Construction in two phases
The geothermal power facility is planned to be constructed in two phases. The first phase is for a 5-MW capacity power plant using an ORC unit and utilizing steam from two production wells complemented by two injection wells. Other surface facilities and infrastructure will be constructed to support the first phase.
Phase 2 will then add 25 MW to the capacity and will see an additional ten production wells and eight injection wells, and a second ORC power generation unit. The geothermal resource to be tapped for both phases will be from a 3500-meter deep permeable sandstone reservoir with expected temperatures of 120 degrees Celsius.
The PPA for the 5-MW Phase 1 facility had already been signed with SaskPower. Additionally, discussions are ongoing between Deep and SaskPower for the Phase 2 PPA.
Drilling plan
Wells will be drilled to 3,500 metres and extend from vertical to horizontal for an additional 3,000 metres. This horizontal drilling design, developed by the oil and gas industry, supports higher volume fluid production than from vertical wells alone.
Significant progress has been made on the design and planning work for the Phase 1 and Phase 2 horizontal field well developments. A Basis of Design (“BOD”) has been developed for drilling equipment selection that satisfies the primary objectives of temperature, flow rate, and corrosion protection from the formation brine. In addition, a wellbore geo-mechanical stability study has been completed to optimize drilling fluid density and well trajectory, and a wellbore thermal stress model has been completed to optimize casing and tubing weight, grade, and connection specifications.
RFPs have been issued to determine current pricing for drilling rigs and materials such as casing, tubing, wellheads, and other supporting services such as directional drilling, drilling fluids, and cementing. This current pricing together with a systematic analysis of DEEP historical drilling performance and a detailed activity planning schedule was used to develop Class III time and cost estimates for the drilling, testing and completion of all wells.
With the design phase complete, the next steps are to commence the contracting process to secure materials and services prioritizing long lead items and to develop detailed drilling, testing and completions program execution documents.
Seismic survey
A 56.2-km2 3D seismic program had been conducted in the development site in Q1 2023. Based on geophysical interpretation, there is sufficient accommodation space in the Deadwood Formation sandstone reservoir to support the drilling of 22 wells for Phase 1 and Phase 2 of the geothermal power project.
The survey extends to the east of the previously acquired 3D seismic and covers the eastern portion of both development phases. This data will be used for the horizontal well trajectory planning and for future expansion planning.
The DEEP project site in Saskatchewan, Canada (source: DEEP)
Surface facilities
SCOVAN Engineering is in charge of up-front engineering and procurement for both Phase 1 and Phase 2 of the project. he team has developed a Project Execution Plan (“PEP”) which details the cost estimating, schedule, contracting strategy, risk mitigation and construction planning for Phase 1. The PEP is complete and is under review by DEEP’s Project Management group.
In addition to the PEP, SCOVAN has been developing the Design Basis Memorandum (“DBM”) which encompasses the detailed design of both phases of the project. The DBM is well advanced and under review by DEEP Management. Under the PPA, the DEEP Project Management team and SCOVAN have had detailed discussions with SaskPower related to the 5MW interconnection
DEEP has overcome many technical hurdles and has amassed the resources, technology, and expertise to achieve on-time and on-budget milestones along the path to operational status.