RU2378494C1 - Slotted filter with wired filtrating element - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention related to mining, particularly to oil-and-gas production and can be used for oil and gas wells development. Slotted filter with wired filtrating element includes perforated pipe with nipple and sleeve parts, concentrically to which executed filtrating element made of spirally reeled wire, connected to wire longitude stringers. At that spiral wire placed loop by loop, at least at one of the wire touching sides tangential or crossing notch, creating filtrating slot executed.

EFFECT: manufacturing simplification and filters mudding decrease during oil and gas production.

5 cl, 15 dwg

Description

The invention relates to the mining industry, namely to oil and gas, and can be used in the development of oil and gas wells.

Known downhole filter according to the USSR AS No. 1645470, containing a perforated pipe on which a wire filter element with protrusions is laid. The protrusions placed quite often on the wire provide a constant gap between the rows.

The disadvantage of the filter is the possibility of deformation of the wire during transportation of the filter or its installation in the well. This can lead to a local increase in the gap between the rows of wire and the passage at the wellhead of large particles of foreign impurities.

Known gravel downhole filter for St. RF for utility model No. 388830, containing a perforated pipe with sleeve and nipple parts, a filter element in the form of a filter mesh and a protective casing. The mesh size of the filter element is 0.15 ... 0.25 mm.

Disadvantage: the filter is not suitable for the production of viscous oil for two reasons: the small mesh size of the filter mesh and the overlap of the filter mesh at the joints on top of each other, which leads to an additional reduction in the cross section at the location of the layers of the filter mesh.

A known filter for water intake, water-reducing and hydrogeological wells according to the USSR AS No. 192125, containing ring elements with supporting platforms, forming radially receiving channels, while the ring elements are bolted together in several places.

The disadvantages of this design are:

- large dimensions and weight of the filter, due to the fact that the outer diameter of the annular elements with this arrangement should be 1.5 ... 2.0 of the diameter of the casing, because on the ring elements, it is necessary to place fixing bolts around the circumference,

- low strength compared to filters in which a perforated pipe is used as a power frame, because the cross section of the pipe, taking into account the perforation, will always be larger than the cross section of several bolts.

- low manufacturing and assembly difficulties due to increased requirements for accurate alignment of bolt holes,

- the possibility of deformation of the filter by filtering elements during descent into directional and horizontal wells due to low rigidity and the absence of a power frame.

In addition, the filter according to the USSR AS No. 192125 is not intended for use in the oil and gas industry. The impossibility of using such filters in the oil and gas industry is due, first of all, to the large diameter of the filter, and secondly, to its low strength. Thus, this filter has a different purpose.

Known well filter designed for oil or gas according to the patent of the Russian Federation for utility model No. 66415, containing a perforated pipe with a nipple and coupling parts, concentrically made filter element made of wire. The ring elements are installed with a gap acting as filter channels. The description does not indicate by what means the installation of ring elements with gaps between them is achieved. In addition, there is no drainage layer between the perforated pipe and the annular elements, therefore, such a filter will have a low flow rate of the produced product and will quickly become clogged by foreign particles. Also, the drawback of slotted well filters is the low strength and the ability to pass through the filter element of large particles having a non-circular shape, and the drawback of the mesh filters is the rapid colmatation of the filter element associated with the cross-sectional profile of the wire mesh cell.

The objective of the invention: increasing the strength of the filter element, reducing the mudding of the downhole filter and increasing the degree of purification of the produced product from non-circular impurities.

The solution to this problem was achieved in a slotted filter with a wire filter element containing a perforated pipe with nipple and sleeve parts, which concentrically made the filter element from a spiral wound wire connected to longitudinal wire stringers, so that the wire was laid in a spiral to turn, and at least one of the contacting sides of the wire has a notch providing a filter gap, while the notch on the wire is tangential or intersecting i. The profile of the notch can be made rectangular, triangular or semicircular. The wire of the filter element is made of stainless steel.

The proposed technical solution has novelty, inventive step and industrial applicability, i.e. all the criteria of the invention.

The novelty of the technical solution and inventive step are confirmed by patent research. Industrial applicability is due to the fact that non-deficient materials and known technologies are used in the manufacture of the filter. The perforated pipe is made of alloy steel, and the wire of the filter element is made of stainless steel.

