期刊
INTERNATIONAL JOURNAL OF COAL GEOLOGY
卷 252, 期 -, 页码 -出版社
ELSEVIER
DOI: 10.1016/j.coal.2022.103942
关键词
Hydraulic fracturing; Coalbed methane; Fractures; X-ray computer tomography; Digital volume correlation
资金
- National Natural Science Founda-tion of China [42072195, 41772162]
- Fundamental Research Funds for the Universities of Henan Province [NSFRF180103]
- Program for Innovative Research Team of Henan Polytechnic University [T2015-1]
This study conducted a laboratory simulation of hydraulic fracturing in coal and used X-ray computer tomography (CT) and digital volume correlation (DVC) to analyze and quantify the changes in fractures induced by hydraulic fracturing. The results showed that hydraulic fracturing increased the aperture, volume, and surface area of fractures in coal, and simplified their morphology. The study also revealed the significant influence range and connectivity of fractures caused by hydraulic fracturing.
Hydraulic fracturing is a key technology for improving the permeability of coal reservoirs. Understanding the variation of hydraulically induced fractures is crucial for improving coalbed methane production. In this study, we conducted a laboratory-simulation of hydraulic fracturing in coal and applied X-ray computer tomography (CT) and digital volume correlation (DVC) to quantify the spatial distribution, structural variation, and propagation of fractures with an aperture greater than 28.4 mu m. Hydraulic fracturing increased the aperture, volume (by 5.3, 32.2, 2.2 and 2.8 times) and surface area (by 1.1, 9.9, 1.8 and 0.8 times), and simplified fracture morphology in the four tested samples. Moreover, the significant influence range in the axial direction of hydraulic fracturing on fracture is 4.2 cm, 4.4 cm, 1.9 cm and 2.9 cm, respectively, with fracture connectivity reaching 61.8%, 99.3%, 77.7%, and 91.1%. A low in-situ stress differential resulted in the formation of a complex network of many fractures with a small volume. A high in-situ stress differential resulted in the formation of large fractures with a simple morphology. The X-ray CT images also showed that new fractures originated in and propagated along the mineral-maceral interface. DVC shows that high volume displacement and strain occur in the fracture area induced by hydraulic fracturing, and it has a good application prospect in the investigation of the microevolution and microdamage of fractures in coal.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据