An enhanced coalbed methane recovery technique based on CO2 phase transition jet coal-breaking behavior

Bai, Xin; Zhang, Dongming; Zeng, Sheng; Zhang, Shuwen; Wang, Dengke; Wang, Fulin

doi:10.1016/j.fuel.2019.116912

Cited by 41 publications

(17 citation statements)

References 39 publications

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“…The size of the dry ice fracturing cylinder in the H1 and H2 drilling holes used in this time is Φ100*600 mm and Φ100*400 mm respectively, and the fracture pressure obtained through the laboratory test is 60MPa.The energy calculation of CO2 phase transformation cracking in the application of coal seam gas [39,40], gas extraction [41], and exploration source are all calculated by the following equations [42]:…”

Section: Analysis and Discussionmentioning

confidence: 99%

Vibration Effect Induced by Rock Breaking Technology Based on Dry Ice and Energy-gathered Agent in Trench Excavation

et al. 2022

J. Phys.: Conf. Ser.

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Rock breaking technology based on dry ice and energy-gathered agent has been developed and successfully applied in trench excavation for construction of oil pipeline. The vibration velocity waveform induced by this technology was monitored in site test to determine the attenuation law of vibration velocity with hypocentral distance. The results show that this rock breaking technology is effective method of trench excavation. It does not excessively damage the adjacent rock mass, ensuring the integrity of ditch walls. The vibration velocity induced by this technology is decay with the increase of hypocentral distance. At the hypocentral distance of 10m, the vibration velocity reduces to less than 20mm/s, which meets the requirements of the safety standard of blasting vibration in general buildings engineering. The results of this experiment have an important guiding effect on the field engineering practice and application of rock breaking technology based on dry ice and energy-gathered agent.

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Section: Analysis and Discussionmentioning

confidence: 99%

Vibration Effect Induced by Rock Breaking Technology Based on Dry Ice and Energy-gathered Agent in Trench Excavation

et al. 2022

J. Phys.: Conf. Ser.

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“…Literature [32] discusses the coupling relationship between fractures in overlying strata and gas seepage fields for pressure relief during mining of outburst-prone coal seam groups to quantitatively characterize the distribution characteristics of favorable areas for coalbed methane (CBM) drainage in mining-induced fractures of overlying strata. And literature [33] bases on the production experience of coal mines and the summaries of experts; a production deployment evaluation system with eleven indices for outburst-prone coal mines is established; CO 2 phase change fracturing and permeability enhancement technology is to inject high concentration of CO 2 into the body by high pressure to achieve phase change fracturing of broken coal-rock mass, thus increasing the permeability of coal and rock [34][35][36]. Deep hole blasting fracturing and permeability-increasing technology is to produce explosion shock wave in the borehole to fracture surrounding coal and rock, so as to achieve the purpose of permeability enhancement [37,38].…”

Section: Introductionmentioning

confidence: 99%

Permeability Enhancement Technology for Soft and Low-Permeability Coal Seams Combined with Hydraulic Perforation and Hydraulic Fracturing

et al. 2022

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The No. 21 coal seam in the Zhengzhou mining area is a soft, three-layer, low-permeability coal seam prone to outbursts. The three-layer structure includes the coal seam and the roof and floor layers, which exhibit high gas contents and poor permeability. The dynamic hazards caused by coal and gas outbursts are very serious. A new permeability-increasing fracturing technique that combines hydraulic perforation and hydraulic fracturing was developed specifically for the geologic conditions of the gas-bearing No. 21 coal seam. Numerical simulations were developed to study the influence of the technique on the stress distribution and permeability of the coal around the borehole. In addition, the extracted borehole gas concentrations and extraction amounts at multiple sites were investigated before and after using the technique. The study shows that the permeability-increasing fracturing technique destroys the concentrated stress coal pillars via the development of fractures between boreholes in exposed hydraulically perforated coal. The coal stress within the zone with an effective increase in permeability decreased by 30%. Furthermore, the permeability in this zone increased by three times, and the average extracted gas concentration increased by over six times. The gas pressure in the No. 21 coal seam decreased from 1.1 MPa to 0.4 MPa, and the gas content decreased from 15.96 m3/t to 5.6 m3/t. All outburst prediction indexes measured on site did not exceed their respective limits. The technique not only effectively eliminated the dynamic hazards caused by coal and gas outbursts but also achieved efficient gas extraction in the Zhengzhou mining area.

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“…Gas injection was found to significantly improve the recovery rate of CH 4 through a comparison of the emission and natural desorption rates [24][25][26]. After injecting CO 2 into coal, the changes in the coal seam gas pressure and permeability were studied, and the key parameters in the process of methane replacement were obtained [27,28]. The injection of CO 2 , N 2 , and mixed gas for the enhanced coalbed methane recovery was also studied.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study of CO2-ECBM by Injection Liquid CO2

et al. 2022

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Coal mine gas disasters have severely restricted production safety. Improving gas extraction efficiency can effectively reduce disasters. Scholars have confirmed that CO2 successfully displaces coal seam CH4. This study conducted displacement and in situ experiments and compared gas drainage under different injection pressures. The displacement experiments indicated that CH4 production rates increased under increased pressures while the displacement ratios decreased. The pressure had a positive effect on sweep efficiency. The in situ experiment showed that CH4 and CO2 concentration trends in the inspection hole remained consistent. Through observing the data of the original and inspection holes, the average gas drainage concentration during low- and medium-pressure injections increased by 0.61 times and 1.17 times, respectively. The low-pressure average gas drainage scalar was increased by 1.08 times. During the medium-pressure injection, the average gas drainage purity increased by 1.94 times. The diffusion ranges of CO2 under low- and medium-pressure injections were 20–25 m and 25–30 m, respectively. The sweep efficiency of medium-pressure injection was 26% better than that of the low-pressure injection, with average pressures of 2.8 MPa and 1.4 MPa, respectively, for sweep efficiency. This study proposes an effective method for improving coal mine gas drainage efficiency.

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An enhanced coalbed methane recovery technique based on CO2 phase transition jet coal-breaking behavior

Cited by 41 publications

References 39 publications

Vibration Effect Induced by Rock Breaking Technology Based on Dry Ice and Energy-gathered Agent in Trench Excavation

Vibration Effect Induced by Rock Breaking Technology Based on Dry Ice and Energy-gathered Agent in Trench Excavation

Permeability Enhancement Technology for Soft and Low-Permeability Coal Seams Combined with Hydraulic Perforation and Hydraulic Fracturing

Experimental Study of CO2-ECBM by Injection Liquid CO2

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