塔河油田西南部古生界碎屑岩地层成藏特征

近期的油气勘探作业已在塔河油田西南部石炭系巴楚组砂砾岩段（C₁b¹）、泥盆系东河砂岩段（D₃d）、下志留统（S₁k）钻遇油气层，其中T707井、S112-2井于C₁b¹，T727井、TP1井于D₃d分别获工业性油气流，充分显示出该区古生界碎屑岩地层的勘探潜力。为此，通过综合研究区域烃源岩特征与油源对比、储盖及圈闭条件、圈闭类型、运移通道和成藏期次，发现该区古生界碎屑岩地层具有油源断层与晚期构造共同控制、晚期成藏的特征，即中-上奥陶统烃源岩主要于喜山中、晚期沿“油源断层”和“疏导层”大量充注于喜山期形成的构造圈闭和构造-地层复合圈闭等油气集聚的有利场所中，喜山中、晚期为该区成藏的关键时期。成藏规律的总结与成藏模式的提出，为该区下一步的勘探提供了依据。

CHARACTERISTICS OF HYDROCARBON ACCUMULATION IN PALEOZOIC CLASTIC RESERVOIRS IN SOUTHWEST TAHE OILFIELD

Recent exploratory drilling in the southwestern part of Tahe oilfield has obtained discoveries in the glutenite interval of Carboniferous Bachu Formation(C1b1) , in the sandstone interval of Devonian Donghe Formation(D3d) , and in the Lower Jurassic(S1k). Industrial oil and gas flows have been tested in C1b1 of T707 and S112-2 wells and in D3d of T727 and TP1 wells, revealing large exploration potentials of Paleozoic clastic rocks in the study area. Based on a comprehensive study of the regional source rock features, oil-source correlation, reservoir-seal-trap conditions, trap types, migration pathways and reser-voiring stages, the reservoiring characteristics of Paleozoic clastic rocks in the study area are summarized as oil source point control, two migration pathways, late structural control and late reservoiring. Large amount of hydrocarbons generated by the Middle-Upper Ordovician source rocks in middle and late Himalayan migrated along the "oil source-related faults" and "carrier beds" into the structural traps and structural-stratigraphic combination traps formed in the Himalayan. The middle and late Himalayan are the critical reservoiring stages in the study area. The reservoiring patterns presented provide a basis for future exploration in the study area.