Rocks under High Water Pressure

Aug 09, 2007
Rocks under High Water Pressure

Today, Thursday the 9th of August 2007, the GFZ Potsdam, Germany's National Lab for Geosciences is starting a new series of experiments at the geothermal research site Gross Schönebeck.

In these so called hydraulic fracturing experiments, huge amounts of water are being pressed under high pressure into the underground, in a 4.4 km deep wellbore. Natural fractures and fissures will be widened through the waterpressure, and new flowpaths generated. The experiments will last about 6 weeks.

Similar test were successfully performed already in a second well at Gross Schönebeck in 2003, when 12 Million literes of water were pumped into the underground. The experiments are aiming at using geothermal energy not just for heating purposes, but for generating electricity. For this, hot natural water will be produced from one well, utilized in a future geothermal powerplant, and than pumped back into the underground, through a second wellbore - a closed water circle.

"Under the local geological conditions, only in a depth of more than 4 km the minimum temperature of 150 °C is found, which is necessary for an electrical power generation. Under these conditions, as much naturally hot water has tobe produced from the well as possible, in order to operate a geothermal powerplant successfully" explains Project Manager Dr. Ernst Huenges of the GFZ Potsdam. "The more permeable the underground rocks are, the more water flows through the reservoir into the production well".

The stimulation will be performed in three injection phases in varions rock layers. After Ernst Huenges, it can be excluded, that the stimulations will cause any weak earthquakes. "We have performed similar experiments in 2003 already at the same location, with its sedimentary rocks that are typical for the northgerman basin - without any recognizable seismicity." Routinely the progress of the hydro-frac experiment will be observed by highly sensitve seismic monitoring instuments. A later long term experiment between the two wells shall prove the success of the stiumulation, and document the increased water flowrates.

At the GFZ-Geothermal Laboritory Gross Schönebeck, scientific experiments and investigations aiming at geothermal electrical power generation are being performed since 2001 already. An earlier natural gas well from the 90s was reopend by the GFZ Potsdam for this purpose and deepend to a depth of 4,3 km. In January 2007 the second well was compleded with a final depth of 4,4 km, in which the stimulation experiments are being performed now.

Source: GFZ Potsdam

Explore further: Fast access to CryoSat's Arctic ice measurements now available

Related Stories

White dwarf may have shredded passing planet

14 minutes ago

The destruction of a planet may sound like the stuff of science fiction, but a team of astronomers has found evidence that this may have happened in an ancient cluster of stars at the edge of the Milky Way ...

Mexico boosts protection of near-extinct porpoise

5 hours ago

Mexico is greatly expanding a protected area of the Gulf of California and boosting navy patrols in an effort to save the vaquita marina, a small porpoise facing imminent extinction.

Court monitor: Apple antitrust cooperation has 'declined'

5 hours ago

Apple Inc.'s cooperation with efforts to improve its compliance with antitrust laws after a federal judge concluded it colluded with electronic book publishers to raise prices five years ago took on an "adversarial tone" ...

Recommended for you

Arctic sea ice maximum reaches lowest extent on record

Apr 16, 2015

The National Snow and Ice Data Center (NSIDC) is part of the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder. NSIDC scientists provide Arctic Sea Ice News ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.