CO2相态变化致裂对煤层吸附性影响机理研究

doi:10.13809/j.cnki.cn32-1825/te.2024.06.019

Abstract

Abstract:

Liquid CO₂ phase transition fracturing（LCPTF） technology is a novel water-free fracturing technique that can enhance coalbed methane recovery. To study the changes in coal adsorption characteristics before and after CO₂ phase transition fracturing, the No. 3 coal seam from the Yuwu coal mine was selected for experimentation. High-pressure mercury intrusion, low-temperature liquid nitrogen adsorption experiments, and CH₄ isothermal adsorption tests were conducted to analyze the impact of liquid CO₂ phase transition fracturing on coal adsorption. The results showed that after liquid CO₂ phase transition fracturing, the pore volume and specific surface area of adsorption pores in coal decreased; the specific surface area of seepage pores decreased while the pore volume of seepage pores increased. The liquid CO₂ phase transition fracturing technique could influence the change in the Langmuir adsorption constant of coal by altering the pore structure. After liquid CO₂ phase transition fracturing, the Langmuir adsorption constant “a” value decreased and the “b” value increased, indicating that the fracturing process reduced the coal’s adsorption capacity and enhanced the desorption rate. This study provides theoretical guidance for the improvement and optimization of liquid CO₂ phase transition fracturing technology for field applications.

Key words: coalbed methane, adsorption, pore structure of coal, liquid CO₂ phase transition fracturing, free gas

CLC Number:

TE372

WANG Zhijian. Mechanism study on effect of CO₂ phase transition fracturing on methane adsorption in coal[J]. Petroleum Reservoir Evaluation and Development, 2024, 14(6): 967-974.

