A new shock-wave test apparatus for liquid CO2 blasting and measurement analysis

Liquid CO2 blasting of coal or rock body technology is widely used for improving permeability, pressure relief, cutting proof, and roadway development. Due to the lack of proper apparatus for blasting measurement, the determination of blasting parameters is often not under scientific basis. A newly designed experimental apparatus is developed to monitor shock-wave pressure of liquid CO2 blasting. The apparatus mainly consists of testing tube and base bracket. The testing tube is fixed on the base bracket by fixed ring. The base bracket is fixed to the ground by expansion bolts to ensure the stability of the apparatus and personnel safety during blasting. Three testing tubes with inner diameter of 48, 68, and 82 mm are designed and manufactured to simulate different sizes of boreholes. Monitoring holes are drilled on the testing tube to monitor blasting shock-wave pressure in real time. The maximum pressure of the shock-wave and its acting duration can be obtained. Experimental results also revealed that the normal direction of the gas outlet is the effective shock-wave acting area where the maximum pressure reaches more than 160 MPa. The shock-wave pressure is in non-linear relationship with the distance from gas outlet. By comparison of the blasting tube sealed to unsealed condition, it is found that sealing can be effected by increment in shock-wave pressure of about 43.3%. The research results provide a basis and reference work for determination and optimization of liquid CO2 blasting parameters.

[1]  Zhaofeng Wang,et al.  Improvement of coal seam gas drainage by under-panel cross-strata stimulation using highly pressurized gas , 2015 .

[2]  Zhao Li-pen.  Technology of Liquid Carbon Dioxide Deep Hole Blasting Enhancing Permeability in Coal Seam , 2013 .

[3]  S. Rahman,et al.  Hydraulic fracture initiation and propagation: roles of wellbore trajectory, perforation and stress regimes , 2000 .

[4]  John Hadjigeorgiou,et al.  The destressability index methodology for the assessment of the likelihood of success of a large-scale confined destress blast in an underground mine pillar , 2008 .

[5]  Yufei Wang,et al.  Carbon geological utilization and storage in China: current status and perspectives , 2014 .

[6]  M. Cai,et al.  Interpretation of the extent of hydraulic fracturing for rockburst prevention using microseismic monitoring data , 2017 .

[7]  T. Caldwell.  A comparison of non-explosive rock breaking techniques , 2004 .

[8]  Baohua Guo,et al.  Improvement of methane drainage in high gassy coal seam using waterjet technique , 2009 .

[9]  Tomoya Niwa,et al.  Acoustic emission monitoring of hydraulic fracturing laboratory experiment with supercritical and liquid CO2 , 2012 .

[10]  Xiangjun Chen,et al.  Increasing permeability of coal seams using the phase energy of liquid carbon dioxide , 2017 .

[11]  W. Ye,et al.  A New Device for Measuring the Supercritical CO2Permeability in Porous Rocks Under Reservoir Conditions , 2015 .

[12]  S. P. Singh,et al.  Non-explosive applications of the PCF concept for underground excavation , 1998 .

[13]  Hani S. Mitri,et al.  Enhanced coalbed gas drainage based on hydraulic flush from floor tunnels in coal mines , 2016 .

[14]  Wang Zhaofen,et al.  Experiment research on strengthening gas drainage effect with fracturing technique by liquid CO_2 phase transition , 2015 .

[15]  L. W. Holm.  Carbon Dioxide Solvent Flooding for Increased Oil Recovery , 1959 .

[16]  Jianhong Kang,et al.  Evaluation of gas drainage and coal permeability improvement with liquid CO2 gasification blasting , 2018 .

[17]  Tao Xu,et al.  A comparative study of hydraulic fracturing with various boreholes in coal seam , 2015, Geosciences Journal.