| 摘要 |
A filtering material for disposal around a base pipe for use in a wellbore wherein the filtering material has a progressively tapered width. Preferably the filtering material comprises a portion which is substantially fabricated from a sintered screen. The filtering material may be supported on a base pipe 52 assembly comprising a tubular body; two spaced termination members 66 disposed on the tubular body; and a plurality of perforations 54 on said tubular body intermediate said termination members, wherein a helical support surface 72 is provided on each of said termination members defining a support surface for receiving at least one continuous layer of the filtering material 74. The filtering material may be pre-cut to a correct diameter and bias to match the diameters and bias of the spiralling termination support surfaces. A protective, perforated outer shroud is optionally disposed around the filtering material. Advantageously the base pipe assembly is suitable for use in a wellscreen for use in a wellbore. |
