摘要
准噶尔盆地北缘油气地质条件复杂,勘探难度大。通过哈拉阿拉特山地区开展了盆地构造属性、地层分布和勘探潜力等方面的研究,认为在裂陷-拉张构造背景下,早二叠世为半封闭残留海相沉积环境,并伴有火山活动,为优质烃源岩的发育提供了条件。受海西晚期—印支期构造运动影响,哈山向盆地方向强烈逆掩,造成了下二叠统的多期推覆叠加和上二叠统的大规模抬升剥蚀,现今盆地边界较沉积期大大萎缩。运用断层-褶皱构造解析技术,建立了哈山逆冲推覆+后期走滑的构造解释模式,发现了哈山推覆构造带之下发育风城组烃源岩,并且其分布向北至少可以延伸至达尔布特断裂附近,有利分布面积较前期扩大了1 000 km2;烃源岩有机质丰度高,热演化程度适中。油源对比结果显示,研究区白垩系、侏罗系、二叠系以及石炭系不同层系的原油主要来自该套烃源岩。推覆体下部下二叠统生油层系的发现,扩大了找油范围,乃至对整个北疆地区油气勘探具有重要影响。
The petroleum geological conditions are very complex in the northern margin of the Junggar basin,imposing great challenges to petroleum exploration.Based on the research of the tectonic attribute,stratigraphic distribution and exploration potential of the basin recently,it is concluded that the sedimentary environment in the Early Permian was an semi-enclosed remnant sea that was formed on the background of rifting and extensional tectonics movements and associa-ted with volcanic activity,providing favorable conditions for the deposition of high-quality source rocks.Influenced by the tectonic movements of the Late Hercynian and Indosinian,the Hashan thrusted towards to the basin,resulting in the superimposition of multi-phase thrust nappes in the Lower Permian and extensive uplifting and erosion of the Upper Per-mian.As a result,the present boundary of the basin is significantly smaller than that of the depositional period.The structure interpretation model of thrust nappe and later strike-slip of Hala＇alt is established with the technology of fault-fold structural analysis.Source rocks of the Fengcheng Formation are identified in the Hala＇alt nappe structure belt.And it is believed that the source rocks can extend northward to the Daerbute fault,enlarging the distribution area of source rocks by 1 000 km2.The source rocks have high organic content and moderate thermal maturity,and their oil-source correlation reveals that the oil in the Cretaceous,Jurassic,Permian and Carboniferous all are derived from this set of source rocks.The identification of this source sequence underlying the Lower Permain thrust nappe enlarges the area of exploration and even is of great significance for hydrocarbon exploration in the whole northern Junggar Basin.
出处
《石油与天然气地质》
EI
CAS
CSCD
北大核心
2013年第2期145-152,共8页
Oil & Gas Geology
基金
国家科技重大专项(2011ZX05002-002)
关键词
构造地质模型
盆地性质
风城组
二叠系
哈山地区
准噶尔盆地北缘
structure geological model
basin nature
Fengcheng Formation
Permian
Hala＇ alt area
northern margin of Junggar Basin
