Greater Sierra is a large oil and gas field

Oil and gas field

An oil and gas field is a field, or vast reservoir, that contains both oil and natural gas.-See also:* Oil field* Natural gas field* Oil reservoir* List of oil fields* List of natural gas fields...

 in northeastern British Columbia

British Columbia

British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

, Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

.

It is located east and north from the town of Fort Nelson

Fort Nelson, British Columbia

Fort Nelson is a town of approximately 5000 residents in British Columbia's northeastern corner. It is the administrative centre of the newly formed Northern Rockies Regional Municipality, a first for BC. The majority of Fort Nelson's economic activities have historically been concentrated in the...

, extending to the Alberta

Alberta

Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...

 and Northwest Territories

Northwest Territories

The Northwest Territories is a federal territory of Canada.Located in northern Canada, the territory borders Canada's two other territories, Yukon to the west and Nunavut to the east, and three provinces: British Columbia to the southwest, and Alberta and Saskatchewan to the south...

 borders (150 and 130km respectively).

Drilling

Drilling rig

A drilling rig is a machine which creates holes or shafts in the ground. Drilling rigs can be massive structures housing equipment used to drill water wells, oil wells, or natural gas extraction wells, or they can be small enough to be moved manually by one person...

 activity takes place largely during the winter months, when the otherwise soft muskeg

Muskeg

Muskeg is an acidic soil type common in Arctic and boreal areas, although it is found in other northern climates as well. Muskeg is approximately synonymous with bogland but muskeg is the standard term in Western Canada and Alaska, while 'bog' is common elsewhere. The term is of Cree origin, maskek...

 and boreal forest can be crossed on winter road

Winter road

Winter roads are temporary highways carved out of snow and ice. They facilitate transportation to and from communities without permanent roads, and are commonly seen in isolated regions in Canada's north....

s. Infrastructure is funded by a combination of private and public funds.

Major projects tap in the large gas reservoirs hosted in Mississippian

Mississippian (geologic period)

The Mississippian is a subperiod in the geologic timescale or a subsystem of the geologic record. It is the earliest/lowermost of two subperiods of the Carboniferous period lasting from roughly 359 to 318 Ma...

 and Devonian

Devonian

The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...

 limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

s such as the Jean Marie Member of the Redknife Formation

Redknife Formation

The Redknife Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin.It takes the name from Redknife River, a tributary of the Mackenzie River, and was first described in the banks of the Trout River, north of Trout Lake, Northwest Territories, at Table Rock...

.

Recent projects extract gas

Natural gas

Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

 from the Muskwa Formation

Muskwa Formation

The Muskwa Formation is a stratigraphical unit of Frasnian age in the Western Canadian Sedimentary Basin.It takes the name from Muskwa River, and was first described in the Western National Gas Fort Nelson a-95-J/94-J-10 well by F.F. Gray and J.R. Kassube, in 1963.-Lithology:The Muskwa Formation is...

 and Horn River Formation

Horn River Formation

The Horn River Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin.It takes the name from the Horn River, a tributary of the Mackenzie River, and was first described in outrop on the banks of Horn River in the Northwest Territories by Whittaker in 1922...

. Horizontal drilling and fracturing

Hydraulic fracturing

Considerable controversy surrounds the current implementation of hydraulic fracturing technology in the United States. Hydraulic fracturing, or fracking, is the process of utilizing pressurized water, or some other liquid, to fracture rock layers and release petroleum, natural gas, or other...

 techniques are used to extract the gas from the low permeability shales.

Due to the large extent, the field is served by several airstrips (Helmet Airport

Helmet Airport

Helmet Airport, , is located north-east of Fort Nelson, in the Greater Sierra , British Columbia, Canada....

, Fort Nelson/Mobil Sierra Airport

Fort Nelson/Mobil Sierra Airport

Fort Nelson/Mobil Sierra Airport, , was located northeast of Fort Nelson, British Columbia, Canada.-See also:*Fort Nelson Airport*Fort Nelson Water Aerodrome*Fort Nelson/Gordon Field Airport...

, Fort Nelson Airport

Fort Nelson Airport

Fort Nelson Airport, , is located east northeast of Fort Nelson, British Columbia, Canada.-Airlines and destinations:-See also:*Fort Nelson Water Aerodrome*Fort Nelson/Gordon Field Airport*Fort Nelson/Mobil Sierra Airport...

).

Companies

Companies with large interests in the area include Devon Energy, EnCana Corporation

EnCana Corporation

Encana Corporation is one of North America's largest natural gas producers, with about 95 percent of its production being natural gas. Its strategy is to be the lowest-cost, highest-growth senior natural gas producer in North America. The company produced approximately of natural gas in 2010.The...

, Canadian Natural Resources and Petro-Canada

Petro-Canada

Petro-Canada was a crown corporation of Canada in the field of oil and natural gas. It was headquartered in the Petro-Canada Centre in Calgary, Alberta. In August, 2009, Petro-Canada merged with Suncor Energy, a deal in which Suncor investors received approximately 60 per cent ownership of the...

.