Migration and Release Mechanism of Methane Microseepage Based on Dawanqi Field Work and Physical Simulations

Table 2

Statistics of CH₄ concentration (layers 1–3).

Group	Day (d^-1)	Max (ppm)	Min (ppm)	Std. dev
Layer 1	1–78	1864.84	278.49	316.11
	79–119	2128.08	1325.48	180.95
	120–290	31502.13	1782.43	5827.44
Layer 2	1–78	712.93	80.07	96.46
	79–119	319.81	142.27	37.27
	120–290	5299.93	85.42	1574.67
Layer 3	1–78	428.21	39.75	74.38
	79–119	133.75	54.71	16.30
	120–290	902.53	49.29	252.80