Microscopic pore-fracture configuration and gas-filled mechanism of shale reservoirs in the western Chongqing area, Sichuan Basin, China

FU Yonghong,JIANG Yuqiang,DONG Dazhong,HU Qinhong,LEI Zhi’an,PENG Hao,GU Yifan,MA Shaoguang,WANG Zimeng,YIN Xingping,WANG Zhanlei

Fig. 2. Organic pores, inorganic pores, and micro-fractures in shale reservoirs of the Wufeng Formation-Long11 sub-member in western Chongqing area. (a) Well Z208, 4366.05 m, a large number of round organic pores distributed in the organic matter; (b) Well Z201, 4356.77 m, organic pores not developed in organic matter partially next to the fracture; (c) Well Z205, 4270.20 m, organic pores deform due to structural movement or compaction; (d) Well Z206, 4268.64 m, connected large pores developed in the organic matter; (e) Well Z201, 4359.60 m, intergranular dissolution pores; (f) Well Z205, 3327.59 m, intragranular dissolution pores; (g) Well Z202, 3890.50 m, a large number of intercrystalline pores developed in the pyrite; (h) Well Z205, 3346.12 m, micro-fractures formed on the contact edge of organic matter and minerals; (i) Well Z203, 4105.07 m, curved dissolution fractures; (j) Well Z208, 4366.05 m, micro-fractures formed by compaction; (k) Well Z201, 4359.60 m, organic pores developed in migrating organic matter strips; (L) Well Z201, 4362.58 m, no organic pores developed in the migrating organic matter connected with micro-fractures.