Classification and control factors of pore-throat systems in hybrid sedimentary rocks of Jimusar Sag, Junggar Basin, NW China

XIAO Dianshi,GAO Yang,PENG Shouchang,WANG Meng,WANG Min,LU Shuangfang

Fig. 3. Thin sections and SEM images of different PTSs. (a) Sample 12-H, cast thin section, dolarenite, with intergranular pores and Type A PTS; (b) Sample 12-H, SEM, with intergranular pores and intergranular dissolved pores; (c) Sample 33, cast thin section, siliceous shale, with feldspar and Type C PTS; (d) Sample 33, SEM, with intergranular and intragranular dissolved pores; (e) Sample 11, cast thin section, argillaceous dolomite, with no pores observed; (f) Sample 11, SEM, with dolomite intercrystalline pores and Type E PTS; (g) Sample 39, cast thin section, silty dolomite, with intergranular pores in the interbedded silt layer and intercrystalline pores in micritic dolomite; (h) Sample 39, SEM, with intergranular pores, intragranular dissolved pores, and Type B PTS; (i) Sample J43-52, cast thin section, calcareous siltstone, with intragranular dissolved pores and calcite blocking the intergranular pore-throats; (j) Sample J43-52, SEM, with calcite filling intergranular pores or metasomatizing intergranular dissolution pores and the Type D PTS; (k) Sample 30, cast thin section, silty mudstone, with mosaic feldspar grains and few pores; (l) Sample 30, SEM, showing dissolved pores connecting with intercrystalline pores and Type D PTS.