Anti-sedimentation pup joint for dirt in oil pipe and manufacturing method of anti-sedimentation pup joint

Abstract

The invention provides an anti-sedimentation pup joint for dirt in an oil pipe and a manufacturing method, and belongs to the technical field of pumping unit exploitation in the petroleum industry, the anti-sedimentation pup joint comprises a sucker rod pup joint, a sheath, a fiber ring and a spring, the sucker rod pup joint comprises a body, an upper connector and a lower connector, and the upper connector and the lower connector are arranged at the two ends of the body; a plurality of sheaths and a plurality of fiber rings are arranged, and the sheaths and the fiber rings are alternately sleeved on the body of the sucker rod pup joint; the middle of the sucker rod pup joint is cut off, and after the sheath, the fiber ring and the spring are installed, notches are connected into a whole through the connecting hoop. The multiple fiber rings are arranged, precipitated solid particles such as dirt, silt and the like are intercepted in advance, the solid particles are prevented from directly settling to the position where a pump is prone to being stuck, and therefore the problem that the pump is stuck to a shaft due to sedimentation of most solid particles can be solved.

Description

Technical Field

[0001] This invention belongs to the field of oil pumping unit extraction technology in the petroleum industry, specifically relating to a short-circuit joint for preventing scale and foam settling inside oil pipes and its manufacturing method. Background Technology

[0002] In oilfield production, oil wells are produced through a mechanical oil production system consisting of tubing, sucker rods, and pumps. When scale buildup occurs in the tubing string, the repeatedly moving sucker rods and their anti-wear blocks repeatedly rub against the tubing wall, causing the scale flakes to detach or be ground into powder. When the pumping unit shuts down due to intermittent shutdowns or unexpected power outages, this scale suspended in the liquid settles down along the tubing string and accumulates directly at the pump outlet or in the gap between the piston and the pump barrel. The longer the shutdown period, the more scale accumulates. When the pumping unit resumes operation, this scale can easily enter the gap between the piston and the pump barrel, causing pump jamming and leading to frequent and ineffective well repairs.

[0003] Currently, no one at the production site is researching this issue. Although some have suggested using the retrieval cup structure used during drilling to solve the problem, the retrieval cup is large and only suitable for temporary use. If it is used continuously downhole in reciprocating motion with the pump (during the up and down strokes, the tubing and sucker rod contract and elongate due to stress), its large size would easily wear through the tubing, leading to new problems. Therefore, this solution cannot be applied in the field. Traditional scale prevention measures, including adding chemical agents or installing magnetic fields for suppression, can only reduce the amount of scale at the source, but are ineffective on the parts of the tubing already scaled. In particular, they are basically unable to prevent solid particles produced in the formation from entering the pump barrel and migrating and settling. Therefore, traditional scale prevention measures are not helpful in solving the pump jamming problem caused by the settling of scale and solid particles in the tubing.

[0004] A search revealed publication number CN211287547U, which discloses an anti-scaling short section belonging to the field of casing connectors for oil drilling. Its structure includes a casing coupling and a short section body. The casing coupling is an API casing coupling with a standard casing female thread inside. The short section body has a tubular structure with casing male threads at both ends. One end of the short section body connects to the casing female thread at one end of the casing coupling via the casing male thread, and the other end of the casing coupling connects to the casing. An anti-scaling coating is applied to the inner wall of the short section body. This anti-scaling short section addresses the fundamental problem of scaling, preventing scaling and corrosion, thus saving on the downtime, uploading, and tubing string tripping associated with physical and chemical descaling methods, reducing costs, and extending the service life of oil and water wells.

[0005] Currently, water injection wells in oilfields have been operating for many years, leading to increasingly frequent and complex scaling issues in the wellbore. In recent years, some wells have adopted an intermittent production system, alternating between pumping and pumping at intervals to reduce ineffective power consumption. When a well transitions from a running state to a stationary state, the previously rising fluid movement within the tubing becomes static. Scale flakes detached from the tubing wall and debris such as sand extracted from the formation settle downwards, accumulating in the pump's inner cylinder and on the piston. Due to the hardness of these scale flakes and sand (poor compressibility), prolonged accumulation, under temperature and pressure, can effectively adhere to the surface of the pump's inner cylinder. Because the gap between the pump's piston and its barrel is very small, these deposits and adhered scale and sand can easily cause jamming (pump jamming) when production resumes. This necessitates the removal of the entire well tubing rod for cleaning and repair, resulting in high costs and production delays. Summary of the Invention

[0006] To overcome the problem that in existing equipment, after a power outage or intermittent shutdown of the pumping unit, scale or solid particles inside the tubing will concentrate and settle at the pump inlet at the end of the tubing string, causing obstruction to the piston that moves up and down during normal operation, this invention provides a short-circuit and manufacturing method for preventing scale settling inside the tubing. This invention adopts a physical isolation mechanism to block the scale and solid particles in sections along the channels where they settle by gravity, thereby effectively blocking the transmission channels of harmful substances to the operating mechanical parts, achieving proactive defense and eliminating potential risks.

