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

Table 1 Electron probe analysis results of minerals in the Lucaogou Formation reservoirs.

Mineral type Na2O/% MgO/% Al2O3/% SiO2/% K2O/% CaO/% FeO/% MnO/% As2O5/% SrO/% CO2/% Dolomite 0.194 18.873 0.051* 0.118* 0.022* 30.681 2.488 0.251 0.484* 0.198 46.640 Ankerite 0.083 14.393 0.036* BDL 0.011* 29.556 8.992 0.349 0.353* 0.188 46.039 Calcite 0.099* 0.490 0.034* 0.050* 0.016* 55.313 0.665* 0.160* 0.394 42.779 Albite 11.388 0.063* 19.022 67.841 0.359 0.438* 0.445 0.023* 0.421 Orthoclase 0.980 0.326 17.725 67.325 12.124 0.772 0.291 0.457 Microcline 3.199 BDL 18.197 66.562 11.331 0.171 0.119 0.421