De-noising for Low Signal to Noise Ratio Surface Microseismic with Wavelet Transform on Gas Shale Hydrofracture

In order to form fracture network and improve drainage area, gas shale reservoir have to be reformed by hydraulic fracturing. The geometric size, extension direction of fracturing can be predicted with microseismic monitoring, the stimulated effect and performance of gas production can be evaluated. Due to the complex environment and diversity of noise types, the signal energy of surface microseismic monitoring is weak, which is easily covered by noise, and the signal-to-noise ratio (SNR) of raw data is very low.