An internal rotating backwash oil pipe short joint device

Abstract

The present invention discloses an inner rotary backwashing oil pipe short joint device, comprising an inner pipe string, an outer casing is sleeved on the outer side of the inner pipe string, the two ends of the inner pipe string extend out of the two ends of the outer casing respectively, the inner sides of the two ends of the outer casing are sleeved on the outer side of the inner pipe string through bearings, an annular protective cover is provided on the outer side of the bearing, the inner ring of the annular protective cover abuts the outer surface of the inner pipe string, and the outer ring of the annular protective cover is fixedly connected to the inner side of the outer casing. The short-circuit device of the present invention can realize the functions of reverse circulation of the wellbore and positive rotation of the downhole tool, so that the pipe string has the function of reverse circulation and flushing while rotating, solving the construction process problem of reverse circulation while rotating on site.

Description

Technical Field

[0001] The invention relates to a well repairing tool, in particular to an internal rotating backwashing oil pipe short joint device. Background Art

[0002] During offshore platform workovers, large amounts of sand often flow through the wellbore, necessitating the connection of a circulation line and the closure of the universal blowout preventer for reverse circulation flushing. To achieve optimal bottomhole sand flushing, the tubing string may even require a rotational function. During overhaul grinding, casing, and milling operations, the tubing string also requires the ability to simultaneously rotate, grind, and flush with reverse circulation, ensuring that the workover fluid can carry debris to the wellhead. Because the annular area of the tubing string is currently much larger than its cross-sectional area, forward circulation flushing is less effective than reverse circulation at the same flow rate. However, existing equipment on the market can only support forward circulation flushing while the tubing string rotates. For example, the Chinese patent with the publication number CN106368630B and the publication date of March 22, 2019: A sand flushing method and special tools. This patent can only meet the requirements of positive circulation washing of the well while the pipe string rotates. Therefore, in order to better carry dust, sand or debris to the wellhead during the grinding, casing and milling process for large-scale sand production in the wellbore and overhaul operations, a pipe string with the function of reverse circulation flushing while rotating is required to solve the construction process problem of reverse circulation while rotating on site. Summary of the Invention

[0003] For this purpose, the present invention designs an internal rotating backwashing oil pipe short joint device, which can realize the reverse circulation of the wellbore and the positive rotation of the downhole tool, so that the pipe string has the function of reverse circulation and flushing while rotating, solving the construction process problem of reverse circulation while rotating on site.

[0004] The technical solution of the present invention is:

[0005] An internal rotary backwash oil pipe short section device includes an inner pipe string, an outer casing is sleeved on the outside of the inner pipe string, two ends of the inner pipe string respectively extend out of the two ends of the outer casing, the inner sides of both ends of the outer casing are sleeved on the outside of the inner pipe string through bearings, an annular protective cover is provided on the outside of the bearing, the inner ring of the annular protective cover abuts the outer surface of the inner pipe string, and the outer ring of the annular protective cover is fixedly connected to the inner side of the outer casing.

[0006] Both ends of the inner string are connected to other strings. The outer casing is locked by the universal blowout preventer. The outer casing can rotate relative to the inner string via bearings. At this time, under the action of the top drive or turntable of the drilling floor, the inner string can rotate relative to the outer casing, realizing reverse circulation in the wellbore and forward rotation of the downhole tool, giving the string a rotating reverse circulation and flushing function. Among them, the annular protective caps on the two ends of the inner string limit the axial movement of the inner string and prevent debris from falling into the bearings and affecting relative rotation.

[0007] Furthermore, both ends of the inner pipe string are female couplings, and the two ends of the inner pipe string are connected to other outer pipe strings through female couplings.

[0008] Furthermore, the buckle type of the female coupling includes common buckle types such as EU, NU or BGT2, which are consistent with the buckle type of the external pipe column.

[0009] Furthermore, a sealing rubber ring is provided between the annular protective cover and the bearing to enhance the sealing between the inner pipe string and the outer casing and prevent external debris from affecting the bearing.

[0010] Furthermore, the annular protective cover is welded to the inner side of the outer casing as a whole, thereby enhancing the overall structural strength of the outer casing and meeting operational requirements.

[0011] Furthermore, the thickness of the inner tube column is 5mm-10mm.

