  Fracturing in reservoir rocks is an important issue for the petroleum
industry - as productivity can be enhanced by a controlled fracturing
operation. Fracturing also has a big impact on CO2 storage, geothermal
installation and gas production at and from the reservoir rocks. Therefore,
understanding the fracturing behavior of different types of reservoir rocks is
a basic need for planning field operations towards these activities. In our
study, the fracturing of rock sample is monitored by Acoustic Emission (AE) and
post-experiment Computer Tomography (CT) scans. The fracturing experiments have
been performed on hollow cylinder cores of different rocks - sandstones and
chalks. Our analysis show that the amplitudes and energies of acoustic events
clearly indicate initiation and propagation of the main fractures. The
amplitudes of AE events follow an exponential distribution while the energies
follow a power law distribution. Time-evolution of the radial strain measured
in the fracturing-test will later be compared to model predictions of fracture
size.
