| Title | Abrasion by Particles in Suspension in Ultra High Enthalpy Geothermal Production (Super- Hot Geothermal Wells) |
|---|---|
| Authors | Heber DIEZ, Cristobal CAMACHO, VÃctor SORIA, Héctor MARTÃNEZ, Felipe SOLANO and Gabriel LUÉVANO |
| Year | 2020 |
| Conference | World Geothermal Congress |
| Keywords | Abrasion, erosion, particles, silica, quartz, deposition, incrustation, corrosion, casing, materials, superheated, enthalpy, modeling, numerical simulation, CFD. |
| Abstract | The hydrothermal geothermal wells of ultra-high enthalpy (supercritical or superheated) are excellent producers. However, despite being a desired resource for their energetic conditions for electricity generation purposes, they bring multiple operational problems, such as scaling, corrosion and abrasion-erosion. This can dramatically reduce the useful life of the production well, impacting the reliability and production costs of geothermal power plants. In this research, it was demonstrated that in geothermal wells that operates in superheated thermodynamic conditions, produces highly abrasive-erosive steam, among other undesirable characteristics, attributable to suspended solids that travel in the production fluid. In spite of the different chemical reactions and operating conditions that can contribute to the degradation of the casing and the equipment in contact with the fluid, it was found that the abrasive-erosive phenomenon has the greatest impact on casing wear and it is considered that it can favor other chemical phenomena in its degradation. In order to demonstrate the aforementioned phenomenon, the production conditions of a well with superheated characteristics were studied, physical evidence was collected in several mechanical elements (deposits) and analyzed, and at the same time an extended review of the state-of the art in experimental research on possible physical-chemical phenomena that could occur in systems under similar conditions has been carried out in order to discriminate and simplify the case of study. Subsequently, a mathematical model was developed that was solved numerically using commercial Computational Fluid Dynamics (CFD) software, and the results were validated against experimental data obtained from a mechanical element (capillary tube) that suffered serious mechanical damage after 251 hours of operation in the well under the mentioned conditions. The simulation succeeded in reproducing the abrasion-erosion phenomena that occurred in the capillary tube in a satisfactory way, and for the casing the mathematical model predicted critical mechanical damage appearing after two years of operation of the well under the reported conditions. Therefore, it is concluded that the abrasion-erosion phenomena have a significant effect on geothermal wells operating under superheated thermodynamic conditions and a dramatic impact on their useful life, as has been observed in some geothermal wells. Therefore, it is suggested to carry on with the research on the development of new materials capable of withstanding such aggressive operating conditions. |