POLYMER SCREENING TO IMPROVE ACID SWEEP EFFICIENCY IN URANIUM ISR PROCESS
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Date
2023-04
Authors
Veintimilla Vela, Santiago David
Journal Title
Journal ISSN
Volume Title
Publisher
School of Mining and Geosciences
Abstract
In-situ leaching (ISL) is a widely used technique for the extraction of uranium from ore bodies.
The ISL process involves the injection of a leaching solution into the ore body through wells
drilled into the formation. The leaching solution dissolves the uranium from the ore, and the
resulting solution is then pumped to the surface for processing.
One of the main challenges in the ISL process is the heterogeneity and anisotropy in the
petrophysical properties of the reservoir. The ore body may contain multiple zones with varying
permeability values and a constant porosity value making it difficult for the acidic solution to
reach the main objective zones for production. As a result, a large volume of acidic solution is
often injected to ensure that the solution reaches the targeted zones by density differentiation.
However, this solution leads to a higher volume of injection solution needed, and the
operational costs of the process become prohibitive.
This study attempts to provide a new direction in the production of uranium through the ISR
process and a practical solution to improve acidic solution use and enhance its sweep efficiency
by the use of polymer flooding. The aim of this study is to screen the performance of different
polymers to identify the most effective ones in enhancing sweep efficiency. The study
investigates the effects of polymer concentration on the viscosity of the polymer on the surface
of the ore. The use of polymers can enhance the viscosity of the acidic solution, reduce the
heterogeneity between the layers on the reservoir and displace the desired resulting solution as
uniform as it can be.
The results of polymer screening will provide data to a simulation of polymer flooding under
determined parameters. The main objective of this simulation is to demonstrate that polymer
can enhance the sweep efficiency of the injected fluid even being under extreme conditions as
low pH values, enabling it to reach the main objective zones for production. This can reduce
the operational costs of the process and increase the sustainability of uranium extraction from
ore bodies. As a result the sweep efficiency was improved from 0.72 in the first case scenario,
only acidic solution injection, to 0.80 after polymer flooding. Furthermore, the study can
contribute to the understanding of the mechanisms of polymer flooding in the ISL process,
providing a foundation for further research on this topic.
Description
Keywords
Type of access: Restricted, In-situ leaching, Polymer screening, uranium ISR process, acid sweep efficiency
Citation
Veintimilla, S. (2023). Polymer screening to improve acid sweep efficiency in uranium ISR process. School of Mining and Geosciences