Design and Implementation of a Coal-Bed Methane Fracture Monitoring System based on Virtual Instrument Technology

Monitoring of fracture orientation is of significance in the exploration and development of coal-bed methane; for this purpose, a monitoring system, based on the principle of differential electric resistivity tomography, has been widely used. The resolution and monitoring scope determine the detection depth of the coal-bed methane fracturing layer. In this article, a coal-bed methane fracture monitoring system with a resolution of less than approximately 10 mu V and 90 channels is reported using virtual instrument technology. Based on the three-dimensional geoelectric field of vertical finite line source by the finite-difference method, the surface potential difference between different depths and the scope of surface fracture anomaly was calculated, which demonstrated the feasibility of this system. The system exhibited satisfactory performance for a coal-bed methane well in Jixian, Shanxi Province. Compared with a microseismic monitoring system, the coal-bed methane fracture system was more convenient and achieved similar results of fracture orientations at a depth of 1263m. Moreover, it avoided the uncertainty of a single method. Therefore, it is expected that this system may be widely applied to the fracture monitoring of coal-bed methane.