Study on acoustic emission response characteristics of sandstone directional fracturing under different filtration surfaces

• Published in: Mei kuang an quan Vol. 53; no. 4; pp. 62 - 67
• Main Authors: YE Hailong, YANG Lusheng, LIU Zhenghe, DENG Qiongwei
• Format: Journal Article
• Language: Chinese
• Published: Editorial Office of Safety in Coal Mines 01.04.2022
• Subjects: acoustic emission; cumulative energy; directional hydraulic fracturing; energy rate; filtration; hard roof; impact disaster
• ISSN: 1003-496X
• DOI: 10.13347/j.cnki.mkaq.2022.04.001

In order to study the influence of filtration on rock directional hydraulic fracturing under different filtration surfaces, 300 mm×300 mm×300 mm sandstone specimens with intermediate drilling holes and directional prefabricated fractures were selected, and the method of applying waterproofing agent on the specimen surface was used to control the fluid loss, and four groups of sandstone specimens with reduced filtration surface were made, including agent A without waterproofing, fracture surface coated with waterproofing agent B, hole wall coated with waterproofing agent C, fully coated with waterproofing agent sandstone specimen D. We carry out true triaxial directional hydraulic fracturing and real-time acoustic emission monitoring to analyze and study the acoustic emission energy rate, cumulative energy and fracture extension law of sandstone specimens under different filtration surfaces. The results show that with the increase of filtration surface, the peak value of acoustic emission energy rate of sandst