Development of an Improved Cement for Geothermal Wells
Trabits Group has been awarded a development grant from the U.S. Department of Energy (DOE) under the American Recovery and Reinvestment Act of 2009. In partnership with University of Alaska Fairbanks, Trabits Group has begun a three-year project to develop a novel, zeolite-containing, lightweight, high temperature, high-pressure cement for use in casing geothermal wells.
U. S. Department of Energy
The project began in March, 2010, and is scheduled for completion September 30, 2013. Successful completion of the project will result in the development of a cementing solution for geothermal wells that is cost effective as well as logistically simple. This should greatly enhance rapid deployment of geothermal energy as a renewable energy source in the USA, thereby reducing the flow of US dollars to petroleum exporting countries.
The cement to be developed would have the following characteristics:
- Thermal stability with little strength retrogression to 300° C.
- Tensile strength to withstand temperature and pressure changes.
- Low-density, low-viscosity slurries with low equivalent circulating densities (ECD) without the need for air or nitrogen foaming.
- A single cement blend allowing density adjustments without adversely affecting slurry properties to eliminate the need for separate blends for lead and tail slurries.
- Resistance to carbonation.
- Accurate downhole densities throughout cement placement without significant changes in viscosity.
- Water absorption capacity without retaining free water.
- Good bonding to casing and formation.
- Adequate compressive strength.