Zonificación del Gradiente Geotérmico en la Cuenca Oriente a partir de Temperaturas de Fondo de Pozos

Abstract

The Oriente Basin (Late Cretaceous-Cenozoic) is one of the most complex and attractive foreland sedimentary basins of the northern Andes. It’s made up of various tectonic and sedimentary cycles developed on a Precambrian basement. In order to evaluate the theoretical geothermal potential and the potential uses of heat in the basin, data on Bottom Hole Temperatures (BHT) of 1683 deep oil wells, distributed in 202 individual fields, have been obtained from the BIPE (Banco de Información Petrolera del Ecuador) and have been plotted on a georeferenced map, covering an area of 57,400 km2. The statistical treatment of the data for the calculation of the geothermal gradient (GG) included corrections of the BHT according to the method proposed by Willet and Chapman, (1987). From the plotted data, it becomes clear that the Central play, along the Sacha-Shushufindi Corridor, shows low GG values (7.38 to 26.1 ºC/km). On the contrary, high GG values (26.1 to 69.01 ºC/km) are present in the Western play (Sub-Andean System) and in the Eastern play (Capirón-Tiputini System). The distribution of temperature anomalies seems to be related to the NNE-SSO structural control of the basin, whose permeability pattern is well known. The extraction of heat for commercial uses is highly facilitated by the existence of deep wells that penetrate high gradient zones, saving the generally prohibitive costs of deep drilling.