| Title | Heavy Metal Sulfide Scaling in a Production Well at the Salton Sea Geothermal Field |
|---|---|
| Authors | Gallup, D. L.; Andersen, G. R.; Holligan, D. |
| Year | 1990 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Production; Brine Technology; USA; California; Imperial; Salton Sea; Sulfides; Scaling; pH; Temperatures; Solubility in Brine; Inhibitors; Corrosion; Case Histories; Gelena; Bornite; Sphalerite; Troilite; Union Oil Company of California; Unocal; Auto Clav |
| Abstract | Deposition of heavy metal sulfide scales in production wells and wellhead piping has been observed during the extraction of energy from the hypersaline, brine dominated Salton Sea, California geothermal field. The primary constituents of these scales, which typically deposit at rates less than on centimeter per year, include galena (PbS), bornite (Cu5FeS4), sphalerite (ZnS) and trolite (FeS). These minerals precipitate as a result of 1) brine temperature reductions which decrease their solubility, and 2) the loss of CO2 to the vapor phase during flashing which increase the pH of the brine. The metal sulfide scales form as hard, tenacious solids that are removed by periodic mechanical cleaning. An example of a scale deposition episode for a well in the field is provided to illustrate the propensity for precipitation of the metal sulfides from the brine. |