Comparison of enhanced coalbed methane recovery by pure N2 and CO2 injection: Experimental observations and numerical simulation
Comparison of enhanced coalbed methane recovery by pure N2 and CO2 injection: Experimental observations and numerical simulation
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纯 N2 与 CO2 注入提高煤层气采收率对比：实验观察与数值模拟
DOI：
10.1016/j.jngse.2015.02.002
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发表时间：
2015-03-01
影响因子：
--
通讯作者：
Chen, Haidong
中科院分区：
文献类型：
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作者：
Wang, Liguo;Wang, Zhaofeng;Chen, Haidong
提高煤层气采收率驱替模拟实验是研究煤层气驱替过程的直接手段。我们进行了两组ECBM实验注入纯N-2和CO2通过四个大的平行标本（300 × 50 × 50 mm煤柱）。在第一个实验（N-2-ECBM）中，在不同的压力下将纯N-2注入到用CH 4饱和的煤柱中，在第二个实验（CO2-ECBM）中，在相同的注入压力和不同的渗透率下将纯CO2注入到用CH 4脱气和再饱和的相同煤柱中。测量气体成分和流出速率随时间的变化。为了掌握驱替过程，我们采用了一维两相（气体和固体）模型。这与我们的实验结果是一致的。煤层渗透率显著影响CO2或N2驱CH 4的效果。在相同条件下，N2-比CO2提前出现在出口。但N2驱替时间（完全驱替CH 4）比CO2长，即煤中CH 4气体被CO2提前驱替完全。CO2-ECBM的输出流量大于N2-。由此看来，CO2作为注入剂比N-2更优越上级。(C)2015爱思唯尔B. V.保留所有权利。
Enhanced coal bed methane recovery (ECBM) displacement simulation experiments are a direct way to research on the gas displacement process. We carried out two sets of ECBM experiments by injecting pure N-2 and CO2 through four large parallel specimens (300 x 50 x 50 mm coal briquette). In the first experiment (N-2-ECBM), pure N-2 is injected at different pressures to a coal briquette saturated with CH4, in the second experiment (CO2-ECBM), pure CO2 is injected at the same injection pressures and various permeability to the same coal briquette outgassed and resaturated with CH4. The gas composition and outflow rate were measured with time. In order to master the displacement process, we employed a one-dimensional, two-phase (gas and solid) model. They are in accordance with our experimental results. Coal seam permeability significantly affects the effect of CO2 or N-2 flooding CH4. Under the same conditions, N-2 appears in the outlet in advance than CO2. But the N-2 displacement time (CH4 is completely displaced) is longer than CO2, namely CH4 gas in the coal is completely displaced by CO2 injection in advance. And flow in the output of CO2-ECBM is larger than that of N-2. judging from above, CO2 as injectant is superior to N-2. (C) 2015 Elsevier B.V. All rights reserved.