准噶尔盆地西北缘哈山地区二叠系风城组页岩油储层特征及其控制因素

准噶尔盆地西北缘二叠系风城组蕴含丰富的页岩油资源，且在玛湖凹陷和乌夏地区的油气勘探取得重大突破，邻近的哈山地区也具有一定的勘探潜力。通过岩石薄片观察、扫描电镜分析、有机地球化学测试、XRD分析和储层物性分析等，对哈山地区风城组页岩油储层特征及其控制因素进行了研究。研究结果表明: ①哈山地区风城组页岩油储层岩性主要为长英质页岩、钙质页岩和混积页岩，风城组页岩整体属于好-最好烃源岩，有机质类型以Ⅱ₁型和Ⅱ₂型为主，有机质主要处于未成熟阶段，部分推覆体下盘页岩有机质进入成熟早期阶段。②研究区页岩油储层孔隙度平均为2.32%，属于低孔储集层，储集空间以无机孔和微裂缝为主，有机质孔含量较低。③研究区风城组页岩油储层的发育主要受沉积相、成岩作用和构造活动的控制，其中沉积相不仅决定了岩石类型，还控制了有机质的富集程度；压实作用和胶结作用对储层物性具有负面影响，溶蚀作用可以大幅改善储集物性；构造活动形成的微裂缝不仅可以为页岩油赋存提供储集空间，还可以为油气运移提供通道，进而改善了页岩油储层的渗透性。

Shale oil reservoir characteristics and controlling factors of Permian Fengcheng Formation in Hashan area,northwestern margin of Junggar Basin

The Permian Fengcheng Formation in the northwestern margin of Junggar Basin is enriched with shale oil resources，and a major breakthrough has been made in oil and gas exploration in Mahu Sag and Wuxia area. There is certain exploration potential in the adjacent Hasan area. Through rock thin section observation，scanning electron microscope analysis，organic geochemical test，XRD analysis and reservoir physical property analysis， the shale oil reservoir characteristics and controlling factors of Permian Fengcheng Formation in Hashan area were studied. The results show that: (1) The lithologies of shale oil reservoirs of Permian Fengcheng Formation in Hashan area are mainly composed of felsic shale，calcareous shale and mixed shale. The shale could be classified as good to best source rocks. The organic matters are mainly typeⅡ₁ and typeⅡ₂，and mainly at the immature stage. Some shale samples in the footwall of the overthrusts were involved into early mature stage. (2) The average porosity of the shale oil reservoirs in the study area is 2.32%，belonging to low porosity reservoir. The reservoir space is dominated by inorganic pores and micro-fractures，and the development degree of organic pores is relatively low. (3) The development of shale oil reservoirs of Fengcheng Formation in the study area is mainly controlled by sedimentary facies，diagenesis and tectonic activities. Sedimentary facies not only determines the rock type，but also controls the enrichment of organic matters. Compaction and cementation can play a negative role in reservoir physical properties，and dissolution can greatly improve reservoir physical properties. Micro-fractures formed by tectonic activities can not only provide reservoir spaces for shale oil，but also provide channels for oil and gas migration，thus improving the percolation condition of shale oil reservoirs.