Presentation Information

[2503]Evaluation of Fracturing Activity around Coal Gasification Zone during Artificial UCG Experiment

蘇発強1, 板倉賢一1, 濱中晃弘1, 高橋一弘1, 佐藤孝紀1, 出口剛太2, 児玉淳一3 (1.室蘭工業大学, 2.地下資源イノベーションネットワーク, 3.北海道大学)
司会:木﨑彰久(秋田大学)

Keywords:

UCG,Acoustic Emission,Artificial Coal Seam

Underground coal gasification (UCG) offers attractive alternatives for the exploitation of the coal resources that remain buried and inaccessible in complicated geological conditions. UCG involves the gasification of coal in the underground by injecting oxidants through an injection well and extracting the syngas through a production well.
For effective coal gasification, fracturing activity must be controlled. Moreover, excess fractures inside the coal seam and surrounding rock can induce gas leakage, underground water contamination, subsidence, etc. Therefore, monitoring and control of fracturing activity in underground areas constitute key technologies for efficient and safe UCG. During burning of the coal, temperatures inside the coal, contents of product gases and acoustic emission (AE) activity were monitored successively under the control of feeding gas (air/oxygen and steam) flow rate.
The UCG experiment described in this paper was performed in an artificial coal seam. The artificial coal seam designed at the rectangular shape possessed dimensions of about 2.7 m (length) × 0.6 m (width) × 0.55 m (height). Results show that coal fracturing developed inside the coal with AE activity during burning. Monitoring the AE during UCG process is available to infer the failure mechanisms, estimate the damage zone development, and to provide important data and parameters for visualization of the gasifier
underground.