Swelling Measurements of a Low Rank Coal in Supercritical CO 2
Swelling Measurements of a Low Rank Coal in Supercritical CO 2
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DOI：
10.4236/ijg.2013.45080
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发表时间：
2013-07
期刊：
影响因子：
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通讯作者：
F. Anggara;K. Sasaki;Y. Sugai
中科院分区：
文献类型：
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作者：
F. Anggara;K. Sasaki;Y. Sugai
煤在水和二氧化碳存在下膨胀是一种众所周知的现象，这可能会影响煤的渗透性。量化膨胀效应正在成为验证特定煤层是否适合二氧化碳强化煤层气回收项目的一个重要问题。在本报告中，利用可视化方法在二氧化碳超临界条件下对碎煤样品进行了煤膨胀实验。该测量装置是专门为目前的溶胀实验而设计的，使用可视化方法。使用碎煤样代替块煤样，以缩短平衡时间并解决核心煤样可用性有限的问题。实验中使用了干煤和湿煤样品，因为关于 CO2 煤的膨胀如何受水饱和度影响的信息相对有限。此外，一些煤层在初始储层条件下是含水饱和的。对于干样品，在 10 MPa 下，最大体积膨胀约为 3%，而在相同压力下，湿样品的最大体积膨胀几乎是其一半。湿煤样表现出比干煤样更低的体积膨胀，因为湿煤样已经被水膨胀。获得的膨胀实验结果与其他报告相当。与使用块状样品测量煤膨胀的其他方法相比，我们使用破碎样品的可视化方法在样品制备和实验执行方面具有优势。
Coal swelling in the presence of water as well as CO2 is a well-known phenomenon, and these may affect the permeability of coal. Quantifying swelling effects is becoming an important issue to verify the suitability of particular coal seams for CO2-enhanced coal bed methane recovery projects. In this report, coal swelling experiments using a visualization method in the CO2 supercritical conditions were conducted on crushed coal samples. The measurement apparatus was designed specifically for the present swelling experiment using a visualization method. Crushed coal samples were used instead of block coal samples to shorten equilibrium time and to solve the problem of limited availability of core coal samples. Dry and wet coal samples were used in the experiments because there is relatively limited information about how the swelling of coal by CO2 is affected by water saturation. Moreover, some coal seams are saturated with water in initial reservoir conditions. The maximum volumetric swelling was around 3% at 10 MPa for dry samples and almost half that at the same pressure for wet samples. The wet samples showed lower volumetric swelling than dry ones because the wet coal samples were already swollen by water. Experimental results obtained for swelling were comparable with other reports. Our visualization method using crushed samples has advantages in terms of sample preparation and experimental execution compared with the other methods used to measure coal swelling using block samples.