Williston Basin Geothermal Power Generation FEED Study

Lead Proponent

DEEP Earth Energy Production Corp (DEEP)

Project Background

Objective of the “Williston Basin Geothermal Power Generation FEED Study” is to prepare and plan for the construction of a geothermal demonstration power plant in Southeast Saskatchewan by performing subsurface targeting and test drilling.  The project was awarded $350,000 from the Energy Innovation Program, and builds on the results of a pre-feasibility desktop study previously funded by Natural Resources Canada’s ecoENERGY Innovation Initiative program.

Follow-on funding (up to $25.6 million) has been provided through Natural Resources Canada’s Emerging Renewable Power Program for construction planning of the geothermal plant.  It will use Organic Rankine Cycle (ORC) technology to produce power from 120⁰C brine from the Deadwood and Winnipeg Formations via production wells drilled to over 3,400 metres deep.

Results

The project drilled and cored the deepest well ever into the Williston Basin Precambrian in Canada.  This was a major step forward for geothermal potential in the Williston Basin.  Previously, the Williston basin was only explored by oil and gas companies – however, there was not enough crude oil in these deposits for commercial extraction to be profitable. It was not until DEEP began exploring in this area that they discovered large volumes of hot water (the foundation of conventional geothermal exploration projects).

Originally, the target formations were the Winnipeg and Deadwood formations.  Detailed geotechnical core analysis was performed that included permeability analysis on 75 samples.  Results of the analysis demonstrated that the permeability was lower than expected in the Deadwood and Winnipeg formations and would not be able to contribute all of the IPR (Inflow Performance Reference) flow rate on their own. 

However, slight over hole (drilled past beyond the initial target) and coring was done into the Precambrian that showed there were fractures present in the Precambrian.  The drilling rig was able to penetrate into the basement rock at a rate that will allow for much deeper exploratory drilling deeper into the basin.  It was expected that this would allow for potential access into even hotter rock if the fracture network is pervasive enough and loaded with water.  Originally it was not anticipated that there would be substantial contribution from Precambrian, however the integrated examination of the core analysis and DST results data shows that flow contribution from Precambrian is significant. 

A flow and build up test was scheduled for the summer of 2019 in order to better understand the flow capacity of the formations in this location.  After the results of the flow test, DEEP was able to better understand and model the design of the wells and facilities needed for a full scale geothermal facility.

Following the flow and build up testing the Reservoir engineer’s adjusted the model back to focus on the Deadwood as the target reservoir.  The reservoir testing and drilling showed that the Deadwood sands are much larger in extent and capacity allowing for increased project size and scope.

The project also achieved another “first-of” - the first horizontal well in the world to be drilled and hydraulically stimulated for the purpose of geothermal power generation. The horizontal well was drilled 2000m laterally, following the drilling of a 3500m deep vertical well, through the target sand reservoir and subsequently hydraulically stimulated to further enhance the producing capabilities. 

Following this drilling and stimulation, surface facilities were constructed to carry out the longer term 1800 m³/day loop test that was needed in order to refine and improve the processes for geothermal energy production in this region.  

DEEP has secured a Power Purchase Agreement with Saskpower.  This is extremely important in that Saskpower is the only major power purchaser/provider in the Province of Saskatchewan.  This gives the project economic viability in that there is an off-taker for the power produced.

Benefits to Canada

This project will be instrumental in increasing the economic viability of producing clean power from similar reservoirs, attracting significant capital into Saskatchewan and other provinces, and continue the research & development of these technologies to harness this renewable resource both efficiently and sustainably.

Next Steps

Following completion of this project, DEEP will continue to focus on fully understanding the reservoir parameters and finalizing plant design for one of Canada's first geothermal power facilities.

Assembled a top tier team of industry professionals to move the project through to full scale geothermal energy production.  This is significant in that with a new project of this complexity, DEEP now has the core group of drilling and energy professionals that have the experience and expertise to overcome the operational and reservoir hurdles to give the project every chance for success and help to advance the project to completion.