Etude des paramètres pétrophysiques du réservoir Dévonien F3, secteur Nord -Est du champ D’ALRAR, Bassin D’ILLIZI

Abstract

Alrar’s oil field is ranked among the largest hydrocarbon deposits in Algeria. The latter consists of several reservoirs (F6, F5, F4, F3 and F2) belonging to Silurian and Devonian deposits. The study area north-East of this field is characterized by hydrocarbon accumulations in the form of oil rings filling the Devonian F3 reservoir. These rings of oil (10m) between the gas-cap and the low-active aquifer, of average depth 2650 m which is located in the clay-sandstone formation. This reservoir is characterized by a heterogeneity that results in extreme variations in petrophysical properties resulting in the variation of production from one zone to another and from one well to another, this heterogeneity can be divided into an upper part with good petrophysical characteristics and which constitutes a useful reservoir and a lower part with low petrophysical properties (compacted and cemented zone). The logging correlation using the TECHLOG software of the reservoir of the study area has made it possible to follow the spatial extension of this reservoir and which makes appear a sandy reservoir at the low clay top and a development clayey occurring at the base of the reservoir. The statistical study of the petrophysical parameters at allows confirmation of the relationship between permeability and porosity of the lithological component of the reservoir and to finish two porosities a matrix related to a diagenetic primary phase and another secondary that may be related to cementing phenomena that is related to lithology (presence of clay)