Double-filtering layer meander circular seam self-cleaning sieve tube

Abstract

The invention discloses a double filtering-layer meandering circumferential weld self-cleaning sieve tube which is composed of a filter element and a basal tube; the filter element is embedded in a stepped hole at the side wall of the basal tube and is composed of a central cap, a plurality of filtering rings, a fixed ring and a protective cover. The size of the inner diameter of the filtering rings are increased one by one and the inner wall of each filtering ring is a double-stair shape, the outer wall of each filtering ring is an inverted double-stair shape. The outer wall of the central cap is an inverted double-stair shape and the central cap are sheathed in the filtering ring with the smallest inner diameter; all the filtering rings are axially sheathed together according to the size order of the inner diameter. The inner wall of the fixed ring is a double-stair shape and the filtering ring with the largest inner diameter is sheathed in the fixed ring; the outer wall of the fixed ring is an inverted double-stair shape and the upper part of the fixed ring is a conical surface and the lower part thereof is a cylindrical surface. The protective cover is covered on the conical surface of the outer wall of the fixed ring, a plurality of air vent windows are opened on the top surface of the protective cover. The double filtering-layer meandering circumferential weld self-cleaning sieve tube can filter the thin-fine sand, the permeability is high, the filter precision is high, and the filtering seam has extremely strong damage-resistance capacity and is not easily to block.

Description

Technical field [0001] The invention relates to a mechanical sand control device used in crude oil exploitation in the petroleum industry, in particular to a sand control screen. Background technique [0002] At present, major oil fields: The most effective means of "sand control" is to produce fine silt with a diameter of less than 40 microns in the formation sand with the oil flow. Otherwise, these fine silt particles will block the downhole permeability and sand control system, and cause oil wells. The output is reduced. [0003] At present, common downhole sand control systems in the oil and gas industry include slotted screens, jacketed wire-wrapped screens, gravel-filled screens, composite screens, and so on. These screens have the following problems: [0004] Slotted screen: can not prevent fine silt, low permeability, poor sand retaining accuracy, easy to block, eroded by formation sand, short life. [0005] Wire-wrapped screen: completely loses its original sand control ...

AI Technical Summary

Problems solved by technology

[0004] Slotted screen: unable to prevent fine silt, low permeability, poor sand retaining accuracy, easy to block, eroded by formation sand, short life

[0005] Wire-wrapped screen: After being squeezed and deformed, it completely loses its original sand control effect, large pipe diameter, difficult downhole operation, and high cost

[0006] Composite screen: low strength, large diameter, short life

[0007] Screen plus gravel packing: there are residues in the well, the workover operation is complicated, the cost is high, and it is not suitable for sand control in fine silt formations

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