Impact of CO2 injection on wettability of coal at elevated pressure and temperature [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 553.495 Platinum metals
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of Science ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2019
• Mô tả vật lý: Size: Article No. 102840 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 267705
• Chủ đề: 1. 01 coal, lignite, and peat; 2. 54 environmental sciences; 3. Carbon dioxide; 4. Coalbed methane; 5. Wettability

Tóm tắt

 Injection of carbon dioxide (CO<
 sub>
 2<
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 ) into coal seams has been demonstrated as an effective technology for enhanced methane recovery and CO<
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 2<
 /sub>
  storage. However, the impacts of the geochemical reactions between CO<
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 2<
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  and coal on the wettability of coal pore surfaces, which influences immiscible multiphase displacement, are not yet well understood. We studied wettability alterations of coal surfaces resulting from reactions with gas, liquid and supercritical (sc)CO<
 sub>
 2<
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  under varied pressure (1?141 bar) and temperatures (?25 - 60 �C) through measuring static and dynamic contact angles with anthracite coal plates. We found that reactions with gas CO<
 sub>
 2<
 /sub>
  only slightly changed the wettability of coal surfaces from water-wet to intermediate-wet with static contact angles from ?60� to 70�-90�. However, reactions with liquid and scCO<
 sub>
 2<
 /sub>
  altered the coal surfaces to strongly CO<
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 2<
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 -wet, with the contact angles up to 115-180�. We also found that both static and dynamic contact angles increase significantly with increasing pressure. Temperature affects the contact angles reversely especially under supercritical pressure conditions. These relationships of contact angles with pressure and temperature may be explained by the CO<
 sub>
 2<
 /sub>
  density dependence on pressure and temperature.