0 引言
1 区域地质概况
图1 琼东南盆地(a)地理位置、(b)构造单元划分(c)样品取样位置与取样站位测井剖面和(d)综合地层柱状图(根据参考文献[17,19,21]修改)Fig.1 (a)The geographical location,(b)the structural unit division,(c)the location of samples and well logging profiles of the sampled sites and (d)the schematic stratigraphic column of the Qiongdongnan Basin(QDNB)(modified from Refs.[17,19,21]) |
2 样品与实验
2.1 实验样品
2.2 实验方法
2.2.1 TOC测定与岩石热解分析
2.2.2 可溶有机质饱和烃和芳烃馏分GC-MS分析
3 结果
3.1 基础地球化学特征
表 1 琼东南海域水合物赋存区沉积物的基础地球化学参数Table 1 Basic geochemical parameters of sediments in gas hydrates reservoirs of the QDNB |
样品编号 | 深度/mbsf | TOC/% | S 1/(mg/g) | S 2/(mg/g) | S 3/(mg/g) | T max/℃ | I H/(mg/g) | I O/(mg/g) | PI |
---|---|---|---|---|---|---|---|---|---|
W08-01 | 2.98~3.06 | 0.46* | 0.06* | 0.26* | 1.35* | 354* | 56.92* | 295.53* | 0.19* |
W08-02 | 8.90~9.00 | 0.56* | 0.06* | 0.36* | 1.46* | 366* | 64.49* | 261.55* | 0.14* |
W08-03 | 9.10~9.15 | 0.71 | 0.32 | 0.57 | 1.57 | 376 | 80.51 | 221.75 | 0.36 |
W08-04 | 18.00~18.12 | 0.66* | 0.03* | 0.17* | 1.48* | 338* | 25.76* | 224.24* | 0.15* |
W08-05 | 27.12~27.29 | 0.47* | 0.03* | 0.18* | 1.42* | 349* | 37.91* | 299.07* | 0.14* |
W08-06 | 52.98~53.05 | 0.47* | 0.06* | 0.28* | 1.31* | 362* | 60.01* | 280.75* | 0.18* |
W08-07 | 54.60~54.70 | 0.41* | 0.02* | 0.18* | 1.34* | 370* | 43.88* | 326.67* | 0.10* |
W08-08 | 63.20~63.30 | 0.43* | 0.01* | 0.13* | 1.35* | 371* | 30.42* | 315.86* | 0.07* |
W08-09 | 81.45~81.55 | 0.29* | 0.04* | 0.16* | 1.30* | 370* | 54.66* | 444.14* | 0.20* |
W08-10 | 112.2~112.25 | 0.58 | 0.12 | 0.23 | 0.74 | 359 | 39.40 | 126.78 | 0.34 |
W08-11 | 115.16~115.29 | 0.35* | 0.05* | 0.24* | 1.29* | 368* | 67.78* | 364.30* | 0.17* |
W08-12 | 145.55~145.65 | 0.36 | 0.09 | 0.16 | 0.69 | 374 | 44.26 | 190.87 | 0.36 |
W08-13 | 167.00~169.20 | 0.33* | 0.05* | 0.19* | 1.23* | 344* | 57.49* | 372.16* | 0.21* |
W09-01 | 3.21~3.27 | 0.68 | 0.00 | 0.01 | 0.94 | 381 | 2.94 | 138.05 | 0.00 |
W09-02 | 11.15~11.20 | 0.47 | 0.08 | 0.11 | 1.43 | 370 | 23.00 | 301.50 | 0.42 |
W09-03 | 16.1~16.2 | 0.47 | 0.08 | 0.00 | 0.65 | 383 | 23.19 | 138.30 | 1.00 |
W09-04 | 44.72~44.79 | 0.46 | 0.09 | 0.16 | 1.37 | 384 | 34.66 | 296.79 | 0.36 |
W09-05 | 58.42~58.50 | 0.52 | 0.07 | 0.12 | 1.00 | 374 | 23.26 | 193.84 | 0.37 |
W09-06 | 72.57~72.65 | 0.53 | 0.10 | 0.18 | 1.01 | 383 | 34.07 | 191.14 | 0.36 |
