Sustainable Utilization of Geothermal Resources Through Stepwise Development

Abstract

Geothermal energy is a renewable energy source that can be utilized in a sustainable or excessive manner. Excessive production from a geothermal resource can only be maintained for a relatively short time. Therefore, excessive production from a field can indicate overinvestment in wells and power-plant equipment. Sooner or later a field operator is forced to reduce the production to the level of maximum sustainable use. Stepwise development of geothermal resources is a methodology that takes into consideration the individual conditions of each geothermal system and minimizes the long-term production cost. The cost of drilling is a substantial component both in the exploration and the development of geothermal fields. With the stepwise development method, production from the field is initiated relatively shortly after the first successful wells have been drilled and the production- and response history of the reservoir during the first development step is used to estimate the size of the next development step. In this way, favorable conditions are achieved for the timing of the investment in relation to the timing of the revenue, resulting in lower long-term production costs than can be achieved by developing the field in one step. Merging the step-wise development method, with the concept of sustainable development of geothermal resources, results in an attractive and economical way to utilize geothermal energy resources.