RU199502U1 - Downhole slotted wire strainer with direct winding on the casing - Google Patents

Abstract

The utility model refers to the oil industry and can be used in the operation of oil, gas, water wells when pumping out liquid media with mechanical impurities. Downhole wire slotted filter with direct winding contains a perforated casing pipe with holes, a sleeve, a nipple part for connection with another casing pipe, a slotted filter element, including tightly fitted support elements - stringers evenly located on the pipe and a wire spirally wound on them with an interference fit ... The fixing of the filter element is carried out by welding stringers and a wound wire at each point of contact, and the edges of the filter element are fixed with rings. The fixing rings are split, the fixing rings have an L-shaped cross-section, and are made with the possibility of tight fit, eliminating a gap, to the ends of the turns of the spirally wound wire due to the lateral displacement of the ends of the split rings, while the split rings are the lower part adjacent to the casing, are attached to the casing by welding, and the cut on the ring is also welded after tightening. EFFECT: increased efficiency of the downhole filter due to installation of split rings, ensuring tight fit of the ring to the slotted filter element and, consequently, no gap between the split ring and the slotted filtering element. 5 p.p. f-ly, 3 dwg

Description

The field of technology.

The utility model refers to the oil industry and can be used in the operation of oil, gas, water wells when pumping out liquid media with mechanical impurities.

State of the art.

Analysis of the prior art in this area showed the following. Downhole screens are commonly used to filter sand and the like. solid contaminants from the produced fluid prior to pumping the fluid to the surface. However, if the filters are not placed in the path of the fluid entering the well, sand and other contaminants entrained in the fluid can significantly reduce the life of the downhole pump and / or other devices to which the well is connected.

There are well screens of various designs.

From the prior art, a wire borehole filter is known containing, RU 76677 U1, E21B 43/08, 09/27/2008, containing a perforated pipe with nipple and coupling parts, concentrically of which a filter element is made of a spiral wound wire connected to longitudinal wire stringers, characterized in that that the wire in the spiral is laid turn to turn, and at least one of the contacting sides of the wire has a notch that provides a filtering gap. The disadvantage of this filter is the unsatisfactory efficiency of the filter element due to clogging of the mesh with mechanical impurities (sand, sludge) during the operation of the borehole pumping unit.

The closest to the claimed utility model, in terms of the technical result and the problem being solved, is a slotted downhole filter including a perforated support pipe, on one side of which a sleeve is made, and on the other, a nipple for installation in a drill pipe string. A slotted filter element is located concentrically on the outer surface of the perforated carrier pipe, on both sides of which there are restrictive rings. The filter element is made of a wire wound on the longitudinal elements in a spiral, and the cross-section of the wire, wound in a spiral, is made predominantly of a triangular cross-section. The perforation in the perforated carrier pipe can be made with holes. Perforation can be made with slits. An annular casing is placed inside the carrier pipe with an annular gap between it and is perforated by the carrier tube. A device for swirling the extracted product is installed inside the annular casing, which is installed with an annular gap between it and the annular casing. The slotted well screen has several filter elements, and they are bounded on both sides by limiting rings by welding. The holes can be made on the perforated support tube in several ways. (RF patent No. 2610738 C1, E21B 43/08, 15.02.2017). However, this filter does not exclude the possibility of displacement or unwinding of the profile wire, does not provide high rotational loads, as well as high resistance to tension and destruction during descent and extraction, which leads to unsatisfactory operation of the filter element

Disclosure of the essence of the utility model.

The technical result, the solution of which is aimed at the declared utility model, is to increase the efficiency of the downhole filter by eliminating the possibility of clogging the mesh with mechanical impurities (sand, sludge) during the operation of the downhole pumping unit, which is achieved by installing split rings ensuring a tight fit of the ring to the slotted filter element and, consequently, the absence of a gap between the split ring and the slotted filter element, tight fit of the support elements and the wire creating the necessary compression around the pipe circumference and forming a nearly ideal cylindrical shape, as well as eliminating the risk of displacement or unwinding of the profile wire and maintaining high rotational loads while ensuring high resistance to tension and fracture during the running and retrieval of the well screen, as well as reducing clogging of the well screen and increasing the degree of purification of the produced product from non-circular impurities.

The specified technical result is achieved due to the fact that the downhole wire slotted filter with direct winding onto the casing pipe contains a perforated casing pipe with holes, a sleeve, a nipple part for connection with another casing pipe, a slotted filter element. The slotted filter element includes tight-fitting support elements - stringers evenly spaced on the pipe and a triangular wire spirally wound on them with an interference fit. The fixation of the filter element is carried out by welding stringers and a wound wire at each point of contact. The edges of the filter element are fixed with rings. The fixing rings are split. The fixing rings have an L-shaped cross-section, and are made with the possibility of a tight fit, excluding a gap, to the ends of the turns of the spirally wound wire due to the lateral displacement of the ends of the split rings. Split rings are attached to the casing by welding, adjacent to the casing with their lower part. The cut on the ring is also welded after tightening. The supporting pipe is perforated in a spiral pattern. The split rings are made of stainless steel. The stringers are located directly on the pipe, with no gap with the pipe. On the perforated casing there are two slotted filter elements, each of which is secured with split rings. The wire has a triangular cross-section.

Description of drawings.

FIG. 1 shows the general diagram of the inventive downhole wire slotted filter with direct winding.

1 - casing pipe;

2 - slotted filter element;

3 - locking split rings;

4 - clutch;

5 - nipple (nipple part).

FIG. 2 shows a locking split ring.

FIG. 3 shows a view of a slotted filter element fixed with a split ring welded to the casing.

