Chapter 12 Table Oil Production from the Winterburn Group
Oil production from the Winterburn Group occurs primarily in south central Alberta from Nisku shelf carbonates draped over Leduc reefs and in west-central Alberta from patch reefs around the margin of the West Pembina Basin.
Twenty Winterburn oil fields have Initial Established Recoverable Oil Reserves of over 1 x 106m3 (6 MMBbls). The ten largest Winterburn oil fields, listed in order of Initial Established Recoverable Reserves, are shown in Table 1. Cumulative production totals include Alberta data released to December 31,1990.
Table 1. Ten Largest Winterburn Oil Fields (m units of 106m3).
|No.||Field||Formation||No. of Pools||Marketable Reserves||In-place Volume||Cumulative Production||Discovery Year|
Four of these ten largest pools occur in patch reefs along the southeast margin of the West Pembina Basin, and a fifth, Meekwap, along the northern margin Another four fields, including the largest, Fenn-Big Valley, occur in structural traps due to underlying Leduc reefs, as do many of the smaller Winterburn oil fields. The Joffre field is a stratigraphic trap caused by facies change on the Nisku shelf. Winterburn oil production is also found m eastern Alberta at the southern end of the Winterburn wedge edge and in minor amounts in the Hummingbird and Kisbey fields m southern Saskatchewan The most recent major Nisku oil discovery was made m 1985 at Enchant m southern Alberta. All oil fields of Winterburn age contain light to medium gravity oil.
Total recoverable oil reserves in the Winterburn Group are relatively small, compared to the other Devonian horizons, and are estimated at 177 x 106m3, of which 148 x 106m3 (i.e. 83%) have already been produced. Initial Established In-Place Volume of Winterburn oil reserves totals 379.0 x 106m3. There are 229 Winterburn oil pools, with average recoverable oil reserves of 774 x 10 m3/pool. Table 2 shows the distribution of Winterburn oil reserves according to In-Place Pool Size.
Table 2. Size Distribution of Winterburn Oil Pools (in units of 106m3).
|In-Place Pool Size Class||No. of Pools||Recoverable Reserves||Cumulative Production|
|less than 0.1||28||0.26||0.18|
|0.1 to 1||136||10.93||6.45|
|1.0 to 10||60||84.39||64.44|
|10.0 to 100||5||81.85||77.04|
|Total||229||177.43 x 106m3||148.11 x 106m3|