CSW1 and CSW2 were successfully drilled to their designed depths and locations within the Phoenix deposit


Image: Denison Installs commercial scale wells. Photo: Courtesy of David Mark from Pixabay.

Denison Mines reports the successful installation of two Commercial Scale Wells (“CSWs”) within the Phoenix deposit (“Phoenix”), as part of the ongoing In-Situ Recovery (“ISR”) field test program at the Company’s 90% owned Wheeler River Uranium Project (“Wheeler River”), located in northern Saskatchewan, Canada.  Additionally, the Company is pleased to report the successful deployment of the MaxPERF Drilling Tool and its plans for completion of long-duration hydrogeological test work during the remainder of the 2019 ISR Field Test program.

Operational Highlights

Installation of the first CSWs designed for ISR mining in the Athabasca Basin: CSW1 (drill hole GWR-031, in Test Area 1) and CSW2 (drill hole GWR-032, in Test Area 2) represent the first large-diameter CSWs successfully installed, for the purpose of ISR mining, in the Athabasca Basin region. The completion of each CSW included the drilling of a large-diameter vertical borehole (~12 inches in diameter) approximately 400 metres from surface, to intersect the Phoenix ore body, and the installation of well materials designed to meet expected environmental and regulatory standards for eventual ISR mining. Locations of the Phoenix Test Areas and CSWs are shown in Figures 1, and Figures 2 and 3 respectively.

Successful lateral penetrations of the Phoenix ore body using the MaxPERF Drilling Tool: Penetrators Canada Inc. (“Penetrators”), developers and operators of the MaxPERF Drilling Tool, successfully deployed the tool within CSW1 and completed 28 lateral drill holes (penetration tunnels) within a variety of ore types associated with the Phoenix deposit. MaxPERF deployment at CSW2 is planned to follow during the remainder of the 2019 ISR Field Test program.

Initial short-duration hydrogeological tests demonstrate effectiveness of MaxPERF at Phoenix: Initial short-duration hydrogeological tests confirmed increased flow rates in Test Area 1 following the completion of the MaxPERF drilling in CSW1. These results demonstrate the effectiveness of the MaxPERF Drilling Tool in providing increased access to hydraulic connectivity associated with the existing permeability of the ore zone.

Long-duration hydrogeological tests planned to complete the 2019 ISR Field Test: Based on the successful completion of CSW1 and CSW2, and following the successful deployment of the MaxPERF Drilling Tool, long-duration hydrogeological tests are planned to be completed during the remainder of the 2019 ISR Field Test. These tests are expected to be carried out in both CSW1 and CSW2 to allow for the simulation of fluid flow, within Test Area 1 and Test Area 2 of Phoenix, under conditions similar to an envisioned commercial production environment.

David Bronkhorst, Denison’s Vice President Operations, commented, “We are very pleased to have completed the successful installation of the first two Commercial Scale Wells at Phoenix.  As part of the Company’s risk managed approach to the 2019 ISR Field Test program, we continue to build on operational successes and advance towards the completion of all of our program objectives – including the testing of the MaxPERF Drilling Tool, which has already proven to be effective when deployed in a CSW.  With the varied geology interpreted at Phoenix, the ability to use MaxPERF, to mechanically engineer increased access to the existing permeability of the ore formation, bodes well for potentially normalizing the geological variations in a production environment.”

Commercial Scale Well (CSW) Installations

CSW1 and CSW2 were successfully drilled to their designed depths and locations within the Phoenix deposit. A directional drilling methodology was employed in conjunction with Measurement-While-Drilling (“MWD”) surveying technology to accurately determine the well path to its desired target location.

Well materials, designed for commercial ISR production, were successfully installed as planned – providing a double-walled and fully-sealed piping system. Additionally, the outer casing of each CSW was successfully grouted in place with a single-stage cement application, providing a further seal between the CSW and outlying sandstone formation. The piping system installed for both CSWs is ISR mining solution ready and is expected to meet environmental and regulatory standards. A CSW is considered complete once the piping system has been installed and the outer casing grouted into position. Further details regarding the design of the CSWs are provided in Denison’s news release dated September 19, 2019.

Source: Company Press Release