Research of Transient Electromagnetic Method Detection on Groundwater Response During Coalbed Methane Well Drainage

In order to monitor hydrogeology dynamic change effectively and discuss the migration of groundwater during drainage, transient electromagnetic metho d ( TEM) was carried out to track and simulate the groundwater of No. 3 Coalbed near PE- 055 Well which was located in Panzhuang Block. The study found that dyna mic changes of hydraulic connection and the storage of groundwater were caused during the process of drainage. That synchronous change between apparent resistivit y and groundwater connectivity were highly coupled showed that TEM could monitor groundwater migration well. Apparent resistivity, reduced within certain range in the area of strong groundwater connectivity by comparison, would increase within different degree in the area of poor groundwater connectivity after drainage. The differenc es of reservoir between before and after drainage as well as instructions of groundwater migration direction were reflected by dynamic change of apparent resistivity, W hich provided new ideas and technologies for groundwater monitoring during CBM well's drainage.