Gravel pack screen having retention means and fluid permeable

Abstract

An apparatus is provided for use on a subterranean well conduit. The apparatus comprises a cylindrically shaped inner tubular member having an interior and exterior walls. A fluid flow passageway is provided within the interior wall and a fluid flow passage extends from the interior of the tubular member through the exterior wall and in communication with the fluid flow passageway. Retention means are disposed around the exterior of the tubular member and pass across the fluid flow passage means having a fluid flow openings therethrough, the retention means preventing particulate solids in a fluid permeable bed of the apparatus from passing into the fluid flow passage and into the fluid flow passageway through the subterranean conduit. The fluid permeable bed of particulate solids, such as sand, bauxite, glass beads, or the like, is placed around the exterior of the retention and is sized to prevent effectively all particulate matter in the well from passing inwardly through the fluid permeable bed and through the fluid flow passage means and into the fluid flow passageway when the conduit and the apparatus are positioned within the well. A fluid permeable housing is positioned around and exterior of said fluid permeable bed has fluid passages therethrough which are sized to permit well production fluids to pass interiorly through the housing but to prevent effectively all of the particulate solids of the fluid permeable bed from passing exteriorly through the housing and into the well. The retention means has a cross-sectional area smaller than the cross-sectional area of the outer fluid permeable housing and directly interfaces circumferentially around and on and is directly secured to the inner tubular member.