The Valhalla Doe Creek I Pool is a hydrocarbon bearing marine sand deposition of Upper Cretaceous age located in Northwestern Alberta, Canada.
It is 750 m deep and contains 12.4 million m3 original oil-in-place. The pool was discovered in 1961 and the primary development was completed in 1984. An 32 hectares 5-spot waterflood scheme comprised Of 43 producers and 38 injectors was implemented in mid 1985. The current oil production Tate is 200 m3 /d and cumulative recovery is 2.32 of the OOIP. Additional infill drilling is planned to convert to a 16 hectares 5-spot and 9-spot in 1987/1988.
From the early stage of the pool's development, reservoir and geological data were gathered and reviewed. Numerous routine and special core studies were performed. Standard analysis procedures were employed to determine porosity, permeability, relative permeability, capillary pressure, fluid saturation and PVT properties. In addition, several studies (SEM, water compatibility, fines migration, and emulsion) were conducted to predict the reservoir sensitivity to injection water.
A 3-D numerical model (Black Oil) was constructed using the validated data. The model, in conjunction with a financial simulator, was used to determine the optimum development scheme for this pool.
A new oil field was discovered near Valhalla, in Northwestern Alberta Canada, in 1981. Figure 1 shows the location of the field. During the period October 1982 to March 1984, Petro-Canada Inc. drilled 40 oil wells and cored 27 of them. By July 1985 Petro-Canada had implemented a 32 ha 5-spot waterflood comprised of 43 oil producers and 38 water injectors. Figure 2 shows the extent of the pool and the well locations.
The objective of this paper is to discuss the aggressive approach that Petro-Canada Inc. took to develop and implement this waterflood scheme in a relatively short period of time. Early planning and a comprehensive geological interpretation of the area, allowed Petro-Canada engineers to design an initial testing program while maintaining ongoing delineation drilling of the field.
The testing program, including routine and special studies was constantly monitored and compared with field production results to decide on additional or modified testing. Numerical simulation was used extensively to validate test data, to confirm field parameters based on primary production results, to determine operation conditions and to predict production performance under different development schemes.
The final field development plan for Va1lhalla was selected based on an economic analysis of several different alternatives. The investment required to develop the waterflood was carefully analyzed to determine the best alternative from an economic and technical point of view. For waterflooding, the optimum approach was a 10 ha spacing pattern, developed in two stages. The first stage, a 5-spot, 32 ha waterflood, was completed in 1985. The second stage, a 16 ha waterflood, varying from 5-spot to 9-spot is being implemented and will be completed during the first quarter of 1988.
