For completing wells in oil and gas reservoirs it is quite common to stimulate the
well with a hydraulic fracture. However, the treatment is often sub-optimal because
the fracture geometry is poorly know. Recent advances in micro-seismic monitoring
have aided in optimizing hydraulic fractures and revealed that fracture geometry
often deviates from simple modeling.
For accurate event location we need first to establish a velocity model and we will
show how this can be improved by a checkshot and using initial events. Furthermore
we will discuss the application in a few field cases with unexpected fracture
geometry. Characterization of fracture height growth, connection with faults and
complex branched fractures will be shown as examples of micro-seismic monitoring.