[0012] Furthermore, the thickness of the outer sleeve is 5mm-10mm.

[0013] Furthermore, the inner pipe string and the outer casing are both made of stainless steel.

[0014] The inner pipe string and outer casing are made of stainless steel of appropriate thickness to enhance the structural strength, meet the extrusion strength during operation, and the material is wear-resistant.

[0015] Furthermore, the surfaces of the inner tube string and the outer tube string are both electroplated with a metal anti-corrosion coating.

[0016] Furthermore, the metal anti-corrosion coating includes a galvanized coating, a tinned coating or a nickel-plated coating.

[0017] The surfaces of the inner and outer tubing strings are coated with a metal anti-corrosion coating to enhance the anti-corrosion performance and extend the service life.

[0018] The beneficial effects of the present invention are:

[0019] According to the structure of the internal rotary backwash tubing nipple device of the present invention, the universal blowout preventer can lock the outer casing of the device. Since the inner tubing string can rotate relative to the outer casing via bearings at both ends, the inner tubing string can be rotated by the top drive or turntable of the drilling floor, thereby achieving reverse circulation in the wellbore and positive rotation of the downhole tool. This invention solves the problem of dust, sand, and debris flowing back to the wellhead during large-scale sand production or overhaul operations such as grinding, casing, and milling. It also solves the problem of simultaneous rotation and reverse circulation in on-site construction processes, avoids accidents such as tubing string obstruction and drill sticking, improves operation time, and achieves the goal of reducing costs and increasing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the short section device of the present invention;

[0021] Figure 2 for Figure 1 A cross-sectional schematic diagram;

[0022] Figure 3 for Figure 1 Schematic top view of

[0023] In the figure: inner pipe string 1, female coupling 101, outer casing 2, bearing 3, annular protective cover 4, sealing rubber ring 5. DETAILED DESCRIPTION

[0024] The drawings are for illustrative purposes only and should not be construed as limiting this patent. To better illustrate the embodiments, some components in the drawings may be omitted, enlarged, or reduced in size, and do not represent actual product dimensions. Those skilled in the art will understand that some well-known structures and their descriptions may be omitted from the drawings. The positional relationships depicted in the drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0025] Example 1:

[0026] like Figure 1-Figure 3 As shown, an internal rotary backwash oil pipe short section device includes an inner pipe string 1, an outer casing 2 is sleeved on the outer side of the inner pipe string 1, two ends of the inner pipe string 1 respectively extend out of the two ends of the outer casing 2, both ends of the inner pipe string 1 are female couplings 101, the inner sides of both ends of the outer casing 2 are sleeved on the outer side of the inner pipe string 1 through bearings 3, an annular protective cover 4 is provided on the outer side of the bearing 3, the inner ring of the annular protective cover 4 abuts against the outer surface of the inner pipe string 1, and the outer ring of the annular protective cover 4 is fixedly connected to the inner side of the outer casing 2.

[0027] In this embodiment, the buckle type of the female coupling 101 includes common buckle types such as EU, NU or BGT2, which are consistent with the buckle type of the external pipe column.

[0028] In this embodiment, a sealing rubber ring 5 is further provided between the annular protective cover 4 and the bearing 3 to enhance the sealing between the inner pipe string 1 and the outer casing 2 and prevent external debris from affecting the bearing.

[0029] In this embodiment, the annular protective cover 4 is welded to the inner side of the outer casing 2 as a whole, thereby enhancing the overall structural strength of the outer casing 2 and meeting operational requirements.

[0030] In this embodiment, the annular protective covers 4 and the sealing rubber rings 5 at both ends restrict the movement direction of the inner pipe string 1, ensuring that the inner pipe string 1 can only rotate along the axis.

[0031] In this embodiment, the inner pipe string 1 and outer casing 2 are both 5mm-10mm thick and are made of stainless steel, with a preferred thickness of 7mm. Using stainless steel of appropriate thickness for the inner pipe string 1 and outer casing 2 enhances structural strength, meets the required extrusion strength during operation, and is also wear-resistant.

