method can also be a beneficial
technique when the oil leg of the
reservoir has underlying water.
There are places in the oil sands where
producers don’t need to heat the
reservoir and sand is not a significant
issue, where production is closer to a
conventional oil play than a typical in situ “A vertical well requires a significant
oil sands project. These areas, primarily in pressure drop to produce economic oil
the Peace River oil sands deposit, have rates. This pressure drop will preferentially
become profitable thanks to the advent of cause water to flow toward the well and
horizontal drilling and the continued water it out. Horizontal wells can produce
application of geological knowledge. In economic rates with much lower pressure
the coming years, the projects under way drops due to the much larger flow area of
are planned to grow bigger and become the horizontal well, thus producing more
more prolific, and more projects are likely oil before the water does come in.”
on the way.
CNRL uses the method of cold horizontal
“Our Peace River oil sands project has the production with no sand at a number of
potential, we feel, to redefine our its heavy oil properties. The company says
business,” says William Andrew, president it and its predecessors first employed the
and CEO of Penn West Energy Trust. Penn technique at Pelican Lake, Alberta and
West’s Seal project uses primary Senlac, Saskatchewan in the late 1980s,
technology and is expected to produce and CNRL is currently using it to produce
4,000 to 5,000 barrels per day by the end about 40,000 barrels of bitumen per day.
of 2006. The Pelican Lake field is located about 120
kilometres north of Edmonton. “As we move production up over the next The theory behind
five to six years, basically the costs that In the late 1990s, BlackRock Ventures took are going to be involved are of very little this cold production concept and looked this secondary
difference to a conventional oil operation. to apply it to other areas, resulting in the Production commences immediately and 2001 announcement of its Seal oil sands method is that
the wells are drilled in a conventional project. President John Festival says the manner horizontally. The oil that is company took a look at the map and water injection
produced is produced with a pump and questioned why the Pelican field was the
goes right into the pipeline, is blended only oil sands area where operators could replaces voids
with light oil and is processed.” economically produce without injecting
steam.
removed by primary
There is another form of primary oil sands
production, known as Cold Heavy Oil “We just thought there had to be other depletion and
Production with Sand (CHOPS), but it is a places where you could do that, and we
significantly different process applicable found a few.” restores reservoir
in significantly different reservoirs. Using
CHOPS, sand production is encouraged because it creates “wormholes” in the pressure
unconsolidated sand reservoir, providing
channels for heavy oil to move towards
the production well. In order to produce
the amount of sand required, the wells
must be vertical.
Seal, which is in the Peace River oil sands
deposit, was a known heavy-oil-bearing
region prior to BlackRock’s interest, but
the company says that before it entered
the play, most companies believed the oil
could be produced only through
capital-intensive thermal recovery
operations. Shell’s thermal in situ Peace
“In reservoirs where the sand is River installation had been operating for
unconsolidated, the production of this more than 20 years nearby, attempting a
sand will increase the flow area for the oil number of well configurations using a
to flow to the well. This reservoir is suited system similar to cyclic steam stimulation
for vertical wells because horizontal wells operations at Cold Lake. In the Peace River
can’t handle the sand effectively or oil sands, though, it doesn’t take a large
economically,” says Canadian Natural distance for the target reservoir to go
Resources Limited (CNRL), Canada’s from requiring in situ heating to simply a
largest heavy oil producer. “In reservoirs horizontal well and a pump.
where the sand is consolidated, horizontal
wells are used to increase the flow area to “The oil quality changes dramatically over
the well by creating a large drainage area a few miles,” Festival explains.
by placing a conduit in the reservoir.”
The oil flows into the well as a result of
gas mixed in the solution that gives it
drive. CNRL says the horizontal cold
Shell is aware of the cold production in
the area, says Simon Brissenden, the
company’s Peace River project
development manager. Although
