Anti-fouling rod type oil well pump

Abstract

The present application relates to the technical fields of downhole tools of oil production engineering, and particularly relates to a rod type oil pump capable of preventing scale, comprising: a bottom end of a plunger is detachably connected with a sealing connecting mechanism, the sealing connecting mechanism is connected with an oil pipe, and a fixed valve is arranged on the plunger; the plunger is located in a pump barrel, a top end of the pump barrel is connected with a sucker rod, the pump barrel is located in the oil pipe, and a traveling valve is arranged on an upper end of the pump barrel; the sucker rod drives the pump barrel to move through up and down movement, when the pump barrel moves downward, the traveling valve is opened, when the pump barrel moves upward, the traveling valve is closed, and when the pump barrel moves upward, liquid in the oil pipe is introduced into the pump barrel through the plunger and the fixed valve, and the fixed valve is used for preventing the liquid in the pump barrel from entering the plunger. The present application can effectively reduce the probability of pump jam caused by scale, prolong the pump inspection cycle, and make the pump barrel and the plunger more closely cooperate without increasing the gap between the pump barrel and the plunger, thereby improving the production efficiency.

Description

Technical Field

[0001] This invention relates to the field of downhole tools technology in oil production engineering, and in particular to a scale-resistant rod-type oil pump. Background Technology

[0002] Existing anti-scaling pumps used in ternary composite drive systems employ a long plunger, short barrel structure. This reduces the real-time contact area between the barrel and plunger, and increases the clearance between them, thus sacrificing pump efficiency to reduce pump jamming caused by detached scale. However, due to this structural characteristic, the long plunger, short barrel anti-scaling pump cannot prevent scale from settling into the clearance between the barrel and plunger during the rod-tube reciprocating motion, thus failing to prevent pump jamming. Field application statistics show that the average pump inspection cycle for the long plunger, short barrel anti-scaling pump is approximately 530 days, which is longer than conventional pumps, but the effect is still unsatisfactory. Summary of the Invention

[0003] This invention proposes a scale-resistant rod-type oil pump to solve the problem that existing scale-resistant oil pumps are prone to scale flakes falling off during operation, causing pump jamming. Increasing the gap between the pump barrel and the plunger to reduce pump jamming leads to reduced pump efficiency, thus affecting production efficiency.

[0004] According to one aspect of the present invention, a scale-resistant rod-type oil pump is provided, comprising: a pump barrel, a plunger, and a sealing connection mechanism; The bottom end of the plunger is detachably connected to the sealing connection mechanism, the sealing connection mechanism is connected to the oil pipe, and a fixed valve is provided on the plunger; The plunger is located inside the pump barrel, the top of the pump barrel is connected to the sucker rod, the pump barrel is located inside the oil pipe, and a floating valve is provided at the upper end of the pump barrel; The sucker rod moves up and down, driving the pump barrel to move. When the pump barrel moves downward, the floating valve opens; when the pump barrel moves upward, the floating valve closes. When the pump barrel moves upward, the liquid in the pump-down oil pipe enters the pump barrel through the plunger and the fixed valve. The fixed valve is used to prevent the liquid in the pump barrel from entering the plunger.

[0005] Preferably, the tip of the floating valve is connected to the sucker rod via an oil outlet valve.

[0006] Preferably, an oil inlet valve is connected between the top of the movable valve and the oil outlet valve.

[0007] Preferably, the movable valve includes: a first valve ball and a first valve seat; The first valve seat is connected between the pump barrel and the sucker rod; The first valve seat is provided with a first inner hole, and the first valve ball is located above the first inner hole.

[0008] Preferably, the first valve seat is connected to the pump cylinder via a first double-threaded pipe.

[0009] Preferably, the fixed valve includes: a second valve ball and a second valve seat; The bottom end of the second valve seat is connected to the top end of the plunger; The second valve seat is provided with a second inner hole, and the second valve ball is located above the second inner hole.

[0010] Preferably, a fixed valve cover is provided at the top of the second valve seat, and a liquid outlet is provided on the side wall of the fixed valve cover.

[0011] Preferably, the second valve seat and the plunger are connected by a second double-threaded pipe.

[0012] Preferably, the bottom end of the plunger is connected to a plunger connector, the plunger connector is connected to one end of a connecting pipe, and the other end of the connecting pipe is connected to the sealing connection mechanism.

