Characterization of favorable lithofacies in tight sandstone reservoirs and its significance for gas exploration and exploitation: A case study of the 2nd Member of Triassic Xujiahe Formation in the Xinchang area, Sichuan Basin

LIU Junlong,LIU Zhongqun,XIAO Kaihua,HUANG Yanqing,JIN Wujun

Fig. 3. Core photos of typical lithofaices in the T3x2 Member of Xinchang tectonic zone. (a) Multiple layer medium-coarse grain sandstone, Well CG561, Tx24 sand group; (b) Parallel bedding medium-coarse grain sandstone, Well CJ566, Tx25 sand group; (c) Massive bedding medium-coarse grain sandstone, Well XC12, Tx24 sand group; (d) Inclined bedding medium-coarse grain sandstone, Well CH127, Tx21 sand group; (e) Charcoal-bearing medium-coarse grain sandstone, Well CH127, Tx21 sand group; (f) Mud gravel-bearing medium-coarse grain sandstone, Well Xin10, Tx24 sand group; (g) Inclined bedding fine sandstone, Well XC7, Tx23 sand group; (h) Wavy bedding siltstone, Well Xin10, Tx24 sand group; (i) Carbonaceous mudstone, Well CH127, Tx22 sand group; (j) Coaly mudstone, Well CH127, Tx22 sand group; (k) Calcarinate inclined bedding medium-coarse grain sandstone, Well CH127, Tx22 sand group; (l) Calcarinate massive bedding medium-coarse grain sandstone, Well XC7, Tx26 sand group.