Mechanism Analysis of Liquid Carbon Dioxide Phase Transition for Fracturing Rock Masses
Abstract
:1. Introduction
- To Calculate the initial pressure acting on the borehole wall in the direction of the release hole at the moment of high-pressure carbon dioxide release.
- Under different confining pressure conditions, initiation characteristic of cracks is to be obtained when the high-pressure gas act on the borehole wall.
- To obtain the expansion radius of the crack under the action of stress wave and relationship between crack radius and stress intensity factor under quasi-static action of high-pressure gas.
2. Calculating the Initial Surge Pressure and Analyzing the Formation Mechanism of Initial Cracks on the Borehole Wall
2.1. Calculation of Initial Surge Pressure on the Borehole Wall
- Coefficient Cd, Cv. These two coefficients have a strong relationship with the pore size and shape of the release hole. Therefore, optimizing the release pore curve and reducing the energy loss are important factors for improving the rock breaking effect.
- The jet pressure is proportional to the value of P1 − P2, where P2 is the atmospheric pressure and is a constant value. Therefore, rock breaking effect can be improved by increasing the pressure P1 of the carbon dioxide in the liquid storage tube.
2.2. The Initial Crack Generation Law without an Initial Stress Field
2.2.1. Theoretical Analysis
2.2.2. Experimental analysis
- (1)
- Most of the test pieces were not broken to a high degree and were mostly of a large size. The surface of the borehole wall was unbroken and no crushing damage was found. After the failure of the specimen, no micro cracks developed on the surface, and the radius of the fracture zone was large.
- (2)
- Two main cracks, which were approximately in a linear distribution, were produced along the vertical release holes around the blasting hole, and ran through the whole experimental specimen. Each of the main cracks was long and narrow and produced few secondary cracks. There were few micro cracks on the circumferential wall of the blasting hole. Most of the cracks extended along the axial direction of the borehole. Whether a crack was a dominant main crack or an undeveloped micro crack, its normal direction was approximately perpendicular to the axial direction of the borehole. In summary, the cracking effect was good.
2.3. Extension Criteria for Initial Cracks with Initial Stress Field
3. Generation and Expansion of Cracks Under Stress Waves and High-Pressure Gas
3.1. The Generation and Expansion of Cracks Under Stress Waves
3.2. Mechanism Analysis of Crack Propagation Under High-Pressure Gas Quasi-Static Action
4. Conclusions
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
- Holm, L.W. Carbon dioxide solvent flooding for increased oil recovery. J. Petrol. Technol. 1959, 216, 225–231. [Google Scholar]
- Global, J. Cardox system brings benefits in the mining of large coal. Coal Int. Redhill 1995, 243, 27–28. [Google Scholar]
- Zhang, C.; Lin, B.Q.; Zhou, Y.; Cheng, Z.; Zhu, C.J. Study on “fracturing-sealing” integration technology based on high-energy gas fracturing in single seam with high gas and low air permeability. Int. J. Min. Sci. Technol. 2013, 23, 841–846. [Google Scholar] [CrossRef]
- Lu, T.K.; Wang, Z.F.; Yang, H.M.; Yuan, P.J.; Han, Y.B.; Sun, X.M. Improvement of coal seam gas drainage by under-panel cross-strata stimulation using highly pressurized gas. Int. J. Rock Mech. Min. Sci. 2015, 77, 300–312. [Google Scholar] [CrossRef]
- Tian, S.C.; He, Z.G.; Li, G.S.; Wang, H.Z.; Shen, Z.H.; Liu, Q.L. Influences of ambient pressure and nozzle-to-target distance on sc-co 2 jet impingement and perforation. J. Nat. Gas Sci. Eng. 2016, 29, 232–242. [Google Scholar] [CrossRef]
- Pal, K.; Rajasekar, R.; Kang, D.J.; Zhang, Z.X.; Pal, S.K.; Jin, K.K.; Das, C.K. Effect of fillers and nitrile blended pvc on natural rubber/high styrene rubber with nanosilica blends: Morphology and wear. Mater. Des. 2010, 31, 25–34. [Google Scholar] [CrossRef]
