RU2813411C1 - Above-packer sludge trap - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: invention relates to the oil industry and is intended for trapping mechanical impurities above the packer in the annular space (inter-tube) of the well between the process string and the production string. Disclosed is a sludge trap above the packer, which includes a branch pipe installed above the packer, on which at least one elastic collar is installed in series, which is located between metal rings. Collar is made in the form of elastic rings, between which there is at least one filter element in the form of a ring. Elastic rings are equipped with longitudinal filtration holes arranged uniformly along the perimeter and directing the liquid flow through the filtering element. Number of elastic rings is odd, but not less than 5 pieces, consisting of serially installed large and small rings with thickness of 10±2 mm. Large rings are installed on the edges of the collar and are made with an outer diameter which is 1–4 mm larger than the inner diameter of the production string, and small rings are by 10±2 mm is less than the outer diameter of the large ring. All collar rings are equipped with additional longitudinal process holes for compression fasteners located along the perimeter between filtration holes. Metal rings are made with inner diameter 0.5–1.5 mm larger than outer diameter of branch pipe, and outer diameter equal to diameter of small rings, and are provided along the perimeter with holes corresponding to said process and filtration holes in the elastic rings of the collar. Filtering element is also equipped with holes corresponding to the specified technological holes.

EFFECT: provision of possibility to use in inclined, horizontal and complex-shaped (with presence of randomly arranged inclined and/or horizontal sections of well shaft) wells due to absence of rigid external elements.

1 cl, 3 dwg

Description

The invention relates to the oil production industry and is intended to trap mechanical impurities above the packer in the annular space (interpipe) of the well between the process string and the production string.

A well-known slurry trap above the packer (patent RU No. 2588111, MPK E21B 37/00, published June 27, 2016, Bulletin No. 18) includes a pipe, pairs of metal rings attached to the pipe, supported by stiffeners, placed in each pair of metal rings between metal rings, upper and lower sealers of the annulus space in the form of a flat ring, holes in each pair of metal rings and sealer, while the number of holes in the upper and lower pairs of metal rings and sealers is the same, the holes are located on diameters, the angles between which are the same, pairs of metal rings and the sealers are installed so that, in projection onto the horizontal plane, the diameters on which the holes are located in the upper pair of metal rings and the sealant and the lower metal ring and the sealant are located at an angle to each other equal to half the angle between the adjacent diameters of one pair of metal rings and the sealant, the ratio of the diameters of the holes of the upper pair of metal rings and the sealer to the diameters of the holes of the lower pair of metal rings and the sealer is (6-10): (1-4) mm, respectively, while the holes are located based on the equality of the distance between adjacent holes, between each hole and the edge seal and pipe.

The disadvantages of this sludge trap are its narrow scope of application due to the impossibility of use on non-metallic nozzles (made of fiberglass or plastic) and in inclined, horizontal and complexly profiled (with the presence of randomly placed inclined and/or horizontal sections of the wellbore) wells, since there is no protection against displacement from the axis and often leads to a violation of the integrity of the upper and/or lower seals of the annulus space, while the design is difficult to manufacture and repair due to the presence of holes of different sizes, which are installed at precise angles relative to each other and are not blocked by anything, which allows some of the mechanical impurities are deposited directly on the packer.

An above-packer trap for mechanical impurities is also known (patent for PM RU No. 166989, MPK E21B 37/00, published December 20, 2016, Bulletin No. 35), consisting of a tubing pipe (tubing), filter elements with an outer diameter equal to internal diameter of the production string, and each filter element consists of two rubber rings with filtration holes, clamped by two metal rings attached to the tubing pipe by welding, while a metal mesh ring is installed between the rubber rings, and contains an additional fitting a branch pipe having an internal polymer coating and rigidly installed inside the tubing pipe branch pipe, wherein said fitting pipe is designed to be installed on tubing pipes with an internal polymer coating.

The disadvantages of this sludge trap are the narrow scope of application due to the impossibility of using it on non-metallic nozzles and in inclined, horizontal and complexly profiled (with the presence of randomly placed inclined and/or horizontal sections of the wellbore) wells, since there is no protection against displacement from the axis and often leads to a violation of the integrity of the upper and/or lower seals of the annulus.

The closest in its technical essence is a trap for mechanical impurities (patent for PM RU No. 137939, IPC E21B 43/08, published on February 27, 2014. Bulletin No. 6), consisting of cuffs with an outer diameter equal to the inner diameter of the production string, and The cuffs are a filter element consisting of two rubber rings with filtration holes, clamped by metal rings and connected to the tubing pipe by welding, while a metal mesh ring is installed between the rubber rings, and is equipped with centralizers, which are rectangular metal prisms attached to the pipe by welding, above and below the cuffs.

The disadvantages of this catcher are its narrow scope of application due to the impossibility of using it on non-metallic pipes due to the need to weld metal rings, and the presence of longitudinal rigid centralizers can lead to jamming in the transitional curved sections of the barrel during hoisting operations in inclined, horizontal and complexly profiled areas (with the presence of randomly placed inclined and/or horizontal sections of the wellbore) wells.

