| Title | Geophysical Thermal Studies Applied to Petroleum and Geothermal Mexican Fields: Conductive Surface Heat Flow, Thermal Models and Geothermal Potential Estimations |
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| Authors | O. M. ESPINOZA-OJEDA, E. RIVERA-CALDERÓN, D. BÃEZ-MAGAÑA, A. BELTRÃN-MORALES |
| Year | 2020 |
| Conference | World Geothermal Congress |
| Keywords | geothermal energy, geothermal boreholes, petroleum boreholes, thermal profiles, heat flow, fluid flow, heat exchanger, Mexico |
| Abstract | Currently, México has a great geothermal potential of high enthalpy under exploitation for power generation. According to several published scientific works, exist a large number of thermal manifestations sites considered as low and medium enthalpy, but some of these sites are poorly studied or explored. Alongside, México has very large continental petroleum zones with hundreds of drilled boreholes, which are abandoned due that petroleum resources have been exhausted. Those abandoned petroleum boreholes can be proposed for a geothermal project, that might reduce the project investment costs more than 50%. This option is considerably attractive when it could be applied to a very large network of abandoned boreholes or complete hydrocarbons fields. The scientific evidence confirms that the majority of petroleum boreholes were drilled in areas with high geothermal gradient, which makes them a possible renewable source of geothermal energy. To define the geothermal potential resources from Geothermal and Petroleum Systems, a reliable knowledge from all the involved geological, geophysical and geochemical parameters is required. One of the most important stages of geophysical exploration is the studying the thermal regime caused by the heat transfer that occurs in the formation or reservoir. The thermal regime is defined by the formation temperature profiles and its specific geological characteristics. In this context, conductive surface heat flow data were calculated through drilling logs [Borehole Transient Temperature (TBT) and/or Bottom-Hole Temperature (BHT), and stratigraphic profiles] from geothermal and petroleum boreholes. Therefore, a numerical simulator was developed to compute the conductive steady state thermal model from Geothermal and Petroleum Systems. And finally, to estimate the geothermal potential of an abandoned petroleum borehole, a numerical-analytical model was developed to simulate the heat and fluid transport process occurring inside the borehole. This model comprise the following processes: (a) the heat transfer between the interface wellbore-formation; (b) the heat transfer in the heat exchanger placed inside the wellbore; (c) the injected fluid flow as heat transport inside the heat exchanger; and (d) the extracted fluid temperature calculation according to the injected fluid temperature, fluid flow velocity and the heat transfer from the formation-wellbore interface. |