Extending The Lifetime of Geothermal Lineshaft Pumps

Geothermal power plants rely on the hot fluid flow from below the surface to generate clean, sustainable, energy. In high enthalpy fields, artesian well flow is common and does not require artificial lift. In a growing number of geothermal fields, artificial lift is required to deliver fluid to the power plants. Today, Ormat operates approximately 150 production wells with artificial lift technologies, and that number is growing every year. Ormat’s geothermal portfolio is currently approximately 950MW , and approximately 75% of the production wells use artificial lift (the majority are Line Shaft Pumps), representing the largest fleet of geothermal production pumps in the world. The magnitude of these machines, set hundreds of meters below surface, makes the importance of minimizing failures and extending their mean time between failures crucial for a geothermal power plant's financial success. Over the years Ormat gained substantial experience and implemented many strategies to minimize geothermal pumps operation and maintenance expenses, reduce downtime, maximize reliability, while also maximizing well production across our geothermal fleet. With such a large variety of geothermal systems in operations, Ormat is experiencing a rise in the lifetime of pump systems (now 6 to 7 years on average), with some pump systems operating more than 15 years without replacement. This paper will present and review the main strategies that proved to be most successful by Ormat’s operation and engineering teams; from the development of new products, validation testing, operational procedures, and data analysis that provided meaningful insights to a standardized control philosophy of geothermal production pumps.