Heat flow, depth-temperature variations and stored thermal energy for enhanced geothermal systems in Canada (original) (raw)
Related papers
2014
Heat flow and geothermal gradient of the sedimentary succession of the Western Canada Sedimentary Basin (WCSB) are mapped based on a large thermal database. Heat flow in the deep part of the basin varies from 30 mW/m 2 in the south to high 100 mW/m 2 in the north. As permeable strata are required for a successful geothermal application, the most important aquifers are discussed and evaluated. Regional temperature distribution within different aquifers is mapped for the first time, enabling a delineation of the most promising areas based on thermal field and aquifer properties. Results of previous regional studies on the geothermal potential of the WCSB are newly evaluated and discussed. In parts of the WCSB temperatures as high as 100-210 °C exist at depths of 3-5 km. Fluids from deep aquifers in these "hot" regions of the WCSB could be used in geothermal power plants to produce electricity. The geothermal resources of the shallower parts of the WCSB (>2 km) could be used for warm water provision (>50 °C) or district heating (>70 °C) in urban areas.
Energies, 2014
Heat flow and geothermal gradient of the sedimentary succession of the Western Canada Sedimentary Basin (WCSB) are mapped based on a large thermal database. Heat flow in the deep part of the basin varies from 30 mW/m 2 in the south to high 100 mW/m 2 in the north. As permeable strata are required for a successful geothermal application, the most important aquifers are discussed and evaluated. Regional temperature distribution within different aquifers is mapped for the first time, enabling a delineation of the most promising areas based on thermal field and aquifer properties. Results of previous regional studies on the geothermal potential of the WCSB are newly evaluated and discussed. In parts of the WCSB temperatures as high as 100-210 °C exist at depths of 3-5 km. Fluids from deep aquifers in these "hot" regions of the WCSB could be used in geothermal power plants to produce electricity. The geothermal resources of the shallower parts of the WCSB (>2 km) could be used for warm water provision (>50 °C) or district heating (>70 °C) in urban areas.
The south-eastern territory of the province of Québec (Eastern Canada), a region located along the Saint-Lawrence River Valley, including the Gaspésie Peninsula and the Madeleine and Anticosti Islands, has been identified as an interesting area for the future use of deep geothermal energy several decades from now. This region includes a thick 1-5 km sedimentary rock wedge deepening southwest towards the Appalachian disturbed belt front. The deep part of the sedimentary wedge offers the potential to produce geothermal heating and power from the deep aquifers in the future. Relatively elevated heat flow densities in some thermal anomalous areas (i.e. >60 mW/m 2 ) also result in prospects for temperatures above 120°C at about 4 km in the sedimentary aquifers. Additionally, geothermal power and heat production from hot dry deep granites located below the sedimentary cover can also be considered using Enhanced Geothermal Systems (EGS). On the other hand, Northern Québec, a vast territory covering nearly 1.2 million km 2 of land located north of the 49 th parallel, presents very low mean annual surface temperatures and a relatively low average heat flow density of about 40 mW/m 2 . This area would require deeper drilling for heat mining, i.e. 80°C at a depth of about 4.5 km. In the medium and long terms, geothermal energy could be feasible in the province of Québec with positive future energy and environmental impacts.
Environmental Earth Sciences, 2015
Northern Québec, a large and cold climate territory located north of the 49th parallel, has low average heat flow density (40 ± 9 mW/m 2) typical of the Canadian Shield. The lack of the thermal blanket otherwise provided by sediments in the platform of southern Québec results in deep drilling requirements for potential mining heat (80°C at some 5 km). Drilling doublet or triplet well systems at such depths into low-enthalpy granitic rocks would be expensive; however, in some cases of heat flow higher by one standard deviation of the mean and fracked permeability allowing flow rates [30 kg/s may make this heat useable in the future. Other options in providing heat are more likely to be applied earlier. These would include shallow geothermal energy use with heat pumps in granites by placement of artificial heat exchanges by directional loop drilling. These systems may have promise in Northern Québec due to its very cold climate and extremely high energy cost based on diesel oil heating for remote communities and mining areas. Findings show that recent industrial age climatic warming increased the mean underground temperatures in the upper circa couple hundred meters. This has resulted in temperature gains and energy ground storage.
Deep Geothermal Heating Potential for the Communities of the Western Canadian Sedimentary Basin
Energies
We summarize the feasibility of using geothermal energy from the Western Canada Sedimentary Basin (WCSB) to support communities with populations >3000 people, including those in northeastern British Columbia, southwestern part of Northwest Territories (NWT), southern Saskatchewan, and southeastern Manitoba, along with previously studied communities in Alberta. The geothermal energy potential of the WCSB is largely determined by the basin’s geometry; the sediments start at 0 m thickness adjacent to the Canadian shield in the east and thicken to >6 km to the west, and over 3 km in the Williston sub-basin to the south. Direct heat use is most promising in the western and southern parts of the WCSB where sediment thickness exceeds 2–3 km. Geothermal potential is also dependent on the local geothermal gradient. Aquifers suitable for heating systems occur in western-northwestern Alberta, northeastern British Columbia, and southwestern Saskatchewan. Electrical power production is lim...
