Four fundamental methods are introduced , namely well temperature , ground potential survey , microearthquake and radioactivity isotope , which were used to monitor the fracture geometry of fractured coalbed methane wells in north china 摘要介绍了井温测试法、放射性同位素法、大地电位测试法和微地震测试法监测煤层水力压裂裂缝的基本原理。