[0007] The technical solution adopted in this invention is as follows: A short connector for preventing scale settling inside an oil pipe includes a sucker rod short connector, a sheath, a fiber ring, and a spring. The sucker rod short connector includes a body and upper and lower connectors located at both ends of the body. Multiple sheaths and fiber rings are alternately fitted onto the body of the sucker rod short connector. The sucker rod short connector is cut off at the middle, and after the sheath, fiber ring, and spring are installed, the cut end is connected as a whole by a connecting clamp. There are two springs, which are respectively sleeved on the two body sections near the cut. The springs are located between the connecting clamp and its corresponding fiber ring. The two ends of the connecting clamp are in contact with the corresponding springs and form a pre-tight state on the corresponding fiber rings and sheaths.

[0008] A limiting washer is provided between the spring and the fiber ring.

[0009] The fiber ring includes fiber filaments and a limiting ring. The limiting ring is sleeved on the body of the sucker rod short connection, and the fiber filaments are arranged circumferentially outside the circumference of the limiting ring.

[0010] The limiting ring is a hollow circular ring with grooves on its outer wall.

[0011] The groove of the limiting ring is used to fix the fiber filament.

[0012] The fiber filaments are distributed circumferentially outside the circumference of the limiting ring to form a ring brush shape, and their maximum outer diameter is greater than the inner diameter of the oil pipe.

[0013] The sheath is a hollow cylinder, and its inner diameter matches the outer diameter of the body to which the sucker rod is shorted.

[0014] The upper connector is connected to a coupling.

[0015] A method for manufacturing a short-circuit joint to prevent scale settling inside an oil pipe, comprising the following steps: First, the complete sucker rod is short-jointed and cut into two sections, and threads are machined at the cut. Then, the sheath and fiber ring are inserted one by one through the cut; Then, insert the springs into the two sections of the sucker rod through the cut to create a short circuit; Finally, the two sections of the sucker rod are short-connected at the cut by connecting couplings to form a short-connector to prevent scale and foam settling inside the tubing.

[0016] The beneficial effects of this invention are: In this invention, the fiber filaments are in contact with the inner cavity of the tubing. They possess a certain degree of flexibility; in motion, the gaps between the filaments and their flexible deformation allow liquid to pass through. However, in a stationary state when the pumping unit is stopped, the fiber filaments adhere to the inner wall of the tubing, and the fiber deflection forms a narrow arched barrier, thereby blocking and bearing the descent of some solid particles. This invention, through multi-layered and multi-segmented barriers, achieves the goal of gradually reducing the number of descending particles and ultimately completely blocking the descent channel of solid particles.

[0017] By using the anti-settlement short-circuit for scale and foam inside the oil pipe provided by the invention, the scale and foam and other solid particles that naturally settle after the oil pump stops have a landing point to support them, so that they do not continue to settle to the pump outlet. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention.

[0019] Figure 2 This is a schematic diagram of the sucker rod short-connection structure with upper and lower joints and couplings of the present invention.

[0020] Figure 3 This is a schematic diagram of the fiber ring structure of the present invention. Figure 4 This is a schematic diagram of the side structure of the fiber ring of the present invention.

[0021] Figure 5 This is a schematic diagram of the limiting ring structure of the present invention.

[0022] The present invention will now be described in further detail with reference to the accompanying drawings.

[0023] In the figure, the attached figures are labeled as follows: 1. Sucker rod short connector; 2. Sheath; 3. Fiber ring; 4. Connecting clamp; 5. Spring; 6. Fiber filament; 7. Limiting ring; 8. Groove; 101. Upper connector; 102. Lower connector; 103. Body. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0026] Example 1: To overcome the problem that in existing equipment, after a power outage or intermittent shutdown of the pumping unit, scale or solid particles inside the tubing will concentrate and settle at the pump inlet at the end of the tubing string, causing obstruction to the piston that moves up and down during normal operation, this invention provides a short-circuit and manufacturing method for preventing scale settling inside the tubing. This invention adopts a physical isolation mechanism to block the scale and solid particles in sections along the channels where they settle by gravity, thereby effectively blocking the transmission channels of harmful substances to the operating mechanical parts, achieving proactive defense and eliminating potential risks.

