Estevan – After nearly a decade of developing the concept of geothermal electric power, Saskatchewan's Deep Energy Energy Production (DEEP) is finally drilling its first hole south of Torquay, overlooking the American border. A successful project will establish the first geothermal power plant in Canada.
On November 8, the company, led by CEO Kirsten Marcia, drilled its conduit and rathole tube, in anticipation of a full drilling the following week. On November 13, the drilling rig was moved and the well was drilled on November 14.
This hole will be significant, aiming to be the deepest in Saskatchewan. It will overtake the two Aquistore wells in 100 meters, to a total vertical depth of approximately 3,500 meters.
Marcia talked to Pipeline News on November 9.
DEEP was formed in 2010. It had "wonderful outbreaks," he noted, where they would move at a huge distance and then be delayed by funding. But in recent weeks, they received $ 4 million in new equity funds that allowed the company to start drilling. They hired a drilling rig that works nearby but will have a window of opportunity.
The well should take 25 days to drill, much more than a typical well in that area. This is partly because they plan to cut 200 meters of core at the bottom of it, including cutting the core in the pre-Cambrian basement, which is the basis of the sedimentary beds.
"I hope we'll get some core in the basement," she said. They intend to go up to 20 meters to the basement as this will provide the depth required for the wood extraction tools that accompany the sweeping of the entire sedimentary column.
While Marcia herself is a geologist who used to sit in wells, DEEP hired John Lake, a prominent Saskatchewan geologist who once appeared on the cover of Pipeline News to sit in that well.
This hole should be the first of six, paving the way for three production wells and two injection wells. The wells should be placed at a distance of 300 to 500 meters.
This initial well will be a bit smaller in diameter, at 7 inches, to the bottom. Subsequent production wells will be 9-5 / 8 inches in diameter.
This is to deal with the considerable submersible electric pumps (ESPs) that will move an enormous amount of water, pulling it of the formations of Winnipeg and Deadwood that compose the last 200 meters of the hole. The Icebox formation, overlapping the Winnipeg formation, acts as a caprock, as in the Aquistore project, approximately 29 kilometers to the east.
Aquistore injects carbon dioxide from the Carbon Capture and Storage Project of the Boundary Dam Unit in a deep saline aquifer, 3,400 meters deep and two kilometers west of the plant. SaskPower, which already contributed $ 1 million to the DEEP project, shared data with the DEEP they had from Aquistore.
Marcia noted that, in this case, the Icebox acts as thermal insulation for its purposes.
That well is a preliminary test of the resource, necessary to refine the assumptions, she explained.
Marcia said this well is "a mile" from a similar deep well drilled by Canadian Natural Resources Limited in the 1980s. This well was registered at a temperature of 95º C, but three days later it registered 126º C.
And that is why the area is so attractive and why they are drilling so deeply. Marcia noted that this is not a volcanic geothermal project, but rather one in a sedimentary basin. "The deeper you go, the hotter it gets," she said as the heat comes from the center of the earth.
"This is heat mining. Heat is the feature. Water is the means to move the resource. "
The plan is to drill this first well and then complete it three weeks later to find its true temperature. They will flow the well for seven days, using it to model complete production wells. They will also test the injectability of the Mannville lineup for future injection wells.
By the end of March, the tests are expected to be fully reviewed. "If the first well provides enough data to convince a lender of production wells, we will," said Marcia.
Then, after the separation of the spring of 2019, the plan is to proceed with the production and injection wells, puncturing them as "doublets".
Injection wells, however, would not reach the depth of the production wells, but rather the more superficial Mannville formation, which is commonly used for the disposal of wells in the region. There is a possibility that this initial well can also be used as an injection well. This may be necessary to maintain the pressure in the reservoir.
Each production well will use an ESP that consumes a megawatt, approximately 1,340 horsepower. The total energy produced by this project is expected to be 10 megawatts, but after considering the energy use of the pumps and installation facilities, the net power output will be five megawatts. He will be tied up at a substation in Bromhead.
Production of energy
The main part of the project is the power plant itself.
The above-ground installation uses the organic Rankine cycle. Using a working fluid with a low boiling point, the hot water withdrawn from the production wells transfers its heat through a heat exchanger, causing the working fluid to begin to flash in a gas (i.e., boil) and power the turbine. A cooling tower cools the working fluid back to the liquid phase for reuse. The water is then pumped into the injection wells.
This system is almost identical in concept and scale to what is already being done at the compression stations in the Alliance Pipeline, which runs through Saskatchewan. These heat recovery plants were installed in Kerrobert, Loreburn, Estlin and Alameda in 2008, and each produces five megawatts of energy.
In fact, the reality that the geothermal concept of DEEP is using well-established and already existing technologies – drilling of production and injection wells using heat to run a Rankine organic cycle plant – has made it somewhat problematic to attract funding, according to Marcia. . There was nothing new by itself. But it was a new application of this technology in a sedimentary basin, and in particular in the Williston Basin, that makes it unique
The project can double in size, she noted, but at some point, it might make more sense to replicate the project instead of adding it. It is scalable and repeatable.
The system will cool the water from 120 ° C to approximately 65 ° C, but this still means that there is plenty of usable heat. Although its purpose is to produce electricity, not cucumbers, it thinks there may be possibilities in the future to use waste heat in greenhouses or other applications.
All told, if things go well in two and a half years, Marcia said they could have power to the grid, renewable energy and base load that was running about 95% of the time. She called it "the most attractive of all renewables" and said it can offset the coal.
Marcia noted that they are using data from oil fields, technology and processes to establish renewable resources and that without this industry, no one would know that there is a geothermal resource here.