Multi-layer screen and downhole completion method

摘要

A downhole completion method and an expandable filtration apparatus are disclosed. The filter assembly comprises a plurality of layers beginning with a coated perforated base pipe. The coating reduces the force required for expansion. A drainage layer overlays the base pipe with the filtration layer above it. The drainage layer improves flow through the filtration layer and protects it from burrs in the base pipe. A filtration enhancement layer fits over the filtration layer and an outer shroud protects the assembly during run in. The assembly can be used as made or expanded downhole in one or a series of expansions.