Experimental research on propagation and attenuation of ultrasonic waves in water-bearing coal

Wang, Gang; Wang, Shibin; Li, Jun; Chen, XueChang; Qin, Cunli; Ju, Shuang

doi:10.1016/j.fuel.2022.124533

Cited by 6 publications

(2 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Before calculating the ultrasonic velocity, it is necessary to calibrate the arrival time of the received ultrasonic signal. Then according to the ultrasonic time difference formula, the ultrasonic velocity of the sample during loading is calculated [ 35 ]: Where V p is the test of ultrasonic velocity, m/s; D is the distance of ultrasonic propagation in the sample, which is the length of the sample, m; Δt is time difference, Δt = t 1 - t 0 , s。…”

Section: Theorymentioning

confidence: 99%

See 1 more Smart Citation

Ultrasonic characteristics and equivalent crack width of coal and rock bodies around boreholes during progressive failure

Zhang

et al. 2023

PLoS ONE

View full text Add to dashboard Cite

The ultrasonic characteristics of the coal and rock bodies around boreholes during failure are closely related to the crack propagation law. To investigate the ultrasonic characteristics and crack propagation law of coal and rock bodies around boreholes, different grouting samples with boreholes were taken to carry out ultrasonic test during progressive failure. The ultrasonic amplitude, velocity and attenuation coefficient of the samples were analyzed. According to the ultrasonic time difference formula, the equivalent crack width of the sample during the failure process is calculated. The influence of grouting material on the crack propagation law is quantitatively analyzed. The results show that: (1) The peak stress, elastic energy at the peak, ultrasonic parameters and crack propagation of the coal and rock bodies around boreholes show obvious differences influenced by the strength of the grouting material. (2) During the loading process, the arrival time of the first wave of the sample with holes is 5μs later than that of the grouting sample, and the ultrasonic energy attenuates fastest in the time domain, and the coda wave is not developed. (3) During the progressive failure, the ultrasonic velocity and attenuation coefficient of all show three stages of stability(0~0.6σp), slow change(0.6σp~0.8σp) and rapid change(0.8σp~1.0σp). According to the "sudden decrease" of velocity and the "sudden increase" of attenuation coefficient to judge the crack propagation of sample. (4) The equivalent crack width of the sample increases exponentially with the increase of stress level. At the time of reaching the peak stress, the equivalent crack width of SH-BH increases about 0.027mm~0.032mm, SH-PU about 0.01mm~0.014mm, and SH-CEM about 0.002mm~0.006mm.

show abstract

Section: Theorymentioning

confidence: 99%

Section: Theorymentioning

confidence: 99%

Ultrasonic characteristics and equivalent crack width of coal and rock bodies around boreholes during progressive failure

Zhang

et al. 2023

PLoS ONE

View full text Add to dashboard Cite

show abstract

Influence of microwave-assisted oxidant stimulation on pore structure and fractal characteristics of bituminous coal based on low-temperature nitrogen adsorption

Li²,

Lü³

et al. 2022

Fuel

View full text Add to dashboard Cite

Response Patterns of Acoustic Wave Characteristics to Reservoir Petrophysical Parameters in Different Bedding Directions: A Case Study of Low- and Middle-Rank Coals in Xinjiang, China

Du,

Jia,

Wang

et al. 2024

ACS Omega

View full text Add to dashboard Cite

The physical properties of coal reservoirs, important parameters for evaluating the production potential of coalbed methane (CBM) resources, can be assessed nondestructively and in real-time using acoustic wave technology. In this study, we collected 48 low-and middle-rank coal samples oriented in different bedding directions from seven typical coal mines, encompassing the Zhunan, Tuha, and Kuqa-Bay coalfields in Xinjiang, China. We clarified the characteristics of the physical parameters (apparent density, fracture, porosity, and permeability) and acoustic wave of coal variations through acoustic wave, porosity, and permeability experiments, revealing the response law of acoustic wave characteristics to the physical parameters of coal. The results indicated that the acoustic wave velocity and dynamic elastic modulus (E d ) of coal samples oriented in the perpendicular bedding direction are larger than those oriented in the parallel bedding direction; however, the dynamic Poisson's ratio (μ d ) of coal samples oriented in different bedding directions does not significantly differ. The existence of fractures significantly reduces the acoustic wave velocity and E d of the coal. The greater the apparent density of coal, the tighter its structure, resulting in a faster acoustic wave velocity. The larger the porosity of coal, the greater its internal voids, leading to a more pronounced attenuation of acoustic energy and a slower acoustic wave velocity. The more developed and interconnected the bedding fractures of coal bodies oriented in the parallel bedding direction, the higher their permeability, resulting in a smaller decrease in acoustic wave velocity. Conversely, the more developed the bedding fractures of coal bodies oriented in the perpendicular bedding direction, the more pronounced their attenuation of acoustic wave velocity. Finally, the regression equations for E d with the square of P-wave velocity (V P 2 ) and μ d with the square ratio of V P to S-wave velocity (V P 2 /V S 2 ) were established for coal. The study findings can help evaluate and predict the reservoir quality of coal seams, assess CBM, and improve the safety and efficiency of its extraction.

show abstract

Experimental research on propagation and attenuation of ultrasonic waves in water-bearing coal

Cited by 6 publications

References 43 publications

Ultrasonic characteristics and equivalent crack width of coal and rock bodies around boreholes during progressive failure

Ultrasonic characteristics and equivalent crack width of coal and rock bodies around boreholes during progressive failure

Influence of microwave-assisted oxidant stimulation on pore structure and fractal characteristics of bituminous coal based on low-temperature nitrogen adsorption

Response Patterns of Acoustic Wave Characteristics to Reservoir Petrophysical Parameters in Different Bedding Directions: A Case Study of Low- and Middle-Rank Coals in Xinjiang, China

Contact Info

Product

Resources

About