张家湾地区长7页岩生烃潜力及孔隙结构特征

为了摸清直罗油田张家湾地区延长组长₇页岩生烃潜力及孔隙特征，通过岩石学、有机地球化学分析以及利用扫描电镜、氩离子抛光等技术手段，对研究区长₇页岩进行了展布特征、地球化学特征和孔隙特征分析。结果表明，研究区延长组长₇段黑色湖相页岩在平面上和纵向上均存在差异，具有"北西厚、南东薄"的特征；长₇油页岩有机质类型以I型和Ⅱ₁型为主，有机质成熟度高，为好的烃源岩，页岩储层属于I类富集型储层；孔隙类型以粒间孔、晶间孔、溶蚀孔和有机质孔为主；孔径以<0.5 μm为主，储层喉道半径主要在100~750 nm，孔隙度变化范围较大，主要在0.5%~1.9%，平均约1.0%。研究认为，研究区"新发现"的长₇页岩生烃潜力较大，可动油含量较高。

Hydrocarbon Generation Potential and Pore Characteristics of Chang 7 Oil Shale in the Zhangjiawan Region

Hydrocarbon generation potential and pore characteristics of Chang 7 oil shale from the Yanchang Formation in the Zhangjiawan Region of the Zhiluo Oilfield were examined in this study. We conducted petrological and organic geochemical analyses, and methods like scanning electron microscopy and argon ion milling were used to analyze the distribution, geochemical characteristics, and pore characteristics of the Chang 7 shale in the study area. The results reveal that the Chang 7 black lake shale from the Yanchang Formation in the study area is heterogeneous both horizontally and vertically. It is thick in the northwest, but thin in the southeast. The organic matter in the Chang 7 oil shale are primarily type I and Ⅱ₁ and are highly mature. Therefore, the shale is a desirable hydrocarbon source rock. The shale reservoir is a type 1 enrichment reservoir. The pores of the reservoir are mainly intergranular pores, intercrystalline pores, dissolution pores, and organic pores, where the pore sizes are mostly <0.5 μm. The throat radius ranges from 100 to 750 nm. There is a relatively porosity range (0.5% to 1.9%) with an average of approximately 1.0%. It is believed that the "newly discovered" Chang 7 shale in the study area has relatively great hydrocarbon generation potential, with a relatively high content of movable oil.