Investigation of the mechanical damage of low rank coals under the impacts of cyclical liquid CO2 for coalbed methane recovery

Xu, Jizhao; Zhai, Cheng; Ranjith, P.G.; Sang, Shuxun; Cong, Yuzhou; Tang, Wei; Zheng, Yangfeng

doi:10.1016/j.energy.2021.122145

Cited by 41 publications

(15 citation statements)

References 44 publications

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“…where V 0 is the volume of the coal core under the condition coal seam reservoir, cm 3 ; M is the coal sample quality, g; ARD is the apparent relative density, g/cm 3 ; and TRD is the true relative density, g/cm 3 . The volume increase in the coal sample before and after sampling can be described using formula 2…”

Section: Determination Methods Of In Situmentioning

confidence: 99%

“…The volume of the coal core under the condition of the coal seam reservoir can be described using formula 1 (1) where V 0 is the volume of the coal core under the condition coal seam reservoir, cm 3 ; M is the coal sample quality, g; ARD is the apparent relative density, g/cm 3 ; and TRD is the true relative density, g/cm 3 .…”

Section: Determination Methods Of In Situmentioning

confidence: 99%

“…The volume increase in the coal sample before and after sampling can be described using formula 2 (2) where ΔV is the in situ volume increase in the coal sample before and after sampling, cm 3 ; V 2 is the volume of the coal sample tank, 483.364 mL; and V 1 is the volume of the pressure measuring coal sample in the coal sample tank, cm 3 .…”

Section: Determination Methods Of In Situmentioning

confidence: 99%

“…Then, the coal samples were ground and sieved by metal sifters of different sizes to a particle size of less than 3 mm. Also, according to the determination of apparent relative density of coal (GB/6949-2010), the apparent relative density (ARD) of the coal sample is 1.51 g/cm 3 .…”

Section: Determination Methods Of In Situmentioning

confidence: 99%

“…China is the world’s largest coal production and consumer. − At the same time, China is also the country with the most serious coal mine gas accidents in the world. − Among them, the proportion of outburst accident deaths in the total number of coal mine accidents gradually increases from 3.44% in 2001 to 6.58% in 2020. − It shows that gas accidents are still at a relatively high level and become more prominent in coal mine accidents. − The original gas pressure of the coal seam is one of the basic parameters for the study of the coal seam gas occurrence and emission law. − It is an important indicator of the danger degree of coal seam gas outburst and the difficulty degree of gas extraction, and it is the basis for coal seam gas prevention and control and coal seam gas extraction design. − Therefore, rapid and accurate measurement of gas pressure plays a vital role in coal mine safety production.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

In Situ Volume Recovery Method for Non-Seal Gas Pressure Measurement Technology: A Comparative Study

Hua

Wang

et al. 2022

ACS Omega

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Coal seam gas pressure is one of the basic parameters for coalbed methane resource exploitation and coal mine gas disaster prevention. However, the present coal seam gas pressure measurement technology requires harsh field measurement conditions and a long testing period. In this study, a novel non-seal gas pressure measurement technology is proposed, and this technology is mainly aimed at three different changes before and after the collection of coal samples and realizes the real gas pressure measurement through the compensation of gas leakage, in situ volume recovery of the coal core, and reservoir temperature simulation. The technique not only can measure the original gas pressure of coal seam quickly and accurately but also does not need to seal the measuring hole. This paper focuses on the study of a key factor that affects the accuracy of non-seal gas pressure measurement: the restoration of in situ volume. Based on this, the influence of four different in situ volume recovery methods on the measurement accuracy is compared with the self-developed non-sealing gas pressure measuring system. Experimental results show that the in situ volume of the coal core cannot be completely restored by stress loading. Although the contact injection method can restore the original volume of the coal core, the pressure recovery error is large due to the replacement and displacement of the gas effect of water and the inclusion of the coal body effect of oil. Interestingly, the combination of stress loading and contact oil injection can not only restore the original volume of the coal core but also minimize the pressure recovery error, which is only less than 10%. Finally, based on the abovementioned experimental results, the in situ volume recovery method of non-seal gas pressure measurement technology is improved. Therefore, the research results of this paper provide a scientific basis for the field application of non-seal gas pressure measurement technology.

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Section: Determination Methods Of In Situmentioning

confidence: 99%