Correlation of heating index with production zones in Cerro Prieto, area IV, Mexico

Abstract

We apply a methodology used in geothermal reservoir engineering in order to look for features related to the production zones of the area. Heating index was calculated for 16 wells located in the area of Cerro Prieto IV in the Cerro Prieto Geothermal Field, Mexico. Graphs including heating index, lithology, thermal logs and well completion were prepared for each well. They show the layer where water enters the reservoir and heat flows from the rock to the well. This permeable zone is known as the silica-epidote zone. The heating index for each well was calculated as a function of time and temperature gradient along the well profile. Cooling due to drilling was also considered to determine heating indices. The heating indices are useful, but they also need to be correlated with other parameters to obtain a complete evaluation of the formation.