Los Azufres II

摘要

The Comision Federal de Electricidad (CFE) recently commissioned an important new geothermal power plant in Central Mexico- Los Azufres II. It consists of four independent 25-MW units, fueled by 14 production wells. Three deep wells are used for injection of brine back to the geothermal reservoir. Technical and economic features of the project are provided in this article. Los Azufres owes its name to small and scarce deposits of native sulphur around some of the field's natural geothermal manifestations. The field lies at 2,800 m above sea level, surrounded by a pine forest in the State of Michoacan, 90 km east of Morelia (Fig. 1). Exploration studies at Los Azufres started in 1975, and the first exploration well was drilled in 1976. The first power units were commissioned in 1982, consisting of five 5-MW back-pressure turbines strategically located across the geothermal field. In 1987, CFE installed a 50-MW condensing unit in the southern part of the field, known as the Tejamaniles Zone. Four additional 5-MW wellhead backpressure turbines were installed later. CFE also installed two 1.5-MW binary-cycle power plants to use rejected heat associated with separated fluid from some of the production wells. With almost 100 MW of generation capacity at Los Azufres, enough information was collected to review the behavior of its reservoir, and to develop a new model for prediction of the field's incremental capacity. Current installed geothermal power capacity at Los Azufres - including the four Los Azufres II units - is 188 MW (Table 1).