English
 
Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
Add to Basket
  Local TagsRelease HistoryDetailsSummary

Released
Journal Article

Permeability Enhancement and Fracture Development of Hydraulic In Situ Experiments in the Äspö Hard Rock Laboratory, Sweden

Authors
/persons/resource/zimm

Zimmermann,  G.
4.8 Geoenergy, 4.0 Geosystems, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;

/persons/resource/zang

Zang,  A.
2.6 Seismic Hazard and Risk Dynamics, 2.0 Geophysics, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;

/persons/resource/ove

Stephansson,  Ove
2.6 Seismic Hazard and Risk Dynamics, 2.0 Geophysics, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;

Klee,  Gerd
External Organizations;

Semikova,  Hana
External Organizations;

External Ressource
No external resources are shared
Fulltext (public)

325992.pdf
(Postprint), 4MB

Supplementary Material (public)
There is no public supplementary material available
Citation

Zimmermann, G., Zang, A., Stephansson, O., Klee, G., Semikova, H. (2019): Permeability Enhancement and Fracture Development of Hydraulic In Situ Experiments in the Äspö Hard Rock Laboratory, Sweden. - Rock Mechanics and Rock Engineering, 52, 2, 495-515.
https://doi.org/10.1007/s00603-018-1499-9


Cite as: https://gfzpublic.gfz-potsdam.de/pubman/item/item_3259924
Abstract
A new advanced protocol of progressively increased cyclic injection and pulsed injection design for hydraulic fracturing experiments was implemented at 410 m depth in the Äspö Hard Rock Laboratory in Sweden. A monitoring array was installed around the tested horizontal borehole to detect the acoustic emissions and micro-seismic events during the fracturing process. The aim is to identify optimized injection schemes to reduce the seismicity related to the fracturing processes. The cyclic stimulation scheme of loading and unloading the fracturing net pressure leads to a lower accompanied seismicity if compared to the conventional hydraulic fracturing with constant flow rates. The related permeability of the tested rock interval can be increased, but this increase is less pronounced than that of the conventional treatments and, especially, if compared to the last of the re-fracturing series with high seismicity increase. Despite these limitations, in field applications with expected high risk of unwanted seismic events, this advanced protocol can be a feasible option to reduce this risk.