Reservoir characteristics and genetic mechanisms of gas-bearing shales with different laminae and laminae combinations: A case study of Member 1 of the Lower Silurian Longmaxi shale in Sichuan Basin, SW China

SHI Zhensheng,DONG Dazhong,WANG Hongyan,SUN Shasha,WU Jin

Fig. 4. SEM photos showing pore types and characteristics of gas-bearing shale in Long-1 Member, Sichuan Basin. (a) Well Ning-209, Long 111. Red zones are organic pores, and pink zones are micro-fractures; (b) Well Wei-202, 2573.5 m, organic pores and dissolution pores; (c) Well Wei-204, 3529.9 m, inter-granular pores; (d) Well Yanjin-1, 1534.6 m, inter-granular pores and micro-fractures; (e) Shuanghe outcrop, Long 111, dissolution pores; (f) Shuanghe outcrop, Long 111, dissolution pores; (g) Shuanghe outcrop, Long 111, well-developed organic pores in clayey laminae. Red zones are organic pores; (h) Shuanghe outcrop, Long 111, well developed inorganic pores in silty laminae. Green zones represent dissolution pores, light yellow zones represent inter-granular pores.