Low-temperature gas from marine shales: wet gas to dry gas over experimental time

Table 2 Gas compositions (% mol) in sequential closed reactions, Floyd Shale at 50°C

	1st hr	2nd hr	3rd hr	4th hr	next 19 hr	next 19 hr	% var
Methane	0.24	0.88	1.34	0.58	1.21	3.28	91
Ethane	3.11	2.77	2.66	2.65	2.82	1.75	8
Propane	35.87	35.04	35.46	39.17	41.74	36.75	18
i-Butane	11.25	10.39	10.25	9.54	13.05	13.67	24
n-Butane	27.05	27.06	27.81	27.46	25.29	26.37	3
i-Pentane	11.27	11.18	10.30	9.20	8.33	9.50	14
n-Pentane	11.21	12.67	12.19	11.41	7.55	8.67	39
μmol/g, cum	0.204	0.263	0.304	0.358	0.422	0.445
	Duplicate Reaction
	1st hr	2nd hr	3rd hr	4th hr	next 19 hr	next 19 hr	% var
Methane	0.31	0.69	-	0.96	1.09	2.59	67
Ethane	3.15	2.82	-	2.48	1.95	1.31	23
Propane	38.30	36.58	-	34.85	41.58	36.52	17
i-Butane	10.40	9.41	-	10.16	11.74	12.68	16
n-Butane	26.33	27.19	-	28.18	26.52	27.76	2
i-Pentane	10.53	10.53	-	10.49	8.42	9.39	9
n-Pentane	10.97	12.78	-	12.87	8.71	9.76	30
μmol/g, cum	0.268	0.328		0.363	0.441	0.468

Yields in μmol C₁-C₅/g are cumulative. Gas compositions represent gas generated during that period, not cumulative gas composition. The dashed lines represent no data. Total gas yield was 24 μg C₁-C₅/g for the first reaction and 26 μg C₁-C₅/g for the duplicate reaction. % var is the variance in compositions over the indicated time periods as % of mean. The average % variance for the seven hydrocarbons is 28% for the first reaction and 24% for the duplicate reaction.

ISSN: 1467-4866