[0013] Preferably, the sealing connection mechanism includes: a support mandrel, a support cup, a locking anchor, and a sealing assembly; The top end of the support mandrel is connected to the connecting pipe, and the bottom end of the support mandrel is connected to the locking anchor. The supporting cup is sleeved on the outside of the supporting mandrel; The sealing assembly is connected to oil pipes at both ends. During connection, the support mandrel is inserted into the sealing assembly and engages with it.

[0014] Preferably, the sealing assembly includes: a cup support joint and a locking support joint; The top end of the diaphragm support joint is connected to an oil pipe, and the bottom end of the diaphragm support joint is connected to the locking support joint. The locking support joint is used to engage with the locking anchor.

[0015] Preferably, the locking anchor is a claw-type connector, and the outer side wall of the locking anchor is provided with a first protrusion; The locking support joint has a second protrusion inside that engages with the first protrusion.

[0016] Preferably, the support cup is fixed to the outside of the support spindle by a cup seat ring and a cup pressure cap.

[0017] The present invention has at least the following beneficial effects: This invention proposes a scale-resistant rod-type oil pump. By setting up a pump barrel sleeved outside the plunger and using a sucker rod to drive the plunger up and down for oil extraction, scale cannot enter the gap between the pump barrel and the plunger during the up and down stroke of the pump barrel, thereby effectively reducing the probability of pump jamming due to scale and extending the pump inspection cycle; without increasing the gap between the pump barrel and the plunger, the two can be more tightly matched, thereby improving production efficiency. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present invention and, together with the specification, serve to explain the technical solutions of the present invention.

[0019] Figure 1 A schematic diagram of a scale-resistant rod-type oil pump according to an embodiment of the present invention is shown. Figure 2 A schematic diagram of the sealing assembly according to an embodiment of the present invention is shown.

[0020] In the diagram, 1-outlet valve, 2-inlet valve, 3-first double-threaded pipe, 4-pump barrel, 5-first protrusion, 6-locking anchor, 7-support seat ring, 8-second valve ball, 9-second valve seat, 10-first valve seat, 11-first valve ball, 12-support spindle, 13-connecting pipe, 14-plunger joint, 15-plunger, 16-second double-threaded pipe, 17-second protrusion, 18-fixed valve cover, 19-support cup, 20-first oil pipe coupling, 21-cup support joint, 22-second oil pipe coupling, 23-locking support joint. Detailed Implementation

[0021] Various exemplary embodiments, features, and aspects of the present invention will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0022] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0023] In this document, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0024] Furthermore, to better illustrate the present invention, numerous specific details are set forth in the following detailed embodiments. Those skilled in the art will understand that the present invention can be practiced without certain specific details. In some instances, methods, means, elements, and circuits well known to those skilled in the art have not been described in detail in order to highlight the spirit of the invention.

[0025] Figure 1 A schematic diagram of a scale-resistant rod-type oil pump according to an embodiment of the present invention is shown. Figure 2 A schematic diagram of the sealing assembly according to an embodiment of the present invention is shown. Figure 1 and 2 As shown, a scale-resistant rod-type oil pump includes: a pump barrel 4, a plunger 15, and a sealing connection mechanism; the bottom end of the plunger 15 is detachably connected to the sealing connection mechanism, the sealing connection mechanism is connected to an oil pipe, and a fixed valve is provided on the plunger 15; the plunger 15 is located inside the pump barrel 4, the top end of the pump barrel 4 is connected to a sucker rod, the pump barrel 4 is located inside the oil pipe, and a floating valve is provided at the upper end of the pump barrel 4; the sucker rod drives the pump barrel 4 to move by moving up and down; when the pump barrel 4 moves downward, the floating valve opens; when the pump barrel 4 moves upward, the floating valve closes; when the pump barrel 4 moves upward, the liquid in the oil pipe below the pump enters the pump barrel 4 through the plunger 15 and the fixed valve, and the fixed valve is used to prevent the liquid in the pump barrel 4 from entering the interior of the plunger 15.

[0026] In embodiments of the present invention, such as Figure 1 As shown, during the well run, the sucker rod is connected to the top of the pump barrel 4, and the plunger 15 is placed inside the pump barrel 4. The outer wall of the plunger 15 is tightly fitted to the inner wall of the pump barrel 4, and the bottom end of the plunger 15 is outside the pump barrel 4. The pump barrel 4 and plunger 15 are lowered into the well using the sucker rod. When the bottom end of the plunger 15 reaches the sealing connection mechanism inside the tubing, it is lowered further to engage the bottom end of the plunger 15 with the sealing connection mechanism.

