Bedretto, IASS Project, double-packer system with integrated geophones
As part of the IASS project, Solexperts designed, manufactured and installed a modular high pressure double packer system. The system includes 4 geophones which are coupled to the borehole wall with specially designed mechanisms. The system can be used to perform hydraulic fracturing tests and simultaneously record seismic events in the immediate vicinity of the injection.
Test site
The test site is the Bedretto Underground Laboratory for Geoenergies (BULG) in southern Switzerland near Airolo. The BULG is located 2 km from the south entrance in an old access tunnel of the Furka Base Tunnel. It lies in the Rotondo granite and has an overburden of about 1100 m.
Borehole ST2
Length: 350 m
Inclination: 35° from the horizontal
Diameter: 8.5″
Specifications of the double packer system:
- 2 high pressure packers
- 2 interval sections
- 4 geophones with coupling mechanism in the lower interval
- In-situ pressure measurement in the upper interval
- Pressure measurement at the surface from the lower interval
- Water injection up to 200 l/min and 18 MPa
