Online Monitoring of Corrosion in a Liquid-Steam Line Pipe of the Miravalles Geothermal Field

 

Monitoreo en Línea de la Corrosión en Tuberías de Flujo Bifásico en el Campo Geotérmico Miravalles

 

 

G. Tres,¹,* E.A. Saborío,² L.R. Ajún,³ A. Arias,⁴ A. Rodríguez,⁵ O. Bravo,⁶ J.M. Malo⁷

 

^1,2 Centro de Investigación en Corrosión (CICorr)- Instituto Costarricense de Electricidad (ICE)

^3,4 Ingeniería de Plantas de Potencia- Instituto Costarricense de Electricidad (ICE)

⁵ Área de Geociencias,  Recursos Geotérmicos- Instituto Costarricense de Electricidad (ICE)

⁶ Centro de Electroquímica y Energía Química (CELEQ), Universidad de Costa Rica

⁷Instituto de Investigaciones Eléctricas (IIE), México

 

Received 9^th July 2007; accepted 21^st December 2007

 

 

Abstract

The goal of this study was to evaluate the internal corrosion in a liquid-steam pipeline (type A515 low carbon steel) of the Geothermal Field of Miravalles (CGM) in Costa Rica, and to determine the corrosion thickness for future geothermal fields. The monitoring was carried out using the following techniques: linear polarization resistance (LPR), electrical resistance (ER), and weight loss. The results show for neutral or alkaline pH conditions and slightly free of oxygen, that the corrosion thickness should be 1.8 mm, in order to guarantee the integrity of the pipe over the field lifetime.

Keywords: erosion, LPR, ER, gravimetric method, ultrasound.

 

 

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* Corresponding author. E-mail address: gtres@ice.go.cr