0 引言
1 地质背景
2 烃源岩地球化学特征
2.1 样品实验信息
2.2 有机质丰度
表1 鄂尔多斯盆地东南部上古生界煤系烃源岩有机质丰度数据Table 1 Organic matter abundance of Upper Paleozoic coal measure source rocks in southeastern Ordos Basin |
层位 | 岩性 | TOC/% | (S 1+S 2)/(mg/g) |
---|---|---|---|
山西组 | 煤层 | 19.9 | 2.5 |
78 | 13.01 | ||
68.2 | 10.72 | ||
29.3 | 5.14 | ||
炭质泥岩 | 11.1 | 1.22 | |
13.5 | 1.83 | ||
7.77 | 0.62 | ||
暗色泥岩 | 3 | 0.44 | |
1.85 | 0.31 | ||
3.24 | 0.52 | ||
2.37 | 0.43 | ||
5.89 | 0.47 | ||
2.33 | 0.45 | ||
4.03 | 0.37 | ||
1.71 | 0.37 | ||
2.62 | 0.4 | ||
0.38 | 0.26 | ||
0.38 | 0.18 | ||
0.43 | 0.26 | ||
0.17 | 0.31 | ||
太原组 | 煤层 | 63 | 9.08 |
60 | 7.11 | ||
48.1 | 2.66 | ||
炭质泥岩 | 6.87 | 0.54 | |
暗色泥岩 | 2.25 | 0.42 | |
1.68 | 0.53 | ||
3.07 | 0.34 | ||
3.95 | 0.39 | ||
本溪组 | 煤层 | 73.3 | 12.99 |
47.3 | 5.60 | ||
66.6 | 7.52 | ||
炭质泥岩 | 25.3 | 1.87 | |
暗色泥岩 | 4.7 | 0.58 |
2.3 有机质类型
2.3.1 干酪根有机质显微组成
表2 鄂尔多斯盆地东南部上古生界煤系烃源岩干酪根显微组成分析数据Table 2 Microscopic composition analysis of kerogen of Upper Paleozoic coal measure source rocks in the southeastern Ordos Basin |
层位 | 岩性 | 腐泥组 | 壳质组 | 镜质组 | 惰质组 | 干酪根类型指数 | 有机质类型 |
---|---|---|---|---|---|---|---|
山西组 | 煤层 | 80 | 20 | -80 | Ⅲ | ||
80 | 20 | -80 | Ⅲ | ||||
80 | 20 | -80 | Ⅲ | ||||
81 | 19 | -79 | Ⅲ | ||||
炭质泥岩 | 48 | 38 | 14 | -18 | Ⅲ | ||
89 | 8 | 3 | 35 | Ⅱ2 | |||
68 | 22 | 10 | 7 | Ⅱ2 | |||
暗色泥岩 | 79 | 15 | 6 | 22 | Ⅱ2 | ||
90 | 7 | 3 | 37 | Ⅱ2 | |||
48 | 38 | 14 | -18 | Ⅲ | |||
72 | 18 | 10 | 12 | Ⅱ2 | |||
52 | 36 | 12 | -13 | Ⅲ | |||
86 | 9 | 5 | 31 | Ⅱ2 | |||
89 | 8 | 3 | 35 | Ⅱ2 | |||
91 | 6 | 3 | 38 | Ⅱ2 | |||
61 | 26 | 13 | -2 | Ⅲ | |||
88 | 8 | 4 | 34 | Ⅱ2 | |||
94 | 4 | 2 | 42 | Ⅱ1 | |||
75 | 18 | 7 | 17 | Ⅱ2 | |||
78 | 15 | 7 | 21 | Ⅱ2 | |||
太原组 | 煤层 | 80 | 20 | -80 | Ⅲ | ||
75 | 25 | -81 | Ⅲ | ||||
82 | 18 | -79 | Ⅲ | ||||
炭质泥岩 | 34 | 46 | 20 | -37 | Ⅲ | ||
暗色泥岩 | 63 | 25 | 12 | 1 | Ⅱ2 | ||
78 | 15 | 7 | 21 | Ⅱ2 | |||
63 | 25 | 12 | 1 | Ⅱ2 | |||
57 | 29 | 14 | -7 | Ⅲ | |||
本溪组 | 煤层 | 83 | 17 | -79 | Ⅲ | ||
78 | 22 | -81 | Ⅲ | ||||
79 | 21 | -80 | Ⅲ | ||||