[0027] A short connector for preventing scale settling inside an oil pipe, characterized in that it includes a sucker rod short connector 1, a sheath 2, a fiber ring 3, and a spring 5. The sucker rod short connector 1 includes a body 103 and an upper connector 101 and a lower connector 102 located at both ends of the body 103. There are multiple sheaths 2 and fiber rings 3, which are alternately sleeved on the body 103 of the sucker rod short connector 1. The sucker rod short connector 1 is cut off in the middle, and after the sheath 2, fiber ring 3, and spring 5 are installed, the cut is connected into one piece by a connecting clamp 4. In this invention, the sheath 2 and fiber ring 3 are fitted onto the body 103 at the cut of the sucker rod short connector 1, and then the cut sucker rod short connector 1 is connected together by the connecting clamp 4. The number of sheaths 2 and fiber rings 3 is set according to the requirements, and the sheaths 2 and fiber rings 3 fitted onto each segment of the sucker rod short connector 1 cut into two segments do not need to be symmetrically arranged.

[0028] In this invention, such as Figure 1 and Figure 2 As shown, the sheath 2 and fiber rings 3 are alternately sleeved on the body 103 of the sucker rod short connector 1, covering the entire exterior of the body 103. During use, multiple fiber rings 3 form a multi-layered barrier, ensuring that scale and sludge do not fall off in large quantities. Simultaneously, multiple anti-sludge and sludge-prevention short connectors provided by this invention can be installed on the sucker rod at desired locations. After multiple locations are equipped with these anti-sludge and sludge-prevention short connectors, multi-segmented barriers for scale and sludge are formed. The segmented and dispersed blocking of a large amount of scale and other solid particles prevents continuous settling, thereby reducing the probability of pump jamming.

[0029] The anti-scaling short connector provided by this invention is the same as the normal sucker rod short connector 1, and is connected to the sucker rod in the form of a threaded connection. It can generally be installed on the upper part of the piston rod of the oil pump. Both the upper connector 101 and the lower connector 102 are connected to the corresponding equipment rods through couplings.

[0030] In use, the anti-scaling short-circuit is installed at the end of the piston rod on the upper part of the piston. The multi-layer flexible fiber filaments 6 together with the inner wall of the oil pipe form a multi-layer anti-scaling system. After the oil well stops pumping, the scale, sand and other solid particles that have settled in the oil pipe are intercepted in advance, preventing these solid particles from settling directly to the position where the pump is prone to jamming. This can solve most of the wellbore pump jamming problems caused by the settling of solid particles.

[0031] The multi-layered flexible fiber filaments 6 remain dispersed and flexible as they move with the sucker rod, preventing them from obstructing the fluid in the wellbore. When the sucker rod is stationary, the fiber filaments 6 form a relatively dense mesh structure with the inner wall of the tubing, effectively blocking and adhering to freely settling solid particles. Upon the next pumping start, due to the flexibility of the fiber filaments 6, the solid particles deposited and adhered to them will not impede the movement of the sucker rod system. Furthermore, under the continuous upward scouring of the fluid, the solid particles will be carried upwards and discharged from the wellbore, thus ensuring that pump jamming accidents caused by solid particle settling do not recur.

[0032] Example 2: Based on Embodiment 1, in this embodiment, preferably, there are two springs 5, which are respectively sleeved on the two body sections 103 near the cut. The springs 5 ​​are located between the connecting clamp 4 and its corresponding fiber ring 3. The two ends of the connecting clamp 4 are in contact with the corresponding springs 5 ​​and form a pre-tightened state on the corresponding fiber ring 3 and sheath 2. In this invention, both ends of the connecting clamp 4 are tightly attached to the spring 5 and the corresponding fiber ring 3 to form a pre-tightened state. Both ends of the connecting clamp 4 are in contact with the corresponding spring 5, respectively, and apply a certain pre-tightening force to the sheath 2 and the fiber ring 3.

[0033] Preferably, a limiting washer is provided between the spring 5 and the fiber ring 3.

[0034] Preferably, the fiber ring 3 includes fiber filaments 6 and a limiting ring 7. The limiting ring 7 is sleeved on the body 103 of the sucker rod short connector 1, and the fiber filaments 6 are arranged circumferentially outside the circumference of the limiting ring 7.

