Análisis térmico de la Cuenca Oriental de Venezuela a partir de información de pozos

The Guárico Sub-basin, located within the Eastern Venezuelan Basin, forms an important region for oil exploitation, with an important number of oil producing wells and significant gas reserves. The geochemical well data and bore hole temperature values clearly shows an anomalous thermic behaviour in the northern region of the Guárico Sub-basin, represented by a high heat follow zone. The well selection and the quality control of their temperature data, allowed the elaboration of a series of thermal sections across the northern zone of the Subbasin where the data is concentrated. With these profiles it is possible to identify high temperature characteristics in the thick layer of the Miocene sediments and elaborate a series of heat flow maps corresponding to different geologic times. With these maps, a high heat flow has been recognized in the northern region of the Eastern Basin, with values between 60 and 75 mW/m2. The high temperature gradients to the north of the Guárico Subbasin and in the proximities of the Maturín Sub-basin are associated to Miocene sediments located between 2000 and 3500 meters depth. This high temperature gradient may be caused locally by the adiabatic compression of gases due to the compressive process associated with the Guárico Deformation Front. The regional cause of the high heat flow values in north-western Venezuela may be related to the subduction of the Caribbean Plate under the South American Plate. Under subduction melted material forms an asthenospheric wedge that erodes thermally the base of the Southamerican lithosphere producing a temperature high in the northwest and northcentral areas of Venezuela.