Corrosion and scaling at Cerro Prieto geothermal field

Abstract

Purpose -The aim of this work is to study the corrosion and scaling factors, mechanisms and processes affecting the materials, equipment and installations of the Cerro Prieto geothermal field (GTF). Design/methodology/approach -The physicochemical characteristics of the geothermal well and fluids were analysed, recorded and related to the corrosion and scaling phenomena. Findings -The high temperature and salinity of the steam-brine mixture and the presence of hydrogen sulphide and carbon dioxide impart a severe level of corrosivity. Originality/value -Corrosion and scaling control assure an efficient production regime, provide for the durability of the GTF engineering materials and equipment and contribute to environmental quality.

Thermal effects on microbial composition and microbiologically induced corrosion and mineral precipitation affecting operation of a geothermal plant in a deep saline aquifer

“…These reactions are related to the degradation of organic matter (Parkes et al 1994(Parkes et al , 2000Whitman et al 1998;Wellsbury et al 2002), rock and mineral weathering and alteration (Rogers et al 1998;Bennett et al 2001;Shock 2009;Gadd 2010), quality of groundwater (Goldscheider et al 2006;Wilson et al 2006;Griebler and Lueders 2009), and failures in engineered subsurface systems caused by corrosion and scaling (Van Hamme et al 2003;Valdez et al 2009;Javaherdashti 2011). Geothermal gradients in the terrestrial crust range from approximately 10°C km -1 to 60°C km -1 (Philpotts 1990).…”

“…Highly mineralized geothermal fluids with an excess of sulfate tend to scale formation (sulfide, carbonate, silica) in the reservoir, pipelines and topside structures when brine is cooled in the course of fluid production and energy extraction (Skinner et al 1967;Dalas and Koutsoukos 1989;Gallup 2002). Furthermore, chemically and microbially induced corrosion additionally occurs in plant infrastructure and adversely affects plant operations and commercial benefits (Gallup 2009;Valdez et al 2009;Miranda-Herrera et al 2010). Therefore, the detrimental effect of microbes on power plant components has increasingly garnered attention.…”

“…Therefore, the detrimental effect of microbes on power plant components has increasingly garnered attention. Indeed, several studies have been conducted to identify the organisms responsible for phenomena such as scaling, biofouling, and corrosion of installed iron or steel in groundwater wells and geothermal plants (Taylor et al 1997;Sand 2003;Cullimore 2007;Little and Lee 2007;Valdez et al 2009) to reduce these sources of failure, plant downtime, and the cost-intensive replacement of plant components. For example, the effectiveness of groundwater wells can be influenced by scaling, as iron and other metallic cations are enriched by precipitation that leads to the formation of amorphous or crystalline structures.…”

“…Biofouling refers to the accumulation of microorganisms that form complex biofilms that include mineral deposits and adversely affect the hydraulic characteristics of water flow (Howsam 1988;Cullimore 1999). Microbiologically influenced corrosion (MIC) usually occurs with various types of corrosion and with scaling (Little et al 1996;Valdez et al 2009). Studies focusing on biofilms in several industrial water systems reported extensive biofouling and associated mineral precipitation leading to reduced efficiency of heat exchangers and reduced flow rates in the piping (Characklis 1990;Flemming 2002;Demadis 2003;Coetser and Cloete 2005).…”

“…Furthermore, new casing materials are used. Although biocorrosion is a common problem, it is site-specific and depends on fluid temperature as well as on the chemical conditions such as salinity and dissolved organic carbon (DOC)-content, and the abundant microbial community (Valdez et al 2009). An understanding of the underlying mechanisms requires knowledge of the carbon and energy sources that support biofilm microorganisms and catalyze such activities.…”