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: Icelandic volcano sits on massive magma hot spot

add to favorites email to friend print save as pdf

Related Stories

Surface properties command attention

Oct 17, 2014

Whether working on preventing corrosion for undersea oil fields and nuclear power plants, or for producing electricity from fuel cells or oxygen from electrolyzers for travel to Mars, associate professor ...

Graphene proves a long-lasting lubricant

Oct 14, 2014

When trying to design a mechanical system to last as long as possible, scientists and engineers have to find ways of overcoming friction. While researchers have found many materials that help to reduce friction, ...

Climate change alters the ecological impacts of seasons

Oct 09, 2014

If more of the world's climate becomes like that in tropical zones, it could potentially affect crops, insects, malaria transmission, and even confuse migration patterns of birds and mammals worldwide. George ...

Recommended for you

Icelandic volcano sits on massive magma hot spot

Oct 24, 2014

Spectacular eruptions at Bárðarbunga volcano in central Iceland have been spewing lava continuously since Aug. 31. Massive amounts of erupting lava are connected to the destruction of supercontinents and ...

NASA sees Tropical Storm Ana still vigorous

Oct 24, 2014

NASA's TRMM satellite saw that Tropical Storm Ana was still generating moderate rainfall is it pulled away from Hawaii. The next day, NASA's Aqua satellite saw that wind shear was having an effect on the ...

User comments : 0