Evolution Characteristics of the Microstructure with Different Fracturing Fluids: An Experimental Study of Guizhou Bituminous Coal

Li, Liangwei; Sun, Haitao; Wu, Wenbin; Zuo, Shaojie; Sun, Peng

doi:10.1021/acsomega.3c04351

Cited by 3 publications

(1 citation statement)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Presently, acid treatment is employed to enhance pore connectivity in coal samples from low-permeability coal seams in Guizhou. Many studies have only focused on the use of a singular type of acid to investigate alterations in pore or chemical structure, while limited investigations have been conducted on the application of mixed acids for this purpose [ 38 , 39 ]. To explore the chemical and pore structure evolution of Wenjiaba tectonic coal, this study employs a mixed acid solution consisting of 15% hydrochloric acid (HCl) and 5% hydrofluoric acid (HF) for coal sample acidification.…”

Section: Introductionmentioning

confidence: 99%

Experimental research on the influence of acid on the chemical and pore structure evolution characteristics of Wenjiaba tectonic coal

Li,

et al. 2024

PLoS ONE

View full text Add to dashboard Cite

The chemical and pore structures of coal play a crucial role in determining the content of free gas in coal reservoirs. This study focuses on investigating the impact of acidification transformation on the micro-physical and chemical structure characteristics of coal samples collected from Wenjiaba No. 1 Mine in Guizhou. The research involves a semi-quantitative analysis of the chemical structure parameters and crystal structure of coal samples before and after acidification using Fourier Transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) experiments. Additionally, the evolution characteristics of the pore structure are characterized through high-pressure mercury injection (HP-MIP), low-temperature nitrogen adsorption (LT-N2A), and scanning electron microscopy (SEM). The experimental findings reveal that the acid solution modifies the structural features of coal samples, weakening certain vibrational structures and altering the chemical composition. Specifically, the asymmetric vibration structure of aliphatic CH2, the asymmetric vibration of aliphatic CH3, and the symmetric vibration of CH2 are affected. This leads to a decrease in the contents of -OH and -NH functional groups while increasing aromatic structures. The crystal structure of coal samples primarily dissolves transversely after acidification, affecting intergranular spacing and average height. Acid treatment corrodes mineral particles within coal sample cracks, augmenting porosity, average pore diameter, and the ratio of macro-pores to transitional pores. Moreover, acidification increases fracture width and texture, enhancing the connectivity of the fracture structure in coal samples. These findings provide theoretical insights for optimizing coalbed methane (CBM) extraction and gas control strategies.

show abstract

Section: Introductionmentioning

confidence: 99%

Experimental research on the influence of acid on the chemical and pore structure evolution characteristics of Wenjiaba tectonic coal

Li,

et al. 2024

PLoS ONE

View full text Add to dashboard Cite

show abstract

LNMR analysis of the retention of different guar gum structure in sandstone: Based on a new characterization method

Shi,

Wang,

Wang

et al. 2024

Geoenergy Science and Engineering

View full text Add to dashboard Cite

Study on the effect of acid fracturing fluid on pore structure of middle to high rank coal

Kang,

Liangwei,

Kun

et al. 2024

Preprint

View full text Add to dashboard Cite

Acid fracturing fluids can effectively improve the microporous structure of coal, thereby enhancing the permeability of coal seam and the efficiency of gas drainage. To explore the effects of acid fracturing fluids on the pore structure modification of coal samples from different coal ranks, hydrochloric acid-based acid fracturing fluids were prepared and used to soak four types of medium to high-rank coal in an experiment. High-pressure mercury intrusion and liquid nitrogen adsorption techniques results demonstrated that the acid fracturing fluid can effectively alter the pore structure of coal. However, the modification effect does not exhibit a linear relationship with coal rank. The porosity of fat coal and coking coal increased by approximately 30%, while the surface area of gas coal and fat coal increased by about 20%. The new micropores produced by the acid fracturing fluid will increase the roughness of the fracture surface, but the widening of the original fracture will reduce the tortuosity of the fracture. Only the fractal dimension of lean coal has a significant change, about 6%. Overall, acid fracturing fluid has the best effect on gas coal and coking coal. The research results provide a reference for the selection and application of acid fracturing fluid in coal seam hydraulic fracturing.

show abstract

Evolution Characteristics of the Microstructure with Different Fracturing Fluids: An Experimental Study of Guizhou Bituminous Coal

Cited by 3 publications

References 31 publications

Experimental research on the influence of acid on the chemical and pore structure evolution characteristics of Wenjiaba tectonic coal

Experimental research on the influence of acid on the chemical and pore structure evolution characteristics of Wenjiaba tectonic coal

LNMR analysis of the retention of different guar gum structure in sandstone: Based on a new characterization method

Study on the effect of acid fracturing fluid on pore structure of middle to high rank coal

Contact Info

Product

Resources

About