Modeling Of The Hêtin-sota Geothermal Reservoir In Benin
Auteurs : Hountondji Babilas . Lanmandjekpogni Maurille Paule S. . Ayitchehou Kpadédji Lambert . Codo François De Paule . Aina Martin Pépin .
Résumé
Numerical models of geothermal reservoirs have been developed by several researchers. Pressure and temperature data have been determined for the Hêtin-Sota geothermal reservoir, but regional flow data are still lacking. This article has enabled the development of a simplified model of the Hêtin-Sota geothermal reservoir. The objective of this study is to understand the regional flow dynamics in the large-scale underground reservoir (aquifer), i.e. to map the flow directions, in order to improve the management of groundwater resources in the Lower and Middle Ouémé Valley, to which the locality of Hêtin-Sota belongs. The natural regional flow of the Hêtin-Sota geothermal reservoir aquifer was assessed using piezometric, groundwater depth, and borehole depth maps of the Benin coastal sedimentary basin. This map, extracted from the aquifers of the Benin coastal sedimentary basin, was produced in 2024 by Benin Water Directorate (DGEau). The average depth of the static level is estimated to be less than 10 m. The gradient was estimated at approximately 0.2%, graphically derived from the piezometric map extract. The piezometric map of the Hêtin-Sota aquifer allowed for the representation of aquifer flow at the regional scale but not at the local scale of the study area. Thus, four (04) radiating directions (A, B, C and D) were identified, confirming the phenomenon of radial flow towards the study area. The hypothesis of relatively homogeneous regional flows of low amplitude, characteristic of the Hêtin-Sota reservoir alone, appears too restrictive. These results, which are currently partial, serve both as support for and as a constraint on the flow model.
Mots clés
Modeling ; hydraulic potential ; porous reservoir ; Hêtin-Sota ; Benin
