Using GIS for Practical Geothermal Applications: an Inventory of the Thermal Insulation Condition of the Cerro Prieto Geothermal Field Pipeline Transportation Network

Abstract

The Cerro Prieto geothermal field (CPGF) steam production and transportation system includes 165 producing wells and more than 160 kilometers of pipes with diameters ranging from 8” to 48” from which 92 km belong to the High Pressure (HP) steam pipeline network, 48 km to the Low Pressure (LP) steam pipeline network and 26 km to mixture pipelines (M). Originally, all pipes are thermally insulated with a mineral wool or fiber glass layer and an external aluminum or iron cover. However, in some parts of the network this insulation shows nowadays different grades of damage. As part of a comprehensive study which included the assessment of the heat losses throughout the CPGF pipeline network, it was necessary to inventory the current insulation condition, for which four different insulation qualities were defined: (A) new or complete, with metallic cover, (B) good or without metallic cover, (C) regular or slightly damaged and (D) totally destroyed or absent. The inventory was surveyed in the field and all data implemented into a Geographical Information System (GIS). This tool successfully helped to easily identify those parts of the network where heat losses may be higher, and facilitated the precise quantification of the length corresponding to each insulation quality for each pipeline network (HP, LP, M) and to each pipe diameter. According to the inventory results, about 80% of the total length of the three networks has thermal insulations belonging to A and B qualities, while the remaining 20% showed insulations with qualities C and D. While the results of this work were eventually used for heat loss calculations of the entire transportation network, the methodology employed and generated datasets constitute a basis for developing several practical GIS applications related with the design, operation and maintenance in the CPGF and other geothermal steam fields.