Coupled thermal?hydrological?mechanical modeling of CO ₂ -enhanced coalbed methane recovery [electronic resource]

• Ngôn ngữ: eng
• Ký hiệu phân loại: 622.3385 *Mining for specific materials
• Thông tin xuất bản: Washington, D.C. : Oak Ridge, Tenn. : United States. Office of the Assistant Secretary of Energy for Fossil Energy ; Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 2017
• Mô tả vật lý: Size: p. 81-91 : , digital, PDF file.
• Bộ sưu tập: Metadata
• ID: 267767
• Chủ đề: 1. 01 coal, lignite, and peat; 2. 58 geosciences; 3. Cbm production; 4. Co2 sequestration; 5. Coupled thm model

Tóm tắt

 CO <
 sub>
 2<
 /sub>
  -enhanced coalbed methane recovery, also known as CO <
 sub>
 2<
 /sub>
  -ECBM, is a potential win-win approach for enhanced methane production while simultaneously sequestering injected anthropogenic CO <
 sub>
 2<
 /sub>
  to decrease CO <
 sub>
 2<
 /sub>
  emissions into the atmosphere. Here, CO <
 sub>
 2<
 /sub>
  -ECBM is simulated using a coupled thermal?hydrological?mechanical (THM) numerical model that considers multiphase (gas and water) flow and solubility, multicomponent (CO<
 sub>
 2<
 /sub>
  and CH <
 sub>
 4<
 /sub>
  ) diffusion and adsorption, heat transfer and coal deformation. The coupled model is based on the TOUGH-FLAC simulator, which is applied here for the first time to model CO <
 sub>
 2<
 /sub>
  -ECBM. The capacity of the simulator for modeling methane production is verified by a code-to-code comparison with the general-purpose finite-element solver COMSOL. Then, the TOUGH-FLAC simulator is applied in an isothermal simulation to study the variations in permeability evolution during a CO <
 sub>
 2<
 /sub>
  -ECBM operation while considering four different stress-dependent permeability models that have been implemented into the simulator. Finally, the TOUGH-FLAC simulator is applied in non-isothermal simulations to model THM responses during a CO <
 sub>
 2<
 /sub>
  -ECBM operation.Our simulations show that the permeability evolution, mechanical stress, and deformation are all affected by changes in pressure, temperature and adsorption swelling, with adsorption swelling having the largest effect. The calculated stress changes do not induce any mechanical failure in the coal seam, except near the injection well in one case of a very unfavorable stress field.