Figures/Tables 13

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References 22

[1]	MOORE T A. Coalbed methane: A review[J]. International Journal of Coal Geology, 2012, 101, 36-81.
[2]	MASTALERZ M, DROBNIAK A. Coalbed methane: Reserves, production, and future outlook[J]. In Future Energy, 2020: 97-109.
[3]	CHENG Y P, PAN Z J. Reservoir properties of Chinese tectonic coal: A review[J]. Fuel, 2020, 260: 116350.
[4]	PAN Z J, CONNELL L D, CAMILLERI M. Laboratory characterisation of coal reservoir permeability for primary and enhanced coalbed methane recovery[J]. International Journal of Coal Geology, 2010, 82(3-4): 252-261.
[5]	XIAN B A, LIU G F, BI Y S, et al. Coalbed methane recovery enhanced by screen pipe completion and jet flow washing of horizontal well double tubular strings[J]. Journal of Natural Gas Science and Engineering, 2022, 99: 104430.
[6]	HU G Z, HE W R, SUN M. Enhancing coal seam gas using liquid CO₂ phase-transition blasting with cross-measure borehole[J]. Journal of Natural Gas Science and Engineering, 2018, 60: 164-173.
[7]	LIU X F, NIE B S, GUO K Y, et al. Permeability enhancement and porosity change of coal by liquid carbon dioxide phase change fracturing[J]. Engineering Geology, 2021, 287: 106-107.
[8]	LIU H, LIU G F, ZHANG Z, et al. Effects of liquid CO₂ phase transition fracturing on mesopores and micropores in coal[J]. Energy & Fuels, 2022, 36(17): 10016-10025.
[9]	FAN S X, ZHANG D, WEN H, et al. Enhancing coalbed methane recovery with liquid CO₂ fracturing in underground coal mine: From experiment to field application[J]. Fuel, 2021, 290: 119793.
[10]	WANG H D, CHENG Z H, ZOU Q L, et al. Elimination of coal and gas outburst risk of an outburst-prone coal seam using controllable liquid CO₂ phase transition fracturing[J]. Fuel, 2021, 284: 119091.
[11]	CAO Y X, ZHANG J S, ZHANG X S, et al. Micro-fractures in coal induced by high pressure CO₂ gas fracturing[J]. Fuel, 2022, 311: 122-148.
[12]	YAO Y B, LIU D M. Developing features of fissure system in Henan coal reserves seams and research on mining of coal bed methane[J]. Coal Science and Technology, 2006, 34(3): 64-68.
[13]	ZHOU D, WU C F, SONG Y, et al. Evolution characteristic and implication of coalbed methane desorption stages division for tectonically deformed coals[J]. Transport in Porous Media, 2022, 141(3): 713-736.
[14]	YAO Y B, LIU D M, TANG D Z, et al. Fractal characterization of adsorption-pores of coals from North China: An investigation on CH₄ adsorption capacity of coals[J]. International Journal of Coal Geology, 2008, 73(1): 27-42.
[15]	YAO Y B, LIU D M, TANG D Z, et al. Fractal characterization of seepage-pores of coals from China: An investigation on permeability of coals[J]. Computers & Geosciences, 2009, 35(6): 1159-1166.
[16]	张震, 刘高峰, 李宝林, 等. CO₂相变致裂煤的纳米孔隙尺度改造效应[J]. 岩石力学与工程学报, 2023, 42(3):672-684.
	ZHANG Zhen, LIU Gaofeng, LI Baolin, et al. Transformed effect of nano-pores in coal by CO₂phase transition fracturing[J]. Chinese Journal of Rock Mechanics and Engineering, 2023, 42(3):672-684.
[17]	LIU G F, LI B L, ZHANG Z, et al. Effects of Liquid CO₂ phase transition fracturing on methane adsorption of coal[J]. Energy & Fuels, 2023, 37(3): 1949-1961.
[18]	王汉鹏, 张冰, 袁亮, 等. 吸附瓦斯含量对煤与瓦斯突出的影响与能量分析[J]. 岩石力学与工程学报, 2017, 36(10):2449-2456.
	WANG Hanpeng, ZHANG Bing, YUAN Liang, et al. Influence of adsorption gas content on coal and gas outburst and energy analysis[J]. Chinese Journal of Rock Mechanics and Engineering, 2017, 36(10): 2449-2456.
[19]	ZOU Q L, LIN B Q, LIU T, et al. Variation of methane adsorption property of coal after the treatment of hydraulic slotting and methane pre-drainage: A case study[J]. Journal of Natural Gas Science and Engineering 2014, 20(20): 396-406.
[20]	PONGTORN C, SAYEED A M, ROBERT L R, et al. Modeling the temperature dependence of supercritical gas adsorption on activated carbons, coals and shales[J]. International Journal of Coal Geology 2015, 138: 113-126.
[21]	MASTALERZ M, DROBNIAK A, DARIUSZ S, et al. Variations in pore characteristics in high volatile bituminous coals: Implications for coal bed gas content[J]. International Journal of Coal Geology 2008, 76(3): 205-216.
[22]	刘高峰, 李宝林, 张震, 等. 不同变质煤的瓦斯膨胀能演化特征及其突出预测启示[J]. 煤田地质与勘探, 2023, 51(10):1-8.
	LIU Gaofeng, LI Baolin, ZHANG Zhen, et al. Gas expansion energy of coals with different metamorphic degrees: Evolutionary characteristics and their implications for the outburst prediction[J]. Coal Geology & Exploration, 2023, 51(10): 1-8.

煤样	工业分析/%			R_max/%
煤样	M_ad	A_ad	V_daf	R_max/%
原煤	0.89	13.19	11.20	2.20

样品	a/(cm³/g)	a均值/(cm³/g)	a均值的变化率/%	b/(MPa^-1)	b均值/(MPa^-1)	b均值的变化率/%
YW-R1	24.062 8	24.622 35	-25.45	0.828 6	0.839 5	43.24
YW-R2	25.181 9	24.622 35		0.850 4	0.839 5
YW-F1	18.908 5	18.354 95		1.133 9	1.202 5
YW-F2	17.801 4	18.354 95		1.271 1	1.202 5

样品	渗流孔孔容/(cm³/g)	渗流孔孔比表面积/（m²/g）
YW-R1	0.050 7	0.048 4
YW-R2	0.046 9	0.043 5
YW-F1	0.061 8	0.027 3
YW-F2	0.058 1	0.021 4

样品	孔容/(cm³/g)	孔比表面积/（m²/g）	平均孔径/nm
YW-R1	0.000 915	0.483 97	14.78
YW-R2	0.000 883	0.572 76	15.12
YW-F1	0.000 600	0.216 40	16.46
YW-F2	0.000 593	0.321 12	16.88

Mechanism study on effect of CO₂ phase transition fracturing on methane adsorption in coal

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Mechanism study on effect of CO2 phase transition fracturing on methane adsorption in coal

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Mechanism study on effect of CO₂ phase transition fracturing on methane adsorption in coal