The technical result of the present invention is the creation of a slurry trap above the packer, which allows its use in inclined, horizontal and complexly profiled (with the presence of randomly placed inclined and/or horizontal sections of the wellbore) wells due to the absence of rigid external elements that can lead to equipment jamming during tripping operations , and expand the scope of application due to the possibility of installation on non-metallic pipes.

The technical solution is implemented by a sludge trap above the packer, which includes a pipe installed above the packer, on which at least one elastic cuff is installed in series, located between metal rings, and the cuff is made in the form of elastic rings, between which at least one filter element in the form of a ring is installed, elastic rings at In this case, they are equipped with longitudinal filtration holes, located evenly around the perimeter and directing the flow of liquid through the filter element.

What is new is that an odd number of elastic rings are used, but not less than 5 pieces, consisting of sequentially installed large and small rings with a thickness of 10±2 mm, with the large rings installed at the edges of the cuff and made with an outer diameter 1–4 mm larger than the inner one diameter of the production string, and the small rings are 10±2 mm smaller than the outer diameter of the large ring, while all cuff rings are equipped with additional longitudinal technological holes for compression fasteners located along the perimeter between the filtration holes, and the metal rings are made with an internal diameter of 0.5 -1.5 mm is larger than the outer diameter of the nozzle, and the outer diameter is equal to the diameter of the small rings, and is equipped with holes around the perimeter corresponding to the technological and filtration openings, and the filter element is also equipped with holes corresponding to the technological openings.

What is also new is that if there are several filter elements in the cuff, they are made with a throughput that decreases from top to bottom.

In fig. Figure 1 shows a general view of the above-packer sludge trap.

In fig. Figure 2 shows a top view of the above-packer sludge trap.

In fig. 3 shows a section A-A of Fig. 2.

The above-packer slurry trap includes a pipe 1 installed above the packer (not shown) (Fig. 1-3), on which at least one elastic cuff 2 is installed in series, located between metal rings 3. The cuff 2 is made in the form of large elastic cuffs 4 (Fig. 1 and 3) and small 5 rings (made from oil and petrol resistant vulcanized rubber, polyurethane, reinforced rubber, polystyrene foam, etc.), between which at least one filter element 6 is installed (Fig. 1-3) in the form of a ring. Elastic rings 4 (Fig. 1 and 3) and 5 are equipped with longitudinal filtration holes 7, located evenly around the perimeter and directing the flow of liquid through the filter element 6. An odd number of elastic rings 4 and 5 are used, but not less than five pieces, consisting of sequentially installed rings of large 4 (Fig. 3) and small 5 rings with a thickness of h = 10 ± 2 mm (the error is caused by an error during vulcanization or manufacturing of the rings). The thickness of rings 4 and 5 h=10±2 mm was determined empirically, since this thickness ensures reliable pressing and fixation of rings 4 and 5 from the inside when compressed to pipe 1, and a “labyrinth seal” is created on the outside, completely eliminating the flow of liquid. In this case, five or more rings 4 and 5 of such thickness h ensure centering of the pipe 1 without the use of rigid centralizers, and their elasticity prevents jamming in the transitional curved sections of the barrel during tripping operations in inclined, horizontal and complexly profiled wells. The large thickness h of rings 4 and 5 increases the weight and dimensions of the sludge trap without adding functionality. Large rings 4 are installed at the edges of the cuff 2 and are made with an outer diameter of D=1–4 mm larger than the inner diameter of the production string (not shown) to ensure a tight fit even after abrasion on the inner surface of the production pipe during descent. Small rings 5 are made with an outer diameter d 10±2 mm smaller than the outer diameter D of a large ring 4 (d=D-10±2 mm) to ensure a “labyrinth seal”. All rings 4 and 5 of cuff 2 are equipped with additional longitudinal technological holes 8 for compression fasteners (bolt 9 with nut 10, stud with nuts, stud with nut and eccentric, etc. - the latter is not shown), located along the perimeter between the filtration holes 7 Metal rings 3 are made with an internal diameter D1 that is 1-3 mm larger than the outer diameter d1 of the pipe (D1=d1+(1÷3) mm), and an outer diameter d equal to the diameter d of small rings 5. The outer diameter d of metal rings 3 ensures uniform compression of all rings 4 and 5 during assembly with fasteners (for example, bolt 9 with nut 10), and the internal diameter D1 is chosen empirically, since it allows the large ring 4 to flow during compression into a gap of 1-3 mm and jam in it (yield strength of elastic materials ), securely fixing the metal rings 3 and, as a result, the cuff 2 relative to the pipe 1, which can be made of any material, including plastic, fiberglass, or the like. When the gap between the metal ring 3 and the pipe 1 is more than 1.5 mm (on the side), jamming of the large ring 4 does not occur, since the elastic material remains elastic, and when the gap is less than 0.5 mm (on the side), there is no leakage to the required level amount of large ring 4 material into this gap. The metal rings 3 are also equipped with holes 11 and 12 around the perimeter, corresponding to technological 8 and filtration 7 holes. In this case, the filter element 6 is also equipped with holes 13 corresponding to the technological holes 8. When using several filter elements 6 in the cuff 2, they can be manufactured with a throughput decreasing from top to bottom for uniform distribution of mechanical impurities and sludge along the length of the filtration holes 7.

