| 摘要 |
A method and apparatus for assembling a wellscreen (50) onto a perforated ba se pipe (52) are provided. The wellscreen defines a tubular body which is suitable for subterranean use in oil, gas, and water wells. In accordance wi th the present invention, the wellscreen first defines a perforated base pipe having termination members (66) at its opposite ends. Disposed on each termination member is a continuous helical, step-tiered surface (72). The helical surface serves as a support surface for a layer of filtering materia l (74) which is rolled around the base pipe. The filtering material is pre-cut to a correct diameter and bias to match the diameters and bias of the spiralling termination support surfaces. The filtering material is connected to the rings to form a substantial seal on the opposite ends. A protective, perforated outer shroud is optionally disposed around the filtering media as well. The filtering material has at least two sections of different filter type. |
