Scaling and corrosion formation mechanism in geothermal piping system based on Pourbaix-Lindal diagram-Ryznar index and fluid velocity profile

Abstract

Geothermal fluid flow contains scale and corrosion species whose levels differ from each location of geothermal sources. The velocity of scale formation and corrosion mechanism due to specific parameters in case of total key species, flow rate, pressure and temperature of the geothermal fluid based on the Pourbaix-Lindal diagram -Ryznar index. The reduction in pipe diameter due to the scaling formation on the internal surface of the pipe correlates with the flow rate of geothermal fluid into the turbine, which drives the generator to produce electrical energy. This paper describes the mechanism of scale formation and the potential for corrosion on the internal surface of the piping through the momentum transfer approach of geothermal fluids to the turbine. Through this mechanism, curative and preventive measures can be taken to prevent premature degradation of the function and economic life of the geothermal piping system. The mathematical simulation results of fluid displacement momentum, the velocity of geothermal fluid flow, show that the velocity profile at the fluid-internal surface contact of the pipe is zero, which means that the species is at rest on the internal surface of the pipe. Thus, for scale species it will form a scale, while for corrosive species there will be a corrosion process on the internal surface of the pipe.

Inspection Based Corrosion Rate Mapping for Remaining Strength and Remaining Life of Two-Phase Geothermal Steel Piping

“…Additionally, several studies have been conducted to improve the integrity of pipes and other machine components [2][3][4] [5][6][7] [8]. Regarding the scaling phenomena, an investigation for the mechanism of scale formation and corrosion based on the pH of geothermal fluids in 2020 using the Pourbaix-Lindal and Rayznar index diagram approach that correlated with the velocity profile of geothermal [9]. In 2021, [10] investigated the phenomena of scaling and corrosion on crude oil pipelines.…”

“…Regarding the scaling phenomena, an investigation for the mechanism of scale formation and corrosion based on the pH of geothermal fluids in 2020 using the Pourbaix-Lindal and Rayznar index diagram approach that correlated with the velocity profile of geothermal [9]. In 2021, [10] investigated the phenomena of scaling and corrosion on crude oil pipelines. The studies could be used to determine the remaining strength, remaining life, corrosion, and scaling phenomena in geothermal steel piping.…”