Acid-base alternation diagenesis and its influence on shale reservoirs in the Permian Lucaogou Formation, Jimusar Sag, Junggar Basin, NW China

WANG Jian,ZHOU Lu,LIU Jin,ZHANG Xinji,ZHANG Fan,ZHANG Baozhen

Fig. 11. Lithofacies characteristics of shale reservoirs in the Lucaogou Formation. (a) Well Ji 174, 3114.00 m, tuffaceous remaining intergranular pore-dissolution pore facies, plane-polarized light; (b) Well Ji 174, 3121.58 m, residual intergranular pore, plane-polarized light; (c) Well Ji 251, 3130.76 m, intragranular dissolution pores in feldspar grains, SEM; (d) Well Ji 30, 4054.76 m, tuffaceous and organic matter-bearing micritic dolomite mixed pore facies, gray-white and gray-black are tuff clasts, orthogonal light; (e) Well Ji 41, 3917.10 m, dolomite intercrystalline pores and throats, SEM; (f) Well Ji 41, 3917.10 m, organic matter pores, SEM; (g) Well Ji 174, 3227.51 m, micritic algal dolomite intercrystalline pore facies, fluorescence slice; (h) Well Ji 174, 3269.74 m, micro/nano pores, argon ion polishing+FESEM; (i) Well Ji 174, 3143.66 m, nanopores and oil film on pore wall, argon ion polishing+FESEM.