| Title | Obtaining Permeability in Geothermal Wells by Targeting Fault Damage Zones |
|---|---|
| Authors | Bogie, Ian; White, P. J.; Lawless, J. V.; Ussher, G. N.; Barnett, P. R. |
| Year | 2006 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Resource Characterization; fault damage, permeability, drilling, targeting |
| Abstract | Fault damage zones that intersect competent lithologies are prime structural permeability targets for geothermal wells. These targets take the form of lozenge shaped zones around an individual fault or much larger zones between major master faults. As exploitable geothermal fields are most commonly hosted by young volcanic piles in extensional (at least locally) tectonic environments, this is most commonly where relatively flat lying andesitic flows are intersected by steeply dipping normal faults. Successful targeting requires achieving not only the longest possible intersection in three dimensions with target zones, but with the well track orientated to most likely intersect the permeable features within them. This can best be done by the drilling of vertical or oblique footwall directional wells. The wells can be most accurately targeted by using information obtained from downhole formation imaging tools. |