Abstract
The paper discusses the discovery, development, and operation of a miscible gas cycling project in a highly undersaturated, volatile oil TAGI reservoir in center of the Berkine Basin, Algeria. Miscible gas injection was initially considered to be high risk and marginally economic; however, with a flexible development plan and careful reservoir management carried out by an integrated team of surface and subsurface disciplines, a successful project was implemented.
In RKF field, a significant portion of the oil-in-place is in the oil-water transition zone, permeability is low, clay content is high, the oil contains asphaltenes, the formation water is salt-saturated, and the fluvial stratigraphy is complex. Design of a successful gas injection project was particularly challenging under these conditions.
The RKF project demonstrates the importance of acquiring dynamic data early in the appraisal phase tracers and extensive data acquisition was critical to project optimisation and for solving operational `problems such as salt and asphaltene precipitation, minimisation of downtime, maximising liquid recoveries, and balancing of reservoir pressure throughout the field. Integrating all surface and subsurface engineering data, on a continuous basis, with the evolving geological and geophysical interpretations was critical to project success.