6 - supporting elements - stringers;

7 - wire.

Implementation of the utility model.

Straight wound slotted wire mesh filter refers to the oil and gas industry, and contains a perforated casing pipe (1) with holes, a sleeve (4), a nipple part (5) for connecting to another casing pipe, a slotted filter element (2) and retaining rings (3) made by split. The slotted filter element (2) includes tightly fitted support elements - stringers (6) evenly located on the casing (1) and a wire spirally wound on them with an interference fit (7).

Fixation of the filter element (2) is carried out by welding stringers and wound wire at each point of contact, and the edges of the filter element (2) are fixed with rings. The fixing rings are split. The fixing rings have a L-shaped cross-section, and are made with the possibility of tight fit, eliminating the gap, to the ends of the turns of the spirally wound wire due to the lateral displacement of the ends of the split rings. Split rings with the lower part adjacent to the casing pipe are attached to the casing pipe by welding. The incision in the locking split ring (3) is also welded after tightening.

A device of this type can be used as part of a liner, for vertical, directional and horizontal wells, as well as when running a string with rotation. Depending on the throughput, the diameter of the round hole and the number of holes per 1 running meter are selected.

Stringers are evenly spaced on the casing and on them with an interference fit, a wire is wound in a spiral. During wrapping, contact welding occurs at the points of contact of the stringer with the winding wire. Perforation in the casing (1) can be made with holes or slots. The location of the holes can be in a spiral, or with an angular pitch. The filtering part can consist of two slotted filtering elements, with a gap between the filters. Along the edges of the slotted filter elements, there are locking split rings (3). The dimensions of the wire (7) and the material are laid at the initial stage when designing the filter at the request of the customer. The geometric dimensions of the wire are different in height and width, as well as the profile of the wire - triangular, trapezoidal. Fixation takes place by welding the stringers and coiled wire at each contact point. The edges of the filter element (2) are fixed with split rings (3), while the edges of the filter element (2) provide a snug fit to prevent the passage of impurities and damage to the filter part. To prevent mechanical impurities from penetrating from the end of the filter element (2), its ends are scalded, and then fixing split rings (3) are installed over the filter element (2) and the slot is closed with a chain key. When pressed with a key, the axial movement of the locking split rings (3) is left. Then lightly tap with the aluminum / brass strip at (X) to close the gap and gently press at (Y) if the locking split ring moves too far. Measure the gap between the ring and the filter element (2) with a feeler gauge.

If the gap exceeds the filter slotted gap, release the key and repeat the steps described above. Then close the slot with a key and grab it in two places by welding. Unclench the key and clean the potholders. When stripping, sparks should fly from the filter element (2). Weld from the inner edge with an offset of 3 mm and bring to the end of the ring. After the weld seam has cooled down, measure the gap between the filter element (2) and the locking split ring with a feeler gauge. The value should not be greater than the filter gap. Weld the retaining split ring (3) and the casing. Grind weld seam flush with base metal. Coupling (4) is designed to connect casing pipes into a single string. The threaded connections of the coupling and the nipple part are protected with a conservation grease, and are also provided against damage to the thread of the protector.

The supporting pipe is perforated in a spiral pattern. The retaining split rings are made of stainless steel. The stringers are located directly on the casing, with no clearance to the casing. Two slotted filter elements can be installed on the perforated casing pipe, each of which is secured with split rings.

According to a broad aspect of the claimed technical solution, the created well screen containing a main pipe with holes, an intermediate filter layer including tightly fitted support elements (stringers) and a wire spirally wound around the casing has a number of advantages:

The tight fit of the support members and the wire creates the necessary compression around the circumference of the pipe and forms an ideal cylindrical shape.

No risk of displacement or unwinding of the profile wire.

Long service life in harsh industrial environments.

Maintaining high rotational loads.

High resistance to pulling and breaking during descent and retrieval.

The possibility of producing filters with a diameter of 60 mm to 178 mm. Tight slit tolerance +/- 50 microns.

Providing conditions for backwashing.

Thus, the proposed technical solution allows to increase the efficiency of the downhole filter and, as a consequence, to increase the reliability of the downhole pumping unit.

The claimed utility model can be used in the oil and gas, mining and other industries when pumping various types of liquid media with mechanical impurities from wells.

Claims (6)

1. Slotted wire hole filter with straight winding, containing a perforated casing pipe with holes, a sleeve, a nipple part for connecting to another casing pipe, a slotted filter element, including tightly fitted support elements - stringers, evenly located on the pipe and spirally wound on them with an interference fit wire, while fixing the filter element is carried out by welding stringers and wound wire at each point of contact, and the edges of the filter element are fixed with rings, characterized in that the fixing rings are split, the fixing rings have an L-shaped cross section, and are made with the possibility of a tight fit, eliminating a gap, to the ends of the turns of the spirally wound wire due to the lateral displacement of the ends of the split rings, while the split rings are attached to the casing by welding with the lower part adjacent to the casing, and the cut on the ring is also welded after tightening. 2. Downhole filter according to claim 1, characterized in that the perforation of the supporting pipe is made in a spiral. 3. Downhole filter according to claim 1, characterized in that the split rings are made of stainless steel. 4. Downhole filter according to claim 1, characterized in that the stringers are located directly on the casing pipe, without a gap with the casing pipe. 5. Downhole filter according to claim 1, characterized in that it is equipped with a second slotted filtering element installed on the perforated casing pipe, each of the filtering elements is fixed with split rings. 6. Downhole filter according to claim 1, characterized in that the wire has a triangular cross-section.

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