Geologic Characterization of the Basal Cambrian System
The oldest layer of sedimentary rock in the northern Great Plains region is dated to the Cambrian and Ordovician period of geologic time―600 million years ago. This Cambrian-age
rock layer is more than 1000 ft thick and reaches a depth of 14,000 feet in the center of the Williston Basin (4400 meters) and is the oldest and deepest rock layer that can be used for the geologic storage of
. Because the pores of the sedimentary rock contain very salty water (up to 10 times as salty as ocean water), the zone of rock is referred to as
the Cambro-Ordovician Saline System (COSS).
Because much of the COSS rock layers are deep underground in the region, they are rarely penetrated by drilling for hydrocarbons. As a result, less is known about the
rocks of the COSS or the chemistry of the fluids they contain in their pores relative to shallow layers of rock. The Basal Cambrian Geological Characterization Project will
remedy this by studying the geology of the COSS and suitability of the COSS rock formations and fluids for geologic storage of CO2
. The project
will feature a close collaboration between Canadian and U.S. scientists and result in a detailed picture of the COSS across the entire region.
In the 1.34-million-km2
area underlain by the COSS, there are 43 large CO2
sources that each emit more than 0.75 Mt CO2
/year. Assuming that all of these emissions from
each of these sources will be stored in the COSS, the main questions to be addressed by this project are:
- What areas of the COSS are suitable for CO2 storage?
- How many years of CO2 emissions can be stored in the COSS?
- How will geologic CO2 storage likely affect the rocks and fluids of the COSS?
- How will the CO2 behave once injected into the rocks and fluids of the COSS?
The project started on October 1, 2010, and is structured in three 1-year phases.
- Phase I focused on delineating and characterizing separately the Canadian and U.S. portions of the COSS.
- Phase II brought together the data from Phase I into a single 2-D model. Data on depth, thickness, and porosity were collected to compute the CO2 storage resource of this saline system.
- Phase II will develop a massive 3-D geologic model encompassing the entire study area.
This binational collaborative effort is led on the U.S. side by the Energy & Environmental Research Center (EERC) through the Plains CO2
Partnership and on the Canadian side by Alberta Innovates – Technology Futures (AITF). Other partners include:
- U.S. Department of Energy
- Lawrence Berkeley National Laboratory
- Princeton University
- Saskatchewan Industry and Resources
- Manitoba Water Stewardship
- Manitoba Innovation – Energy and Mines
- Natural Resources Canada
- TOTAL E&P Ltd.
- University of Regina Petroleum Technology Research Centre