W09-07 | 101.70~101.75 | 0.45 | 0.08 | 0.12 | 1.06 | 367 | 26.46 | 233.69 | 0.40 |
W09-08 | 126.79~126.87 | 0.50 | 0.08 | 0.14 | 0.96 | 381 | 28.03 | 192.23 | 0.36 |
W09-09 | 150.50~150.55 | 0.48 | 0.06 | 0.10 | 0.75 | 381 | 21.03 | 157.70 | 0.38 |
W09-10 | 158.45~158.55 | 0.38 | 0.05 | 0.08 | 0.85 | 373 | 21.07 | 223.86 | 0.38 |
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3.2 正构烷烃和类异戊二烯烃特征
图2 琼东南海域水合物赋存区沉积物提取物中正构烷烃分布特征(m/z 85)Fig.2 Distribution of n-alkanes (m/z 85 mass fragmentograms) in saturated hydrocarbon fractions of sediment extracts in gas hydrates reservoirs of the QDNB |
表2 琼东南海域水合物赋存区沉积物提取物饱和烃气相色谱Table 2 GC of saturated hydrocarbons of sediment extracts in gas hydrates reservoirs of the QDNB |
样品编号 | 深度/mbsf | TAR | CPI | OEP1 | OEP2 | Pr/Ph | Pr/nC17 | Ph/nC18 | |
---|---|---|---|---|---|---|---|---|---|
W08-01 | 2.98~3.06 | 0.38* | 3.70 | 2.08* | 0.81 | 6.57 | 1.28* | 1.19* | 1.08* |
W08-03 | 9.10~9.15 | 0.93 | 1.70 | 3.05 | 0.74 | 6.01 | 1.11 | 0.74 | 0.66 |
W08-04 | 18.00~18.12 | 0.33* | 4.16 | 2.6* | 1.03 | 7.15 | 1.08* | 0.61* | 0.68* |
W08-06 | 52.98~53.05 | 0.26* | 5.10 | 2.37* | 0.94 | 6.29 | 1.01* | 0.81* | 0.91* |
W08-07 | 54.60~54.70 | 0.2* | 5.69 | 2.61* | 1.00 | 7.17 | 1.6* | 1.14* | 0.84* |
W08-09 | 81.45~81.55 | 0.26* | 5.50 | 2.29* | 1.00 | 6.37 | 0.86* | 0.92* | 0.99* |
W08-10 | 112.2~112.25 | 1.52 | 0.58 | 1.96 | 0.92 | 8.00 | 0.88 | 0.65 | 0.65 |
W08-11 | 115.16~115.29 | 0.17* | 1.20 | 2.82* | 0.98 | 7.50 | 0.82* | 1.13* | 1.06* |
W08-12 | 145.55~145.65 | 1.57 | 0.13 | 0.71 | 0.98 | 5.43 | 1.24 | 0.83 | 0.72 |
W09-01 | 3.21~3.27 | 0.44 | 3.41 | 3.18 | 1.12 | 6.96 | 1.00 | 0.66 | 0.57 |
W09-02 | 11.15~11.20 | 0.52 | 2.56 | 3.12 | 1.24 | 6.95 | 0.45 | 1.03 | 2.45 |
W09-03 | 16.1~16.2 | 0.43 | 3.06 | 2.93 | 1.02 | 5.77 | 1.03 | 0.73 | 0.71 |
W09-04 | 44.72~44.79 | 0.46 | 3.27 | 2.96 | 0.96 | 5.75 | 0.56 | 0.62 | 0.94 |
W09-05 | 58.42~58.50 | 0.46 | 3.07 | 3.00 | 1.13 | 6.50 | 0.93 | 0.74 | 0.61 |
W09-06 | 72.57~72.65 | 0.77 | 1.52 | 2.81 | 1.13 | 5.99 | 1.20 | 0.64 | 0.55 |
W09-07 | 101.70~101.75 | 0.35 | 1.74 | 0.75 | 1.04 | 5.59 | 1.38 | 1.12 | 0.83 |
W09-08 | 126.79~126.87 | 0.59 | 1.99 | 2.88 | 1.07 | 5.73 | 1.19 | 0.71 | 0.61 |
W09-09 | 150.50~150.55 | 0.70 | 1.58 | 1.92 | 1.00 | 2.74 | 1.16 | 0.72 | 0.66 |
W09-10 | 158.45~158.55 | 1.35 | 0.38 | 1.65 | 1.16 | 2.68 | 0.88 | 0.79 | 0.81 |
3.3 萜烷类化合物特征
