The slotted or perforated section of casing across the producing zone that lets water in and keeps sediment out.
The screen is the working interface between the aquifer and the well. Slot size is matched to the formation or the gravel pack so water flows freely while sand stays out. Screens can be machine-cut PVC, stainless wire-wrap, or louvered steel. A properly designed screen is the single biggest factor in long-term well performance.