Abstract:During the in-situ leaching process of sandstone type uranium deposits, it is necessary to inject leaching solution into the ore-bearing aquifer and extract uranium-containing groundwater to create an artificial local flow field. This flow field controls the migration of leaching agents and the leaching range, so understanding the characteristics of the underground flow field is beneficial for the process control of uranium in-situ leaching wellfields. Taking an experimental mining area of a uranium in-situ leaching mine in Ordos Basin as an example, the spatial and temporal characteristics of the underground water flow field of 80 production wells operating for 8 years were analyzed. The following conclusions were drawn: 1) In the study area, the extraction flow rate of 30 extraction units is approximately equal to the injection flow rate in general, and the extraction and injection is basically balanced. 2) C8-1 unit has the highest extraction capacity and the lowest water level. The water level in the study area ranges from 1186 to 1344 meters, and the water flow direction is mainly from injection well to adjacent extraction well. 3) The distance between unit C7-10 extraction well and injection well in the upper left corner is too large, resulting in a leaching dead zones between extraction wells. 4) If the flow rate of each extraction unit is balanced and the distance between each extraction well is similar, the extraction unit is easy to form a moderate flow rate field and smaller leaching dead zones. However, if there is a large difference in the extraction or injection flow rate of each well in the well site, it is easy to form leaching dead zones, and unreasonable well spacing will increase the range of leaching dead zones.