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

作者：LI Xiu-hua · 发表于：Tianranqi gongye · 年份：2007 · 研究领域：Hydrocarbon exploration and reservoir analysis、Geological Studies and Exploration、Geological and Geophysical Studies

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 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 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.