Slotted composite screen pipe

Abstract

The utility model relates to a slotted composite sieve tube. According to the technical scheme, the double-layer slotted pipe comprises an outer-layer slotted pipe body, an inner-layer slotted pipe body, a middle screen layer, end rings and welding seams, the middle screen layer is arranged between the outer-layer slotted pipe body and the inner-layer slotted pipe body, and one end of the outer-layer slotted pipe body, one end of the inner-layer slotted pipe body and one end of the middle screen layer are welded together through the end rings and the welding seams; threads are arranged at the two ends of the outer-layer slotted pipe. The utility model has the beneficial effects that the middle screen layer is welded on the inner-layer slotted pipe in a straight seam welding manner, so that not only is the passing rate of oil improved, but also the manufacturing cost is low, and a circulating hole of a bridge type counter bore does not need to be designed on the outer-layer slotted pipe; moreover, the outer-layer slotted pipe and the inner-layer slotted pipe are slotted, and the middle screen layer adopts filter screens with different mesh numbers, so that the designed sand blocking precision can be achieved, the service life of the screen pipe can be greatly prolonged by combining the three layers, and the cost of oil exploitation operation is also effectively reduced.

Description

Technical Field

[0001] The utility model relates to an oil well downhole tool, in particular to a slotted composite screen pipe. Background Art

[0002] In oil exploitation, sand production in oil and gas wells is a common problem, which easily causes sand burial of oil layers and pump sticking accidents. Moreover, it aggravates the wear of oil production related equipment. More seriously, fracturing sand returns and buries the sand control screen pipe and the sucker rod pump, resulting in the complete failure of the sucker rod pump lift. During operation and treatment, the pipe string is stuck by sand, and conventional operations cannot lift it or cause the pipe string to fall off, requiring major repairs, which increases the cost of oil well operations.

[0003] Currently, the mechanical sand control method is mainly adopted in the oil and gas exploitation market. Common mechanical sand control methods include filter screen pipes, wire-wound screen pipes, slotted screen pipes, etc. Each type of screen pipe has its own advantages, but the problems are: short service life, fast wear speed, serious sand production in the middle and later stages, and the sand control effect cannot reach satisfaction.

[0004] The Chinese patent document with the publication number of CN103452534A and the patent name of "Composite Sand Control Screen Pipe" includes a base pipe provided with flow holes and a sand control filter sleeve covering the flow hole section of the base pipe. The sand control filter sleeve is a composite sand control filter sleeve, which is composed of an inner protective sleeve at the bottom layer in contact with the base pipe, a metal mesh cloth diffusion layer, a metal mesh cloth filter layer, and an outer protective sleeve at the surface layer in sequence. The composite sand control filter sleeve is fixed on the base pipe through end rings arranged at both ends. The problems are: the composite sand control filter sleeve is made of an inner protective sleeve, a metal mesh cloth diffusion layer, a metal mesh cloth filter layer, and an outer protective sleeve at the surface layer. In order to improve the passing rate of oil fluid, a plurality of flow holes of bridge-shaped sunken holes formed by stamping are also arranged on the outer surface of the outer protective sleeve. Its structure is complex and the manufacturing cost is high. Content of the Utility Model

[0005] The purpose of the utility model is to provide a slotted composite screen pipe aiming at the above defects existing in the prior art. By welding the middle screen layer to the inner slotted pipe in a straight seam welding manner, not only the passing rate of oil fluid is improved, but also the manufacturing cost is low. Moreover, the outer slotted pipe and the inner slotted pipe adopt slotted treatment, and different mesh number filter screens are selected for the middle screen layer, so as to achieve the designed sand control precision. The combination of the three can greatly extend the service life of the screen pipe.

[0006] A slotted composite screen pipe mentioned in the present utility model has the following technical solution: It includes an outer slotted pipe (1), an inner slotted pipe (2), an intermediate screen layer (3), a coupling (4), an end ring (5), and a weld seam (6). An intermediate screen layer (3) is arranged between the outer slotted pipe (1) and the inner slotted pipe (2), and one end of the outer slotted pipe (1), the inner slotted pipe (2), and the intermediate screen layer (3) is welded together through the end ring (5) and the weld seam (6). Threads are provided at both ends of the outer slotted pipe (1), where a coupling (4) is installed on the thread at one end, and the other end is a male connector.

[0007] Preferably, a plurality of axially arranged slots are evenly distributed on the above-mentioned outer slotted pipe (1) and inner slotted pipe (2).

[0008] Preferably, a plurality of screen slots are evenly distributed on the above-mentioned intermediate screen layer (3), and the screen slots are perpendicular to the slots on the outer slotted pipe (1) and the inner slotted pipe (2).

[0009] Preferably, the above-mentioned intermediate screen layer (3) is sleeved on the outer wall of the inner slotted pipe (2) and is welded to the outer wall of the inner slotted pipe (2) through more than one straight seam weld (7).

[0010] Preferably, the above-mentioned end ring (5) is located between the end of the outer slotted pipe (1) and the end of the inner slotted pipe (2), and is located on one side of the end of the intermediate screen layer (3), and a weld seam (6) is formed by welding on the other side of the end ring (5).