炭质泥岩 | 24 | 58 | 18 | -49.5 | Ⅲ | ||
暗色泥岩 | 91 | 6 | 3 | 38 | Ⅱ2 |
|
图3 鄂尔多斯盆地东南部上古生界煤系烃源岩干酪根显微组分照片(a)D11井,山西组煤,2 133 m,腐泥组+壳质组:含量0%,镜质组:含量80%, 惰质组:含量20%;(b)B1井,太原组煤,2 362 m,腐泥组+壳质组:含量0%,镜质组:含量82%,惰质组:含量18%;(c)B1井,本溪组煤,2 415.1 m,腐泥组+壳质组:含量0%,镜质组:含量78%,惰质组:含量22%;(d)D5井,山西组炭质泥岩,1 925.2 m,腐泥组+壳质组:含量89%,镜质组:含量8%,惰质组:含量3%;(e)B1井,太原组炭质泥岩,2 369.6 m,腐泥组+壳质组:含量34%,镜质组:46%,惰质组:含量20%;(f)B1井,本溪组炭质泥岩,2 409.8 m,腐泥组+壳质组:含量24%,镜质组:含量58%,惰质组:含量18%;(g)B1井,山西组暗色泥岩,2 330.1 m,腐泥组+壳质组:含量89%,镜质组:含量8%,惰质组:含量3%;(h)B1井,太原组暗色泥岩,2 364.9 m,腐泥组+壳质组:含量57%,镜质组:含量29%,惰质组:含量14%;(i)N3井,本溪组暗色泥岩,2 189.65 m,腐泥组+壳质组:含量91%,镜质组:含量6%,惰质组:含量3%;注:A为镜质体;B为壳质组 Fig.3 Photo of kerogen macerals of Upper Paleozoic source rocks in the southeastern Ordos Basin |
图4 鄂尔多斯盆地东南部上古生界煤(a)、炭质泥岩(b)和暗色泥岩(c)干酪根类型指数分布直方图和煤(d)、炭质泥岩(e)和暗色泥岩(f)干酪根稳定碳同位素(δ13C)分布直方图Fig.4 Distribution histograms of kerogen type parameters of Upper Paleozoic in the southeastern Ordos Basin, kerogen type index of coal (a), carbonaceous mudstone (b) and dark mudstone (c) and stable carbon isotope (δ13C) of coal (d), carbonaceous mudstone (e), and dark mudstone (f) |
2.3.2 干酪根碳同位素
表3 鄂尔多斯盆地东南部上古生界煤系烃源岩干酪根稳定碳同位素(δ13C)分析数据Table 3 Stable carbon isotope(δ13C) of Upper Paleozoic coal measure source rocks in the southeastern Ordos Basin |
层位 | 岩性 | 干酪根稳定碳同位素(δ13C) | 有机质类型 |
---|---|---|---|
山西组 | 煤层 | -23.7 | Ⅲ |
-23.7 | Ⅲ | ||
-24.2 | Ⅲ | ||
-24.3 | Ⅲ | ||
炭质泥岩 | -24.3 | Ⅲ | |
-24.4 | Ⅲ | ||
-24.0 | Ⅲ | ||
暗色泥岩 | -23.5 | Ⅲ | |
-23.8 | Ⅲ | ||
-23.6 | Ⅲ | ||
-23.5 | Ⅲ | ||
-23.9 | Ⅲ | ||
-24.3 | Ⅲ | ||
-23.7 | Ⅲ | ||
-24.1 | Ⅲ | ||
-24.1 | Ⅲ | ||
-23.8 | Ⅲ | ||
-23.6 | Ⅲ | ||
-26.9 | Ⅱ2 | ||
-24.9 | Ⅲ | ||
太原组 | 煤层 | -23.9 | Ⅲ |
-23.8 | Ⅲ | ||
-23.8 | Ⅲ | ||
炭质泥岩 | -23.8 | Ⅲ | |
暗色泥岩 | -25.2 | Ⅲ | |
-24.3 | Ⅲ | ||
-24.2 | Ⅲ | ||
-23.9 | Ⅲ | ||
本溪组 | 煤层 | -24.4 | Ⅲ |
-24.6 | Ⅲ | ||
-24.4 | Ⅲ | ||
炭质泥岩 | -23.9 | Ⅲ | |
暗色泥岩 | -24.4 | Ⅲ |
2.4 有机质成熟度
表4 鄂尔多斯盆地东南部上古生界煤系烃源岩有机质成熟度数据Table 4 Organic matter maturity of Upper Paleozoic coal measure source rocks in the southeastern Ordos Basin |
