RU2486332C1 - Well strainer - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: device consists of tubular casing with threaded ends and punched holes and metal casing in the form of shell with punched holes made as slots of squamous shape. The housing is made with protruding under beginning and end of each slot. The upper part of protrusion in each squamous slot has a shelf.

EFFECT: increase of performance rating, improvement of safety.

5 dwg

Description

The invention relates to the oil industry and may find application in the filtration of well fluid in oil production.

Known downhole filter, including a perforated tubular body, support rods with thread, a winding wire (RF Patent No. 2209299, publ. July 27, 2003).

The disadvantage of the filter is the low resistance of the winding wire to mechanical stress during the descent and ascent of the filter in the well.

Closest to the proposed invention in technical essence is a downhole filter, comprising a tubular housing with connecting threads at the ends and with perforations, a filter mesh mounted on its outer surface to catch mechanical impurities, and a protective metal casing in the form of a shell with holes. The filter mesh is made of an all-metal expanded metal sheet with a reduced mesh size of 0.05 mm or more, depending on the size of the mechanical impurities. The protective casing is made of a metal sheet with perforations made in the form of slits of a scaly shape located in a checkerboard pattern or cylindrical holes. The filter mesh and casing are rigidly attached to the housing (Application for invention of the Russian Federation No. 2006140039/03, publ. 05.20.2008 - prototype).

The known filter has a low throughput due to the lack of space for fluid flow between the casing and the casing, in addition, the sharp edges of the slots on the casing make it possible to injure hands working with the filter, the possibility of cutting effects during descent and ascent in the well.

The proposed invention solves the problem of increasing the filter capacity and eliminating the possibility of cutting effects on the filter surface.

The problem is solved in that in the downhole filter, including a tubular body with threads at the ends and with perforations and a metal casing in the form of a shell with perforations in the form of slits of a scaly shape, according to the invention, the metal casing is made with protrusions under the beginning and end of each gap, and the upper part of the protruding part of each scaly slit is made with a shelf.

SUMMARY OF THE INVENTION

Figure 1 shows a section of the claimed filter, figure 2 shows a section along aa filter, figure 3 shows a scan of a metal casing, figure 4 shows a section bb on a scan of a casing, figure 5 shows a view of on a scan of the casing.

The claimed downhole filter consists of a metal tubular body 1 with threads 2 at the ends and with perforation holes 3 and a metal casing 4 in the form of a shell with perforation holes in the form of slits of a scaly shape 5 arranged in a checkerboard pattern. The metal casing 4 is made with protrusions 6 under the beginning 7 and the end 8 of each slit 5, and the upper part of the protruding part of each scaly slit is made with a shelf 9.

The metal casing 4 is attached to the housing 1, for example, by welding, screw or bolt connection, etc. (not shown). Due to the protrusions 6, the contact between the housing 1 and the casing 4 occurs at the points of contact of the protrusions 6 with the housing 1. Between the housing 1 and the casing 4, a space 10 is formed for the filtered liquid to flow.

Through thread 2, the filter is connected to the pipes or to the plug and lowered into the well. Pumping equipment is located above the filter in the well, with the help of which liquid, for example, oil, is taken from the well.

The housing 1 is made of a tubing or casing. For the manufacture of the casing, a metal sheet, for example, 0.5 mm thick, is used, in which slits of a scale-like form 5 are cut or cut. The sheet is rolled between the rollers to form protrusions 6 and shelves 9 on each slot 5.

The filter works as follows.

The borehole fluid passes through the slits of a scaly shape 5, through the space 10 between the housing 1 and the casing 4, through the perforation holes 3 inside the filter and is directed to the deep well pump, which is fed through the pipe string to the surface. Pollution larger than the size of cracks 5 remain in the well.

Due to the space 10, the liquid flows unhindered to the perforation holes 3. This increases the throughput of the filter. In the prototype of this space is not, in addition, between the body and the casing there is a grid that interferes with the flow of fluid along the housing 1 and the distribution of fluid between the perforation holes 3.

Due to the shelf 9, a sharp sharp edge disappears on the slit 5.

The application of the proposed downhole filter will allow to increase the filter capacity and eliminate the possibility of cutting effects on the filter surface.

Claims (1)

A downhole filter, including a tubular housing with threads at the ends and with perforations and a metal casing in the form of a shell with perforations in the form of slits of a scaly shape, characterized in that the metal casing is made with protrusions under the beginning and end of each gap, and the upper part of the protruding part each scaly slit is made with a shelf.

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