A Case Study on Preservation Conditions and Influencing Factors of Shale Gas in the Lower Paleozoic Niutitang Formation, Western Hubei and Hunan, Middle Yangtze Region, China

Table 2

The table of the Є₁n shale gas composition in study area and its adjacent areas [25, 50].

Location	Well	Gas content (m^3·t^-1)	Average N2 content percentage	Average CH4 content percentage
Youyang, Chongqing	YY1	0.03-1.12	97.40%	1.20%
	YC1	—	84.10%	15.81%
Xiushan, Chongqing	XY6	0.02-2.2	85.60%	3.86%
Fenggang, Guizhou	FC1	0.4-3.5	84.00%	5.00%
Suiyang, Guizhou	SY1	0.02-0.6	85.36%	13.04%
Meitan, Guizhou	MY1	0.06-0.64	94.62%	4.63%
Cengong, Guizhou	TX1	1.10-2.88	16.20%	79.57%
	TM1	0.1-0.4	>95%	/
Zhengan, Guizhou	ZY1	0.9-2.05	61.37%	6.68%
Suntao, Guizhou	SY-1	0.02-0.85	12.23%	82.20%
Cili, Hunan	CY-1	0.32-0.94	20.00%	80.00%
Changde, Hunan	CY1	0.5-2.1	72.09%	8.65%
Baojin, Hunan	BY2	0.11-0.71	91.45%	8.55%
Huayuan, Hunan	HY1	<0.029	83.87%	12.5%