川南ZX向斜五峰组—龙马溪组页岩孔隙特征及差异性

Characteristics and differences of shale pores in Wufeng-Longmaxi Formation of ZX syncline, southern Sichuan Basin

张喜淳 胡晨林 田继军 吝文 张介辉 杨斌

新疆大学地质与矿业工程学院，新疆 乌鲁木齐 830017 中国石油勘探开发研究院，北京 100083 中国石油浙江油田分公司，浙江 杭州 310023 中石化经纬有限公司，山东 青岛 266075

School of Geology and Mining Engineering, Xinjiang University, Urumqi 830017, China Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China Zhejiang Oilfield Company, PetroChina, Hangzhou 310023,China Sinopec Matrix Corporation, QingDao 266075, China

文中选取四川盆地南缘ZX向斜五峰组—龙马溪组下段页岩样品进行研究，系统分析了其纳米孔隙结构特征和产生差异性的主要影响因素，根据Frenkel-Halsey-Hill模型计算了页岩孔隙的分形维数。结果表明：页岩孔隙的比表面积主要受控于微孔和介孔，孔体积主要受控于介孔和宏孔，随着埋深增加，比表面积明显增大；总有机碳质量分数（TOC）与比表面积和孔体积呈正相关性，镜质组反射率（Ro）对纳米孔隙发育有积极影响，钙质硅质混合页岩的分形维数较大。总体上，TOC和Ro是影响页岩纳米孔隙发育的主要因素，钙质硅质混合页岩具有更复杂的孔隙结构，是有利于开发的优质储层。

 In this paper, shale samples from the Lower Member of Wufeng-Longmaxi Formation in the ZX syncline in the southern margin of  Sichuan Basin were selected to systematically analyze the structural characteristics of nano-pores and the main factors influencing their differences, and the fractal dimension of shale pores was calculated according to the Frenkel-Halsey-Hill model. The results show that the specific surface area of shale pores is mainly controlled by micropores and mesopores, and the pore volume is mainly controlled by mesopores and macropores. The specific surface area increases obviously with the increase of burial depth. The total organic carbon(TOC) mass fraction is positively correlated with specific surface area and pore volume, the vitrinite reflectance(Ro) has positive influence on nano-pore development, and the fractal dimension of calcareous siliceous mixed shale is large. In general, TOC and Ro are the main factors affecting the development of nano-pores in shale. The calcareous siliceous mixed shale has a more complex pore structure and is a good reservoir for development.

10.6056/dkyqt202204006