October 26, 2007 No Analogues For Alberta's Bitumen Carbonates; Research Project Planned
By Pat Roche
Anyone who thinks there are analogues for Alberta's bitumen
carbonates among producing reservoirs elsewhere in the world should talk to the
Alberta Research Council.
About two years ago ARC and the Alberta Energy Research
Institute (AERI) began a review of data from Alberta's bitumen carbonate pilots
from the 1970s and 1980s, and also a review of global heavy oil reservoirs in
carbonate rock.
The review found that producing bitumen from northern
Alberta's Grosmont formation -- which accounts for most of Alberta's
bitumen-bearing carbonates -- will be vastly more challenging than any heavy oil
carbonate reservoirs on which information is publicly available.
One of the most dramatic differences is in the viscosity of
the oil at reservoir conditions. The viscosity of the Grosmont bitumen is a
challenging 1.6 million centipoise. This shallow reservoir is relatively cool
and the pressure has been recorded at only about 200 pounds per square inch
(psi).
"What it's telling us is there [are] no analogue reservoirs in
the world for the Grosmont," said Jose Alvarez, a research scientist with ARC's
heavy oil and oilsands section.
"So extrapolating or bringing any technology that they have
been applying in these reservoirs to our reservoirs will be difficult. So we
need to adapt or to create a new technology for facing these challenges."
At a technical forum held Tuesday by Petroleum Technology
Alliance Canada (PTAC) in Calgary, Alvarez and Roy Coates, a senior research
engineer in the research council's heavy oil and oilsands section, described
ARC's and AERI's work to date, and outlined plans for a three-year research
program with industry.
Such a project is needed because to date there is no proven
technology for recovering the more than a quarter of Alberta's vast bitumen
resource that is locked in carbonate rock, said Coates.
The Grosmont formation in the Athabasca oilsands region
contains an estimated 71% of Alberta's bitumen carbonate resource. Alberta also
has smaller bitumen deposits in Peace River region carbonates.
Of the world's original-bitumen-in-place found in carbonate
rock, about 96% is in the Grosmont carbonates, Alvarez said.
So far, the researchers haven't been able to find a reservoir
outside Canada that is analogous to the Grosmont. Alvarez said only 17
reservoirs classified as heavy oil carbonates have data in the public
domain.
Comparing the Grosmont with heavy oil carbonate reservoirs
elsewhere, the research scientist said the oil viscosity at reservoir conditions
in the non-Canadian reservoirs is only in the thousands of centipoise versus
much more than a million centipoise in the Grosmont.
Other challenges include vugs, fractures and variable
permeability. Loss of circulation during drilling (where drilling fluids escape
into the formation) is expected to be a problem.
Only two per cent of the heavy oil in global carbonate
reservoirs can be produced on primary recovery, Alvarez said. One exception is a
reservoir in France with 22-degree API gravity oil and good aquifer support.
Another -- located in Iran -- is blessed with high reservoir pressure (about
15,000 psi), high temperature and a deep, thick pay zone.
Technologies used in those reservoirs include cyclic steam
stimulation, steam drive, horizontal drilling, carbon dioxide injection and
acidizing the reservoir.
ARC's proposed three-year project is meant to speed up
development of Alberta's bitumen carbonates by advancing lab research
sufficiently to pave the way for a field pilot. While the pilot design could
occur within the research program, there is no plan at this point to include a
pilot because the cost is considered prohibitive.
Alvarez said producers who were canvassed want the project to
focus on geology (e.g., reservoir characterization, sharing seismic data,
reservoir delineation), recovery processes (concentrating on known thermal
techniques in the short term), production engineering (e.g., borehole stability,
managing lost circulation, sharing experiences on problems such as drilling
through karsts and coring carbonates) and design and support of a field
pilot.
The organizers are fairly confident they can secure $2.1
million in funding for the first year of the three-year effort. The fee for each
participant is $350,000 a year.
Coates said project participants would
benefit from an integrated research program drawing on the best expertise from
multiple research organizations.
Participants would also get the right to use data from some of
the early Alberta pilots as well as the ARC/AERI work done since November 2006.
Another benefit would be royalty-free, worldwide rights use to any intellectual
property developed in the program.
Coates said 10 producers agreed to sit on a committee to
design the research program. Those companies who had initial input are Shell
Canada Limited/SURE Northern Ltd. (both since absorbed into Royal Dutch Shell
plc), ConocoPhillips Canada, Husky Energy Inc., Laricina Energy Ltd., Suncor
Energy Inc., UTS Energy Corporation, Paramount Resources Ltd., Sherritt
International Corporation and Total E&P Canada Ltd. Companies that have
signed on for the actual three-year research program haven't yet been
identified.
Coates hopes to start the research project next month. The
first step will be to put together a steering committee, decide exactly what the
project will entail and start the actual research.
Organizers are also looking for expressions of interest from
other research providers as well as comments on any needs or gaps in the
technical program.
Tuesday's PowerPoint presentation will be posted on the PTAC
website in the next few days. For more information contact Coates at (780)
450-5261 or roy.coates@arc.ab.ca.
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