Abstract
The paper shows a field application of gas tracer technology for improving the reservoir description and optimising RKF miscible gas injection project.
In a miscible gas injection process, the dynamic characterisation of flow paths is critical. Gas tracer technology is emerging as a powerful tool to quantify reservoir properties that control gas displacement processes. The Capillary Absorption Tube (CAT) combined with Gas Chromatography with Mass Spectrometer detection (GC/MS) method has significantly improved the ease and safety of tracer sample collection and transport, providing cost-efficient information.
RKF field, operated by the Sonatrach/CEPSA Association in the Berkine Basin of Algeria, is producing mainly from TAGI formation by peripheral down dip miscible gas scheme. Perfluorocarbon gas tracers were injected as part of the initial 1997 reservoir management plan and monitoring allowed to building good tracer production profiles.
CEPSA has developed an "integrated tracer-reservoir performance analysis" program consisting of qualitative and numerical analysis techniques. Operational plan modifications are developed from this program to optimise field performance. Slim tube and sector model, were built with VIP™ to evaluate tracer flow simulation under miscible gas injection conditions. Following these studies, tracer breakthrough times were history matched in the full field simulation model.
Some operational changes made to gas injection patterns, as a result of the tracer monitoring program, have increased oil production and improved recovery.
