Fort Liard Reservoir Characterization Project
The southern Northwest Territories (SNWT) has been the focus of geothermal energy project interest since approximately 2010. Such interest is largely the result of peer-reviewed publications with maps that showed the SNWT region as an area of high geothermal potential (e.g., Majorowicz and Grasby 2010). In the Fort Liard area, the Manetoe dolomite facies (Manetoe Facies) of the Nahanni Formation might constitute a good geothermal basin-type reservoir target. It has demonstrated very good reservoir storage and flow capacity where it has been successfully drilled for thrusted foothills gas plays west of the hamlet of Fort Liard. Unfortunately, there is a lack of detailed peer-reviewed geoscience that adequately describes and documents reservoir quality and continuity associated with this facies. The purpose of the Fort Liard Reservoir Characterization Project is to produce peer-reviewed geoscience that will address knowledge gaps associated with reservoir quality, mineralogy, pore geometry and clay content, continuity, and areal extent for the Manetoe Facies of the Nahanni Formation within the study area.
Majorowicz, J.A. and Grasby, 2010, Heat flow, depth–temperature variations and stored thermal energy for enhanced geothermal systems in Canada, Journal of Geophysics and Engineering, Volume 7, pages 232-241.
The Fort Liard Reservoir Characterization Project focus area is located in the southwest corner of the Northwest Territories (Figure 1) near the hamlet of Fort Liard. The study region is broadly defined by the coordinates NW corner 62° 00’ N 124° 00’ W and SE corner 60° 00’ N 122° 00’ W (Figure 2 – Yellow Rectangle).
Figure 1. Fort Liard Reservoir Characterization Project Location.
Figure 2. Fort Liard Reservoir Characterization Project Study Area.
The hamlet of Fort Liard is located along the Fort Liard River and is populated by approximately 600 Acho Dene Koe First Nations (ADKFN) people. Three diesel generators with a total capacity of 1.32 MW (https://www.ntpc.com/our-community/community-map) supplies energy for the hamlet. Recent federal, provincial, and territorial mandates include the interest to reduce greenhouse gas (GHG) emissions from high GHG emitting diesel generators through the development of low GHG alternative energy resources such as geothermal energy. This study will result in the delivery of the geoscience required to understand the Nahanni Manetoe Facies reservoir, a potential geothermal energy resource target near the hamlet of Fort Liard. Favorable results will support the second phase of research that would include the acquisition of accurate geothermal gradient data, Manetoe Facies reservoir heat flow measurements and modeling, geothermal resource estimates, and reservoir production modeling. Positive results for both research phases would provide technical support for a Manetoe Facies geothermal demonstration project.
The first phase of this study will produce a reservoir assessment of the Nahanni Formation carbonate, including the Manetoe Facies dolomite. Cores and samples from the Nahanni Formation in Liard area wells and three Manetoe facies outcrops were selected for detailed analysis. Assessment methods include core and sample geological descriptions, sampling for thin section analysis, x-ray diffraction (mineralogy and fractions), small plug core analysis (porosity and permeability measurements) and scanning electron microscopy (SEM) (pore geometry and interconnectivity, types of minerals present in the pores). Outcrops will be measured and described in the field, and samples will be taken and analyzed as previously described for the core. Manetoe Facies reservoir areal extents and continuities will be documented as observed in outcrop.
Northwest Territories Geological Survey (NTGS) Energy Geosciences conceived the project during the first quarter of 2019. It was reviewed with Infrastructure-Energy Group during the second quarter, and an interdepartmental NTGS – Infrastructure- Energy collaboration was formed during the third quarter of 2019. NTGS initiated project work in October 2019, and the project is on track for completion during the fourth quarter of 2020.
Partners and Support
Internal Partner: Infrastructure – Energy Division
Fort Liard, geothermal, energy, Manetoe Facies, Nahanni Formation, dolomite, reservoir, core, porosity, permeability, pore geometry, reservoir continuity, mineralogy, outcrop