Equal To Or Better

Any land disturbed by oil sands mining must be returned to a sustainable landscape. The bad news is, it takes a long time. For example, the first barrel of oil was shipped from the Syncrude site in 1978, but it wasn’t until 2008 that reclamation was completed for a 104-hectare parcel and a reclamation certificate was issued.

The area overlying the Alberta oil sands comprises 142,200 square kilometres, but only about three per cent of that, 4,802 square kilometres, are suitable for mining operations. Of that, only 662 square kilometres have been disturbed to date and of that, about 10 per cent has been reclaimed.

Reclamation begins with the initial stages of mine development. Top soil is cleared and saved for reuse. Processed sand is returned to areas no longer being mined. Tailings ponds are reclaimed. The area is contoured, top soil replaced and native plant species are cultivated. It sounds simple, but it’s a lengthy process.

The other 97 per cent of the oil sands area will be accessed by in-situ methods, which are similar to conventional oil wells and have a much smaller footprint. Never the less, when operations cease, infrastructure and equipment must be removed, contaminated material treated and the land rehabilitated.

Reclamation is the responsibility of the developer. However, the Alberta government created the Environmental Protection Security Fund, comprising security deposits from oil sands developers to be used to fund reclamation the companies neglect to do. A controversial new plan, called the Mine Financial Security Program, would see small contributions early in the development of a mine, and larger ones as the mine nears depletion. Either way, critics of the programs say that the amounts being collects are nowhere near enough.

And reclamation doesn’t apply to just oil and gas operations. Any mines, quarries, gravel pits, right of ways, transmission corridors and other industrial sites must be reclaimed too.

So, what does reclamation actually mean? It does not mean an exact replication of the landscape prior to disturbance. It means returning the land to a condition that will sustain biodiversity equal to or better than was present prior to disturbance.

The Great Oil Sands Journey Part 2

Do I have to separate you three?

So now that you know the origins of the sands, what then of the process that brings the oil from the sand to your car?  Two important areas of discussion around this include the separation process, which we discuss this week, and next week it’s the upgrading/refining process, which is part three of this five part series.

Wells to Wheels
Part two of a five-part series

First, in order to appreciate the great deal of work that goes into this process, let’s look at the relationship between the bitumen, the water and the sand on a smaller scale. As you can see, water, bitumen and sand are pretty tight.

As you could probably imagine, having sand and water mixed with the bitumen just won’t do. Not for our purposes anyways. About 200 years ago explorers reported the naturally occurring bitumen seeping up on the banks of Athabasca River and, for many years to come, scientists would rack their brains over how to separate the precious bitumen from the sand and water. In fact, even 60 years ago observers doubted the feasibility of producing oil sands economically. Like celebrity marriages these components were costly to separate, but time has proved that it can be done at increasing rates of speed and efficiency.

So this is as much a story about creativity, perseverance and innovation as it is about the origins and makeup of the oil sands. It is the process and evolution of oil sands technology and innovation that has ultimately transformed the oil sands into a profitable resource today. And the evolution is still in progress.

Around 1915, Sidney Ells, an engineer with the federal Department of Mines, was the first to suggest using hot water to separate the three. In 1925, a man with the Alberta Research Council named Karl Clark successfully demonstrated a separation method using hot water and caustic soda, a technique employed by two mining operations today. Most mining operations today, however, do not require caustic soda.

Mining is the approach of choice when bitumen deposits lie close enough to the surface to be removed using trucks and shovels.

Here’s mining in a nutshell

Mining, one of two techniques employed in oil sands extraction, receives the most attention from environmentalists, journalists and concerned energy consumers because it disrupts the land and results in tailings ponds. A mixture of water, clay, sand, residual bitumen  and other hydrocarbons, salts and trace metals produced through the extraction process, tailings are often stored in discontinued mine pits where the mixture is left to settle. Problem is, due to all the fine particles, it takes a while to settle on its own.

Mining technology and research today are focused around ways to hasten the settling process, to reduce or eliminate tailings ponds altogether or speed up the process of reclaiming the land back to its original state and, finally, to reduce the amount of energy used in the extraction process. Examples of today’s oil sands mining innovations include:

• Syncrude’s low energy extraction process (Aurora Mine)
• Canadian Natural’s CO2 injection process (Horizon Mine)
• Canadian Natural, Syncrude, Imperial Oil and Suncor’s dry stackable tailings (also called consolidated tailings)
• Gradek Energy Inc.’s polymer beads (used by Syncrude)

Despite all these neat advancements in mining technology, only 20 per cent of all oil sands reserves contain bitumen close enough to the surface to be mined. The remaining 80 per cent lies too deep below the earth’s surface.

In-situ techniques are used for extracting oil from oil sands reservoirs deep beneath the surface using heat or solvents or other processes to soften the bitumen enough so it can flow up through the well.

Here’s in-situ in a nutshell

Most major in-situ projects inject steam through a well, heating the bitumen enough so it can be pumped to the surface. While this is often accomplished by injecting steam, there are also other approaches, including injecting solvents, natural gas liquids, or oxygen, which causes an underground combustion. In-situ bitumen production requires further processing to remove water and sand particles and recycles 90 per cent of the water used. Remaining solids are put in landfills, injected underground or used to pave roads. After processing, the bitumen is diluted with pentanes and heavier hydrocarbons obtained from natural gas processing. The resulting mixture is then shipped by pipeline to an upgrader or refinery.

The most popular in-situ method is called Steam-assisted Gravity Drainage, or SAGD, which involves two horizontal wells, one of which (the upper one) is used to inject the steam. The steam heats the bitumen enough so it can flow into the production well (the lower one) and is then pumped to the surface. Cyclic Steam Stimulation (CSS) is a similar method that uses only one well instead of two.Now, the astute observer might be keen to ask how in-situ fans respond to environmentalists concerned about the use of water and energy needed to make the steam.

One has to dig deeply for the answer to this one… deep underground that is. That’s because in-situ operators use heat and undrinkable water from subsurface aquifers to generate the steam, which means use of water from the Athabasca River or other local water supply is negligible. As well, some in-situ operators are turning to alternative energy sources to power their operations, such as geothermal energy, which also resides deep underground. So whether you’re talking about energy, water use or the overall technique, conversations about in-situ can get pretty deep.

Ultimately, in-situ technology advancements today focus on using cleaner energy and less of it as well as minimizing or eliminating water use. Examples of this include:

• Firefloods, such as Petrobank’s Toe to Heel Air Injection (THAI) which uses underground combustion rather than steam to generate heat. This technique also reduces GHGs as it partially upgrades the heavy oil into a lighter oil while it is still underground. It does this through coking, which is explained further down.
• Vapour extraction, or VAPEX, which is similar to SAGD described above but instead of steam, natural gas liquids such as ethane, propane or butane are injected, acting as a solvent to loosen the bitumen.
• Cold production which produces sand along with the oil, improving oil recovery rates.

So next time you encounter a pair of people who get along like peas and carrots, and they happen to be engineers or in the oil industry, just say, “Those two are so close, they’re just like bitumen and sand.” Then pause for effect and say, “except not even mining or in-situ technology could separate them.”

Next week:  The second part of Wells to Wheels – Bitumen finally grows up