Abstract:
Induced seismicity associated with energy production is becoming an increasingly important issue
worldwide for the hazard it poses to the exposed population and structures. We analyze one of the
rare cases of induced seismicity associated with the underwater gas storage operations observed in
the Castor platform, located in the Valencia gulf, east Spain, near a complex and important geological
structure. In September 2013, some gas injection operations started at Castor, producing a series of
seismic events around the reservoir area. The larger magnitude events (up to 4.2) took place some
days after the end of the injection, with EMS intensities in coastal towns up to degree III. In this
work, the seismic sequence is analyzed with the aim of detecting changes in statistical parameters
describing the earthquake occurrence before and after the injection and identifying possible proxies
to be used for monitoring the sequence evolution. Moreover, we explore the potential predictability
of these statistical parameters which can be used to control the field operations in injection/storage
fluid reservoirs. We firstly perform a retrospective approach and next a perspective analysis. We use
different techniques for estimating the value of the expected maximum magnitude that can occur due
to antropogenic activities in Castor.
