Geothermal Energy and Associated Drilling, Monitoring, and Development Challenges
Douglas Blankenship
Sandia National Laboratories
Abstract
In the broader public, geothermal energy is the often the forgotten source of renewable energy but it has the potential to have a substantive impact on our Nation’s future energy portfolio. As a base load provider of electricity, geothermal derived power is an excellent complement to intermittent sources of renewable power such as solar and wind. Today, geothermal derived electricity is obtained from exploiting naturally occurring hydrothermal systems and as such it is limited in geographic extent. However, the heat resource is vast and if methods can be developed to economically “mine” this heat it will expand the impact of geothermal energy. However, exploiting geothermal energy requires accessing the subsurface through drilling to both confirm and develop the resource. Drilling is expensive and can easily exceed 50% of the capital costs associated with a development project. While there are similarities between oil & gas and geothermal drilling, there are differences and these differences adversely impact the economics of geothermal development. Sandia National Laboratories is pursuing applied research aimed at reducing the cost of geothermal energy development, particularly with regard to hard rock drilling technology, harsh environment monitoring, and novel reservoir stimulation methods — without such cost reductions geothermal energy will be a bit player in the power generation sphere.