Pore Structure Characteristics, Genesis, and Its Controlling Effect on Gas Migration of Quaternary Mudstone Reservoir in Qaidam Basin

Figure 2

Photos of cores and thin sections of mudstones of different lithofacies in the Qigequan Formation. (a) S-23: pure mudstone; horizontal bedding develops and sandwiches organic layers. (b) Tn-18: pure mudstone; pores are difficult to observe. (c) Tn-18: pure mudstone; pores are difficult to observe. (d) Tn-18: silty mudstone; horizontal bedding is developed and microfractures are visible. (e) Tn-18: silty mudstone; the grains are mainly quartz and feldspar, and a small number of pores can be seen. (f) Tn-18: silty mudstone; the grains are mainly quartz and feldspar, and a small number of pores can be seen. (g) Tn-18: sandy mudstone; the mudstone diagenesis is weak. (h) Ts-1: sandy mudstone; the sandy particles are distributed in bands, and the particles are mainly quartz and feldspar. (i) Ts-1: sandy mudstone; obvious intergranular pores are developed in the sandy belt.

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