[0035] like Figure 3 and Figure 4 As shown, in this invention, the fiber ring 3 is a ring-shaped device that binds the fiber filaments 6 to the limiting ring 7. The limiting ring 7 is a ring with a groove 8. The fiber filaments 6 can preferably be thin filaments similar to those used in brooms. The fiber filaments 6 are preferably made of a high-temperature resistant and elastic material. The fiber ring 3 formed by binding the fiber filaments 6 needs to have a certain density to block and bear some solid particles in a static state. If flat fiber filaments 6 are used, the effect is better. After the fiber filaments 6 are arranged and bound to the limiting ring 7 at a certain density, a fiber ring 3 is formed that has both liquid flowability and solid particle blocking function. In actual processing, the fiber filaments 6 can be bound in multiple layers. If the fiber filaments 6 are cylindrical, the thickness is preferably 0.5-1mm, which can be adjusted and optimized according to actual conditions. If the fiber filaments 6 are flat and thin, the thickness is about 0.5mm. The binding can be made of rust-proof metal or non-metal materials, as long as it can be fastened. After fastening, glue is added to ensure that the fiber filaments 6 do not fall apart if they break at the bend.

[0036] In this invention, the fiber filaments 6 on the fiber ring 3 allow liquid to pass through during the movement of the sucker rod, but prevent solid particles from settling naturally.

[0037] Preferably, the limiting ring 7 is a hollow circular ring with a groove 8 on its outer wall.

[0038] Preferably, the groove 8 of the limiting ring 7 is used to fix the fiber filament 6.

[0039] like Figure 5 As shown, in this invention, the groove 8 on the limiting ring 7 is for better fixing of the fiber filament 6. The fiber filament 6 is connected and fixed to the limiting ring 7 by bundling, gluing, or other fixing methods.

[0040] Preferably, the fiber filaments 6 are circumferentially distributed around the periphery of the limiting ring 7 to form a brush shape, and their maximum outer diameter is greater than the inner diameter of the oil pipe.

[0041] In this invention, the maximum outer diameter of the ring formed by the fiber filament 6 only needs to be slightly larger than the inner diameter of the oil pipe. This ensures that solid particles will not fall along the oil pipe wall.

[0042] like Figure 3 and Figure 4 As shown, in this invention, there are multiple fiber filaments 6, with their density determined according to requirements, and they are radially distributed in a circumferential pattern within the grooves 8 on the limiting ring 7. The radial distribution of the fiber filaments 6 can be one or more layers, as long as it ensures that the fiber filaments 6 are fixed to the limiting ring 7 and do not fall off, and that the outer diameter of the brush formed by the fiber filaments 6 is larger than the inner diameter of the oil pipe. In this way, the fiber filaments 6, based on their own deflection and overall density, intercept solid particles.

[0043] By using the anti-settlement short-circuit for scale and foam inside the oil pipe provided by the invention, the scale and foam and other solid particles that naturally settle after the oil pump stops have a landing point to support them, so that they do not continue to settle to the pump outlet.

[0044] In this invention, preferably, the fiber filament 6 is distributed in two layers, with the middle of the fiber filament 6 tied to the groove 8 of the limiting ring 7, and both ends being free ends that are in contact with the inner wall of the oil pipe.

[0045] Preferably, the sheath 2 is a hollow cylinder, and the inner diameter of the sheath 2 matches the outer diameter of the body 103 of the sucker rod short connector 1.

[0046] In this invention, the size of the sheath 2 is selected according to the requirements. While protecting the main body 103, the sheath limits the two adjacent fiber rings 3.

[0047] Preferably, the sheath 2 is a PVC pipe.

[0048] In this invention, the sheath 2 is preferably made of PVC pipe, which is inexpensive and effective.

[0049] Example 3: Based on Embodiment 1 or 2, this embodiment provides a method for manufacturing a short-circuit joint to prevent scale settling inside an oil pipe. The specific steps are as follows: First, cut the complete sucker rod short section 1 into two parts, and then process threads at the cut. Then, insert the sheath 2 and the fiber ring 3 one by one through the cut; Then, spring 5 is inserted into the two sections of the sucker rod shorting 1 from the cut. Finally, at the cut, the two sections of the sucker rod are connected together by the connecting coupling 4 to form a short-connector to prevent scale and foam settling inside the tubing.

[0050] In this invention, the complete sucker rod short connector 1 is cut into two sections, with a total length not exceeding 30cm. Threads are machined at the cut points, and matching connecting clamps 4 are added. After other accessories are installed, the connection is reset to the state of sucker rod short connector 1, thus enabling its use. When using the anti-settling short connector for tubing provided by this invention, both the upper connector 101 and the lower connector 102 are connected to the corresponding equipment via clamps. An anti-settling short connector provided by this invention is installed on the sucker rod at least every 500m. In this way, under static conditions, the multi-layer fiber rings 3 in the anti-settling short connector block and bear some of the settling of solid particles.

