Fig. 11

Microscopic characteristics of carbonate rocks. (A): Well FY1, 3458.57 m, grain carbonate rock, cathodoluminescence imagery; (B): Well FY1, 3458.57 m, grain carbonate rock, fluorescence imagery; (C): Well FY1, 3458.57 m, grain carbonate rock, scanning electron microscopy showing the coexistence of carbonate and ankerite; (D): Well FY1, 3458.57 m, grain carbonate rock, scanning electron microscopy revealing cubic-shaped pyrite crystals (Pr), indicate Cc is crystalline carbonate, I\S is IUite/smectite interstratified layer, with the energy spectrum analysis shown in the bottom left; (E): Well FY1, 3128.6 m, micritic carbonate rock, cathodoluminescence imagery; (F): Well FY1, 3128.6 m, micritic carbonate rock, fluorescence imagery; (G): Well FY1, 3128.6 m, micritic carbonate rock (Cc), scanning electron microscopy displaying spherical carbonate minerals, with the energy spectrum analysis shown in the bottom left; (H): Well FY1, 3128.6 m, micritic carbonate rock, scanning electron microscopy illustrating spherical pores on the sample surface indicate Cc is crystalline carbonate, Fs is ferrosilite; (I): Well NY1, 3294.3 m, micritic carbonate rock (Cc), scanning electron microscopy revealing filamentous and sheath-like carbonate minerals, with the energy spectrum analysis shown in the bottom left.