Analysis of the relation between bottom hole temperature data and Curie temperature depth to calculate geothermal gradient and heat flow in Coahuila, Mexico

Abstract

Estimations of the Curie temperature depth using aeromagnetic data are commonly employed to study the thermal structure of the crust. In this research, we estimated the Curie temperature-depth with the “de-fractal” method and calculated the geothermal gradient and the heat flow of 24 blocks uniformly distributed in the Mexican state of Coahuila. The reliability of the “de-fractal” method was evaluated by comparing the geothermal gradient results with the Bottom Hole Temperature data available from petroleum boreholes. The maps show that the regional faulting is associated with recent volcanism characterized by shallow Curie temperature-depth (~17 km); furthermore, changes of the fractal parameter have a relationship to the tectonic history of this region and the geology of each analyzed block. The results of our statistical analyses showed that the geothermal gradient estimated with the “de-fractal” method is more closely related to the Bottom Hole Temperature data than the estimations obtained with the “centroid” method. Additionally, the similarity between Bottom hole temperature and Curie temperature-depth calculated geothermal gradient indicated that conduction is the predominant heat transfer mechanism.