Rocks under High Water Pressure

August 9, 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: Crop rotation boosts soil microbes, benefits plant growth

Related Stories

Crop rotation boosts soil microbes, benefits plant growth

September 3, 2015

In the first study of its kind, new research from the University of New Hampshire shows that crop rotations, in isolation from other management factors, can increase the functions performed by soil microbial communities that ...

Staying safe in sandy beaches

August 28, 2015

Beach sand contains all kinds of microorganisms, including those that can harm human health. Yet current guidelines are focused exclusively on monitoring the levels of microbes in the water.

The gas giant Jupiter

August 26, 2015

Ever since the invention of the telescope four hundred years ago, astronomers have been fascinated by the gas giant known as Jupiter. Between it's constant, swirling clouds, its many, many moons, and its red spot, there are ...

Recommended for you

History shows more big wildfires likely as climate warms

October 5, 2015

The history of wildfires over the past 2,000 years in a northern Colorado mountain range indicates that large fires will continue to increase as a result of a warming climate, according to new study led by a University of ...

Predictable ecosystems may be more fragile

October 7, 2015

When it comes to using our natural resources, human beings want to know what we're going to get. We expect clean water every time we turn on the tap; beaches free of algae and bacteria; and robust harvests of crops, fish ...


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.