Numerical Modeling of Complex Geothermal Steam Transportation Networks: the Cases of Cerro Prieto and Los Azufres, Mexico

Abstract

Modeling and simulation of steam flow in the transportation networks of the Cerro Prieto and Los Azufres geothermal fields, Mexico were carried out in order to determine steam pressures, temperatures, flow directions and velocities, using commercially available simulation software. For each field, a detailed hydraulic model of the pipeline network was first constructed and then each model validated by comparing simulation results with specific data measured for calibration purposes. Then, flow simulations were performed for specific dates and cases for each network. The results showed in general a good agreement between computed and measured well pressures and flow rates at the power plants inlet, with mean relative differences of less than 10%, which is considered a highly satisfactory result given the geometrical complexity and length of each geothermal field network. The low-pressure network of the CPGF showed originally larger pressure and steam flowrate differences, so that an analysis was made in order to reduce these differences and to try to explain the more likely causes of such differences. The experience from these study cases demonstrate the usefulness and suitability of numerical modeling as a tool to evaluate the overall performance of complex steam transportation systems under different operating conditions, and the feasibility of simulating large pipeline network systems reliably using state-of-the-art simulation tools.