Sintered spherical plastic bead prepack screen aggregate

Abstract

A prepack well screen assembly for separating particulate material from formation fluid has inner and outer screens concentrically mounted in radially spaced relation around a perforated mandrel, thereby defining a prepack annulus in which a plurality of spherical plastic members are disposed. The concentric inner screen includes longitudinally extending rib wires spaced circumferentially around the mandrel, and a screen wire wrapped externally about the rib wires in a longitudinally spaced pattern to define spaced screen apertures for conducting formation fluids through the inner screen. The outer screen is a cylindrical fluid-porous, particulate-restricting member which is radially spaced from the inner screen to form the prepack annulus. The particulate-restricting member includes rib wires which are spaced circumferentially around the inner screen within the prepack annulus, and an outer screen wire wrapped externally about the rib wires to define the annulus. The outer screen wire is wrapped about the rib wires in a longitudinally spaced pattern to delineate spaced screen apertures for conducting formation fluids through the outer screen. The spherical plastic members are disposed within the prepack annulus and heated until the spherical plastic members become tacky and bond to each other to form a sintered, homogenous mass.