RESEARCH ARTICLE


Research of Network Fracturing Method for Coalbed Methane Reservoirs



Ting Li1, 2, Jifang Wan*, 3
1 Hubei Cooperative Innovation Center of Unconventional Oil and Gas, Yangtze University, Wuhan 430100, China
2 Petroleum Engineering College of Yangtze University, Wuhan 430100, China
3 Mechanical Engineering College of Yangtze University, Jingzhou 434023, China


Article Metrics

CrossRef Citations:
0
Total Statistics:

Full-Text HTML Views: 2542
Abstract HTML Views: 1576
PDF Downloads: 315
ePub Downloads: 210
Total Views/Downloads: 4643
Unique Statistics:

Full-Text HTML Views: 1126
Abstract HTML Views: 795
PDF Downloads: 237
ePub Downloads: 162
Total Views/Downloads: 2320



© Li and Wan; Licensee Bentham Open

open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution-Non-Commercial 4.0 International Public License (CC BY-NC 4.0) (https://creativecommons.org/licenses/by-nc/4.0/legalcode), which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.

* Address correspondence to this author at the School of Mechanical Engineering, Yangtze University,1 Nanhuan Road , 434023 Jingzhou City, Hubei Province, P. R. China; Tel/Fax: +8613797507143; E-mails: wanjifang@126.com, 2695377412@qq.com.


Abstract

The application of conventional hydraulic fracture treatment is not ideal in coalbed methane reservoirs, which influences the industry development in China, thus, the present technique should be improved. From two aspects of net pressure and stress sensibility of permeability, it is analyzed and considered that permeability around hydraulic fractures is damaged severely, so this is the main flaw of conventional hydraulic fracturing in CBM. It is proposed to shear natural fractures by fracturing treatment, which are plentiful in coalbed methane reservoirs, and the mechanical condition to generate sheared fractures is presented, in the meanwhile, it is verified that the permeability of sheared fractures is much larger than coal matrix permeability. When the angle between natural and hydraulic fractures is small in coalbed methane reservoirs, the natural fractures will shear easily at low net pressure, so network fractures can be formed. In comparison with conventional hydraulic fracturing, this new methodology can make natural fractures shear at low net pressure to form transverse network fractures, hence, the stimulated reservoir volume is larger, and damage to coal permeability is avoided. This new technique is advantageous in both stimulated reservoir volume and permeability improvement, and it is more adaptable for coalbed methane reservoirs, thus, it has a wide application prospect and significant value.

Keywords: Artificial fractures, Coalbed methane, Field application, Natural fractures, Network fracturing method, Sheared fractures.