准噶尔盆地南缘前陆冲断带油气成藏差异性分析

准噶尔盆地南缘前陆冲断带构造演化与成藏过程复杂。为深化对这种复杂性的认识，以给区域油气勘探和基础石油 地质研究提供参考信息，针对区域构造上存在东西分段、南北分带的特点，从不同角度详细分析了不同区段油气成藏的特 征及其差异，包括烃源、储层、圈闭、输导、保存、成藏模式和主控因素。结果表明，不同区段的油气藏分布层位和成藏 特征均不同，展示出油气成藏的差异性。其中，东段阜康断裂带主要是二叠系（包括侏罗系）的油气聚集于侏罗系储层中， 成藏主控因素是圈闭、保存条件和储层；中段山前冲断带主要是侏罗系和二叠系（包括白垩系）的油气聚集于古近系和白 垩系储层中，成藏主控因素是烃源岩、油源断裂和储层；西段四棵树凹陷地区主要是侏罗系（包括古近系）的油气聚集于 古近系-新近系和白垩系储层中，油气成藏主控因素是运移通道和储层条件。

Difference of Hydrocarbon Accumulation in the Foreland Thrust-fold Belt of the Southern Junggar Basin

The  tectonic evolution and hydrocarbon accumulation  in  the  foreland  fold-and-thrust belt of  the southern Junggar Basin  is complex.  In order  to  reveal  this complexity and  in  turn provide basic  information  for  regional petroleum exploration and  fundamental geological studies,  this paper analyzes petroleum accumulation  features. The study area  is characterized by structurally different segments along the east-west direction, and by structurally different belts along the north-south direction. The hydrocarbon accumulation  in  these different areas was discussed  from a variety of aspects,  including sources,  reservoirs,  traps, conduits, preservation, hydrocarbon accumulation and controlling factors. A strong difference in hydrocarbon formation is shown by reservoir age and source-reservoir-cap type in different geotectonic units. In the eastern segment (i.e., the Fukang fault belt), the Permian-sourced (including Jurassic-sourced) hydrocarbons were mainly accumulated in Jurassic reservoirs, and the hydrocarbon accumulation was predominantly controlled by  traps, preservation and reservoirs; In  the middle segment  (i.e.,  the  foreland  fold- and-thrust belt),  the Jurassic- and Permian-sourced  (including Cretaceous-sourced) hydrocarbons were mainly accumulated  in Paleogene and Cretaceous reservoirs, and the hydrocarbon accumulation was predominantly controlled by source rocks, oil-source faults and  reservoirs;  In  the western segment  (i.e.,  the Sikeshu sag area),  the Jurassic-sourced  (including Paleogene-sourced) hydrocarbons were mainly accumulated in Paleogene-Neogene and Cretaceous reservoirs, and the hydrocarbon accumulation was predominantly controlled by migration pathway and reservoirs.