- Uhlmann, E.; Hollan, R. Blasting with solid carbon dioxide—Investigation of thermal and mechanical removal mechanisms. Procedia CIRP 2015, 26, 544–547. [Google Scholar] [CrossRef]
- Guo, Z.X. Liquid carbon dioxide blasting cylinder and on-site test explosion. Blasting 1994, 8, 72–74. [Google Scholar]
- Xu, Y.; Cheng, Y.S.; Wang, J.L. Foreign high pressure gas explosion. Coal Sci. Technol. 1997, 25, 52–53. [Google Scholar]
- Sun, K.M.; Xin, L.W.; Wang, T.T.; Wang, J.Y. Simulation research on law of coal fracture caused by supercritical CO2 explosion. J. China Univ. Min. Technol. 2017, 46, 501–506. [Google Scholar]
- Wang, Z.F.; Sun, X.M.; Lu, T.K.; Han, Y.B. Experiment research on strengthening gas drainage effect with fracturing technique by liquid co2 phase transition. J. Henan Polytech. Univ. (Nat. Sci.) 2015, 34, 1–5. [Google Scholar]
- Zhou, K.P.; Ke, B.; Li, J.L.; Zhang, Y.N.; Cheng, L. Pressure dynamic response and explosion energy of liquid carbon dioxide blasting system. Blasting 2017, 34, 7–13. [Google Scholar]
- Huang, L.G.; Zhang, F.L.; Zhang, Z.; Cheng, K. Study on application of CO2 fracturing apparatus in pre-splitting blasting of rock deep hole. Blasting 2017, 34, 131–135. [Google Scholar]
- Zhou, X.H.; Men, J.L.; Song, D.P.; Li, C.Y. Research on optimal borehole parameters of antireflection in coal seam by liquid CO2 blasting. Chin. J. Rock Mech. Eng. 2016, 35, 524–529. [Google Scholar]
- Wang, H.Z.; Li, G.S.; He, Z.G.; Shen, Z.H.; Wang, M.; Wang, Y.W. Mechanism study on rock breaking with supercritical carbon dioxide jet. Atomization Sprays 2017, 27, 383–394. [Google Scholar] [CrossRef]
- Wang, R.H.; Huo, H.J.; Huang, Z.Y.; Song, H.F.; Ni, G.J. Experimental and numerical simulations of bottom hole temperature and pressure distributions of supercritical CO2 jet for well-drilling. J. Hydrodyn. 2014, 26, 226–233. [Google Scholar] [CrossRef]
- Hu, J.H. Non-explosive blasting technology symposium held in Beijing. Eng. Blast. 2016, 22, 89. [Google Scholar]
- Wang, G.B.; Peng, J.Y.; Xu, Z.Y. Application of carbon dioxide fracturing for blasting technology in buzhaoba open-pit mine. Opencast Min. Technol. 2017, 32, 40–42. [Google Scholar]
- Wang, J.; Xiao, Y.S. Marble stone is mined in a limestone mine based on carbon dioxide blasting technology. Mod. Min. 2015, 554, 15–17. [Google Scholar]
- Zhang, Y.N.; Deng, J.R.; Deng, H.W.; Ke, B. Peridynamics simulation of rock fracturing under liquid carbon dioxide blasting. Int. J. Damage Mech. 2018. accept. [Google Scholar]
- Wang, W.X. Rockmass Mechanics, 1st ed.; Central South University: Changsha, China, 2004. [Google Scholar]
- Xu, Y. Development of high pressure gas blasting coal mining technology and its application in China. Blasting 1998, 15, 67–69. [Google Scholar]
- Zhan, D.S.; Huang, L.G.; Qiu, T.D. Study on mechanism and experiment of high pressure carbon dioxide blasting and permeability improved technology. Mine Constr. Technol. 2016, 37, 31–34. [Google Scholar]
- Yao, J.J. Damage rock blasting parameter calculate based on blasting fissure fractal dimensions. Chin. J. Solid Mech. 2008, 29, 95–98. [Google Scholar]
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Gao, F.; Tang, L.; Zhou, K.; Zhang, Y.; Ke, B. Mechanism Analysis of Liquid Carbon Dioxide Phase Transition for Fracturing Rock Masses. Energies 2018, 11, 2909. https://doi.org/10.3390/en11112909
Gao F, Tang L, Zhou K, Zhang Y, Ke B. Mechanism Analysis of Liquid Carbon Dioxide Phase Transition for Fracturing Rock Masses. Energies. 2018; 11(11):2909. https://doi.org/10.3390/en11112909
Chicago/Turabian StyleGao, Feng, Leihu Tang, Keping Zhou, Yanan Zhang, and Bo Ke. 2018. "Mechanism Analysis of Liquid Carbon Dioxide Phase Transition for Fracturing Rock Masses" Energies 11, no. 11: 2909. https://doi.org/10.3390/en11112909