Sedimentary Basins
Sedimentary basins present great potential as an energy resource. Unlike hydrothermal systems, potential projects are not limited to volcanic or tectonic areas that are less extensive than sedimentary basins in their areal dimension. Sedimentary basins are present on all continents and having been explored for oil and gas resources, a large body of data is available for geothermal exploration. Technological advancements in binary cycle power plants (e.g., an Organic Rankine Cycle system ) have made power production possible for sedimentary basins with average geothermal gradients (temperatures greater than 120°C at 3- to 4-kilometer depths).
Sedimentary systems typically consist of production and injection wells that recirculate produced fluid through the reservoir.
- The well flow rates depend on the acceptable pressure change (parasitic load) and the transmissivity of the formations.
- The lifetime of the system is determined by the thermal breakthrough time, which depends on the well spacing.
PROJECT SPOTLIGHT
DEEP Feasibility and Drilling
Deep Earth Energy Production Corp. // Estevan, SK, Canada // 2015 - Present
RESPEC has completed resource exploration and development feasibility studies for DEEP in southern Saskatchewan’s Williston Basin. DEEP is endeavoring to tap the sedimentary heat to produce geothermal power from the hot brines of the basal aquifers at a 3,500‑meter depth in the Williston Basin in southern Saskatchewan. RESPEC completed a geothermal resource feasibility and mapping study that included the temperature, thickness, depth, and permeability of the basal aquifers. The pilot exploration well targets were based on the study. Drilling began on the pilot-resource characterization wells in early 2018.
RESPEC is currently leading the reservoir engineering for DEEP and has designed and analyzed several single-well and multiwell, long-term flow tests. We have designed an innovative wellfield to produce power from a challenging resource. The wellfield design will be the first of its kind to be implemented for geothermal power generation in a low‑temperature sedimentary basin setting. RESPEC continues to support DEEP with reservoir modeling, geomechanical studies, and overall geothermal power project development.
PROJECT SPOTLIGHT
Tu Deh-Kah Development
Barkley Project Group // Fort Nelson, BC, Canada // 2018 - Present
RESPEC is the prime subsurface science and engineering contractor for the Tu Deh-Kah geothermal project in British Columbia. We worked with Barkley Project Group to help the Fort Nelson First Nation secure the initial grant of $49 million from Natural Resources Canada to kick off this innovative geothermal power project in 2018. RESPEC began work in 2019 on the initial feasibility study by creating a geothermal resource conceptual model; performing a preliminary analytical well-performance modeling and numerical reservoir simulation; and determining the plan for the reservoir characterization, well drilling, and testing.
Phase 3 of the project began in 2021. RESPEC participated in well targeting and design for a full-size production well and temporary injection well to characterize and test the reservoir. Both wells were successfully drilled and completed in 2021 under RESPEC’s recommendation and oversight. We designed a long-term, well-flow loop test and sampling program that was implemented in the fourth quarter of 2021 and an additional long-term flow test that was implemented in 2022.
RESPEC is supporting well targeting and design, surface facility design, and project financing through detailed reservoir simulation, well test analysis, and final well design.
PROJECT SPOTLIGHT
Geothermal Resource PreFeasibility Study
Petroleum Technology Research Centre (PTRC) // Estevan, SK, Canada // 2023 - Present
RESPEC conducted a geothermal resource prefeasibility study to determine the geothermal resource potential of the subsurface formations in Estevan, Saskatchewan, Canada. The heat from subsurface formations is intended to be a thermal energy source for a district heating system. The geothermal resource potential is defined by the reservoir’s ability to sustain flows and deliver high enough fluid temperatures for the heating application with minimal corrosion and scaling issues.
This study ranked formations with the best geothermal potential based on key reservoir parameters, including quality, permeability, thickness, depth, temperature, and fluid geochemistry. The megawatt thermal value associated with each resource formation was then calculated assuming the amount of heat that can be extracted from the reservoir fluid before reinjection.