[0011] Preferably, the above-mentioned weld seam (6) is of a circumferential weld seam structure.

[0012] Another slotted composite screen pipe mentioned in the present utility model has the following technical solution: It includes an outer slotted pipe (1), an inner slotted pipe (2), an intermediate screen layer (3), an end ring (5), and a weld seam (6). An intermediate screen layer (3) is arranged between the outer slotted pipe (1) and the inner slotted pipe (2), and one end of the outer slotted pipe (1), the inner slotted pipe (2), and the intermediate screen layer (3) is welded together through the end ring (5) and the weld seam (6). An external thread is provided at one end of the above-mentioned outer slotted pipe (1), and an internal thread is provided at the other end.

[0013] Preferably, a plurality of axially arranged slots are evenly distributed on the above-mentioned outer slotted pipe (1) and inner slotted pipe (2); a plurality of screen slots are evenly distributed on the above-mentioned intermediate screen layer (3), and the screen slots are perpendicular to the slots on the outer slotted pipe (1) and the inner slotted pipe (2); the above-mentioned intermediate screen layer (3) is sleeved on the outer wall of the inner slotted pipe (2) and is welded to the outer wall of the inner slotted pipe (2) through more than one straight seam weld (7).

[0014] The beneficial effects of the present utility model are:

[0015] The utility model welds the middle screen layer to the inner slotted pipe by straight seam welding, which not only improves the oil passing rate but also has low production cost, and there is no need to design a flow hole of a bridge-type countersunk hole in the outer slotted pipe; moreover, the outer slotted pipe and the inner slotted pipe are slotted, and the middle screen layer uses filter screens with different mesh sizes to achieve the designed sand retaining accuracy, and the combination of the three can greatly extend the service life of the screen pipe; after a period of production, when the outer slotted pipe and the middle screen layer are worn out, that is, when the designed sand retaining particle size value is exceeded, the inner slotted pipe still plays a sand retaining role, and the service life is equivalent to more than twice that of an ordinary slotted pipe, thereby greatly reducing the production operation cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0017] Figure 2 yes Figure 1 An enlarged schematic diagram of part A in FIG.

[0018] In the above figure: outer slotted pipe 1, inner slotted pipe 2, middle screen layer 3, coupling 4, end ring 5, weld 6, straight weld 7. DETAILED DESCRIPTION

[0019] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0020] Example 1, reference Figure 1 and Figure 2 The utility model mentions a slotted composite screen pipe, comprising an outer slotted pipe 1, an inner slotted pipe 2, an intermediate screen layer 3, a coupling 4, an end ring 5 and a weld 6, wherein the intermediate screen layer 3 is arranged between the outer slotted pipe 1 and the inner slotted pipe 2, and one end of the outer slotted pipe 1, the inner slotted pipe 2 and the intermediate screen layer 3 are welded together through the end ring 5 and the weld 6; threads are arranged at both ends of the outer slotted pipe 1, wherein a coupling 4 is installed on the threads of one end for externally connecting an oil pipe, and the other end is a male joint.

[0021] Wherein, a plurality of groups of axially arranged slits are evenly distributed on the outer slit tube 1 and the inner slit tube 2 .

[0022] The middle screen layer 3 is evenly distributed with a plurality of screen slots, and the screen slots are perpendicular to the slots on the outer slotted tube 1 and the inner slotted tube 2 .

[0023] The intermediate screen layer 3 is sleeved on the outer wall of the inner slotted tube 2 and is welded to the outer wall of the inner slotted tube 2 through one or more sets of straight welds 7 .

[0024] In addition, the end ring 5 is located between the end of the outer slotted tube 1 and the end of the inner slotted tube 2 and is located on one side of the end of the middle screen layer 3 , and is welded to the other side of the end ring 5 to form a weld 6 .

[0025] The weld 6 is a circumferential weld structure.

[0026] When the utility model is prepared, the inner and outer pipes are first slit according to the design to form an inner slit pipe 2 and an outer slit pipe 1 respectively, and then the screen is welded to the surface of the inner slit pipe 2 by straight seam welding, the welded inner slit pipe 2 and the middle screen layer 3 are inserted into the outer slit pipe 1, and the inner slit screen pipe 2 and the middle screen layer 3 are welded to the outer slit pipe 1 through the end ring 5 and the weld 6, and the two ends of the outer slit pipe 1 are respectively processed with threads, wherein one end is threadedly connected to the coupling 4, and the oil pipe is externally connected through the coupling 4, and the other end of the outer slit pipe 1 forms a male joint.

