Impact of Differential Densification on the Pore Structure of Tight Gas Sandstone: Evidence from the Permian Shihezi and Shanxi Formations, Eastern Sulige Gas Field, Ordos Basin, China

Figure 16

ESEM image showing typical cement habits. (a) Chlorite rim is developed at the margins of mineral grains, and intergranular pores are well preserved, SD24-55, 2799.78 m. (b) Silica-like and flaky illite forms networks or bridge-type cementation, SD24-55, 2954.586 m. (c) Feldspar dissolution is associated with kaolinite. Kaolinite intercrystalline pores are developed, and kaolinite illitization can be seen locally, SD24-55, 2976.21 m. (d) Feldspar dissolution is associated with kaolinite. Kaolinite intergranular pores are developed, and kaolinite illitization can be seen locally. Authigenic quartz is developed in intergranular pores, SD24-55, 3043.7 m.

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