层位 | 岩性 | R O/% | T max/℃ |
---|---|---|---|
山西组 | 煤层 | 3.01 | 559 |
2.51 | 557 | ||
2.61 | 558 | ||
2.88 | 558 | ||
炭质泥岩 | 2.57 | 558 | |
2.32 | 556 | ||
2.85 | 559 | ||
暗色泥岩 | 2.58 | 559 | |
2.64 | 558 | ||
2.32 | 553 | ||
2.35 | 549 | ||
2.9 | 560 | ||
2.68 | 557 | ||
2.96 | 559 | ||
2.36 | 558 | ||
2.54 | 559 | ||
2.54 | 557 | ||
2.48 | 541 | ||
2.53 | 548 | ||
2.62 | 554 | ||
太原组 | 煤层 | 2.62 | 559 |
2.88 | 560 | ||
2.93 | 559 | ||
炭质泥岩 | 2.96 | 559 | |
暗色泥岩 | 2.52 | 561 | |
2.51 | 558 | ||
2.61 | 558 | ||
3.00 | 560 | ||
本溪组 | 煤层 | 2.53 | 558 |
2.97 | 560 | ||
3.11 | 560 | ||
炭质泥岩 | 2.66 | 559 | |
暗色泥岩 | 2.68 | 558 |
3 烃源岩有机碳含量(TOC)测井解释模型及厚度平面分布特征
3.1 烃源岩有机碳含量(TOC)测井解释模型
3.1.1 烃源岩测井响应特征
表5 鄂尔多斯盆地东南部上古生界煤系烃源岩多元回归有机碳含量测井解释模型Table 5 Log interpretation model of multiple regression organic carbon content of Upper Paleozoic coal source rocks in the southeastern Ordos Basin |
岩性 | 测井参数 | TOC测井解释模型 | 相关系数 | |
---|---|---|---|---|
煤 | 单参数 | AC | TOC=0.067 4×AC+48.627 | 0.72 |
GR | TOC=-0.161 2×GR+79.713 | 0.69 | ||
CNL | TOC=0.423×CNL+48.326 | 0.21 | ||
DEN | TOC=-11.709×DEN+88.495 | 0.27 | ||
双参数 | AC、GR | TOC=0.042 8×AC-0.097 07×GR+63.067 2 | 0.84 | |
三参数 | AC、GR、DEN | TOC=0.041 8×AC-0.086 32×GR-3.198 7×DEN+68.431 1 | 0.84 | |
炭质泥岩 | 单参数 | AC | TOC=0.070 8×AC-2.071 2 | 0.68 |
GR | TOC=-0.166 4×GR+39.594 | 0.17 | ||
CNL | TOC=0.288 4×CNL+4.745 2 | 0.19 | ||
DEN | TOC=-18.292×DEN+54.183 | 0.66 | ||
双参数 | AC、DEN | TOC=0.043 02×AC-10.581 4×DEN+27.304 5 | 0.75 | |
三参数 | AC、CNL、DEN | TOC=0.043 5×AC+0.067 48×CNL-9.425×DEN+21.917 53 | 0.73 | |
暗色泥岩 | 单参数 | AC | TOC=0.038 9×AC-6.543 | 0.47 |
GR | TOC=0.012 1×GR+0.633 9 | 0.10 | ||
CNL | TOC=0.082 9×CNL+0.118 7 | 0.33 | ||
DEN | TOC=-4.158 8×DEN+12.91 | 0.59 | ||
双参数 | AC、DEN | TOC=0.014 84×AC-3.112 65×DEN+6.896 74 | 0.60 | |
三参数 | AC、CNL、DEN | TOC=0.014 54×AC+0.004 31×CNL-3.018 94×DEN+6.617 2 | 0.60 |
3.1.2 多元回归有机碳含量测井解释模型
