資源開発技術

[2503] UCG人工炭層試験におけるガス化領域の破壊活動について

^○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)

キーワード：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.