0 前言
1 气源岩分析
Fig. 2 TOC content (a) and organic matter types (b) of shallow sediments in Baiyun Sag ( after reference [16])图2 白云凹陷浅层沉积物TOC含量(a)及有机质类型(b)(修改自文献[16]) |
2 混源天然气二元混合的碳、氢同位素模型
3 南海北部天然气水合物气源混合类型与混合比例的定量计算
3.1 端元气的选取
Table 1 Parameters of typical thermogenic gas and biogenic gas in Baiyun Sag表1 白云凹陷典型热成因气和生物成因气参数 |
盆地 | 气体类型 | 井号 | 深度 / m | δ13C1 / ‰ | C1/(C2+C3) | δDCH4 / ‰ | 备注 |
---|---|---|---|---|---|---|---|
珠江口盆地 | 热成因气 | LW3-1-1Sa | 3 067.5 ~ 3 070.0 | -37.1 | 12.2 | -158.1 | 文献[19] |
LW3-1-1 | 3 144.5 ~ 3 144.5 | -36.6 | 12.5 | -158.4 | |||
LW3-1-1Sa | 3 183.5 ~ 3 189.5 | -36.8 | 12.5 | -155.8 | |||
LW3-1-1 | 3 499.5 ~ 3 499.5 | -36.6 | 10.7 | -175.6 | |||
生物气 | PY35-2-5 | 754.0 | -68.8 | - | - | ||
PY35-2-5 | 792.0 | -69.3 | - | - | |||
PY34-1-1 | 811.0 | -61.5 | - | - | |||
PY34-1-1 | 837.0 | -63.9 | - | - | |||
PY34-1-1 | 936.0 | -58.7 | - | - | |||
PY34-1-1 | 966.0 | -62.6 | - | - |
3.2 混合类型
Table 2 Isotopic parameters of gas hydrate in Shenhu area表2 神狐海域天然气水合物气体的同位素参数 |
站位 | 深度 / m | δ13C1 / ‰ | C1/(C2+C3) | δDCH4 / ‰ | 文献 |
---|---|---|---|---|---|
SH2B | 197.5 ~ 197.9 | -56.7 | - | -199 | [26] |
SH3B | 123.0 ~ 123.8 | -62.2 | - | -225 | |
SH3B | 190.5 ~ 191.3 | -60.9 | - | -191 | |
SH5C | 114.0 ~ 114.9 | -54.1 | - | -180 | |
HS-23PC-1 | - | -57.0 | 2 185 | - | [27] |
HS-23PC-2 | - | -62.4 | 2 027 | - | |
HS-23PC-3 | - | -64.9 | 1 524 | - | |
HS-23PC-4 | - | -62.1 | 1 551 | - | |
HS-23PC-5 | - | -61.7 | 1 804 | - | |
HS-23PC-6 | - | -59.5 | 1 473 | - | |
HS-23PC-7 | - | -69.5 | 1 833 | - | |
HS-4PC-1 | - | -60.7 | 1 708 | - | |
HS-4PC-2 | - | -62.1 | 1 205 | - | |
HS-4PC-3 | - | -74.3 | 2 200 | - | |
HS-4PC-4 | - | -46.2 | 575 | - | |
HS-4PC-5 | - | -56.9 | 616 | - | |
HS-4PC-6 | - | -63.0 | 639 | - | |
HS-4PC-7 | - | -51.8 | 605 | - | |
W19-010 | 134.0 ~ 137.0 | -46.5 | - | -184 | [29] |
W19-011 | 134.0 ~ 137.0 | -46.2 | - | -168 | |
W19-012 | 134.0 ~ 137.0 | -45.5 | - | -148 |
Table 3 Ratios of mixed source gas表3 混源气的定量比例 |
站位 | 深度 / m | δ13C1 / ‰ | 成因类型 | 生物气贡献 / % | 热成因气贡献 / % |
---|---|---|---|---|---|
SH5C | 114.0 ~ 114.9 | -54.1 | 混源气 | 63 | 37 |
HS-4PC-4 | - | -46.2 | 混源气 | 34 | 66 |
HS-4PC-7 | - | -51.8 | 混源气 | 55 | 45 |
W19-010 | 134.0 ~ 137.0 | -46.5 | 混源气 | 36 | 64 |
W19-011 | 134 .0 ~ 137.0 | -46.2 | 混源气 | 35 | 65 |
W19-012 | 134.0 ~ 137.0 | -45.5 | 混源气 | 32 | 68 |