Sand cleaning nipple

Abstract

The utility model discloses a sand cleaning nipple, and belongs to the field of downhole tools of petroleum drilling engineering. The sand cleaning nipple comprises a main body 1, a composite spiral runner, grooves 4 and a cladding alloy strip 5, the composite spiral runner is located in the middle section of the main body 1, the grooves 4 are formed in the two ends of the composite spiral runner, the composite spiral runner comprises a front spiral runner 2 and a rear spiral runner 3, the front spiral runner 2 rotates rightwards, the rear spiral runner 3 rotates leftwards, the section of the front spiral runner is in an inclined U shape, and the section of the rear spiral runner 3 is in an inclined U shape. The section of the rear spiral flow channel is in a U shape, the connecting position of the front spiral flow channel and the rear spiral flow channel is in a V shape, and a plurality of cladding alloy strips 5 are evenly distributed on the outer surface of the front spiral flow channel and the outer surface of the rear spiral flow channel. By transferring and grinding a large amount of rock debris, the rock debris deposition probability is reduced, friction resistance and abrasion of a drilling tool assembly and a rock stratum are reduced, the drilling efficiency is improved, and the service life of a drilling tool is prolonged. The drilling tool is suitable for gas drilling and liquid drilling, and has wide market application prospects.

Description

Technical Field

[0001] The utility model belongs to the field of downhole tools for petroleum drilling engineering, and in particular relates to a sand cleaning short section for cleaning a wellbore. Background Art

[0002] When drilling high-angle wells, horizontal wells, and extended-reach wells, due to the difficulty in moving cuttings underground, cuttings are likely to accumulate on the wellbore wall, forming a cuttings bed of a certain length. The formed cuttings bed not only increases the drilling torque, but also easily induces the drill string support pressure problem, which in turn causes the risk of drill sticking and causes huge economic losses.

[0003] Patent CN102220847A discloses a vortex cleaning drill rod, which has the function of changing the annular gas flow field. However, due to the small size of the vortex generating structure, the cleaning drill rod has limited ability to lift cuttings, and a cuttings bed is easily formed near the drill bit at the drill collar.

[0004] Patent CN1318726C discloses a drill tool centralizer for gas drilling horizontal wells. Although it can eliminate the low-speed flow area caused by the eccentric annulus and thus transport cuttings, the cleaning tool on the centralizer can only allow suspended cuttings to pass through the centralizer, but cannot lift a large amount of cuttings accumulated on the cuttings bed into the annulus.

[0005] The borehole cleaning tool disclosed in patent CN201738848U can change the annular flow field and break the rocks in the cuttings bed, but it cannot lift a large amount of cuttings into the annular space for transportation. When used for gas drilling horizontal wells, the cuttings bed is easier to form than conventional drilling because the gas has a small mass and kinetic energy and a weak ability to carry cuttings during flow.

[0006] In view of the fact that there is no tool for cleaning cuttings beds that combines the three functions of changing flow field, re-breaking rock and lifting cuttings, the utility model proposes a new wellbore cleaning tool for drilling to overcome the deficiencies and defects of the prior art. Utility Model Content

[0007] The purpose of the utility model is to provide a sand cleaning sub that can realize the function of transporting and grinding a large amount of rock cuttings, reduce the probability of rock cuttings deposition, thereby reducing the friction and wear between the drill tool assembly and the rock formation, improving the drilling efficiency, and extending the service life of the drill tool. The utility model is suitable for gas drilling and liquid drilling, and has broad market application prospects.

[0008] In order to achieve the above technical objectives, the utility model adopts the following technical solutions.

[0009] A sand cleaning nipple comprises a main body, a composite spiral flow channel, a cladding alloy strip, a groove and a wear-resistant belt. The composite spiral flow channel is located in the middle section of the main body and comprises a front spiral flow channel and a rear spiral flow channel. A groove is arranged at the lower end of the front spiral flow channel, and a groove is arranged at the upper end of the rear spiral flow channel.

