川东地区龙潭组/吴家坪组泥页岩微观孔隙差异特征及影响因素
Microscopic Pore Difference Characteristics and Influencing Factors of Mud Shale of Longtan Formation/Wujiaping Formation in Eastern Sichuan

为明确四川盆地东部龙潭组/吴家坪组微观孔隙结构特征差异及发育主控因素，本文以川东南地区龙潭组和川东北地区吴家坪组泥页岩为研究对象，联合应用图像分析方法与流体注入技术对泥页岩孔隙主要类型及微观孔隙结构特征进行定性表征和定量分析，并结合沉积相差异对孔隙发育特征及影响因素进行分析，结果表明：① 川东南龙潭组处于滨岸沼泽相，有机质主要为镜质组III型干酪根，富含黏土矿物，有机质孔不发育，主要孔隙类型为平板状、狭缝状黏土矿物粒内孔，以介孔和宏孔为主；② 川东北吴家坪组处于深水陆棚相，有机质主要为腐泥组II型干酪根，矿物组分以石英等脆性矿物为主，有机孔发育，主要孔隙类型为细瓶颈和墨水瓶状有机质孔，以介孔为主；③ 龙潭组泥页岩主要受黏土矿物含量影响，孔隙比表面积、比孔容与黏土矿物含量正相关；吴家坪组泥页岩孔隙发育主要受TOC含量影响，孔隙比表面积、比孔容与TOC含量正相关。
In order to clarify the differences in microscopic pore structure characteristics and the main controlling factors of the development of Longtan formation/Wujiaping formation in the eastern Sichuan Basin, this paper takes the mud shale of Longtan formation in Southeast Sichuan and Wujiaping formation in Northeast Sichuan as the research objects, and uses image analysis methods and fluid injection technology to qualitatively characterize and quantitatively analyze the main types of pores and microscopic pore structure characteristics of mud shale. Combined with the difference of sedimentary facies, the pore development characteristics and influencing factors are analyzed. The results show that: ① Longtan formation in Southeast Sichuan is located in the shore swamp facies. The organic matter is mainly vitrinite and type III kerogen, rich in clay minerals. The organic matter pores are not developed. The main pore types are flat and slit clay mineral intergranular pores, mainly mesopores and macropores; ② Wujiaping formation in Northeastern Sichuan is located in deep-water continental shelf facies. The organic matter is mainly type II kerogen of sapropel formation. The mineral components are mainly quartz and other brittle minerals. The organic pores are developed. The main pore types are fine bottleneck and ink bottle shaped organic pores, mainly mesopores; ③ The mud shale of Longtan Formation is mainly affected by the content of clay minerals, and the pore specific surface area and pore volume are positively correlated with the content of clay minerals; The pore development of Wujiaping formation mud shale is mainly affected by TOC, and the pore specific surface area and specific pore volume are positively correlated with TOC.