Effect of solid deposition on geothermal utilization and methods of control

Abstract

Solid deposition presents a significant constraint in the design and operation of geothermal fields and power plant equipment. To improve the efficiency of geothermal utilization and to have reliable plant operation, solid deposition must be controlled or avoided. The objective of geothermal exploitation is to maintain a continuous supply of geothermal fluid to the power plant. Scaling problems can adversely affect that, but fortunately countermeasures are available, as will be described in this report. The intent is to show what effect solid deposition has on production wells and power plant operations and to indicate the possible location of solid depositions. Describing commonly applied methods of control is one of the objectives. Two case histories illustrating the effects of solid deposition are included, from Svartsengi geothermal power plant in Iceland and from Aluto-Langano geothermal power plant in Ethiopia, where there are actual influences of solid deposition on well flow and turbine output.