[0010] The front spiral flow channel is right-handed, the rear spiral flow channel is left-handed, the cross section of the front spiral flow channel is an oblique U-shape, and the cross section of the rear spiral flow channel is a regular U-shape. During the rotation of the sand cleaning sub, the rock chips are scraped into the oblique U-shaped groove and then carried into the annulus with the rotation.

[0011] A number of cladding alloy strips are evenly distributed on the outer surfaces of the front spiral flow channel and the rear spiral flow channel. The laser cladding technology makes the alloy strips more tightly combined with the main body, making them less likely to fall off, while reducing costs. The cladding alloy strips play the role of crushing rock debris and disturbing the surrounding air during the rotation process, thereby improving the sand cleaning and rock carrying capabilities of the tool.

[0012] The grooves are respectively located at the lower end of the front spiral flow channel and the upper end of the rear spiral flow channel, and are transitionally connected to the main body through diameter change. The setting of the grooves is conducive to the clamping and loading and unloading of the tool, and the diameter change process avoids stress concentration.

[0013] The wear-resistant belt is located at the transitional connection between the main body and the groove, which can reduce the wear of the tool main body and increase the service life of the tool.

[0014] The outer diameters of the front spiral flow channel and the rear spiral flow channel are both smaller than the outer diameter of the main body, which can effectively avoid the wear of the spiral section that plays a major role during the rotation process, extend the service life of the tool, and ensure that the tool always works normally.

[0015] The connection between the front spiral flow channel and the rear spiral flow channel is in a V-shape. The V-shaped structure is conducive to the tool to shovel and roll up the cuttings, fully drive the cuttings into the flow field, and enhance the cleaning ability of the tool.

[0016] The main body of the utility model adopts high-strength low-alloy steel as the material, which has high strength, long service life and mechanical properties higher than general structural steel.

[0017] The utility model is connected to the position of the drill collar close to the drill bit, and one is installed every 100 meters, so the use effect is better.

[0018] Compared with the prior art, the advantages of the present invention are:

[0019] The utility model adopts a composite flow channel, a cladding alloy strip, and a V-shaped structure, combining the three functions of changing the flow field, crushing rock chips, and lifting rock chips. The front and rear spiral flow channels have opposite rotation directions, which can realize turbulence of the annular fluid, thereby reducing the probability of forming a rock cutting bed in the wellbore; the opening of the oblique U-shaped groove improves the ability to collect rock cuttings, making up for the deficiency that the existing technology cannot lift a large number of rock cuttings; the application of laser cladding technology enhances the combination of the alloy strip and the main body, making the alloy strip not easy to fall off, reducing the cost; the setting of the alloy strip improves the ability to crush rock cuttings and can more effectively remove the rock cutting bed; the design of the V-shaped structure at the junction of the front and rear spiral flow channels can fully drive the rock cuttings into the flow field, enhancing the cleaning ability of the tool; the addition of the groove is conducive to the installation and unloading of the tool.

[0020] The utility model can achieve a good effect of cleaning rock cuttings in a well. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the utility model.

[0022] Figure 2 yes Figure 1 Schematic diagram of the structure of the AA section (front spiral flow channel).

[0023] Figure 3 yes Figure 1 Schematic diagram of the structure of the BB section (rear spiral flow channel).

[0024] In the figure: 1-main body; 2-front spiral flow channel; 3-rear spiral flow channel; 4-groove; 5-cladding alloy strip; 6-wear-resistant belt. DETAILED DESCRIPTION

[0025] The present invention is further described below with reference to the accompanying drawings so that those skilled in the art can understand the present invention. However, it should be clear to those skilled in the art that any changes within the spirit and scope of the present invention as defined and determined by the appended claims are protected.

[0026] See also Figure 1 , Figure 2 , Figure 3 .

