Experimental study on the influence of coal-rock interface strength on crack propagation law of supercritical carbon dioxide fracturing

被引：23

作者：

Yan, Hao ^{[1
,2
,3
]}

Wang, Wenlong ^{[2
,3
]}

Zhang, Jixiong ^{[2
,3
]}

Ma, Dan ^{[2
,3
]}

Zhou, Nan ^{[2
,3
]}

Wan, Zihao ^{[2
]}

机构：

[1] China Univ Min & Technol, Jiangsu Key Lab Coal Based Greenhouse Gas Control, Xuzhou 221008, Jiangsu, Peoples R China

[2] China Univ Min & Technol, Sch Mines, Xuzhou 221116, Jiangsu, Peoples R China

[3] China Univ Min & Technol, State Key Lab Coal Resources & Safe Min, Xuzhou 221116, Jiangsu, Peoples R China

来源：

GAS SCIENCE AND ENGINEERING | 2023年 / 112卷

关键词：

Coal -rock interface; Supercritical CO 2 fracturing; Crack propagation; Strength; Acoustic emission; MODEL;

D O I：

10.1016/j.jgsce.2023.204943

中图分类号：

TE [石油、天然气工业]; TK [能源与动力工程];

学科分类号：

0807 ; 0820 ;

摘要：

Supercritical CO2 (SC-CO2) fracturing technology has become a new way of waterless fracturing of coal seams, which not only changes the fracture structure of coal, but also achieves the purpose of CO2 geological storage. When the SC-CO2 cracks propagate to the roof and floor of coal seams, the sudden change in the rock mass properties on both sides of the coal-rock interface makes the crack propagation law more complicated. To study the influence of coal-rock interface on crack propagation of SC-CO2 fracturing, the preparation method of different coal-rock interface strength specimens was proposed. Moreover, the true triaxial SC-CO2 fracturing test system was used to study the influence of different coal-rock interface strengths on the SC-CO2 fracturing injection pressure-time evolution law, and the SC-CO2 fracturing acoustic emission signal response of different coal-rock interface strengths was also analyzed. Meanwhile, the propagation mode of the SC-CO2 cracks in the coal-rock interface area was analyzed, and the influence of coal-rock interface strength on crack propagation law was revealed. The research results show that the SC-CO2 cracks in the coal-rock interface area have various types of crack propagation, such as extending along the interface, directly passing through the interface, and compound propagation. The higher the coal-rock interface strength is, the more likely the SC-CO2 crack is to propagate across the interface. The results can provide theoretical guidance for applying and promoting SC-CO2 fracturing technology in coal mines.

引用

页数：10

共 33 条

[31] Crack propagation patterns and factors controlling complex crack network formation in coal bodies during tri-axial supercritical carbon dioxide fracturing [J].