EXPERIMENTAL RESEARCH ON DOUBLE-LAYERGRAVEL-PRE-COATED SCREEN

摘要

With reliable effectiveness, relatively lower price, and easy installing, gravel-pre-coated screen has become the majorrnscreen used in wells in silt-fine-sand aquifers in many countries. In the 1970s, steel-based and plastic-based gravel-pre-coated screensrnwere developed in China but not widely used due to its vulnerability of being jammed. The experimental research on double-layerrngravel-pre-coated screen is aimed to solve the problem. Compared with conventional gravel-pre-coated screen, the double-layer onernhas a different structure: from the exterior layer to the inner layer, the gravel size diminishes. The structure was designed with somernnew ideas absorbed from the process of artificially well filling with gravels. The experiments show that the new structure greatlyrnimproved the permeability of the new screen as well as its ability to avoid being jammed.