A new exploration concept to develop the hydrocarbon
potential in Québec
Jean-Yves Laliberté, eng. M.Sc
Direction du développement des hydrocarbures
Explorationists are increasingly optimistic
Activities related to oil & gas exploration
are thriving in Québec. Oil & gas exploration licences
now cover nearly 5 million hectares, a new twenty-year peak.
Map showing licensed areas (PDF Format, 421 Kb)
Seismic reflection geophysical surveys carried
out by the MRNFP over the past three years have undoubtedly contributed
in improving the geological understanding of the Bas-Saint-Laurent
and Gaspésie regions and have spurred interest in these two
resource-based regions. This new flurry of activity centered on
the hydrocarbon potential in Québec may also be fuelled by
numerous discoveries in nearby basins. These new fields are for
the most part located in the carbonate complex that formed along
the margin of the North American continent during the Ordovician
The concept of hydrothermal dolomites
The classic example of this type of carbonate-sequence
reservoir is the Albion-Scipio and Stoney Point fields in the Michigan
basin, where the HTD-RF (Hydrothermal Dolomite Reservoir Facies)
model was developed in recent years.
This type of deposit occurs in sedimentary units
equivalent to those in the St. Lawrence Lowlands, and more specifically
those of the Black River and Trenton groups. Reservoir development
is intimately linked to orogenic and diagenetic processes. Consequently,
they always occur along extensional faults that were active during
the Taconic Orogeny (Ordovician), i.e. shortly after the deposition
of the Black River and Trenton groups.
These faults played a crucial role, by facilitating
the migration of high-pressure high-temperature fluids. The hydrothermal
fluids leached, dolomitized and fractured Black River and Trenton
limestones, thereby creating breccias and secondary porosity, which
allowed hydrocarbons to build up.
Click to enlarge
The HTD model, Tedesco 1994
This relatively new model now constitutes
a prime target for companies involved in hydrocarbon exploration.
The model has never been tested in Québec, while in Ontario,
Michigan and New York, major discoveries are piling up. For example,
Talisman Energy Inc. announced on September 2, 2003, the completion
of a new natural gas well in New York State, with an output capacity
of 10 million cubic feet per day.
Click to enlarge
the Gloades Corner reservoir in New York State
Provided by AAPG Explorer-March 2001
Basins in the St. Lawrence Lowlands and Anticosti
are highly prospective for this type of deposit. Recent seismic
reflection geophysical surveys, mentioned above, have proven useful
in determining the location of future drilling targets.
A new approach
This new type of hydrocarbon deposit represents
quite a challenge for explorationists. Rather than searching for
conventional structures likely to trap hydrocarbons such as anticlines,
faults or stratigraphic wedges, explorationists must now look for
collapse structures associated with faults, where the seismic signature
of reflectors has been fairly altered due to the action of hydrothermal
Existing data must be re-examined in a new light!
Québec Exploration 2003
Under the theme “New Frontiers”,
Québec Exploration 2003 will offer a series of oral
presentations namely dealing with new geological data, new regions
to explore as well as new technologies and new exploration models.
A speaker session entitled Oil & Gas
will focus on the latest developments related to hydrocarbon exploration
in Québec and the search for HTD-type deposits. Mr. Graham
R. Davies, internationally renowned geologist in this specific field,
will be our keynote speaker for the occasion.