Impact of silica scaling on the efficiency of heat extraction from high-temperature geothermal fluids

In high-temperature geothermal fields, precipitation of amorphous silica from solution to form silica scales is the main obstacle to efficient heat extraction from the hot fluids. The silica deposits cause operational problems and may even clog pipelines and injection drillholes. The rate of silica-...

Full description

Saved in:
Bibliographic Details
Published in:Geothermics 2005-06, Vol.34 (3), p.320-329
Main Authors: Gunnarsson, Ingvi, Arnórsson, Stefán
Format: Article
Language:English
Subjects:
Earth sciences
Earth, ocean, space
Engineering and environment geology. Geothermics
Exact sciences and technology
Geothermics
High-temperature systems
Injection
Polymerization
Scaling
Silica
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In high-temperature geothermal fields, precipitation of amorphous silica from solution to form silica scales is the main obstacle to efficient heat extraction from the hot fluids. The silica deposits cause operational problems and may even clog pipelines and injection drillholes. The rate of silica-scale formation can be reduced by ageing amorphous silica super-saturated waters, thus allowing the aqueous silica in excess of saturation to polymerize. Polymeric silica shows less tendency to precipitate from solution than monomeric silica. Studies of separated water from the Nesjavellir geothermal power station, Iceland, indicate that silica-scale formation can be avoided during heat extraction by rapid cooling of the water in “capillary heat exchangers”, followed by ageing the water for 1–2 h and subsequently mixing it with condensed steam. It is thus possible to avoid scale formation during injection of the amorphous silica super-saturated water leaving the heat exchanger.
ISSN:0375-6505
1879-3576
DOI:10.1016/j.geothermics.2005.02.002