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Effect of permeability and its horizontal anisotropy on enhanced coalbed methane recovery with CO2 storage: quantitative evaluation based on staged CH4 output inhibition.
- Source :
- Frontiers of Earth Science; Sep2023, Vol. 17 Issue 3, p856-866, 11p
- Publication Year :
- 2023
-
Abstract
- The permeability and its horizontal anisotropy induce a critical influence on staged CH<subscript>4</subscript> output inhibition process. However, a quantitative evaluation of this influence has been rarely reported in the literature. In this work, the impact of horizontal anisotropic permeability on CO<subscript>2</subscript>-ECBM was numerically investigated. The variation in the staged CH<subscript>4</subscript> output inhibition was analyzed. The ideal displacement profile of the CO<subscript>2</subscript>-ECBM process was established for the first time. Moreover, the variation in CH<subscript>4</subscript> output of different wellbores was discussed. The results showed that 1) low-permeable or weak-anisotropic reservoirs were not conducive to enhanced CH<subscript>4</subscript> recovery owing to long inhibition time (> 1091 days) and high inhibition level (> 36.9%). As permeability and anisotropy increased, due to the accelerated seepage of free water, the hysteresis time and inhibition time could decrease to as short as 5 days and 87 days, respectively, and the inhibition level could weaken to as low as 5.00%. Additionally, the CH<subscript>4</subscript> output and CO<subscript>2</subscript> injection could increase significantly. 2) Nevertheless, high permeability and strong anisotropy easily induced CO<subscript>2</subscript> breakthrough, resulting in lower CH<subscript>4</subscript> production, CO<subscript>2</subscript> injection and CO<subscript>2</subscript> storage than expected. While maintaining high efficiency of CO<subscript>2</subscript> storage (> 99%), upregulating CO<subscript>2</subscript> breakthrough concentration from 10% to 20% might ease the unfavorable trend. 3) Along the direction of fluid flow, the ideal displacement profile consisted of CO<subscript>2</subscript> enriched bank, CO<subscript>2</subscript> and CH<subscript>4</subscript> mixed bank, CH<subscript>4</subscript> enriched bank, and water enriched bank, whereas a remarkable gap in the displacement profiles of the dominant and non-dominant seepage directions was observed. 4) The potential of CH<subscript>4</subscript> output might vary greatly among different wellbores. The producers along the dominant seepage direction held more potential for CH<subscript>4</subscript> recovery in the short-term, while those along the non-dominant seepage direction avoided becoming invalid only if a long-time injection measure was taken for the injectors. These findings pave the way to understand fluid seepage in real complex reservoirs during CO<subscript>2</subscript>-ECBM and conduct further field projects. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 20950195
- Volume :
- 17
- Issue :
- 3
- Database :
- Complementary Index
- Journal :
- Frontiers of Earth Science
- Publication Type :
- Academic Journal
- Accession number :
- 174268264
- Full Text :
- https://doi.org/10.1007/s11707-022-1039-5