Geochemical Characteristics of Natural Gas and Hydrocarbon Charge History in the Western Qaidam Basin, Northwest China
Table 3
Component and isotope properties of natural gas in the western Qaidam Basin.
Well
Main components (%)
Dryness
C1/(C2+C3)
δ13C (‰, VPDB)
(%)
(%)
C1
C2
C3
i-C4
n-C4
i-C5
n-C5
CO2
N2
H2S
C1
C2
C3
S205
79.49
6.41
4.37
0.94
2.08
0.86
0.93
0.60
3.02
0.00
0.84
7.4
-40.6
-29.8
-26.4
0.8
S58
78.77
5.98
3.54
0.79
1.92
0.76
0.99
1.44
2.74
1.74
0.85
8.3
-40.0
-27.7
0.9
HN5-43-3
67.54
5.97
2.42
0.40
0.74
0.24
0.26
1.61
16.87
0.00
0.87
8.1
-54.6
-35.9
-28.1
0.6
YP3
72.94
10.97
0.89
1.09
0.02
0.33
0.31
1.24
5.35
0.00
0.84
6.2
-40.6
-27.9
-23.1
0.8
Y8-371
80.09
5.77
0.47
0.69
0.00
0.28
0.32
2.18
6.59
0.00
0.91
12.8
-42.1
-28.4
-26.8
0.8
YІІ5-13
91.01
1.75
0.50
0.38
0.01
0.17
0.24
1.82
1.71
0.00
0.97
40.5
-47.7
-28.2
-21.0
0.7
Y1-2-B1
73.34
9.91
1.00
1.24
0.01
0.31
0.25
1.70
4.33
0.00
0.85
6.7
-37.9
-27.2
-24.7
0.9
Y1-2-B4
87.93
4.27
0.38
0.48
0.00
0.17
0.16
0.68
2.85
0.00
0.94
18.9
-36.6
-26.8
-23.2
0.9
Y27-1-A6
86.30
4.95
0.43
0.58
0.00
0.20
0.20
0.75
3.20
0.00
0.93
16.0
-37.7
-26.7
-24.3
0.9
Y38-3-C
88.03
4.95
0.44
0.58
0.00
0.20
0.21
0.00
2.14
0.00
0.93
16.3
-39.5
-27.6
-25.0
0.9
Y29-1
81.66
6.29
0.60
0.74
0.01
0.19
0.19
1.38
4.10
0.00
0.91
11.8
-40.5
-30.9
-25.6
0.9
Y4-2
79.50
6.73
0.79
1.04
0.01
0.33
0.29
1.61
4.12
0.00
0.90
10.6
-39.6
-27.8
-24.4
0.9
Y9-4
81.61
3.59
0.60
0.79
0.01
0.28
0.26
0.70
7.22
0.00
0.94
19.5
-40.0
-28.7
-27.4
0.9
YD301
80.39
6.09
0.88
1.20
0.00
0.25
0.31
1.27
3.92
0.00
0.90
11.5
-39.5
-27.0
-23.9
0.9
YD3-3
79.96
6.63
0.68
1.01
0.01
0.41
0.40
1.78
4.37
0.00
0.90
10.9
-40.5
-26.8
-24.3
0.9
L4-5
80.76
7.14
0.64
0.89
0.01
0.31
0.42
1.15
3.64
0.00
0.90
10.4
-39.5
-27.0
-25.0
0.9
W8-11
87.32
6.20
2.51
0.41
0.60
0.17
0.17
0.09
2.17
0.00
0.90
10.0
-28.6
-24.3
-23.9
1.5
WB6-19
86.33
6.28
0.62
0.72
0.01
0.21
0.28
0.00
1.42
0.00
0.91
12.5
-42.1
-26.1
-24.2
0.8
Z11-33-5
88.05
5.24
2.35
0.46
0.74
0.27
0.28
0.05
2.47
0.00
0.90
11.6
-34.8
-26.1
n.d.
1.0
Z11-4-45
86.63
6.18
2.61
0.43
0.70
0.21
0.23
0.14
2.47
0.00
0.89
9.9
-33.5
-25.1
-23.4
1.1
Z11-8-5
95.65
0.18
0.10
0.15
0.00
0.08
0.11
0.09
2.82
0.00
0.99
336.4
-39.1
-26.0
-25.2
0.9
Z218
67.97
14.23
7.12
1.20
2.06
0.60
0.58
2.15
3.58
0.00
0.73
3.2
-42.8
-29.4
-25.2
0.8
Z7-1-5
73.98
9.47
0.81
0.95
0.01
0.20
0.20
2.03
6.24
0.00
0.86
7.2
-42.0
-26.8
-23.6
0.8
Z7-2-3
80.87
9.62
3.33
0.48
0.80
0.21
0.23
0.71
3.47
0.00
0.85
6.2
-41.0
-27.2
-23.9
0.8
Z9-2-1
82.11
6.27
0.56
0.69
0.00
0.24
0.32
1.12
4.30
0.00
0.91
12.0
-39.2
-25.3
n.d.
0.9
ZP1
71.52
12.43
5.67
1.01
1.74
0.41
0.39
0.91
5.70
0.00
0.77
4.0
-39.4
-26.5
-23.5
0.9
ZT3
73.81
11.10
0.90
1.11
0.02
0.34
0.31
1.59
3.97
0.00
0.84
6.2
-36.8
-21.8
n.d.
0.8
Q12-H5-11
58.66
17.43
9.41
1.23
2.08
0.40
0.35
0.66
8.70
0.00
0.66
2.2
-30.6
-25.9
-23.0
1.3
N105
86.89
5.56
2.15
0.32
0.36
0.11
0.08
1.10
3.25
0.00
0.91
11.3
-33.0
-23.8
-21.8
1.1
N14
90.31
2.12
0.16
0.00
0.01
0.00
0.01
6.08
1.22
0.00
0.98
39.6
-32.1
-20.5
-20.7
1.2
N2-5
90.56
5.60
1.63
0.23
0.31
0.09
0.10
0.00
1.38
0.00
0.92
12.5
-34.3
-25.9
-23.8
1.0
Note: dryness defined as C1/(C1-C5); n.d.: not determined. (%) values of humic type gases were calculated based on the δ13C1- relationship suggested by Dai and Qi [18], ; (%) values of sapropelic-type gases were calculated according to the δ13C1- relationship suggested by Shen et al. [19], .
