Geothermal Assessment of Two Regionally Extensive Upper Devonian Carbonate Aquifers in Alberta, Canada (original) (raw)
Related papers
Geothermal exploration of Paleozoic formations in Central Alberta
Canadian Journal of Earth Sciences, 2013
Recent geothermal exploration indicated that the Cambrian Basal Sandstone Unit (BSU) in central Alberta could be a potential target formation for geothermal heat production, due to its depth and extent. Although several studies showed that the BSU in the shallower Western Canada Sedimentary Basin (WCSB) has good reservoir properties, almost no information exists from the deeper WCSB. This study investigated the petrography of the BSU in central Alberta with help of drill cores and thin sections from six wells. Porosity and permeability as important reservoir parameters for geothermal utilization were determined by core testing. The average porosity and permeability of the BSU is 10% and <1 × 10 −14 m 2 , respectively. A zone of high porosity and permeability was identified in a well located in the northern part of the study area. This study presents the first published geomechanical tests of the BSU, which were obtained as input parameters for the simulation of hydraulic stimulation treatments. The BSU has a relatively high unconfined compressive strength (up to 97.7 MPa), high cohesion (up to 69.8 MPa), and a remarkably high friction coefficient (up to 1.22), despite a rather low tensile strength (<5 MPa). An average geothermal gradient of 35.6°C/km was calculated from about 2000 temperature values. The temperature in the BSU ranges from 65 to 120°C. Results of this study confirm that the BSU is a potential geothermal target formation, though hydraulic stimulation treatments are required to increase the permeability of the reservoir.
Geothermal Assessment of Paleozoic Aquifers in the Central Alberta Basin, Canada
The Alberta Basin as foreland basin of the Rocky Mountains is known for its resources of oil, gas and coal. Due to its characteristic flexure of the foreland lithosphere this basin type deepens significantly towards the orogenic belt. These foreland deeps host potentially sedimentary layers containing hot fluids and structurally or facies controlled high permeability domains. Two focus regions are studied by well data analysis, 2D seismic sections, stress field analysis and temperature modeling. The study areas are located around the city of Edmonton in central Alberta (basin depth 1.8 – 3.5km) and in northeastern Alberta around the town of Peace River (basin depth 1.7 – 2.4 km). Extension and thickness of potential geothermal target formations is investigated by 3D structural geological modeling, and geostatistical methods are applied to analyze the distribution of porosity, permeability and temperature within these formations. For central Alberta, the medium to coarse grained Camb...
2020
Exploitation of hydrocarbon resources throughout the Western Canadian Sedimentary Basin has been accompanied by the production of trillions of cubic meters of aqueous fluids, i.e. brines, which are either recirculated to maintain reservoir pressure, or reinjected in far-flung disposal wells. Basin-wide, these brines carry petawatts of thermal power to the Earth’s surface. Socioeconomic demand for renewable power, coupled with recent advances in low-enthalpy waste heat recovery, has led to increasing interest from oil field operators in geothermal co-production. This paper explores the potential scale of geothermal co-production from an oil-producing pinnacle reef in the Swan Hills Complex of central Alberta, Canada. In this study, we combine geospatial, hydrogeological, and thermodynamic data to build reservoir volume-based model of the Virginia Hills field. We analyze the effects of variable temperature, porosity, thermal recovery factor and engine efficiency on the geothermal powe...
Applied Sciences
The Alberta No. 1 project is a planned power and heat (direct use) geothermal project located within the County of Grande Prairie and Municipal District of Greenview. For the project to successfully produce power and heat on a commercial scale, temperatures of 120 °C are desirable. The produced fluids must also be from highly permeable formations from depths of less than 4500 m. Bottomhole temperature measurements and wireline logs from Alberta’s extensive oil and gas database were used to determine the depths to target formations and temperatures within these formations in the project area. The target formations include the dolomitized carbonate units of Devonian age from the Beaverhill Lake Group to the top of the Precambrian Basement. Permeable Devonian-aged sandstone units such as the Granite Wash Formation are also targets. Results suggest that elevation to the top of the Beaverhill Lake Group range from 3104 m to 4094 m and temperatures at the top of the formation range from 8...
