The CO2 miscible flood project in the Joffre Viking pool is unique. It was the first commercial CO2 flood in Canada and is a true tertiary oil recovery application from an abandoned waterflood project. The project uses waste CO2 from the adjacent NOVA chemical plant, as miscible solvent. A significant amount of CO2 has been sequestrated in the Joffre Viking pool.
The project is a technical and economical success with tertiary oil recovery ranging 12 – 25 percent of the original oil-in-place for diverse developmental patterns. This paper summarizes the development history of the project and illustrates the effectiveness of CO2 and water injection in terms of oil recovery and CO2 utilization. This paper also demonstrates the importance of reservoir monitoring to optimize sweep efficiency, as the patterns become mature.
Even after 19 years since the initial pilot program, the project still produces a significant volume of oil economically. Penn West Petroleum Ltd., the main working interest owner and operator, is currently proceeding with pattern expansion within the Joffre Viking Tertiary Oil Unit.
Penn West Petroleum Ltd. operates the CO2 miscible flood project in the Joffre Viking Tertiary Oil Unit (JVTOU), northeast of Red Deer, Alberta, Canada (Figure 1). This is the only commercial CO2 flood project in Alberta.
Since the original two pattern pilot program in 1984, the CO2 flooding has been progressively expanded. The project is currently composed of 13 CO2 injection patterns with 32 oil producers, 14 CO2 injectors and 3 fence peripheral water injectors, as shown in Figure 2. About 70% of the JVTOU is under CO2 miscible flooding. Penn West is currently undertaking pattern expansion into the undeveloped part of the unit.
The CO2 project has been effective in recovering tertiary oil with cumulative oil production of 580 × 103 m3. It is currently producing oil at 100 m3/d with 265 × 103 sm3/d CO2 injection.
The project has experienced early CO2 breakthrough. Typical water-alternating-gas (WAG) process does not control CO2 fingering effectively in the JVTOU. Simultaneous CO2-water injection seems to stabilize CO2 fingering much better, improving areal sweep efficiency.
In addition to the review on the project geology and development history, this paper discusses the practical aspects of reservoir monitoring and optimization including the performance of individual injection patterns, critical monitoring parameters, mobility control and the current pattern expansion.
The Joffre Viking oil is trapped stratigraphically in an elongated barrier sand bar, which is 32 km long and 1.5 – 3.5 km wide.
Sediments of the Lower Cretaceous Viking Formation in the Joffre area were deposited as coarse grained to conglomeratic, northwest-southeast trending clastic sand bodies. The Albian aged Viking formation overlays the marine shales of the Joli Fou and is, in turn, overlain by transgressive marine shales of the Colorado Group.
The Viking sands in the Joffre area appear to be transgressive shoreface deposits that are often erosionally truncated during sea-level falls. The Viking sands have a shore-parallel orientation, with the shoreline to the southwest and the marine basin towards the northeast.