[0032] In this embodiment, the surfaces of the inner pipe string 1 and the outer pipe string 2 are electroplated with a metal anti-corrosion coating, and the metal anti-corrosion coating includes a galvanized coating, a tinned coating or a nickel-plated coating, etc. The metal anti-corrosion coating is coated on the surfaces of the inner pipe string 1 and the outer pipe string 2 to enhance the anti-corrosion performance and extend the service life.

[0033] In this embodiment, the outer casing 1, the sealing rubber ring 5, and the inner pipe string 2 have strong anti-wear properties and meet the on-site requirements.

[0034] The internal rotary backwashing oil pipe short joint device of the present invention mainly includes the following steps:

[0035] (1) The female coupling 101 at the lower end of the inner tubing string 1 is connected to the tubing string of the lower oil pipe or other tubing strings of the same threading type, and the threading torque meets the API standard.

[0036] (2) The upper female coupling 101 of the inner pipe string 2 is connected to other pipe strings of the same type and finally connected to the mud pool.

[0037] (3) Place the outer casing 2 of the device under the rubber core of the universal blowout preventer, close the universal blowout preventer, and start reverse circulation well washing after the pressure test is passed.

[0038] (4) Using the drill floor turntable or top drive, rotate the inner tubing string 1 at a reasonable speed so that the inner tubing string 1 rotates relative to the outer casing 2, thereby driving the downhole tool to rotate.

[0039] The universal blowout preventer can lock the outer casing 2 of the device. Since the inner pipe string 1 can rotate relative to the outer casing 2 through bearings 3 at both ends, the inner pipe string 1 can be rotated under the action of the top drive or turntable of the drilling floor, thereby achieving reverse circulation in the wellbore and positive rotation of the downhole tool. The present invention solves the problem of dust, sand, and debris flowing back to the wellhead during large-scale sand production or overhaul operations such as grinding, casing, and milling; it solves the problem of rotating and reverse circulation during on-site construction processes, avoids accidents such as pipe string obstruction and drill sticking, improves operation time, and achieves the goal of reducing costs and increasing efficiency.

[0040] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. An internal rotary backwash oil pipe short joint device, characterized in that: The invention comprises an inner tubing string, wherein an outer casing is sleeved on the outer side of the inner tubing string, and two ends of the inner tubing string extend out from the two ends of the outer casing respectively, and the inner sides of both ends of the outer casing are sleeved on the outer side of the inner tubing string through bearings, and an annular protective cover is provided on the outer side of the bearing, the inner ring of the annular protective cover abuts against the outer surface of the inner tubing string, and the outer ring of the annular protective cover is fixedly connected to the inner side of the outer casing; the outer casing is used to be locked by a universal blowout preventer; both ends of the inner tubing string are female couplings, and the female couplings are used to connect with other outer tubing strings; The steps for use include: (1) The female coupling at the lower end of the inner tubing string is connected to the tubing string of the lower oil pipe or other tubing strings of the same threading type, and the threading torque meets the API standard; (2) The upper end female coupling of the inner pipe string is connected to other pipe strings of the same buckle type and finally connected to the mud pool; (3) Place the outer casing under the rubber core of the universal blowout preventer, close the universal blowout preventer, and start reverse circulation well washing after the pressure test is passed; (4) Using the drill floor turntable or top drive, the inner tubing is rotated at a reasonable speed so that the inner tubing rotates relative to the outer casing, thereby driving the downhole tool to rotate.

2. The short section device according to claim 1, characterized in that: Female couplings are available in EU, NU or BGT2 styles.

3. The short section device according to claim 1, characterized in that: A sealing rubber ring is further provided between the annular protective cover and the bearing.

4. The short section device according to claim 1, characterized in that: The annular protective cover is welded to the inner side of the outer sleeve as a whole.

5. The short section device according to claim 1, characterized in that: The thickness of the inner tube column is 5mm-10mm.

6. The short section device according to claim 1, characterized in that: The thickness of the outer sleeve is 5mm-10mm.

7. The short section device according to claim 1, characterized in that: The inner pipe string and the outer casing are both made of stainless steel.

8. The short section device according to claim 7, characterized in that: The surfaces of the inner pipe string and the outer casing are both electroplated with a metal anti-corrosion coating.

9. The short section device according to claim 8, characterized in that: The metal anti-corrosion coating includes a galvanized coating, a tinned coating or a nickel-plated coating.

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