The invention is illustrated in figure 1 ... 15, where:

- figure 1 shows the filter assembly with plugs,

- figure 2 shows a wire filter without plugs,

- figure 3 shows a view A,

- figure 4 shows a view of B,

- figure 5 shows a section bb,

- figure 6 shows a view G of the first embodiment,

- figure 7 shows a view of the second option,

- Fig.8 shows a view of the third option,

- figure 9 shows the operation of applying triangular notches on one side of the wire,

- figure 10 shows the appearance of the wire with triangular notches on one side of the wire,

- figure 11 shows the operation of applying triangular notches on two sides of the wire,

- Fig.12 shows the appearance of a wire with a triangular notch on two sides,

- Fig.13 shows a piece of wire with a rectangular notch,

- Fig.14 shows a piece of wire with a triangular notch,

- Fig.15 shows a piece of wire with a semicircular notch.

The proposed design (figure 1 ... 15) contains a perforated pipe 1 with holes "D", nipple and coupling parts, respectively 2 and 3, a filter element 4 mounted concentrically perforated pipe 1 between the supports 5 and 6. The filter element 4 is made of wire and contains turns 7, wound without a gap and in contact with each other on the side surface. The turns 7 are connected to the stringers 8, for example, by spot welding. In the holes "D" of the perforated pipe 1 can be installed plugs 9 (figure 1). The plugs 9 are cut off after installing the filter in the well. They are made of low-strength or brittle material, such as aluminum or ceramic. It is possible to supply well filters without plugs 9 (Fig.2).

The wire used for the filter element can have any, for example, a round, rectangular or triangular cross-section. Figures 3 and 4 show an example of a wire with a triangular cross section. At the ends “E” of the turns 7 (FIGS. 3 and 4), notches 10 are made. The notches 10 can be made radially (FIG. 6), or tangentially (FIG. 7), or crosswise (FIG. 8).

The notches 10 can be rolled by a knurling roller 11 on one side of the wire (Fig. 9), while a smooth roller 12 is mounted on the other side. The appearance of the resulting wire is shown in Fig.10. The notch 10 can be made on two sides (11 and 12) by means of two knurled rollers 11.

The profile of the notches 10 can be any, for example, rectangular (Fig. 13), triangular (Fig. 14) or semicircular (Fig. 15).

The filter gap of the downhole filter can be 0.1 ... 1.0 mm. The width of the notches "a" (Fig.13 ... 15) may be equal to their depth "b".

The downhole filter is installed at the bottom of the casing. After installation in the well of the downhole filter with plugs 9 (Fig. 1), they are cut with a milling cutter or bit. In the absence of traffic jams 9, this operation is not performed.

During operation, the extracted product containing foreign impurities passes through the notches 10 along the drainage layer formed between the longitudinal elements 8, the extracted product spreads along the perforated pipe 1 and enters through the holes “D” into the filter. Due to the fact that the size of the notches 10 turns 7 of the filter element 4 is 0.1 ... 1.0 mm at the inlet, larger particles are filtered out and do not get to the pumping equipment and valves installed at the wellhead, which prevents their premature wear. An increase in the depth of notches “b” from the side surface from the filter axis (due to the use of a triangular section wire) reduces the likelihood of its clogging. Particles having a size smaller than the width “a” of the notch 10 pass into it and do not clog the filter gap, because it expands further downstream. Large particles fall down outside the filter along its outer surface, forming a natural gravel filter. The optimal shape of the notches prevents the filter from clogging during prolonged use during oil or gas production from reservoirs containing a significant amount of sand particles.

The use of the invention will allow to obtain a number of advantages compared to previously used downhole filters, namely:

1. Increase the strength of the filter element.

2. Reduce the clogging of the downhole filter.

3. To improve the quality of cleaning the produced product from impurities of non-circular shape.

4. Provide filtration with the same quality in two mutually perpendicular planes.

5. Simplify the design of the filter.

6. To ensure high adaptability of the filter and reduce the cost of its manufacture.

7. Facilitate the manufacture of any size well filter based on the invention.

8. To reduce the cost of manufacturing a well filter and well development.

Claims (5)

1. A slit filter with a wire filter element, containing a perforated pipe with a nipple and sleeve parts, concentric with which the filter element is made of a spiral wound wire connected to longitudinal wire stringers, characterized in that the wire is laid in a spiral to turn, and, as at least one of the contacting sides of the wire has a notch providing a filter gap, while the notch on the wire is tangential or intersecting. 2. The slit filter according to claim 1, characterized in that the notch profile is rectangular. 3. The slit filter according to claim 1, characterized in that the notch profile is triangular. 4. The slit filter according to claim 1, characterized in that the notch profile is made semicircular. 5. The slit filter according to claim 1, characterized in that the wire of the filter element is made of stainless steel.

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