[0051] In this invention, multiple anti-settling short-circuit joints are installed at the required locations on the sucker rod to block scale in multiple stages. Each anti-settling short-circuit joint is further reinforced with multiple fiber rings 3 for multi-layer scale blocking.

[0052] In this invention, fiber filament 6 contacts the inner cavity of the tubing; it has a certain degree of flexibility. In motion, the gaps and flexible deformation of fiber filament 6 allow liquid to pass through. However, in a stationary state when the pumping unit is stopped, the fiber filament 6 adheres to the inner wall of the tubing, and the deflection of the fiber filament 6 forms a narrow arched barrier, thereby blocking and bearing the sinking of some solid particles. This invention achieves the purpose of gradually reducing the number of sinking particles and ultimately completely blocking the sinking channel of solid particles through multi-layered and multi-segmented barriers.

[0053] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0054] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0055] The examples above are merely illustrative of the present invention and do not constitute a limitation on the scope of protection of the present invention. All designs that are the same as or similar to the present invention fall within the scope of protection of the present invention. Device structures and method steps not described in detail in this invention are prior art and will not be further described in this invention.

Claims

1. A short-circuit connector for preventing scale and foam settling inside oil pipes, characterized in that: The device includes a sucker rod short connector (1), a sheath (2), a fiber ring (3), and a spring (5). The sucker rod short connector (1) includes a body (103) and an upper connector (101) and a lower connector (102) located at both ends of the body (103). There are multiple sheaths (2) and fiber rings (3), which are alternately fitted onto the body (103) of the sucker rod short connector (1). The sucker rod short connector (1) is cut off in the middle. After the sheath (2), fiber ring (3), and spring (5) are installed, the cut is connected into one piece by a connecting clamp (4).

2. The anti-settling short-circuit for scale buildup inside an oil pipe according to claim 1, characterized in that: There are two springs (5), which are respectively sleeved on the two body sections (103) near the cut. The springs (5) are located between the connecting clamp (4) and its corresponding fiber ring (3). The two ends of the connecting clamp (4) are in contact with the corresponding springs (5) and form a pre-tight state on the corresponding fiber ring (3) and sheath (2).

3. The anti-settling short-circuit for scale buildup inside an oil pipe according to claim 2, characterized in that: A limiting washer is provided between the spring (5) and the fiber ring (3).

4. The anti-settling short-circuit for scale buildup inside an oil pipe according to claim 1, characterized in that: The fiber ring (3) includes fiber filaments (6) and a limiting ring (7). The limiting ring (7) is sleeved on the body (103) of the sucker rod short connector (1). The fiber filaments (6) are arranged circumferentially outside the circumference of the limiting ring (7).

5. A short-circuit connector for preventing scale settling inside an oil pipe according to claim 4, characterized in that: The limiting ring (7) is a hollow circular ring with a groove (8) on its outer wall.

6. The anti-settling short-circuit for scale buildup inside an oil pipe according to claim 5, characterized in that: The groove (8) of the limiting ring (7) is used to fix the fiber filament (6).

7. The anti-settling short-circuit for scale buildup inside an oil pipe according to claim 4, characterized in that: The fiber filaments (6) are circumferentially distributed around the circumference of the limiting ring (7) to form a ring brush shape, and their maximum outer diameter is greater than the inner diameter of the oil pipe.

8. A short-circuit connector for preventing scale settling inside an oil pipe according to claim 1, characterized in that: The sheath (2) is a hollow cylinder, and the inner diameter of the sheath (2) matches the outer diameter of the body (103) of the sucker rod short connector (1).

9. A short-circuit connector for preventing scale settling inside an oil pipe according to claim 1, characterized in that: The upper connector (101) is connected to a coupling.

10. The method for manufacturing any one of the anti-settling short-circuit joints for scale and foam inside oil pipes according to claims 1-9, characterized in that: The specific steps are as follows: First, cut the complete sucker rod short section (1) into two parts and process threads at the cut position; Then, the sheath (2) and the fiber ring (3) are inserted into the cut in sequence; Then, spring (5) is inserted into the two sections of the sucker rod short circuit (1) from the cut. Finally, the two sections of sucker rod are connected together at the cut by connecting coupling (4) to form a short joint to prevent scale and foam settling inside the tubing.

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