Geomechanics and Geophysics for Geo-Energy and Geo-Resources
Geothermal resource quantification requires underground temperature and volume information, which can be challenging to accurately assess at the regional scale. The analytical solution for steady-state heat conduction with internal heat generation is often used to calculate temperature at depth, while geological models can provide volume information. Both approaches were originally combined in a single 3D geological model, in which the underground temperature is directly computed, to accurately evaluate geothermal resources suitable for power generation in the St. Lawrence Lowlands sedimentary basin covering 18,000 km 2 in Quebec, Canada, and improve methods for geothermal resource quantification. This approach, used for the first time at such a large scale, allowed to determine the volume of each thermal unit providing a detail assessment of resource depth, temperature and host geological formation. Only 5% of geothermal resources at a temperature above 120°C that is suitable for power generation were shown to be hosted in the Cambro-Ordovician sedimentary rock sequences at a depth of 4 to 6 km, while 95% of the resource is hosted by the underlying Precambrian basement.
The research into a geothermal energy option for a deeper crystalline basement heat source in the Northern Alberta basin as a potential artificially fractured subsurface heat exchanger to deliver heat for oilsands processing and/or deep geothermal energy for heating to offset CO2 emission is currently underway as part of the University of Alberta Helmholtz-Alberta Initiative (HAI) geothermal energy project. Temperature logging into old Precambrian granites beneath 0.5 km thin sedimentary column in the 2.35 km deep Hunt well near Fort McMurray shows that there is a rather limited amount of heat in granites. It would require drilling some 4-5 km to get to 80-100 oC in Fort McMurray area and 120-150 oC in Peace River area, respectively. This temperature is not sufficient to generate steam for the in-situ recovery of heavy-oil and bitumen but the demand for hot water for surface processing is limited to only 40-70 oC. Our current effort is to generate hot-water through engineered gother...
Renewable Energy, 2014
The identification, mapping and evaluation of geothermal resources are an important component of a diversified and resilient energy system. Geothermal resources offer an important series of contributions from direct (low temperature) heat to electric generation (from EGS or Enhanced Geothermal Systems). While not ideal, Alberta has a wide range of subsurface heat resources that are coincident with load and can be developed in the future at reasonable cost. We assess that geothermal energy output from sources at depth for temperature range between 120 and 150 C accessed from 4 to 5 km wells in very western portions of the Alberta basin can be as competitive as gas burning even at these prices. For the 5 km depth and 150 C, the cost of thermal energy can be as low as 2 $ per GJ thermal equivalence for expected EGS flow rates of 5e50 kg/s, with 30 year expected plant life. Replacement of gas heating utilizing EGS systems could form part of a long range target for industry emission reductions. For example, 1000 (2 wells each) heat generating systems across Alberta drawing 100 C from deep wells in deep sedimentary basin or deep granites can save >30 MT CO 2 per year. Oilsands operations generate some >40 MT per year and in Alberta more than 300,000 wells have been drilled by oil and gas industry.
Geothermal energy potential in the St-Lawrence River area, Québec
Geothermics, 2012
Previous estimates of geothermal energy potential in Canada give an indication of available heat to be 'farmed' at depth with focus on Western Canadian Cordillera and Western Canadian Sedimentary basin as prime targets. This paper examines in more detail temperature-depth realtionships near large population centres in Québec, in order to provide a first order assesment of enhanced geothermal systems (EGS) potential for electrical and heat generation. Results show areas with significant EGS potential in the St-Lawrence River valley related to high heat flow density and thermal blanketing of thick sedimentary cover. At >120 • C found to be a prospect for several areas in Québec (drilled to depths of over 4.5 km in Trois-Rivières area, near 4.5 km in the Eastern St-Lawrence River (Rimouski, Gaspé and Golf, including Anticosti Island) and just 4 km in Quebec area) the potentially available geothermal power from EGS hydrothermal systems in deep sediments can be of significance.
Subsurface temperature analysis along the Williston Basin, Canada for geothermal energy prospecting
International Journal of Advanced Science and Research
The paper focuses on the thermal evaluation of geological well data along the Williston Basin in Canada. The analysis delved into determining the thermal gradients, surface heat flow and most importantly subsurface temperatures at and. The uncorrected well data were reevaluated using the Harrison correction method and temperatures within the range was attained (potential binary type application). The paper serves to identify a prospective production region for geothermal energy exploitation. This was accomplished by analyzing subsurface temperature 2D contour distribution maps. However, correlating these findings with hydraulic parameters can prove to enhance the quality of the region identified. It was determined that within the coordinate ranges of and , there exist an area of interest within the Williston Basin for geothermal energy exploitation.