@Article{cmc.2020.011430,
AUTHOR = {Dan Ma, Hongyu Duan, Qi Zhang, Jixiong Zhang, Wenxuan Li, Zilong Zhou, Weitao Liu},
TITLE = {A Numerical Gas Fracturing Model of Coupled Thermal, Flowing  and Mechanical Effects},
JOURNAL = {Computers, Materials \& Continua},
VOLUME = {65},
YEAR = {2020},
NUMBER = {3},
PAGES = {2123--2141},
URL = {http://www.techscience.com/cmc/v65n3/40159},
ISSN = {1546-2226},
ABSTRACT = {Gas fracturing, which overcomes the limitation of hydraulic fracturing, is a
potential alternative technology for the development of unconventional gas and oil 
resources. However, the mechanical principle of gas fracturing has not been learned 
comprehensively when the fluid is injected into the borehole. In this paper, a damagebased model of coupled thermal-flowing-mechanical effects was adopted to illustrate the 
mechanical principle of gas fracturing. Numerical simulation tools Comsol Multiphysics 
and Matlab were integrated to simulate the coupled process during the gas fracturing. 
Besides, the damage evolution of drilling areas under several conditions was fully 
analyzed. Simulation results indicate that the maximum tensile stress, which occurs in the 
upper and lower of the injection hole, decreases with the increase of the tectonic stress 
coefficient (TSC). As the TSC increases, shear fractures increase, a crushed area is 
gradually formed and the seepage area increases rapidly. The influence of TSC on 
fracture expansion is concluded as follows: with the decrease of TSC, the relative width 
of fractures decreases whilst the depth increases. It indicates that thermal stress and pore 
pressure promote the expansion of tensile fractures but restrain the expansion of shear 
fractures. Therefore, a relatively lower injection gas pressure is required to obtain the 
same degree of fracturing with a coupled thermal gradient.},
DOI = {10.32604/cmc.2020.011430}
}