Cexuan Liu , Egor Dontsov , Manchao He , Fengshou Zhang
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引用次数: 0
Abstract
Hydraulic fracturing involves injecting a high-pressure fluid mixture to create fractures in underground rock formations, thereby enhancing hydrocarbon flow. Recent field observations, such as those from the Hydraulic Fracture Test Site (HFTS) project and tests in the Eagle Ford, have revealed surprising complexity of hydraulic fractures, including the presence of densely distributed fracture swarms. These findings challenge conventional expectations and necessitate a deeper understanding of fracture mechanisms. Existing studies have explored the propagation, connectivity, and implications of multiple fractures, but questions remain about the mechanisms behind the formation of fracture swarms, particularly the distribution of these secondary fractures. Our research introduces an alternative mechanism, proposing that secondary fractures result from a pore-pressure wave in which the pore pressure exceeds the compressive stress. This hypothesis suggests that pore-pressure variations within the rock and fluid exchange between the fracture and rock after shut-in can initiate secondary fractures. Through theoretical modeling and scaling, we have identified the governing dimensionless parameters that determine the number and distribution of secondary fractures. Numerical simulations enabled us to construct the parametric space for these parameters. Finally, we propose a procedure to interpret field observations of fracture swarms. Our approach provides new insights into predicting fracture swarms and using the observed fracture swarms to constrain some parameters that are relevant to hydraulic fracturing.
期刊介绍:
The International Journal of Solids and Structures has as its objective the publication and dissemination of original research in Mechanics of Solids and Structures as a field of Applied Science and Engineering. It fosters thus the exchange of ideas among workers in different parts of the world and also among workers who emphasize different aspects of the foundations and applications of the field.
Standing as it does at the cross-roads of Materials Science, Life Sciences, Mathematics, Physics and Engineering Design, the Mechanics of Solids and Structures is experiencing considerable growth as a result of recent technological advances. The Journal, by providing an international medium of communication, is encouraging this growth and is encompassing all aspects of the field from the more classical problems of structural analysis to mechanics of solids continually interacting with other media and including fracture, flow, wave propagation, heat transfer, thermal effects in solids, optimum design methods, model analysis, structural topology and numerical techniques. Interest extends to both inorganic and organic solids and structures.