Research progress and prospect of deep coalrock fracturing

被引：0

作者：

Li, Xiaogang ^{[1
]}

Tang, Zheng ^{[1
]}

Zhu, Jingyi ^{[1
]}

Yang, Zhaozhong ^{[1
]}

Li, Yang ^{[2
]}

Xie, Peng ^{[3
]}

Liao, Yu ^{[1
]}

机构：

[1] State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Sichuan, Chengdu,610500, China

[2] Chengdu North Oil Exploration & Development Technology Co., Ltd., Sichuan, Chengdu,610066, China

[3] Baikouquan Oil Production Plant, PetroChina Xinjiang Oilfield Company, Xinjiang, Karamay,834000, China

来源：

Natural Gas Industry | 2024年 / 44卷 / 10期

关键词：

Coal deposits - Coal industry - Cost engineering - Enhanced recovery - Geologic models - Low permeability reservoirs - Petroleum reservoir evaluation - Proven reserves - Radioactive prospecting;

D O I：

10.3787/j.issn.1000-0976.2024.10.010

中图分类号：

学科分类号：

摘要：

In China, there are abundant deep coal-rock gas resources with immense exploration and development potential. Hydraulic fracturing is an important engineering technique for the development of deep coal-rock gas. At present, however, the hydraulic fracturing technology for deep coal-rock gas reservoirs still faces a technical bottleneck, which restricts the exploration and development of the resource to some extent. In order to further clarify the current situation and the development trend of hydraulic fracturing technology for deep coal-rock gas reservoirs, this paper analyzes the distinct geological characteristics of deep coal-rock fracturing based on the case studies of deep coal-rock gas exploration and development in the Ordos Basin and Qinshui Basin. Then, the current situation of deep coal-rock fracturing technology is illustrated, and the theoretical and technical challenges to deep coal-rock fracturing are analyzed. Finally, the development directions of fracturing stimulation theories and technologies are predicted. The following results are obtained. First, compared with medium-deep shale, low-permeability tight sandstone, and shallow coal seams, deep coal rocks have a more complex fracture and cleat network system, and are characterized by low porosity, low permeability, intact coal structure, high in-situ stress, high elastic modulus, and low Poisson’s ratio. Due to these differences in geological characteristics, the fracturing technology for deep coal rocks should be different in essence. Second, the mainstream fracturing technologies for deep coal rocks include the super large-scale extreme volume fracturing in horizontal well and the multi-round diverting fracturing technology to form a merged fracture network. Third, it is necessary to study the geological characteristic differences, hydraulic fracture initiation and propagation patterns, low-cost fracturing materials and efficient fracturing technologies corresponding to deep coal-rocks at various ranks and in different regions. In conclusion, as to the fracturing stimulation of deep coal-rocks for gas development, a multi-scale geological model shall be constructed depending on the fracturing geological characteristics, a geology-engineering sweet spot prediction model shall be established, and low-cost and environmentally-friendly fracturing materials and supporting technologies shall be developed, so as to realize the large-scale and beneficial development of deep coal-rock gas. © 2024 Natural Gas Industry Journal Agency. All rights reserved.

引用

页码：126 / 139