Researchers at Pacific Northwest National Laboratory (PNNL) have developed a self-healing cement that could repair itself in as little as a few hours. Wellbore cement for geothermal applications has a life-span of only 30 to 40 years. When the cement inevitably cracks, repairs can easily top $1.5 million dollars per well. Scientists are developing cement that fixes itself, sidestepping enormously expensive repairs. The cement is suitable for both geothermal and oil and gas applications. With thousands of subsurface energy development wells annually, this technology can have a dramatic impact on the cost of energy production.