Interferometric Seismic Imaging of Sparsely-sampled Data

Micro-seismicity induced by fluid migration can be used to monitor the migration of fluids during reservoir production and hydro-fracturing operations. The seismicity is usually monitored with sparse networks of seismic sensors. The sparsity of the sensor networks degrades the accuracy of the estimated event locations. This inaccuracy often makes it impossible to infer the fluid pathways at the desired accuracy. Micro-seismicity can be located using an imaging approach based on wave-equation imaging under the exploding reflector model. This idea in itself is not new. What is new, however, is the use of an interferometric imaging algorithm which suppresses artifacts in the location of targets (microseismic) and create crisper images, which translates into more accurate location estimates. The images produced with the interferometric imaging method can be used for robust automatic location of micro-earthquakes with application to 4D monitoring of fluid injection.