Oil Sands in the Forest

Exploration for oil sands deposits is underway in northwestern Saskatchewan. Oil companies have found deposits and are looking for more.

Oil sands in Saskatchewan's boreal region are located deep below the surface and must be extracted using in situ (in place) techniques. Such techniques are different then the open-pit oil sands mining located near Fort Mc Murray, Alberta. Instead, the deep oil is accessed and extracted using networks of underground and surface pipelines.

Environmental Impacts of In Situ Oil Recovery

Impacts to the land will be significant, stemming from a mix of exploration, production (extraction) and processing activities.

Although in situ recovery is less destructive than open pit mining, it is considerably more damaging than conventional oil extraction methods. Moreover, the area impacted by in situ recovery will be vast, impacting forest areas much greater than the area of a mining zone. The recovery activities will touch immense areas of the landscape, introducing well pads and a high density of roads, powerlines and pipelines.

Saskatchewan's boreal forest is home to many wildlife species known to be sensitive to industrial disturbances. For these species, useable habitat within a SAGD development area is reduced to scattered islands. Once a threshold is reached where the remnant habitat patches are too small and scattered to maintain a breeding population, the local population is extinguished. Multiply this effect by a series of potential SAGD developments and the result is serious decline in biodliversity1.

Some of the major environmental impacts from in situ activities will include:

• major loss of wildlife habitat
• declining wildlife populations
• permanent loss of wetlands (bogs and fens)
• acidification of water and land
• depletion of freshwater reserves
• disruptions of normal flows in aquatic ecosystems
• regional contamination of ground and surface waters
• increase in greenhouse gas emissions

The In Situ Oil Recovery Process

	Schematic of SAGD process Photo courtesy of the Pembina Institute (www.OilSandsWatch.org)

SAGD Extraction Process: The type of oil found in our deep oil sands deposits is called bitumen. It is heavy and tar-like, and difficult to extract. The primary in situ extraction technique used to recover bitumen is called Steam Assisted Gravity Drainage (or SAGD). It involves the use of high-pressure steam to liquefy the bitumen so it can be piped to the surface. Two horizontal wells (or pipelines) are placed along the bottom of an oil sands formation, one well above the other. The top horizontal well is used to inject high pressure steam into the formation. The steam heats the bitumen to the point where it flows by gravity to the lower horizontal well, where it is collected and pumped to the surface.

Exploration: Obviously, the first step in oil sands recovery is finding the oil sands. Exploring involves several steps using core sampling and seismic modeling techniques. Seismic involves the use of underground sound waves to generate computer models of subsurface geological structures. Dynamite charges placed in series of shot holes are detonated to generate the sound waves.

Core hole to map location of deep oil sands Photo by David Dodge, Pembina Institute (www.OilSandsWatch.org)

The initial exploration phase is focused on assessing the commercial viability of the deposit and mapping its extent. This is done through drilling a systematic grid of core holes across the land, taking samples and conducting two-dimentional seismic exploration. Access routes, clearings (1/2 ha to 1 ha) and drilling equipment facilitate the work.

	Dense seismic grid to map location of oilsands Photo by David Dodge, Pembina Institute (www.OilSandsWatch.org)

The second phase is focused on producing detailed three-dimensional information to facilitate accurate placement of underground pipelines (wells). This is done by employing a tight cross-hatch pattern of seismic lines (roughly 60 m spacing).

In some cases, seismic programs are repeated to monitor changes in the deposit over time.

Production and Processing: To enable removal of the oil from the ground, a collection of above-ground well pads are constructed to host several paired underground wells. Each pad may occupy 3 to 4 hectares of land and is serviced by a road.

Aboveground pipelines to transport steam and bitumen across project site Photo by David Dodge, Pembina Institute (www.OilSandsWatch.org)

In addition, an above ground interconnecting pipeline system is built between the well pads and a central facility where the bitumen is processed before delivery (via pipeline) to an off-site upgrader. The upgrader turns the bitumen into synthetic crude oil.

A detailed description of in situ, deep oil sands recovery process is documented in the CPAWS/Pembina report entitled Death by a Thousand Cuts: Impacts of In Situ Oil Sands Development in Alberta's Boreal Forest. The report discusses case studies in Alberta, details ecological impacts and offers solutions to reduce environmental risks.

1 Schneider, R. and S. Dyer. 2006. Death by a Thousand Cuts: Impacts of In Situ Oil Sands Development on Alberta's Boreal Forest