[0027] When the utility model is used:

[0028] During the production process of oil and gas wells, the outer slotted pipe 1 is firstly worn away. After the sand-carrying fluid flowing through the middle screen layer 3 and the inner slotted pipe 2 is blocked by the outer slotted pipe 1 for most of the gravel and buffered, the gravel can smoothly pass through the middle screen layer 3 and the inner slotted pipe 2, and is not easy to be blocked. After a period of production, when the outer slotted pipe 1 and the middle screen layer 3 are worn away and fail, that is, when the designed sand retaining particle size value is exceeded, the inner slotted pipe 2 still plays a sand retaining role. Therefore, the life of the sand prevention is equivalent to more than twice that of an ordinary slotted pipe, and the manufacturing cost is simple in structure and greatly reduced compared with the prior art, thereby reducing the overall cost of oil extraction operations.

[0029] In addition, the utility model can achieve the designed sand retaining accuracy by selecting filter screens with different mesh sizes as the middle screen layer 3. The outer slit tube 1 has both a filtering effect and a function of protecting the middle screen layer 3. Moreover, the sand retaining capacity of the middle screen layer 3 is better than that of the 1.5 mm thick stainless steel protective cover of the screen-type sand filter pipe.

[0030] Embodiment 2 is different from Embodiment 1 in that:

[0031] The utility model mentions a slotted composite screen pipe, comprising an outer slotted pipe 1, an inner slotted pipe 2, an intermediate screen layer 3, an end ring 5 and a weld 6, wherein the intermediate screen layer 3 is arranged between the outer slotted pipe 1 and the inner slotted pipe 2, and one end of the outer slotted pipe 1, the inner slotted pipe 2 and the intermediate screen layer 3 are welded together through the end ring 5 and the weld 6; one end of the outer slotted pipe 1 is provided with an external thread as a male joint, and the other end is extended and provided with an internal thread as a female joint to achieve the purpose of connecting with the oil pipe.

[0032] A plurality of axially arranged slits are uniformly distributed on the outer slotted pipe 1 and the inner slotted pipe 2; a plurality of screen slits are uniformly distributed on the intermediate screen layer 3, and the screen slits are perpendicular to the slits on the outer slotted pipe 1 and the inner slotted pipe 2; the intermediate screen layer 3 is sleeved on the outer wall of the inner slotted pipe 2 and is welded to the outer wall of the inner slotted pipe 2 through more than one straight seam weld 7.

[0033] As described above, the foregoing is only a preferred embodiment of the present invention, and any person skilled in the art may modify the present invention by using the technical solutions described above or modify it into an equivalent technical solution. Therefore, any simple modification or equivalent transformation made according to the technical solution of the present invention falls within the scope of protection required by the present invention.

Claims

1. A slotted composite screen pipe, characterized by: The invention comprises an outer slotted pipe (1), an inner slotted pipe (2), an intermediate screen layer (3), a coupling (4), an end ring (5) and a weld (6); the intermediate screen layer (3) is arranged between the outer slotted pipe (1) and the inner slotted pipe (2); and one end of the outer slotted pipe (1), the inner slotted pipe (2) and the intermediate screen layer (3) are welded together via the end ring (5) and the weld (6); threads are arranged at both ends of the outer slotted pipe (1), wherein a coupling (4) is arranged on the threads of one end, and the other end is a male joint.

2. The slotted composite screen pipe according to claim 1, characterized in that: A plurality of groups of axially arranged slits are evenly distributed on the outer slit tube (1) and the inner slit tube (2).

3. The slotted composite screen pipe according to claim 2, characterized in that: The middle screen layer (3) has multiple groups of screen slots evenly distributed thereon, and the screen slots are perpendicular to the slots on the outer slotted tube (1) and the inner slotted tube (2).

4. The slotted composite screen pipe according to claim 3 is characterized in that: The middle screen layer (3) is sleeved on the outer wall of the inner slotted tube (2) and is welded to the outer wall of the inner slotted tube (2) through one or more sets of straight welds (7).

5. The slotted composite screen pipe according to claim 4, characterized in that: The end ring (5) is located between the end of the outer layer slotted tube (1) and the end of the inner layer slotted tube (2), and is located on one side of the end of the middle screen layer (3), and is welded to the other side of the end ring (5) to form a weld (6).

6. The slotted composite screen pipe according to claim 5, characterized in that: The weld (6) is a circumferential weld structure.

7. A slotted composite screen pipe, characterized by: The invention comprises an outer slit tube (1), an inner slit tube (2), an intermediate screen layer (3), an end ring (5) and a weld (6); the intermediate screen layer (3) is arranged between the outer slit tube (1) and the inner slit tube (2); and one end of the outer slit tube (1), the inner slit tube (2) and the intermediate screen layer (3) are welded together via the end ring (5) and the weld (6); one end of the outer slit tube (1) is provided with an external thread, and the other end is provided with an internal thread.

8. The slotted composite screen pipe according to claim 7, characterized in that: The outer slotted tube (1) and the inner slotted tube (2) are evenly distributed with a plurality of groups of axially arranged slots; the intermediate screen layer (3) is evenly distributed with a plurality of groups of screen slots, and the screen slots are perpendicular to the slots on the outer slotted tube (1) and the inner slotted tube (2); the intermediate screen layer (3) is sleeved on the outer wall of the inner slotted tube (2) and is welded to the outer wall of the inner slotted tube (2) by one or more groups of straight seam welds (7).

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