Methane in Soil Gas and Its Migration to the Atmosphere in the Dawanqi Oilfield, Tarim Basin, China

Table 3

Gas concentration analyses of soil gas and absorbed gas in Dawanqi oilfield.

		Average	Standard deviation	Range
Soil gas	CH4	907.1	906.3	22.5–3333.6
	C2H6	62.3	53.1	1.8–198.1
	C3H8	21.7	18.5	0.9–71.0
	C4H10	11.0	9.1	0–38.0
	C5H12	5.9	9.0	0–59.8
	C1/C2+	9.1	3.6	1.1–19.2
	Gas wetness	0.12	0.07	0.05–0.49
Absorbed gas	CH4	5.24	3.79	1.91–22.06
	C2H6	1.77	2.59	0.13–10.75
	C3H8	0.3	0.3	0.10–1.96
	C4H10	0.17	0.15	0.04–0.70
	C5H12	0.08	0.10	0.01–0.62
	C1/C2+	3.75	2.21	0.71–9.61
	Gas wetness	0.26	0.13	0.09–0.59

Gas concentration of soil gas samples is in ppmv. Concentration of absorbed gas is in μl/kg of soil.