0 引言
1 地质背景及计算方法
1.1 地质背景
1.2 计算方法
表1 鄂西地区不同地质埋深下的地温梯度、温度和压力Table 1 Geothermal gradient, temperature and pressure with geological depth in western Hubei |
埋深/m | 地温梯度/(oC/100 m) | 温度/K | 温度/°C | 压力/MPa |
---|---|---|---|---|
400 | 3.80 | 303.35 | 30.2 | 4 |
600 | 4.43 | 314.75 | 41.6 | 6 |
800 | 3.95 | 319.75 | 46.6 | 8 |
1 000 | 3.61 | 324.25 | 51.1 | 10 |
1 200 | 3.43 | 329.35 | 56.2 | 12 |
1 400 | 3.34 | 334.85 | 61.7 | 14 |
1 600 | 3.25 | 340.15 | 67.0 | 16 |
1 800 | 3.18 | 345.45 | 72.3 | 18 |
2 000 | 3.13 | 350.75 | 77.6 | 20 |
2 200 | 3.00 | 354.05 | 80.9 | 22 |
2 400 | 3.09 | 362.35 | 89.2 | 24 |
2 600 | 3.04 | 367.24 | 94.1 | 26 |
2 800 | 2.97 | 371.25 | 98.1 | 28 |
3 000 | 2.94 | 376.35 | 103.2 | 30 |
3 200 | 2.89 | 380.75 | 107.6 | 32 |
1.2.1 黑色页岩地质结构模型构建
1.3 黑色页岩结构模型参数评价
2 结果与讨论
2.1 页岩气在干酪根中的吸附
图3 页岩气在干酪根(a)、伊利石(b)和干酪根—伊利石中(c)的吸附量随地质埋深的变化Fig.3 The adsorption capacity of shale gas in kerogen (a), illite (b) and kerogen-illite(c) varies with geological burial depth |
表2 页岩气在干酪根中随地质埋深的吸附量、吸附热以及平均吸附能Table 2 Adsorption capacity, adsorption heat and average adsorption energy of shale gas in kerogen with geological depth |
埋深/m | 吸附量 /(m3/t) | 吸附热 /(kcal/mol) | 平均吸附能 /(kcal/mol) |
---|---|---|---|
400 | 74.82 | 5.32 | -5.36 |
600 | 75.86 | 5.33 | -5.46 |
800 | 77.56 | 5.31 | -5.65 |
1 000 | 80.66 | 5.35 | -5.13 |
1 200 | 80.97 | 5.33 | -5.32 |
1 400 | 80.89 | 5.34 | -5.40 |
1 600 | 81.87 | 5.33 | -5.40 |
1 800 | 76.60 | 5.31 | -5.43 |
2 000 | 83.81 | 5.27 | -5.18 |
2 200 | 80.81 | 5.30 | -5.16 |
2 400 | 82.03 | 5.30 | -5.36 |
2 600 | 77.30 | 5.32 | -5.39 |
2 800 | 81.84 | 5.31 | -5.20 |
3 000 | 79.73 | 5.34 | -5.13 |
3 200 | 76.21 | 5.27 | -5.50 |
2.2 页岩气在伊利石狭缝孔中的吸附
表3 页岩气在伊利石中随地质埋深的吸附量、吸附热以及平均吸附能Table 3 adsorption capacity, adsorption heat and average adsorption energy of shale gas in illite with geological depth |
埋深/m | 吸附量/(m3/t) | 吸附热/(kcal/mol) | 平均吸附能/(kcal/mol) |
---|---|---|---|
400 | 9.70 | 1.51 | -1.54 |
600 | 13.20 | 1.54 | -1.47 |
800 | 16.51 | 1.56 | -1.44 |
1 000 | 19.64 | 1.60 | -1.29 |
1 200 | 21.05 | 1.51 | -1.17 |
1 400 | 24.15 | 1.56 | -1.08 |
1 600 | 26.04 | 1.53 | -1.04 |
1 800 | 29.62 | 1.60 | -0.99 |
2 000 | 30.58 | 1.58 | -0.97 |
2 200 | 30.76 | 1.50 | -0.84 |
2 400 | 33.46 | 1.58 | -0.86 |
2 600 | 34.10 | 1.55 | -0.83 |
2 800 | 35.80 | 1.55 | -0.84 |
