Issues in the design of production strings of process wells for insitu uranium leaching

Background. Uranium mining by in-situ leaching (ISL) requires specialized methods for the construction and operation of process wells to ensure their reliable performance throughout the entire mining period of cells, blocks, and deposits. During operation, polymer production casing strings are subjected to various loads, among which thermal and hydrostatic loads are particularly significant. This article presents a calculation-b ased justification for the selection of well equipment and waterproofing materials for preventing violations of the integrity of production casing strings through the use of displacement centralizers, wellhead centralizers, and viscoelastic materials. Methods for determining the cementing (waterproofing) intervals and the permissible height for filling the annular space with bulk materials are presented.

Aim. To ensure the integrity of polymer production strings of process wells operated under variable temperature conditions during uranium mining by insitu leaching.

Materials and methods. Physical processes occurring during the construction and operation of process wells were analyzed. The effectiveness of available engineering solutions was compared based on the period of accident-free operation of polymer production strings.

Results. Effective engineering solutions proposed for equipping polymer production casing strings are those that provide the possibility of their linear movement in the axial direction at the stages of construction and operation of process wells.

Conclusion. The use of latest engineering solutions for equipping production strings makes it possible to mitigate the risk of accidents during the development of uranium deposits by in-situ leaching.

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