Etude de l’efficacité d’injection de gaz dans le champ de Hassi Messaoud

Abstract

The success of a gas injection project in an oil field requires good management at all levels, a good injection-production balance must be maintained at field and cell level, adequate functioning of the producing wells and injectors must be ensured and any well failure must be prevented. Throughout the life of a gas injection project, huge amounts of data are collected and stored by operators. This data can be of great use in the ongoing evaluation of the effectiveness of such a project and in the identification and diagnosis of problems that may arise at any time. In this work, we are focused on the mission of evaluating the efficiency of the gas injection implemented in zone 25 of the Hassi Messaoud field using a set of monitoring techniques applied at two scales: the entire area and the injection cell. At the area level, we reassessed the initial reserves in place using the material balance method in order to determine the level of recovery achieved by natural depletion and then by gas injection. We have also followed the evolution of the injection-withdrawal balance at the zone level in order to determine the effect which its maintaining on production level can have. In terms of injection patterns and after selecting and validating the injection configuration using the pressure profile rendition technique, we analysed and evaluated the performance of each pattern to determine which of them required action to improve production. The study showed that in zone 25 of the said field, gas injection improved production from 3% to 44.6% from 1973 to 2020.