Dolomite Reservoir Project
Multi-Client Project Summary (27kb
Structurally-controlled hydrothermal dolomite
(HTD), variably associated with productive leached limestones,
is a major reservoir facies in North America, and is receiving
increased exploration focus on a global scale. HTD is productive
in the Devonian and Mississippian of western Canada, in the
Ordovician of Ontario, Quebec and into Newfoundland in eastern
Canada, in the Ordovician to Devonian in the Appalachian
and Michigan Basins of the northeastern USA, and more controversially
in the Ordovician to Silurian of Texas. Exploration along
the rifted Atlantic margins of North and South America indicates
that the HTD-leached limestone association may be common
in structurally involved Jurassic-Cretaceous hosts. In the
Middle East, emerging data suggest that structurally-controlled
hydrothermal processes may be significant in Jurassic to
Cretaceous reservoirs, including the world’s largest
oil and gas fields.
Vertical hydrothermal dolomite 'chimneys'
(arrows) and stratiform dolomite in Middle Cambrian
on west face of Mt. Wapta in southeastern British
HTD project places strong emphasis on understanding the origin,
tectonic and structural setting, fabrics, and reservoir characteristics
of HTD in western Canada, but also takes a global comparative
view of HTD reservoirs and associated hydrothermal mineral
deposits. When viewed from a global perspective, most hydrothermal
dolomite and mineral deposits show a close association
with extensional tectonic settings with elevated heat flow,
focussed flow through fault/fracture conduits (with a strong
strike -slip fault component), but still with a significant
facies influence on fluid flow, dolomitization, and reservoir
'Floating clast' dolomite breccia
cemented by saddle dolomite, characteristic of dilational
extensional space along fault, formed under conditions
of high pore fluid pressure/pressure drops. Middle
Cambrian outcrop, southwestern Alberta.
Major aspects of the project include:
Multi-client, non-exclusive project
- Project leader/principal
geologist: Graham Davies
- Global in scope, utilizing western
Canada core control
- Comprehensive report on all aspects
of hydrothermal dolomite reservoir trends: tectonic setting,
rock fabrics, geomechanics, fluid flow and faulting,
significance of wrench /strike-slip faults, seismic signatures of sags,
importance of basal sandstone aquifers, western Canadian
and US hydrothermal dolomite reservoir trends, reservoir
quality, and other controls and aspects.
- Report documents
and builds on the recognition that emplacement of hydrothermal
dolomite is a process driven not only
by temperature but by pressure (hence the alternative term 'thermobaric'
dolomite), with a range of newly-defined fabrics as well
as breccias and zebra structures formed under superhydrostatic
to possibly supralithostatic fluid pressures.
also reviews hydrothermal dolomite plays in Cambro-Ordovician
in Michigan, Appalachian and Permian Basins, from Anticosti
Island through southern Ontario, the eastern US, and
(albeit controversially) to west Texas.
- Description of over 480 cores from 153
wells in hydrothermal dolomite or proximal limestone facies
from Alberta, NE
BC, Yukon, NWT, in hard copy and CD-ROM with selected thin-sections
and core photographs.
- Upgraded Hydrothermal Dolomite
Map of western Canada (multiple copies).
- Report contains
548 pages, 506 text figures, 24 tables, 568 references
and 5 appendices. Also includes: new organic
petrographic analyses, fluid inclusion, temperature data, mass spectrometry
of fluid inclusions, and other analyses, leading to new
insights on hydrothermal dolomite processes.
- Cambrian field guidebook
- Core seminars and field trips