表3 琼东南海域水合物赋存区沉积物提取物中萜类化合物参数Table 3 Parameters of terpenoid of sediment extracts in gas hydrates reservoirs of the QDNB |
样品编号 | 深度/mbsf | (C19+C20)TT/C23TT | C24TeT/C26TT | Ts/(Ts+Tm) | C3122S/(22S+22R) | 奥利烷/C30H | 伽马蜡烷/C30H |
---|---|---|---|---|---|---|---|
W08-01 | 2.98~3.06 | 0.13 | 1.33* | 0.82* | 0.38* | 0.14 | 0.07 |
W08-03 | 9.10~9.15 | 0.22 | 1.11 | 0.43 | 0.49 | 0.09 | 0.04 |
W08-04 | 18.00~18.12 | 0.24 | 1.98* | 0.41* | 0.51* | 0.06 | 0.12 |
W08-06 | 52.98~53.05 | 0.63 | 1.47* | 0.88* | 0.57* | 0.07 | 0.01 |
W08-07 | 54.60~54.70 | 0.45 | 1.73* | 0.68* | 0.48* | 0.11 | 0.14 |
W08-08 | 81.45~81.55 | 0.24 | 1.59* | 0.77* | 0.48* | 0.12 | 0.09 |
W08-10 | 112.2~112.25 | 0.53 | 0.67 | 0.81 | 0.51 | 0.34 | 0.00 |
W08-11 | 115.16~115.29 | 0.60 | 1.48* | 0.85* | 0.86* | 0.09 | 0.11 |
W08-12 | 145.55~145.65 | 0.66 | 0.53 | 0.43 | 0.56 | 0.11 | 0.11 |
W09-01 | 3.21~3.27 | 0.17 | 0.54 | 0.26 | 0.22 | 0.05 | 0.03 |
W09-02 | 11.15~11.20 | 0.15 | 0.75 | 0.44 | 0.33 | 0.10 | 0.05 |
W09-03 | 16.1~16.2 | 0.09 | 0.64 | 0.48 | 0.33 | 0.09 | 0.04 |
W09-04 | 44.72~44.79 | 0.12 | 0.61 | 0.39 | 0.34 | 0.05 | 0.04 |
W09-05 | 58.42~58.50 | 0.17 | 0.56 | 0.41 | 0.26 | 0.08 | 0.05 |
W09-06 | 72.57~72.65 | 0.24 | 0.82 | 0.43 | 0.35 | 0.08 | 0.08 |
W09-07 | 101.70~101.75 | 0.07 | 0.53 | 0.48 | 0.51 | 0.08 | 0.09 |
W09-08 | 126.79~126.87 | 0.21 | 0.68 | 0.43 | 0.26 | 0.09 | 0.05 |
W09-09 | 150.50~150.55 | 0.18 | 0.73 | 0.47 | 0.47 | 0.13 | 0.08 |
W09-10 | 158.45~158.55 | 0.18 | 0.53 | 0.38 | 0.28 | 0.08 | 0.08 |
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3.4 甾烷类化合物特征
表4 琼东南海域水合物赋存区沉积物提取物中甾类化合物参数Table 4 Parameters of sterane of sediment extracts in gas hydrates reservoirs of the QDNB |
样品编号 | 深度/mbsf | C27/% | C28/% | C29/% | C27规则/ C29规则 | C29ααα20S/(20S+20R) | C29αββ/(αββ+ααα) |
---|---|---|---|---|---|---|---|
W08-01 | 2.98~3.06 | 23.58 | 33.16 | 43.26 | 0.57 | 0.44* | 0.43* |
W08-03 | 9.10~9.15 | 26.66 | 23.79 | 49.55 | 0.55 | 0.39 | 0.36 |
W08-04 | 18.00~18.12 | 38.72 | 23.67 | 37.61 | 0.58 | 0.44* | 0.41* |
W08-06 | 52.98~53.05 | 38.98 | 14.28 | 46.74 | 0.63 | 0.43* | 0.36* |
W08-07 | 54.60~54.70 | 39.68 | 18.72 | 41.60 | 0.56 | 0.38* | 0.33* |
W08-09 | 81.45~81.55 | 24.52 | 8.79 | 66.69 | 0.54 | 0.38* | 0.36* |
W08-10 | 112.2~112.25 | 50.34 | 25.82 | 23.84 | 0.76 | 0.58 | 0.47 |
