Calcul des réserves du réservoir Cambro-ordovicien d’Unité IV dans le Champ d’In Akamil (Bassin d’Illizi)

Abstract

The present study was conducted as part of the evaluation of the Cambro-Ordovician Tank Unit IV of In Akamil field, located in the central part of the Tinrhert Plateau. This plateau is part of the Illizi basin which is among the most hydrocarbon-rich basins in the Algerian Sahara. This evaluation was approached by studying the geometry of the reservoir, followed by petrophysical characterization before starting the calculations of reserves in place by the volumetric method. The top and bottom of the Cambro-Ordovician Reservoir Unit IV have two high zones in the center and north-west of the study area, ranging in thickness from 122 to 269m, and showing thickening in the upper areas of the field. Its porosity is low and does not exceed 16% whereas its permeability does not reach 24 mD. These values are due to the glacial environment which is known by the very poor sorting of its deposits. The proven reserves calculated of the Cambro-Ordovician IV unit are 72.88 billion cubic meters, the probable reserves in place are 767.52 billion cubic meters and the possible reserves obtained are 2620.61 billion cubic meters. These results concern units IV-1 and IV-3, unit IV-2 is absent in the study area. According to previous sedimentological studies, this hiatus is due to erosion. It is for this reason that the results obtained are to be revised downwards. Indeed, units IV-1 and IV-3 may be affected by this known erosion in the region.