Numerical modeling of cracking behaviors of coal reservoirs subjected to cryogenic shock

Songcai Han, Xinchuang Yan, Lile Li, Lei Wang, Liang Yang, Rui Wang, Qi Gao, Junchao Yang, Xian Shi

Research output: Chapter in Book/Conference paperConference paperpeer-review

Abstract

Thermally-induced cracking has attracted extensive attention in improving reservoir permeability. In this paper, a thermo-elastic coupling model incorporating the strain-based elastic-brittle damage theory is used to analyze the cracking behaviors of the coal reservoir subjected to cryogenic liquid nitrogen shock. The evolution of temperature and thermally-induced stress with damage is analyzed. The effect of different factors including in-situ stress difference, elastic modulus, thermal expansion coefficient, thermal conductivity and quenching temperature on the induced crack morphology is investigated. It is found that the failure mechanism of the coal rock during cryogenic shock is mainly dominated by elastic brittle tensile damage. The induced fracture morphology is more sensitive to elastic modulus and thermal expansion coefficient relative to in-situ stress difference and thermal conductivity. The increases in elastic modulus and thermal expansion coefficient will bring about more fractures with greater complexity. The higher in-situ stress difference or lower thermal conductivity can generate more short thermal fractures. The critical quenching temperature for inducing thermal cracks around the wellbore is between -110 ℃ and -105 ℃. The results of this study can provide some guidelines for cryogenic fracturing in coal reservoirs.

Original languageEnglish
Title of host publication57th US Rock Mechanics/Geomechanics Symposium
PublisherAmerican Rock Mechanics Association (ARMA)
Number of pages8
ISBN (Electronic)9780979497582
DOIs
Publication statusPublished - 25 Jun 2023
Event57th US Rock Mechanics/Geomechanics Symposium - Atlanta, United States
Duration: 25 Jun 202328 Jun 2023

Publication series

Name57th US Rock Mechanics/Geomechanics Symposium

Conference

Conference57th US Rock Mechanics/Geomechanics Symposium
Country/TerritoryUnited States
CityAtlanta
Period25/06/2328/06/23

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