New Design and Advanced Processing for Frac Jobs Monitoring

The main goal of frac monitoring is to obtain a clear definition of event characterization to ultimately compute SRV. Enhancement in signal-to-noise ratio is one of the key elements used to discriminate a successful technique from others. While in the buried sensors design the noise reduction is a wellaccepted advantage, the simple layout of surface sensors arrayis still under discussion. This abstract presents results obtained with a new surface design used in hydraulic fracturation monitoring showing how geometry and spatial distribution of the sensors can improve SNR and therefore sensitivity. This new design is named‘patch design’.The name is self-explanatory: OnePatch consists in a given number of sensors closely distributed; a patch design is a series of patches sparsely distributed above the region of interest. This design has several advantages; we will discuss here the economic and technical benefits of this method. Sensor deployment can be easily adapted to the environment optimizing permitting, line clearing, access and avoiding noise prone areas. The economic advantage does not weaken the technical benefit: at the patch scale, the short distance between sensors allowsadvanced summation to optimallypreserve the signal and reduce the noise. The patch design provides a much higher signal-tonoise ratio compared to the usual surface designs. Real cases examples will show how the patch design combines the advantages of both surface and shallow buried array designs.