Petroleum geological conditions and exploration potential of Lower Paleozoic carbonate rocks in Gucheng Area, Tarim Basin, China

CAO Yinghui,WANG Shan,ZHANG Yajin,YANG Min,YAN Lei,ZHAO Yimin,ZHANG Junlong,WANG Xiandong,ZHOU Xiaoxiao,WANG Hongjiang

Table 2 Composition and carbon isotope composition of gas produced from Ordovician Yingshan Formation in the Gucheng area.

Well Depth /m Dry coefficient Gas composition/% δ13C/‰ C1 C2 C3 C4 C5+ N2 CO2 δ13C1 δ13C2 δ13C3 GC6 6 169.0 0.997 90.7 0.25 0.015 0.002 0.29 4.26 4.71 -33.6 -37.6 -34.9 GC8 6 080.6 0.996 83.4 0.31 0.018 0.008 0.40 4.50 11.50 -34.8 -38.7 0.995 82.9 0.34 0.020 0.020 0.38 4.60 11.90 -35.1 GC9 6 116.4 0.997 71.6 0.21 0.010 0 0.22 2.30 25.70 -34.6 -32.9 -31.3 0.997 65.6 0.22 0.010 0 0.23 4.77 29.10 -33.9