煤的吸附能力是决定煤层含气量大小和煤层气开发潜力的重要储层参数。通过对沁南–夏店区块二叠系山西组3号煤层72个煤样进行等温吸附实验，剖析了3号煤层煤的吸附性能，建立了基于 Langmuir方程的煤层含气量预测方法，揭示了研究区3号煤层煤的吸附性能及含气量分布。研究结果表明，沁南–夏店区块3号煤层主要为贫煤和无烟煤，煤的空气干燥基 Langmuir 体积为18.15~34.75 m3/t，平均29.36 m3/t；Langmuir 压力为1.47~2.71 MPa，平均2.03 MPa；煤储层压力梯度0.11~1.06 MPa/hm，平均0.49 MPa/hm，煤储层压力随着煤层埋藏深度的增加而增高；煤层含气饱和度整体呈欠饱和状态。通过预测模型预测研究区3号煤层含气量2.87~24.63 m3/t，平均13.78 m3/t，且随着埋藏深度的增加而增高，其含气量相对沁水盆地南部偏低。煤储层含气量分布主要受控于本区煤层生气、储气和保存等因素。%Adsorption capacity of coal is a significant parameter for gas-bearing measurement and development potential of coal reservoir.the content prediction method of coal bed methane (CBM) based on Langmuir equation was established, Ad-sorption capacity and gas content distribution in coal seam No.3 reservoir in the study area was revealed. It is shown that the main coal type of No.3 coal seam in target area are meagre coal and anthracite coal. The Langmuir volume of air dried coal samples is between 18.15 m3/t and 34.75m3/t, with a mean value of 29.36 m3/t; Langmuir pressure is between 1.47 MPa and 2.71MPa, with a 2.03 MPa mean value. The pressure gradient of coal reservoir is between 0.11MPa/100 m and 1.06 MPa/100 m, with a mean value of 0.49 MPa/100 m. The pressure of coal reservoir increase with burial deepth; and gas saturation of coalbed is under-saturation. According to Langmuir equation, the content prediction method of coal bed meth-ane (CBM) was established, and the gas content in coal seam No.3 reservoir in the study area was predicted. The result show that, the gas content in coal seam No.3 reservoir in the study area is between 2.87 m3/t and 24.63 m3/t, with a mean value of 13.78 m3/t, the gas content increases with burial deepth and it is lower than southern Qinshui Basin. The gas content distribu-tion of coal reservoir is mainly controlled by generating, storing and preserving.
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