TOP > Technology > Fractured Reservoir
The Yufutsu oil and gas field is located in the
Southern Ishikari Plain, central Hokkaido, in northern Japan.
The reservoir, seated at around 4 km depth, is known as a so called
"fractured reservoir", meaning that oil and gas are
stored in cracks in the granite and overlain conglomerates. Performances
of fractured reservoirs are strongly controlled by distribution
and orientation of natural fractures and faults. Spaces for storage
of gas/oil and paths for transporting them are considered to be
provided by fractures of various scales. These fractures connect
to each other and make networks in reservoirs. For optimizing
E & P strategies, it is a critical issue to characterize the
fracture networks precisely by taking suitable approaches. JAPEX
takes multidisciplinary researches listed below.
Reliable fracture network model is created by integrating various
kinds of information including core analysis, borehole measurement,
acoustic emission(AE) monitoring and geological survey.
Hydraulic shearing is a kind of hydraulic injection aiming to
induce shearing of rock along pre-existing fractures. This treatment
improves fracture permeability and also induces AE activity.
Monitoring and analysis of AE signals provide us with information
about the spatial distribution of the fracture system.
SHIFT is an originally developed numerical simulator, which
calculates shearing of fractures and relates AE activities and
permeability enhancements during hydraulic stimulations.
