2;油气源对比分析结果显示,塔东地区存在来自却尔却克组烃源岩的油气。结论认为:西北部的草湖、东北部的英东、西南部的古城等地区烃源岩较发育,热演化程度成熟度适中,是现今油气运聚的有利指向区。草湖地区、古城地区的寒武—奥陶系台缘带可勘探面积达8 000 km2,发育大型礁滩型圈闭,其侧向与烃源岩直接接触,有利于形成大型碳酸盐岩岩性油气藏。东北部的英东地区志留系、侏罗系碎屑岩发育多套储盖组合,断背斜圈闭发育,油源断裂发育,是寻找中小型次生油气藏的有利方向。更多还原

【Abstract】 It has been basically accepted that source rocks are poorly developed in the Middle-Upper Ordovician Queerqueke Formation in the eastern Tarim Basin,so-called the Tadong area.However,recent systematic sampling and analysis of cores reveal the existence of source rocks with an organic content up to 8.59% and a thickness around 200 m.On basis of this,their characteristics of development and exploration potentials were discussed in combination with seismic tracing and sedimentary facies study.Sedimentary facies analysis shows that source rocks are absent in the wellblocks with well developed turbidite,while they occur in the wellblocks with mudstone of basin facies.Seismic calibration with well data shows that chaotic reflections occur in the wellblocks with turbidite,while continuous to relatively continuous seismic facies with moderate-to-high amplitude occur in areas with source rocks.Based on regional seismic tracing,it is believed that the distribution area of source rocks in the Queerqueke Formation is up to 50000 km2.Hydrocarbon-source correlation reveals that some of the oil/gas in the Tadong area is derived from the source rocks in the Queerqueke Formation.Caohu in the northwest,Yingdong in the northeast,and Gucheng in the Southwest have well-developed source rocks with moderate thermal maturity are favorable areas for hydrocarbon accumulation.In the Caohu and Gucheng areas,the Cambrian-Ordovician play with an area of 8000 km2 has large traps of reef-shoal type and are laterally in direct contact with the source rocks,thus having great possibilities of discovering large lithologic carbonate reservoirs.It is thought to be possible to discover moderate-small secondary hydrocarbon reservoirs in the Yingdong area,where several reservoir-seal combinations occur in the Jurassic and Silurian clastic rocks and faulted anticline traps and source faults are both well developed.更多还原