Renewable Energy, 2019
Low efficiency of turbines used in geothermal power production, along with large power demand for geothermal fluid pumping, limits use of geothermal resources for power production in the Canadian low to mid enthalpy basins. Much larger areas of Canadian sedimentary basins have potential for geothermal direct heating, but use will be dependent on the amortization period of the installation cost as well as the parasitic power demand to maintain large flow rates in injection and production wells. Maximum exergy (kJ/kg) potential for the most perspective geothermal resources in the deeper parts of Canadian basins (150 kJ/kg (0.15 MJ/kg)), are compared to exergy contained by the intrinsic chemical energy in oil, gas and coal (30-35 MJ/kg) that is required to be replaced in order to reduce carbon emissions. The calculated number of geothermal producing doublet well systems, at very high assumed flows of 0.08 m 3 /s (80 L/s), required to replace an average oil producing well in Alberta-WCSB will be > 10. But, such high exergy is available only in the deepest northern parts of the WCSB.
Canadian Journal of Earth Sciences, 1985
A large number of bottom-hole temperature (BHT) data from Alberta (55 246 BHT from 28 260 wells) have been used to construct Paleozoic and Precambrian surface-temperature maps. A northward increase of average heat flow in Alberta results in higher subsurface temperatures at the Precambrian basement and at the top of the Paleozoic toward the north and northeast than at the same depths in the south and southeast. However, the temperature distribution at these surfaces is more depth dependent than gradient dependent, and so higher temperature values occur in the western part of the basin. As a result, good geothermal energy potential exists throughout the western half of the province, especially for regions west of the Calgary -Swan Hills -Grande Prairie -Rainbow Lake line. Through the central part of the basin, zones occur where the isotherms and the isopach lines of the Phanerozoic are parallel. These zones probably represent regions where little disturbance to heat transport by vertical water motion occurs. It is suggested that zones in the central part of the basin where such parallelism does not occur may represent areas where conductive transport of heat is perturbed by local, nonlateral fluid flow or zones with nonuniform heat contribution from the crystalline crust or upper mantle. The effect of hydrodynamics in the deeper sediments of the Paleozoic that lie below the BHT observations may also contribute to such zones.
Geothermal potential of the St. Lawrence Lowlands sedimentary basin from well log analysis
Geothermics, 2018
The heterogeneous distribution of minerals in different rock types poses several challenges for assessing thermal conductivity, heat flow and temperature of sedimentary basins, especially when databases coming from the oil sector are the only source of information. The objective of this study was to develop a new methodology that uses well log data to better infer the thermal conductivity variations of sedimentary formations in order to evaluate heat flow and extrapolate temperature at depth. The methodology was applied to the St. Lawrence Lowlands basin, with constrains from the available oil and gas database not designed for geothermal exploration purposes. The main idea was to analyze quantitatively well log data with an inversion approach from limited reference wells and derive empirical relationships to calculate a thermal conductivity profile for each available well. Pressure and temperature corrections were then considered. These continuous logs of thermal conductivity were used to estimate the Earth's heat flux density using bottomhole temperatures and to extrapolate temperature at depth. A modified version of Poisson's equation was solved by the finite difference method for this purpose. The average temperature and its standard deviation obtained with this approach for the St.
Geothermal Energy, 2020
Anticosti Island is located in the Anticosti sedimentary basin, an Ordovician/Silurian carbonate platform. This platform is mainly composed of limestone and shale with some dolomite and sandstone and reaches up to 5 km depth in the southwest. It overlies a Precambrian basement of the Grenville Province made of magmatic and metamorphic rocks. Like most remote and off-grid regions in Canada, it relies heavily on fossil fuels for energy supplies. An assessment of deep geothermal resources was achieved in this area with the objective of diversifying energy resources to help develop renewable energy for villages deserved by micro-grid systems. Despite sparse and low-quality bottom-hole data (15 wells of 1111 m to 2762 m depth), a 3D temperature model was developed for this sedimentary basin and its underlying Precambrian basement up to 40 km (mantle depth). Quantifying confidence intervals for thermal parameters, namely bottom-hole temperature, thermal conductivity, heat generation rate ...
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...
Journal of Geophysics and Engineering, 2012
Subsurface temperature data from industrial sources may contain significant biases that greatly reduce their overall quality. However, if these biases can be identified and removed, the data can provide a good preliminary source of information for further studies. In this paper, industrial thermal data from three sources: bottom hole temperatures, annual pool pressure tests and drill stem tests are evaluated to provide an updated view of the subsurface temperatures below the oil sand regions of Northern Alberta. The study highlights some of the potentially large systematic biases inherent in industrial temperature data which affect estimates of geothermal gradient and regional mapping of the geothermal field.