TY - JOUR
T1 - Geometrical description and permeability calculation about shale tensile micro-fractures
AU - Qu, Guanzheng
AU - Qu, Zhanqing
AU - Hazlett, Randy Doyle
AU - Freed, David
AU - Mustafayev, Rahman
N1 - Funding Information:
Received date: 27 May 2015; Revised date: 30 Nov. 2015. * Corresponding author. E-mail: [email protected] Foundation item: Supported by China National Science and Technology Major Project (2011ZX05051) and China Natural Science Foundation of China (51404288). Copyright © 2016, Research Institute of Petroleum Exploration and Development, PetroChina. Published by Elsevier BV. All rights reserved.
Publisher Copyright:
© 2016 Research Institute of Petroleum Exploration & Development, PetroChina.
PY - 2016/2/1
Y1 - 2016/2/1
N2 - To study fluid flow in shale tensile micro-fractures, five shale core samples, taken from Barnnet Shale, were splitted into artificial tensile fractures based on Brazilian test. The morphology of the artificial fractures was obtained by a 3-D laser sensor profilometer. Then, 3-D information was transformed into 2-D information and the quantitative parameters, such as tortuosity, surface angularity and roughness, were calculated based on the scanning principle. Cluster analysis was introduced to make sure the distance among the parameters, the fluid flow in shale micro-fractures with the opening of 0.05-0.40 mm was simulated by Lattice Boltzmann Method (LBM), and an equation was derived for calculating the shale tensile micro-fracture permeability. The results show that, the tortuosity of the samples is close to 1.10, the angularity is among 0.99°-8.86°, and the roughness is among 0.062-0.162 mm; the parameters cannot be substituted by one another and their effects should be considered at the same time; the micro-s is less 19%-29% than the parallel plate model permeability, so the roughness should be included. It is verified that the deviation of the equation is less than 4%, and it can be used to calculate shale tensile micro-fracture permeability.
AB - To study fluid flow in shale tensile micro-fractures, five shale core samples, taken from Barnnet Shale, were splitted into artificial tensile fractures based on Brazilian test. The morphology of the artificial fractures was obtained by a 3-D laser sensor profilometer. Then, 3-D information was transformed into 2-D information and the quantitative parameters, such as tortuosity, surface angularity and roughness, were calculated based on the scanning principle. Cluster analysis was introduced to make sure the distance among the parameters, the fluid flow in shale micro-fractures with the opening of 0.05-0.40 mm was simulated by Lattice Boltzmann Method (LBM), and an equation was derived for calculating the shale tensile micro-fracture permeability. The results show that, the tortuosity of the samples is close to 1.10, the angularity is among 0.99°-8.86°, and the roughness is among 0.062-0.162 mm; the parameters cannot be substituted by one another and their effects should be considered at the same time; the micro-s is less 19%-29% than the parallel plate model permeability, so the roughness should be included. It is verified that the deviation of the equation is less than 4%, and it can be used to calculate shale tensile micro-fracture permeability.
KW - Fluid flow simulation
KW - Fracture angularity
KW - Fracture morphology
KW - Fracture permeability model
KW - Fracture roughness
KW - Fracture tortuosity
KW - Shale
KW - Tensile micro-fracture
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U2 - 10.1016/S1876-3804(16)30014-3
DO - 10.1016/S1876-3804(16)30014-3
M3 - Article
AN - SCOPUS:84959140176
SN - 1876-3804
VL - 43
SP - 124
EP - 130
JO - Petroleum Exploration and Development
JF - Petroleum Exploration and Development
IS - 1
ER -