Horn River Formation | |
---|---|
Stratigraphic range: | |
Type | Geological formation |
Sub-units | Muskwa Member, Otter Park Member, Evie Member |
Underlies | Fort Simpson Formation |
Overlies | Pine Point Formation |
Thickness | up to 320 metres (1,050 ft) [1] |
Lithology | |
Primary | Shale |
Other | Limestone |
Location | |
Coordinates | 61°44′00″N117°45′00″W / 61.73333°N 117.75000°W |
Region | British Columbia, Northwest Territories |
Country | Canada |
Type section | |
Named for | Horn River |
Named by | Whittaker, 1922 |
The Horn River Formation (also Horn River Shale) is a stratigraphic unit of Devonian (early Givetian to late Frasnian) age in the Western Canadian Sedimentary Basin. [2]
It is a thick sequence of marine sediments that was first described in outcrop on the banks of the Horn River, a tributary of the Mackenzie River, in the Northwest Territories (at the time District of Mackenzie) by Whittaker in 1922, [3] and it takes its name from that river. In 1963 it was redefined in the subsurface of the Fort Nelson area of British Columbia (well Fort Nelson a-95-J/94-J-10) by F.F. Gray and J.R. Kassube. [4] It is significant for its shale gas resources.
The Horn River Formation is composed of dark siliceous and calcareous shale, and argillaceous bituminous limestone. [1]
The Horn River Formation is included in the Beaverhill Lake Group. [2] It is subdivided into the following members, from top to base:
The Horn River Formation is present in the subsurface in northeastern British Columbia and extends to Great Slave Lake in the Northwest Territories, where it outcrops. [2] It reaches a maximum thickness of 320 metres (1,050 ft) in the subsurface of the Fort Nelson area. [1]
The Horn River Formation is overlain by the Fort Simpson Formation and underlain by the limestones of the Lonely Bay Formation, Nahanni Formation or Pine Point Formation. [1] It is equivalent to the Slave Point Formation. [2] In the Northwest Territories it includes the Muskwa Formation, and the Waterways Member of the Hay River Formation. It includes the pinnacle reefs of the Horn Plateau Formation.
Shale gas is present in the siliceous shales of all three members of the Horn River Formation in northeastern British Columbia, and it is produced in the Greater Sierra oil field north of Fort Nelson. Horizontal drilling and fracturing techniques are used to extract the gas from the low permeability shales. [8] The original-gas-in-place volumes are estimated to be up to 500 Tcf, [9] making it the third largest North American natural gas accumulation discovered prior to 2010. [10] Companies involved in the extraction of natural gas from the Horn River Shale include Ovintiv, EOG Resources, Stone Mountain Resources, ExxonMobil, Quicksilver Resources, and CNOOC Petroleum North America ULC. Horn River gas contains 10-12% CO2, much higher than the 2–4.5% of conventional natural gas. If this gas is processed normally about 500 million tonnes of CO2 will be released into the atmosphere. [11] [12]
Massive hydraulic fracturing has been widely used in Alberta since the late 1970s. [13] : 1044 The method is currently used in development of the Cardium, Duvernay, Montney and Viking formations in Alberta, Bakken formation in Saskatchewan, Montney and Horn River formations in British Columbia.
The Bluesky Formation is a stratigraphic unit of Lower Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the hamlet of Bluesky, and was first described in Shell's Bluesky No. 1 well by Badgley in 1952.
The Montney Formation is a stratigraphical unit of Lower Triassic age in the Western Canadian Sedimentary Basin in British Columbia and Alberta.
The Cardium Formation is a stratigraphic unit of Late Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the fossilized heart-shaped cockle shells in the family Cardiidae present. It was first described along the Bow River banks by James Hector in 1895. It is present throughout western Alberta and in northeastern British Columbia, and it is a major source of petroleum and natural gas.
The Muskwa Formation is a stratigraphical unit of Frasnian age in the Western Canadian Sedimentary Basin.
The Fort St. John Group is a stratigraphic unit of Lower Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the city of Fort St. John, British Columbia and was first defined by George Mercer Dawson in 1881.
The Spirit River Formation is a stratigraphical unit of middle Albian age in the Western Canadian Sedimentary Basin.
The Redknife Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin.
The Dunvegan Formation is a stratigraphical unit of Cenomanian age in the Western Canadian Sedimentary Basin.
The Exshaw Formation is a stratigraphic unit in the Western Canada Sedimentary Basin. It takes the name from the hamlet of Exshaw, Alberta in the Canadian Rockies, and was first described from outcrops on the banks of Jura Creek north of Exshaw by P.S. Warren in 1937. The formation is of Late Devonian to Early Mississippian age as determined by conodont biostratigraphy, and it straddles the Devonian-Carboniferous boundary.
The Viking Formation is a stratigraphical unit of Cretaceous age in the Western Canadian Sedimentary Basin.
The Doig Formation is a geologic formation of middle Triassic age in the Western Canadian Sedimentary Basin. It takes the name from Doig River, a tributary of the Beatton River, and was first described in the Texaco N.F.A. Buick Creek No. 7 well by J.H. Armitage in 1962..
The Fort Simpson Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin.
The Beaverhill Lake Group is a geologic unit of Middle Devonian to Late Devonian age in the Western Canada Sedimentary Basin that is present in the southwestern Northwest Territories, northeastern British Columbia and Alberta. It was named by the geological staff of Imperial Oil in 1950 for Beaverhill Lake, Alberta, based on the core from a well that they had drilled southeast of the lake, near Ryley, Alberta.
The Elk Point Group is a stratigraphic unit of Early to Middle Devonian age in the Western Canada and Williston sedimentary basins. It underlies a large area that extends from the southern boundary of the Northwest Territories in Canada to North Dakota in the United States. It has been subdivided into numerous formations, number of which host major petroleum and natural gas reservoirs.
The Woodbend Group is a stratigraphical unit of Frasnian age in the Western Canadian Sedimentary Basin.
The Duvernay Formation is a stratigraphical unit of Frasnian age in the Western Canadian Sedimentary Basin.
The Besa River Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin.
The Slave Point Formation is a stratigraphical unit of Middle Devonian age in the Western Canadian Sedimentary Basin.
The Sulphur Mountain Formation is a geologic formation of Early to Middle Triassic age. It is present on the western edge of the Western Canada Sedimentary Basin in the foothills and Rocky Mountains of western Alberta and northeastern British Columbia. It includes marine fossils from the time shortly after the Permian-Triassic extinction event.
Toad Formation, Grayling Formation, and Toad-Grayling Formation are obsolete names for the strata of the Early to Middle Triassic Doig and Montney Formations. They were applied in the foothills and Rocky Mountains of northeastern British Columbia, on the western edge of the Western Canada Sedimentary Basin. Although the names are considered obsolete, their usage persists.