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祁连走廊贺兰坳陷区在石炭纪发育为一大型坳陷型盆地 ,以三角洲和滨浅海相为主要沉积岩相类型。石炭系受后期改造影响较大 ,华力西末期石炭系盆地萎缩 ,但构造格局基本未变 ,仍为坳陷盆地 ;印支期盆地遭受剥蚀 ,强烈的褶皱不但使二叠系剥蚀夷尽 ,石炭系也遭受了不同程度的剥蚀 ;燕山期盆地开始解体 ,但在中生界分布区石炭系保存有利 ;喜山期残存盆地深埋 ,石炭系仅零星残存在造山带的低洼地带。巴颜浩特盆地的东部坳陷和南部坳陷 ,石炭系残留面积大 ,沉积厚度大 ,烃源岩类型齐全 ,既有暗色泥岩又有碳酸盐岩和可燃有机岩 ,具有较高的生烃潜力 ;由于油气形成较晚 ,第三纪构造变动又不强烈 ,地震剖面上具坳陷特征 ,加之上有侏罗系的覆盖 ,因之保存条件最好 ,为油气勘探的首选区。
The Helan Depression in the Qilian Corridor developed into a large-scale depression-type basin in the Carboniferous, with deltaic and coastal shallow marine facies as the major sedimentary facies. Carboniferous was greatly affected by the later alteration, and the Carboniferous basin in the late Hurix was shrinking. However, the structural pattern remained basically unchanged. In the Indosinian basin, due to the erosion and strong folds, the Permian was not only eroded, Carboniferous also suffered different degree of denudation. The Yanshanian basin began to disintegrate but was favorable for carboniferous preservation in the Mesozoic distribution area. The remnant basins in the Himalayan period were buried deeply and the Carboniferous only remained in the low-lying areas of the orogenic belt. In the eastern depression and southern depression of the Bayanhaote basin, the Carboniferous has a large residual area, a large sedimentary thickness and a complete source rock type. Both dark mudstone, carbonate rock and combustible organic rock have high hydrocarbon generation Potential. Because of the late formation of oil and gas, the Tertiary tectonic changes are not intense. The seismic profiles are characterized by depressions and Jurassic coverings, which are the best preserved conditions for oil and gas exploration.