Filling characteristics and plugging mechanisms of hydraulic fractures near CBM vertical wells

被引：4

作者：

Chen, Lichao ^{[1
,2
]}

Wang, Shengwei ^{[2
,3
]}

He, Junhua ^{[3
]}

Li, Rui ^{[3
]}

Liu, Jianhua ^{[3
]}

Lü, Shuaifeng ^{[3
]}

机构：

[1] School of Mining and Technology in Inner Mongolia University of Technology, Hohhot,010051, China

[2] State Key Laboratory of Coal and CBM Co-mining in Jincheng Anthracite Mining Group, Jincheng,048204, China

[3] Faculty of Earth Resources in China University of Geosciences, Wuhan,430074, China

来源：

Zhongguo Shiyou Daxue Xuebao (Ziran Kexue Ban)/Journal of China University of Petroleum (Edition of Natural Science) | 2017年 / 41卷 / 06期

关键词：

Coal deposits - Coal mines - Boreholes - Coal bed methane - Oil field equipment - Fracture - Natural gas wells - Bandpass filters - Firedamp - Fracturing fluids - Methane - Flow of fluids - Coal - Proppants;

D O I：

10.3969/j.issn.1673-5005.2017.06.014

中图分类号：

学科分类号：

摘要：

Particle migration and blocking in fracturing fractures near wellbore area can be one of the important factors to production reduction of coalbed methane (CBM) wells. It is essential to reveal the filling characteristics and plugging mechanism of fracturing fractures in order to remove the plug and increase production. In this study, based on the in-site observations of the fractures appeared in tunnels of underground coal mines, the filling characteristics and blocking mechanisms in the fractures of vertical CBM wells in southern Qinshui Basin were investigated. The observation shows that the fillings contain coal fines, proppant and well completion filter cake in the fractures near wellbore. Completion filter cake can control the initiation and propagation of fractures, and proppant distribution, and it can reduce the filtration rate of fracturing fluid. But when the fluid flows through the location where the filter cake is pinched out, significant fluid-loss can occur, which can take off sands and form sand wedge, and further the wedges become compacted and filled with coal fines carried by gas-liquid phase flow, then blocking or plugs of the fractures can be formed, reducing the flow capacity of the fracture seriously. It proposes that, based on a particle gathering model and the golden filtration principle, the size of proppants used in fracturing should be greater than 0.900 mm in order to reduce the plugging coal fines with median size of 0.045 mm that found in the study CBM area. © 2017, Periodical Office of China University of Petroleum. All right reserved.

引用

页码：117 / 122