Structural elements, technological connections and seals that do not affect the performance of the sludge trap are not shown in the drawings (Figs. 1 and 3) or are shown conditionally.

The above-packer sludge trap operates as follows.

Outside the pipe 1 (Fig. 3) a metal ring 3 is installed, onto which an odd number of rings 4 and 5 (at least five pieces) are placed sequentially, starting from the large ring 4 (Fig. 1), with at least one filter element 6. Another metal ring 3 is placed on top. Technological 8 (Fig. 3) and filtration 7 holes of rings 4 and 5 are combined with each other, and holes 13 of filter element 6 are combined with technological holes 8. Holes 11 and 12 of metal rings 3 is also combined with the corresponding technological 8 and filtration 7 holes. As a result, the filtration holes 7 of rings 4 and 5 and holes 11 (Fig. 2) are able to direct the flow of liquid through the filter element 6. Into the technological holes 7 (Fig. 3) of rings 4 and 5, holes 13 of the filter element 6 and holes 11 of metal rings 3, fasteners are inserted (for example, bolt 9), with the help of which (for example, nuts 10) rings 4 and 5 are compressed evenly around the perimeter until it stops. In this case, the material of the upper and lower large rings 4 flows into the gap between the metal ring 3 and the pipe 1, where it jams and securely fixes the cuff 2 on the surface of the pipe 1.

If it is necessary to use several sludge traps (a large amount of impurities and sludge in the well is determined by the technologists servicing the well), several pipes 1 with cuffs 2 can be assembled in the same way and connected in series (for example, using threads 14, couplings, flanges, etc. . – the latter is not shown).

The branch pipe 1 (Fig. 3), using threads 14, couplings or flanges (not shown), is connected from below to a packer, and from above to a process string (not shown), on which it is lowered into the well in the interval where the packer is installed (most often above the exposed productive formation). During descent, the well fluid flows through the holes of the holes 12 of the metal rings 3, the filtration holes 7 of the rings 4 and 5 through the filter element 6 (Fig. 2), without interfering with the descent of the above-packer slurry trap. After installing the packer, the well is put into operation as an injection or production one (after lowering the well pump). In this case, mechanical impurities and slurry located in the well are removed by at least one filter element 6 of at least one cuff 2.

Upon completion of the work, the packer is removed or torn off and raised to the surface on the process string together with the above-packer slurry trap. In this case, the well fluid is drained through the holes of the holes 12 of the metal rings 3, the filtration holes 7 of the rings 4 and 5 through the filter element 6, excluding pistoning and pouring onto the surface.

After disconnecting pipe 1 from the packer and the process string (Fig. 3), the fasteners (for example, bolt 9 with nut 10) are unscrewed and removed, metal rings 3 and rings 4 and 5 are removed from pipe 1, and at least one filter element 6 is removed. which is cleaned and washed from mechanical impurities and sludge. Large rings 4 worn out during hoisting operations are replaced entirely and the above-pressure sludge trap is assembled on pipe 1 in the manner described above for further use.

The proposed above-packer sludge trap allows its use in inclined, horizontal and complexly profiled (with the presence of randomly placed inclined and/or horizontal sections of the wellbore) wells due to the absence of rigid external elements that can lead to equipment jamming during tripping operations, and expands the scope beyond due to the possibility of installation also on non-metallic pipes.

Claims (2)

1. Above-packer sludge trap, including a pipe installed above the packer, on which at least one elastic cuff is installed in series, located between metal rings, and the cuff is made in the form of elastic rings, between which at least one filter element in the form of a ring is installed, elastic rings at the same time equipped with longitudinal filtration holes located evenly around the perimeter and directing the flow of liquid through the filter element, characterized in that an odd number of elastic rings are used, but not less than 5 pieces, consisting of sequentially installed large and small rings with a thickness of 10 ± 2 mm, with the large rings installed from the edges of the cuff and made with an outer diameter 1-4 mm larger than the inner diameter of the production string, and small rings 10±2 mm smaller than the outer diameter of the large ring, while all cuff rings are equipped with additional longitudinal technological holes for compression fasteners, located along perimeter between the filtration holes, and the metal rings are made with an internal diameter 0.5-1.5 mm larger than the outer diameter of the pipe, and an outer diameter equal to the diameter of the small rings, and are equipped with holes around the perimeter corresponding to the technological and filtration holes, and the filter element also equipped with holes corresponding to the technological holes. 2. Above-packer sludge trap according to claim 1, characterized in that if there are several filter elements in the cuff, they are made with a throughput capacity that decreases from top to bottom.