Evolution diagénétique et interprétation sédimentologique des grès ordoviciens «Quartzite Hamra» de la région de Hassi-Tarfa.

Abstract

This study, conducted in the area Hassi Tarfa, aims to provide an evaluation of the main sedimentological characteristics of Hamra Quartzite reservoir, which is the one of the largest oil reservoirs in the Algerian Palaeozoic basin. The results show that the "Quartzite Hamra" with homogeneous facieswas deposited in Arenig in a shallow marine environment Petrographic analysis reveals that Hamra Quartzite are classified as quartzsarénites (orarenites quartzite) consisting essentially of rocks associated quartz grains with some heavy resistant minerals. The Formation khew during burial , diagenetic processes that have modified its mechanical properties and resulted in the complete degradation of its porosity ; The diagenetic sequence of the Hamra Quartzite reservoir occurred in three phases: eodiagenesis (early), mesodiagenesis (mid), and telodiagenesis (late) phases. These phases are directly related to tectonic events that affected the study area, and are controlled mainly by the Hercynian unconformity The fracturing study shows that the Quartzite Hamra reservoir contains a network of natural fracturing important, which can play a very important role in improving performance in this field and increasing its primary Petrophysical characteristic especially the permeability.