[0027] A sand cleaning pup joint comprises a main body 1, a composite spiral flow channel, a groove 4 and a cladding alloy strip 5, wherein the composite spiral flow channel is located in the middle section of the main body 1, and grooves 4 are arranged at both ends thereof, the composite spiral flow channel comprises a front spiral flow channel 2 and a rear spiral flow channel 3, the front spiral flow channel 2 is right-handed, and the rear spiral flow channel 3 is left-handed, the cross section of the front spiral flow channel 2 is an oblique U-shape, the cross section of the rear spiral flow channel 3 is a regular U-shape, the connection between the front spiral flow channel and the rear spiral flow channel is in a V-shape, and a plurality of cladding alloy strips 5 are evenly distributed on the outer surfaces of the front spiral flow channel 2 and the rear spiral flow channel 3.

[0028] Furthermore, the groove 4 is located at the lower end of the front spiral flow channel 2 and the upper end of the rear spiral flow channel 3, and is transitionally connected to the main body 1 through a diameter change to avoid stress concentration.

[0029] Furthermore, the outer surfaces of the front spiral flow channel 2 and the rear spiral flow channel 3 are smoothly connected after chamfering and rounding, and the edges at the connection are V-shaped to form a V-shaped groove.

[0030] Furthermore, a wear-resistant belt 6 is provided at the transitional connection between the main body 1 and the groove 4, which can effectively reduce the wear of the main body 1.

[0031] Furthermore, the cladding alloy strips 5 are evenly distributed on the outer surface of the composite spiral flow channel, with a thickness of 1-2 mm, to ensure that the cuttings with larger diameters in the cuttings bed are fully crushed.

[0032] Furthermore, the outer diameters of the front spiral flow channel 2 and the rear spiral flow channel 3 are both smaller than the outer diameter of the main body 1, thereby avoiding wear of the spiral flow channel section and extending its service life.

[0033] The utility model is connected to the position of the drill collar close to the drill bit, and the working process is as follows:

[0034] When the main body 1 rotates with the drill string, the composite spiral flow channel accelerates the gas in the flow field, the flow state changes, the cuttings in the cuttings bed are blown up, and the V-shaped groove at the junction of the front spiral flow channel 2 and the rear spiral flow channel 3 further scoops up the cuttings. The larger cuttings are ground into smaller diameter cuttings by the cladding alloy strip 5 on the outer surface of the spiral flow channel. Then a large amount of cuttings are scraped into the oblique U-shaped groove of the front spiral flow channel 2, and are sent to the rear spiral flow channel 3 with the rotation and then blown away from the flow field.

Claims

1. A sand cleaning sub, comprising a main body (1), a composite spiral flow channel, a groove (4) and a cladding alloy strip (5), characterized in that: The composite spiral flow channel is located in the middle section of the main body (1), and grooves (4) are arranged at both ends thereof. The composite spiral flow channel comprises a front spiral flow channel (2) and a rear spiral flow channel (3), the front spiral flow channel is right-handed, and the rear spiral flow channel is left-handed. The cross section of the front spiral flow channel is an oblique U-shape, and the cross section of the rear spiral flow channel is a regular U-shape. The connection between the front spiral flow channel and the rear spiral flow channel is in a V-shape, and a plurality of cladding alloy strips (5) are evenly distributed on the outer surfaces of the front spiral flow channel and the rear spiral flow channel.

2. A sand cleaning sub as claimed in claim 1, characterized in that: The groove (4) is located at the lower end of the front spiral flow channel (2) and the upper end of the rear spiral flow channel (3), and is transitionally connected to the main body (1) through a diameter change to avoid stress concentration.

3. The sand cleaning sub as claimed in claim 1, characterized in that: The outer surfaces of the front spiral flow channel (2) and the rear spiral flow channel (3) are smoothly connected after being chamfered and rounded, and the edges at the connection are V-shaped, forming a V-shaped groove.

4. The sand cleaning sub as claimed in claim 1, characterized in that: A wear-resistant belt (6) is provided at the transition connection between the main body (1) and the groove (4).

5. The sand cleaning sub as claimed in claim 1, characterized in that: The cladding alloy strips (5) are evenly distributed on the outer surface of the composite spiral flow channel and have a thickness of 1 to 2 mm.

6. The sand cleaning sub as claimed in claim 1, characterized in that: The outer diameters of the front spiral flow channel (2) and the rear spiral flow channel (3) are both smaller than the outer diameter of the main body (1).

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