Eagle has reservoir characteristics that are similar to the Ekofisk field in the Norwegian sector of the North Sea (Table 2.4). Ekofisk is an offshore chalk reservoir that has produced commercially since 1971 and contains vast reserves of both oil and natural gas. Ekofisk is located in water depths ranging from 70 to 75 m with Eagle in similar water depths of approximately 50 m.
Field |
Age |
Primary Lithology |
Porosity (%) |
Matrix Permeability (mD) |
---|---|---|---|---|
Eagle |
Late Cretaceous |
Chalk |
19 – 36 |
0.2 – 1.4 |
Ekofisk |
Late Cretaceous |
Chalk |
25 – 40 |
0.1 - 10 |
Table 2.4 Eagle and Ekofisk comparison.
Due to the nature of chalk reservoirs, enhanced production techniques such as acidizing, hydraulic fracturing and multiple fracture horizontal wells, are often required to improve production. The CNSOPB conducted reservoir engineering studies of the Eagle field and estimated that recovery factors of up to 60% are possible if the field is developed using multiple fracture horizontal wells. The results of this reservoir simulation were used to guide the recovery factors used in the Eagle probabilistic resource assessment (Tables 2.5 and 2.6).
Eagle - Original Gas in Place |
|||
---|---|---|---|
P90 |
P50 |
P10 |
Mean |
25.3 E9M3 |
35.4 E9M3 |
47.3 E9M3 |
36.0 E9M3 |
892 Bcf |
1,250 Bcf |
1,670 Bcf |
1,270 Bcf |
Table 2.5 Eagle Field probabilistic resource assessment results for original gas in place.
Eagle - Recoverable Gas in Place |
|||
---|---|---|---|
P90 |
P50 |
P10 |
Mean |
8.0 E9M3 |
13.3 E9M3 |
20.4 E9M3 |
13.8 E9M3 |
283 Bcf |
471 Bcf |
720 Bcf |
489 Bcf |
Table 2.6 Eagle probabilistic resource assessment results for recoverable gas in place.