W08-11 | 115.16~115.29 | 29.56 | 17.70 | 52.74 | 0.39 | 0.37* | 0.35* |
W08-12 | 145.55~145.65 | 16.25 | 30.93 | 52.82 | 0.46 | 0.32 | 0.35 |
W09-01 | 3.21~3.27 | 41.03 | 20.45 | 38.52 | 0.69 | 0.39 | 0.36 |
W09-02 | 11.15~11.20 | 35.07 | 7.68 | 57.25 | 0.55 | 0.30 | 0.40 |
W09-03 | 16.1~16.2 | 26.64 | 12.34 | 61.03 | 0.55 | 0.26 | 0.42 |
W09-04 | 44.72~44.79 | 21.77 | 18.92 | 59.31 | 0.43 | 0.33 | 0.36 |
W09-05 | 58.42~58.50 | 28.05 | 11.58 | 60.36 | 0.40 | 0.30 | 0.30 |
W09-06 | 72.57~72.65 | 21.84 | 19.96 | 58.20 | 0.52 | 0.32 | 0.37 |
W09-07 | 101.70~101.75 | 34.70 | 20.15 | 45.15 | 0.84 | 0.45 | 0.45 |
W09-08 | 126.79~126.87 | 45.30 | 25.62 | 29.08 | 0.61 | 0.55 | 0.45 |
W09-09 | 150.50~150.55 | 29.78 | 18.95 | 51.27 | 0.60 | 0.41 | 0.42 |
W09-10 | 158.45~158.55 | 9.74 | 26.21 | 64.05 | 0.26 | 0.08 | 0.29 |
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3.5 芳烃化合物特征
表5 琼东南海域水合物赋存区沉积物提取物中芳烃参数Table 5 Parameters of aromatic hydrocarbon of sediment extracts in gas hydrates reservoirs of the QDNB |
样品编号 | 深度/mbsf | MPI-1 | R c/% | TNR-2 | R cb/% |
---|---|---|---|---|---|
W08-01 | 2.98~3.06 | 0.59* | 0.75* | 0.60 | 0.76 |
W08-03 | 9.10~9.15 | 0.62 | 0.77 | 0.61 | 0.77 |
W08-04 | 18.00~18.12 | 0.75* | 0.85* | 0.63 | 0.78 |
W08-06 | 52.98~53.05 | 0.76* | 0.86* | 0.62 | 0.77 |
W08-07 | 54.60~54.70 | 0.7* | 0.82* | 0.64 | 0.78 |
W08-09 | 81.45~81.55 | 0.72* | 0.83* | 0.68 | 0.81 |
W08-10 | 112.2~112.25 | 0.77 | 0.86 | 0.66 | 0.80 |
W08-11 | 115.16~115.29 | 0.79* | 0.87* | 0.65 | 0.79 |
W08-12 | 145.55~145.65 | 0.76 | 0.85 | 0.64 | 0.78 |
W09-01 | 3.21~3.27 | 0.58 | 0.75 | 0.64 | 0.78 |
W09-02 | 11.15~11.20 | 0.55 | 0.73 | 0.60 | 0.76 |
W09-03 | 16.1~16.2 | 0.69 | 0.82 | 0.55 | 0.73 |
W09-04 | 44.72~44.79 | 0.63 | 0.78 | 0.64 | 0.78 |
W09-05 | 58.42~58.50 | 0.67 | 0.80 | 0.60 | 0.76 |
W09-06 | 72.57~72.65 | 0.64 | 0.79 | 0.60 | 0.76 |
W09-07 | 101.70~101.75 | 0.46 | 0.67 | 0.60 | 0.76 |
W09-08 | 126.79~126.87 | 0.63 | 0.78 | 0.60 | 0.76 |
W09-09 | 150.50~150.55 | 0.56 | 0.74 | 0.57 | 0.74 |
W09-10 | 158.45~158.55 | 0.78 | 0.87 | 0.65 | 0.79 |
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4 讨论
4.1 有机质成熟度
4.2 有机质母质来源
4.3 沉积物中成熟有机质的来源分析
表6 琼东南海域不同层位沉积物或烃源岩部分地球化学参数Table 6 Part of organic geochemical data of different formation sediments or source rocks in the QDNB |
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