鄂尔多斯盆地杭锦旗东部地区上古生界天然气成藏模式

为了弄清鄂尔多斯盆地杭锦旗地区上古生界天然气成藏模式，用以指导该区的油气勘探，从烃源岩分布、天然气运移及圈闭分布特征等角度展开深度剖析，总结了该区的油气成藏模式。结果表明：该区烃源岩呈南厚北薄的展布特征，泊尔江海子断裂以南地区烃源岩成熟度高于断裂以北地区；区内构造圈闭主要分布在泊尔江海子断裂北部地区（什股壕地区）；泊尔江海子断裂以南地区天然气密度大于北部地区，整体呈现由南向北逐渐降低的趋势，而天然气干燥系数则整体由南向北逐渐增大，反映了缺少烃源岩的什股壕地区天然气主要由泊尔江海子断裂以南地区运移而来；泊尔江海子断裂以南地区发育优质的烃源岩，天然气高密度、低干燥系数的分布特征表明了该区域天然气为原地聚集；阿镇地区断裂及伴生构造圈闭成为该区油气运移的通道和聚集场所，十里加汗地区普遍不发育断裂，在砂岩储层物性的控制作用下，形成了近源天然气藏；杭锦旗东部地区上古生界天然气成藏模式划分为3类，即横向远距离运移异地成藏模式、垂向近距离运移原地成藏模式和准连续致密砂岩气成藏模式。该研究成果为杭锦旗地区下一步勘探指明了方向。

Natural gas accumulation patterns of Upper Paleozoic in eastern Hangjinqi area,Ordos Basin

In order to understand the gas accumulation model of the Upper Paleozoic in Hangjinqi area of Ordos Basin,and to guide the oil and gas exploration in this area,based on the depth analysis of the distribution of source rock,natural gas migration and trap distribution,this paper summarized the hydrocarbon accumulation model in this area.The results show that:source rocks in the study area are thick in the south and thin in the north,with high maturity in the south and low maturity in the north.These traps are mainly distributed in the northern region of Boerjianghaizi fault(Shenguhao region).The density of natural gas in the south is higher than that in the north.The whole shows a downward trend from south to north.The natural gas drying coefficient of the study area is also increasing gradually from south to north.The natural gas in Shenguhao area,which reflects the lack of hydrocarbon source rocks,is mainly transported from the south area of Boerjianghaizi fault.Highquality hydrocarbon source rocks are developed in the south area of Boerjianghaizi fault.The distribution characteristics of high natural gas density and low drying coefficient indicate that the natural gas is in situ accumulation in this area.The faults and associated structural traps are the migration channels and gathering places of oil and gas in Azhen area.Near source natural gas reservoir is formed in Shirigaohan area under the control of sandstone reservoir property and the influence of fault nondevelopment.The nature gas accumulation patterns of Upper Paleozoic in eastern Hangjinqi were divided into three types:horizontal long-distance migration,vertical near-distance in-situ accumulation and reservoir forming model of quasi continuous tight sandstone gas.The research results indicate the direction for the next exploration in Hangjinqi area.