基于测氡法的煤层注气(CO_2)后运移监测

CO_2 Movement Monitoring After CO_2 Injection in Coal Seam Based on Radon Measurement

通过对注气(CO2)压裂后煤层中氡析出、运移产生影响的研究,探讨测氡法在煤层注气后CO2运移监测的可行性。运用趋势面分析法对测氡法探测结果进行分析,结果表明:煤层注气(CO2)压裂,有利于增加煤层的射气系数,从而在地面形成可观测的氡值异常;CO2在低变质煤层中的运移受煤层走向的影响,容易沿煤层走向方向发生运移。活性炭能谱测氡法可以作为监测注气后CO2运移的方法。

Based on the research on the effects of radon exhalation and migration caused by the CO2 injection,the feasibility is discussed that the application of radon measurement method in CO2 migration monitoring after gas injection in coal seam. The trend surface analysis method is used to deal with the detection results of radon measurement,the results show that the gas（ CO2） injection fracturing in coal seam,it is beneficial to increase radon emanation coefficient,which makes radon anomalies measurable on the ground. The coal seam direction can affect the CO2 migration in low metamorphic coal seam,the migration happens easily along the coal seam direction. The radon measurement method with activated carbon spectrum can be used to monitor CO2 migration after gas injection.