Although there are many factors influencing the future of Canadian oilsands, including technology
advances and oil price, production will not grow without the consent of local public. Various options
have been discussed on regulatory requirements; these include the carbon tax, renewable fuel
standard, low carbon fuel standard and regulations by US Environmental Protection Agency.
Oilsands companies are investing effort and money in optimizing plant operations including
development and implementing new processes and technologies to reduce GHG emissions. As the majority
of oilsands emissions come from the consumption of energy, it is important to understand the key
parameters that drive energy consumption during oilsands production.
The production methods on oilsands are:
- Open pit mining (20%) – only a small percentage of total production as major deposits are deep
beneath the reach of mining methods.
- In-situ (80% ) – the majority of production is done by this method and is considered the most
common method of producing oilsands namely:
(a) SAGD (Steam Assisted Gravity Drainage)
(b) CSS (Cyclic Steam Simulation)
(c) CCS (Carbon Capture and Storage, one of the methods used to enhance oil recovery)
The Alberta government has committed $2Billion+ to support CCS research, development and
demonstration projects and this is helping Alberta reduce 4milliontonnes annual GHG emissions (i.e.
700,000 vehicles on the road). While there are risks, there are also solutions to minimize risks and
we do not have to make the wrong choice between bitumen and biodiversity.
In this article we are discussing aspects of using knife gate valves in open pit mining
application (20% of Canadian oilsands production only). Mining requires tough valves – ones that
withstand intense abrasion, extreme pressures and temperatures of the tundra in Alberta winters. Some
applications such as hydrotransport slurry, carrying bitumen ore from the mining pits to extraction
plants, include large, jagged stones as well as coarse sand and clay. Bitumen itself has a density
similar to cold molasses, so it requires heat and high pressures to transport long distances to
The valves most commonly used for such an application are heavy-duty knife gate valves, installed
with sharp blades to cut through sticky bitumen. They often include scrapers engineered to remove
bitumen from gates as part of opening and closing. The valve gates are made of hardened materials
such as 17-4ph stainless material in addition to abrasion-resistant coatings such as tungsten carbide
to extend the life of the valve.
Heavy duty knife gate valves can withstand abrasive, high pressure oilsands slurries. They are
used in the froth flotation area, where break down is considered a loss of production, and for
applications where highly concentrated slurries require nondischarging valves so precious product is
not discharged to the ground or localized drains. Improved production methods have been developed
enough to justify the extra barrel production costs of oilsands mining. These trends see leading
mining companies who extract from the oilsands eager to find ways to increase production rates and
Industry continuously works with users of these applications and major industry players to jointly
develop custom solutions to meet growing demands for such valves.
As production has increased and the cost expenditure ratio continues to improve with the rising
global costs of oil, more stringent specifications continue to drive innovation. Valves involved in
every stage of transport are subject to wear and tear from the nature of bitumen slurries. If there
are not fist sized stones in the mix, there are highly abrasive sands. Slurry flow speeds have been
increased to help reduce the slurry’s stickiness. However, this causes high abrasion rates. In any
case, bitumen transport takes place under incredibly high pressures at up to 700 psi or more.
All of this has combined to create a demand for knife gate valves that can withstand the extreme
abrasive qualities of oilsands mixtures and the high pressures required to transporting slurries over
long distances. Engineers are looking for more robust valves that can endure longer intervals between
required maintenance. Around 2000 leading companies in the Canadian oilsands underwent a major growth
step at various plant sites, adding new processing units including the largest fluid coker and
hydrogen plants ever built, in addition to upsizing another 100 processing units. That process
involved the purchase of about 100,000+ manual isolation valves and brought the oilsands daily
production capacity up to 750,000bpd. A variety of valves were in use including modified versions of
standard knife gate valves.
Oilsands producers utilize over 1Billion+manual isolation valves in various processes, including
some 70000 pressure safety valves, 150,000 control valves, dampers and large actuated isolation
valves. Few knife gate valves are in this mix today, though those that are have been specially
fabricated and deployed to meet unique needs in situations where standard valves could not stand up.
The processes were becoming more and more rigorous and the need for a super duty valve became
apparent. As time passed, more robust valve designs were required by multiple leading Canadian
oilsands. At this time, there were so many different applications for valves emerging in oilsands
mining and refinement that there truly was no such thing as a standard valve. This need spurred a
drive to innovate and evolve the knife gate valves used in the oilsands, reducing maintenance and
meeting ever increasing specifications.
Energy demand continues to drive future innovation in valve technologies
With increasing demands surely on the horizon for valves in the Athabasca oilsands of Alberta,
sturdier system components will need to evolve and improve for the foreseeable future. These demands
will result in increased unconventional oil mining, production processes and advanced challenges.
Heightened complexity will be unavoidable and demand for more customized and durable components will
follow suit. The endless global demand for energy should drive the growth of new processes such as in
situ. One primary area for growth is deep extraction in the oilsands using in situ methods. Certain
methods using in situ such as steam and water treatment, require valves requiring high alloy steels
to be compatible with the aggressive temperatures and chemical characteristics in the process. Heavy
scaling will continue to be a growing challenge and new product evolutions with improved designs will
be better equipped to tackle heavy scaling. The future will demand that engineers build longevity
into their products and continually push to improve engineering technologies with interchangeable
internal parts, more robust materials and improve coatings to reduce wear. The oilsands of Alberta
will continue to drive innovation and progress with its endless energy opportunities.
Photos courtesy of ITT Engineered Valves LLC, USA.