图7 鄂尔多斯盆地东南部上古生界烃源岩实测与多元回归计算TOC对比Fig.7 Comparison of TOC between measured and multiple regression calculations of Upper Paleozoic source rocks in the southeastern Ordos Basin |
表6 研究区预测TOC与实测TOC误差分析Table 6 Error analysis of predicted TOC and measured TOC of Upper Paleozoic source rocks in the southeastern Ordos Basin |
岩性 | 实测TOC/% | 预测TOC/% | 绝对误差 |
---|---|---|---|
煤 | 60.00 | 63.96 | 6.6 |
68.20 | 68.14 | 0.1 | |
63.00 | 61.68 | 2.1 | |
78.00 | 77.91 | 0.1 | |
48.10 | 46.27 | 3.8 | |
73.30 | 76.96 | 5.0 | |
66.60 | 61.65 | 7.4 | |
47.30 | 50.35 | 6.4 | |
87.00 | 77.71 | 10.7 | |
69.75 | 71.96 | 3.2 | |
71.91 | 76.57 | 6.5 | |
炭质泥岩 | 10.44 | 13.86 | 32.8 |
11.53 | 13.17 | 14.3 | |
22.32 | 18.50 | 17.1 | |
26.70 | 23.66 | 11.4 | |
26.70 | 21.76 | 18.5 | |
14.82 | 19.71 | 33.0 | |
6.87 | 9.43 | 37.3 | |
7.77 | 5.33 | 31.4 | |
13.50 | 11.07 | 18.0 | |
11.10 | 8.90 | 19.8 | |
27.60 | 25.26 | 8.5 | |
29.30 | 30.62 | 4.5 | |
暗色泥岩 | 2.62 | 2.25 | 14.0 |
1.85 | 1.67 | 9.8 | |
3.02 | 1.99 | 34.1 | |
2.37 | 1.86 | 21.6 | |
2.33 | 1.94 | 16.6 | |
2.25 | 2.56 | 13.9 | |
4.70 | 3.39 | 27.9 | |
3.07 | 2.43 | 21.0 | |
2.59 | 2.72 | 5.1 | |
1.86 | 2.01 | 7.9 | |
1.72 | 1.95 | 13.4 | |
1.59 | 1.93 | 21.0 | |
1.60 | 1.93 | 21.3 | |
1.94 | 1.90 | 1.7 | |
1.75 | 1.55 | 11.8 | |
2.90 | 1.93 | 33.3 | |
2.32 | 1.91 | 17.8 | |
2.05 | 1.94 | 5.4 | |
1.62 | 1.98 | 22.3 | |
2.07 | 2.29 | 10.9 | |
6.59 | 5.72 | 13.1 | |
6.35 | 5.71 | 10.0 | |
2.07 | 1.84 | 11.4 | |
1.53 | 1.91 | 24.8 | |
2.11 | 1.84 | 12.9 | |
1.83 | 1.94 | 6.1 | |
2.12 | 2.03 | 4.1 | |
1.56 | 1.40 | 10.3 | |
1.42 | 1.14 | 20.2 | |
0.79 | 1.09 | 38.3 | |
1.85 | 1.77 | 4.3 | |
1.86 | 1.75 | 6.1 | |
1.89 | 1.77 | 6.2 | |
2.02 | 1.89 | 6.3 | |
2.92 | 2.33 | 20.3 | |
1.80 | 2.24 | 24.8 | |
1.24 | 1.65 | 33.5 | |
2.91 | 2.60 | 10.6 |
3.2 厚度平面分布特征
4 生烃潜力
4.1 生烃强度计算
4.2 结果分析
表7 鄂尔多斯盆地东南部上古生界煤系烃源岩生烃强度Table 7 Hydrocarbon generation intensity of Upper Paleozoic coal source rocks in the southeastern Ordos Basin |
井区 | 生烃强度/(108 m3/km2) | |||
---|---|---|---|---|
煤 | 炭质泥岩 | 暗色泥岩 | 累计 | |
东区 | ||||
南区 | ||||
北区 |