3 000 | 37.84 | 1.59 | -0.87 |
3 200 | 38.52 | 1.56 | -0.76 |
2.3 页岩气在干酪根—伊利石狭缝孔中的吸附
表4 页岩气在干酪根—伊利石中随地质埋深的吸附量、吸附热以及平均吸附能Table 4 Adsorption capacity, adsorption heat and average adsorption energy of shale gas in kerogen-illite with geological burial depth |
埋深/m | 吸附量 /(m3/t) | 吸附热 /(kcal/mol) | 平均吸附能 /(kcal/mol) |
---|---|---|---|
400 | 10.22 | 1.98 | -2.08 |
600 | 13.29 | 1.84 | -1.62 |
800 | 16.07 | 1.88 | -1.66 |
1 000 | 19.18 | 1.92 | -1.47 |
1 200 | 20.71 | 1.87 | -1.47 |
1 400 | 22.88 | 1.84 | -1.35 |
1 600 | 24.23 | 1.85 | -1.22 |
1 800 | 25.61 | 1.85 | -1.29 |
2 000 | 27.75 | 1.85 | -1.28 |
2 200 | 29.86 | 1.88 | -1.30 |
2 400 | 31.05 | 1.86 | -1.16 |
2 600 | 31.43 | 1.79 | -1.02 |
2 800 | 32.22 | 1.86 | -1.17 |
3 000 | 32.97 | 1.83 | -1.16 |
3 200 | 34.55 | 1.83 | -1.22 |
2.4 页岩气在不同孔隙含水率的干酪根—伊利石复合模型中的吸附
2.4.1 含孔隙水的黑色页岩地质结构模型的构建
2.4.2 页岩气在孔隙含水率为10%和20%的干酪根-伊利石复合模型中吸附
图10 页岩气在孔隙含水率为10%的干酪根—伊利石复合模型中随地质埋深的最优吸附构型Fig. 10 Optimal adsorption configuration of shale gas with geological burial depth in a kerogen-illite composite model with a 10% pore water content |
表5 页岩气在孔隙含水率为10%、20%的干酪根—伊利石复合模型中随地质埋深的吸附量、吸附热以及平均吸附能Table 5 Adsorption capacity, adsorption heat and average adsorption energy of shale gas with geological burial depth in the kerogen-illite composite model with pore water content of 10% and 20% |
埋深 /m | 吸附量/(m3/t) | 吸附热/(kcal/mol) | 平均吸附能/(kcal/mol) | |||
---|---|---|---|---|---|---|
10% | 20% | 10% | 20% | 10% | 20% | |
400 | 2.035 | 0.015 | 0.590 | 1.579 | -0.81 | -34.57 |
600 | 2.914 | 0.011 | 0.611 | 1.590 | -0.68 | -70.17 |
800 | 3.769 | 0.015 | 0.634 | 1.691 | -0.52 | -37.30 |
1 000 | 4.834 | 0.014 | 0.691 | 1.697 | -0.42 | -49.89 |
1 200 | 5.562 | 0.029 | 0.702 | 1.832 | -0.40 | -23.08 |
1 400 | 6.451 | 0.020 | 0.738 | 1.540 | -0.38 | -33.21 |
1 600 | 7.099 | 0.024 | 0.743 | 1.595 | -0.27 | -22.11 |
1 800 | 7.563 | 0.012 | 0.781 | 1.616 | -0.32 | -43.53 |
2 000 | 8.495 | 0.012 | 0.813 | 1.398 | -0.32 | -46.37 |
2 200 | 9.439 | 0.042 | 0.879 | 1.736 | -0.36 | -22.71 |
2 400 | 9.756 | 0.056 | 0.881 | 1.578 | -0.29 | -13.74 |
2 600 | 10.258 | 0.040 | 0.871 | 1.572 | -0.25 | -14.05 |
2 800 | 10.756 | 0.034 | 0.915 | 1.645 | -0.37 | -15.40 |
3 000 | 11.436 | 0.021 | 0.939 | 1.258 | -0.30 | -21.17 |
3 200 | 12.303 | 0.041 | 0.982 | 0.982 | -0.29 | -13.42 |