准噶尔盆地中央坳陷带油气成藏过程分析

An analysis on the process of hydrocarbon accumulation in the central depression belt of the Junggar Basin

车-莫古隆起的形成、演化控制了中央坳陷带中生界油气的成藏与演化。中、晚侏罗世,油气较大规模充注,形成了早期"车-莫古油气聚集带";侏罗纪末期地层抬升剥蚀,部分油藏遭受破坏;早白垩世末—古近纪,油气大规模充注,形成了中期"车-莫古油气聚集带",是中央坳陷带侏罗系和白垩系原生油气藏的主要成藏期;新近纪以来,"车-莫古油气聚集带"最终破坏,中央坳陷带现今油气分布面貌最终形成。总体而言,早期(中侏罗世晚期—古近纪)隆起背景控制中央坳陷带中生界的油气富集,晚期(新近纪以来)构造调整决定该区现今的油气分布。车-莫古隆起及两翼油气资源丰富,尤其是其南翼的中、上侏罗统剥蚀区,保存条件好,受后期构造运动影响小,是下一步油气勘探的重点地区。

The formation and evolution of the Che-Mo palaeo-high controlled lution in the central depression. The relatively large volume of hydrocarbon c hydrocarbon accumulation and evo- harging during the Middle and Late Jurassic formed the early ＂Che-Mo fossil hydrocarbon accumulation belt＂, part of which was wrecked by the uplifting and denudation in the Late Jurassic. Another large-scale hydrocarbon charging happened and formed the middle ＂Che-Mo fossil hydrocarbon accumulation belt＂ during the late Early Jurassic-Paleogene, which was also the main reservoiring stage for the primary oil and gas reservoirs in the Jurassic and Cretaceous in the central depression. The ＂Che-Mo fossil hydrocarbon accumulation belt＂ was finally destructed since the Neogene, resulting in the present distribution of oil and gas. Generally speaking, the early uplifting during the late Middle Jurassic- Paleogene controlled the oil and gas accumulation of the Mesozoic in the central depression, while the late structural adjustment since the Neogene determined the present distribution of oil and gas. The Che-Mo paleo-high and its flanks, especially areas in its south flank where the Middle and Upper Jurassic were denuded, are rich in oil and gas resources because of the favorable preserving conditions and slight influence from later tectonic movement, thus are important areas for future exploration.