Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Making Geothermal More Productive: $10.2 Million Study

09.09.2009
University of Utah researchers will inject cool water and pressurized water into a “dry” geothermal well during a five-year, $10.2 million study aimed at boosting the productivity of geothermal power plants and making them feasible nationwide.

“Using these techniques to increase pathways in the rock for hot water and steam would increase availability of geothermal energy across the country,” says geologist Ray Levey, director of the Energy & Geoscience Institute (EGI), which is part of the university’s College of Engineering.

EGI geologist Joe Moore – who will head the research effort at U.S. Geothermal Inc.’s Raft River power plant in southeast Idaho – says most geothermal power in the United States now is produced west of the Rocky Mountains, where hot rocks are found closest to the surface.

“Hot rock is present across the United States, but new methods have to be developed to use the heat in these rocks to produce geothermal power,” says Moore. “We want to use oil and gas industry techniques to create pathways in the rock so that we can use the heat in the rocks to generate electricity.”

“There’s incredible potential in Utah and other states for geothermal development,” he adds. “Engineered geothermal systems [in which water is injected to enhance natural cracks in the rock] could provide a means of developing these resources much faster.”

The U.S. Department of Energy on Sept. 4 signed an agreement with the University of Utah and EGI to pay almost $7.4 million of the project’s cost.

The University of Utah is providing $1.1 million through the Office of the Vice President for Research. Another $1.7 million will be provided by discounts or cash or in-kind donations by two of EGI’s partners in the project: U.S. Geothermal, Inc. of Boise, and Apex HiPoint, LLC, of Littleton, Colo.

Moore says the university’s contribution will help fund involvement of graduate and undergraduate students from the College of Engineering and College of Mines and Earth Sciences.

Experiment at Raft River

“We’re going to take a geothermal field and improve its productivity,” Moore says. “We’re going to test the techniques on one well at Raft River. We’re testing methods to take wells that are not productive and make them productive.”

Moore says the Department of Energy did geothermal research for three decades at the site, located 11 miles from Interstate 84 in southeast Idaho halfway between Boise and Salt Lake City. Raft River is now a U.S. Geothermal power plant producing 10.5 to 11.5 megawatts of electricity – enough for roughly 10,000 homes. The power is sold to Idaho Power Co.

Some estimate the site may be capable of producing 110 megawatts of power. Researchers believe production can be increased because underground temperatures measure 275 to 300 degrees Fahrenheit at depths of 4,500 to 6,000 feet.

The Raft River plant currently has five “production” wells that produce geothermal energy and four “injection” wells where water from the production wells is returned to the underground geothermal reservoir. Water must be re-injected to maintain pressure in a geothermal power system.

One well drilled in recent years did not produce enough hot water to be used as a production well because it did not connect with enough of the underground cracks that carry the hot water.

“Geothermal wells are like oil wells – some wells produce and some don’t,” Moore says. “Drilling wells is expensive. That is why we need to develop low-cost techniques to improve their productivity.”

If the experiments run by EGI work, U.S. Geothermal eventually will operate the test well and put it into service.

Stimulating Geothermal Power by Cracking Hot Rock

To produce geothermal power, hot rock is not enough. The rock also must be permeable to the flow of water and-or steam, says John McLennan, an engineer at EGI. Many geothermal reservoirs have heat, but the rock is impermeable, which is the problem at the Raft River well known as RRG-9.

The experiment will try to make RRG-9 into an effective injection well because U.S. Geothermal must inject more water into the ground to increase the productivity of its existing production wells. Moore says all the water-injection “stimulations” will be done during 2010, with the well monitored over the rest of the five-year study period. All the water will come from production wells, not from streams.

Researchers will first let cold water flow into the hot rocks around the 6,000-foot-deep well, hoping to crack them extensively, and then pump water into the ground under high pressures to force the cracks to open wider. The goal of this “hydraulic stimulation” is to create a network of underground conduits that connect the well with underground cracks that already carry hot water.

“When the cold water reaches the hot rock it will crackle,” Moore says. “Stimulation is the process of generating new cracks.”

Apex Petroleum Engineering, Inc. of Englewood, Colo., will help design the water injection operations to create “hydraulic fractures.” Apex HiPoint’s monitoring equipment will listen to microseismic activity in the rural area to determine the extent of the cracking and thus the growth of the underground geothermal reservoir. Groundwater flow and pressures will be monitored.

Moore says three “stimulations” will occur. During the first two, relatively cool water (40 to 135 degrees Fahrenheit) will flow into the well to crack the rock at a depth of 6,000 feet. Then, a third “stimulation” will involve pumping large volumes of water into the well at high pressure to expand the cracks and keep them open to the flow of water and steam.

The lower half of the well is uncased by piping. The researchers will insert more piping so that the injected water will flow to the depths where it is needed.

McLennan says semi-sized trucks carrying large pumps will come to the well site and may pump as much as 4,200 gallons of water per minute into the ground during each “stimulation.” The total amount injected “could be on the order of 1 million gallons” for each of three “stimulations,” he adds.

The goal, says Moore, is “to create a complex fracture network over an extensive area.”

The Department of Energy wants to develop methods that can “stimulate” geothermal production in various geological environments with various rock types, Moore says. If the techniques used at Raft River prove effective, they could be used anywhere rock is hot.

“It will definitely be an advantage to Raft River if they can improve the productivity of the well, but the Department of Energy is funding this as a research program because hot rock exists everywhere,” Moore says.

The Energy & Geoscience Institute is a contract research organization. Levey says that in terms of the number of participating companies, EGI is the largest university-based research consortium working with the energy exploration and production industry.

In addition to their positions at EGI, Levey and Moore are research professors of civil and environmental engineering at the University of Utah, and McLennan is a research professor of chemical engineering and civil and environmental engineering.

Contacts:

-- Joe Moore, geologist, Energy & Geoscience Institute – office (801) 585-6931, cellular (801) 231-0393, jmoore@egi.utah.edu

-- John McLennan, engineer, Energy & Geoscience Institute – office (801) 587-7925, cellular (801) 634-4412, jmclennan@egi.utah.edu

-- Ray Levey, geologist and director, Energy & Geoscience Institute – office (801) 585-3826, cellular (801) 673-0554, rlevey@egi.utah.edu

Lee Siegel | Newswise Science News
Further information:
http://www.utah.edu

More articles from Studies and Analyses:

nachricht Multi-year study finds 'hotspots' of ammonia over world's major agricultural areas
17.03.2017 | University of Maryland

nachricht Diabetes Drug May Improve Bone Fat-induced Defects of Fracture Healing
17.03.2017 | Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>