[0027] During oil extraction, the up-and-down movement of the sucker rod drives the pump barrel 4 to move along the plunger 15. When the sucker rod drives the pump barrel 4 downward, the top of the pump barrel 4 approaches the top of the plunger 15, reducing the internal space of the pump barrel 4. The floating valve installed inside the pump barrel 4 automatically opens under the upward thrust of the liquid below. The liquid inside the pump barrel 4 passes upward through the floating valve and enters the oil pipe.

[0028] When the pump barrel 4 moves downward to its maximum limit, the sucker rod drives the pump barrel 4 to move upward. The floating valve automatically closes under the downward thrust of the liquid above. When the pump barrel 4 moves upward, the internal space increases. Under pressure, the liquid in the pump lower oil pipe below the plunger 15 moves upward through the plunger 15 and the fixed valve and enters the pump barrel 4.

[0029] When the pump barrel 4 moves upward to its maximum limit, the sucker rod drives the pump barrel 4 downward, the floating valve opens automatically, and the liquid inside the pump barrel 4 passes through the floating valve and enters the oil pipe above the pump barrel 4, and is lifted to the ground through the oil pipe.

[0030] A fixed valve is installed at the top of the plunger 15 to prevent liquid inside the pump barrel 4 from entering the plunger 15 when the pump barrel 4 moves downward.

[0031] In this invention, the top of the floating valve is connected to the sucker rod via the oil outlet valve 1.

[0032] In this embodiment of the invention, a liquid outlet is provided on the side wall of the oil outlet valve 1. When the pump cylinder 4 moves downward, the internal liquid enters the oil outlet valve 1 through the floating valve and finally enters the oil pipe from the liquid outlet on the side wall of the oil outlet valve 1.

[0033] In this invention, the top of the movable valve is connected to the oil outlet valve 1 via an oil inlet valve 2.

[0034] In this embodiment of the invention, the top of the oil inlet valve 2 is provided with a flow channel. When the pump cylinder 4 moves downward, the internal liquid enters the oil inlet valve 2 through the floating valve, enters the oil outlet valve 1 through the flow channel at the top of the oil inlet valve 2, and finally enters the oil pipe through the liquid outlet on the side wall of the oil outlet valve 1.

[0035] The inlet valve 2, outlet valve 1, and floating valve are connected by a threaded structure.

[0036] In this invention, the floating valve includes: a first valve ball 11 and a first valve seat 10; the first valve seat 10 is connected between the pump barrel 4 and the sucker rod; the first valve seat 10 is provided with a first inner hole, and the first valve ball 11 is located above the first inner hole.

[0037] In this invention, the first valve seat 10 and the pump cylinder 4 are connected by a first double-threaded pipe 3.

[0038] In this embodiment of the invention, when the sucker rod drives the pump barrel 4 downward, the internal space of the pump barrel 4 decreases. Due to the action of the fixed valve, the liquid cannot enter the plunger 15 downward. Therefore, the liquid inside the pump barrel 4 pushes the first valve ball, which is located in the first valve seat 10, upward. The first valve ball moves upward away from the first valve seat 10, thereby opening the first inner hole. The liquid inside the pump barrel 4 passes upward through the first inner hole, then through the inlet valve 2 and the outlet valve 1, and enters the oil pipe.

[0039] When the sucker rod drives the pump barrel 4 to move upward, the liquid pressure above the pump barrel 4 increases. Under the action of gravity and the liquid pressure above, the first valve ball falls downward into the first valve seat 10. The diameter of the first valve ball is larger than the first inner hole, so the first valve ball blocks the first inner hole. After the first inner hole is closed, the liquid above the pump barrel 4 cannot enter the pump barrel 4 from below.

[0040] In this invention, the fixed valve includes: a second valve ball 8 and a second valve seat 9; the bottom end of the second valve seat 9 is connected to the top end of the plunger 15; the second valve seat 9 is provided with a second inner hole, and the second valve ball 8 is located above the second inner hole.

[0041] In this invention, the second valve seat 9 and the plunger 15 are connected by a second double-threaded pipe 16.

[0042] In this embodiment of the invention, when the sucker rod drives the pump barrel 4 to move downward, the second valve ball 8 is located above the second inner hole, blocking the second inner hole. Therefore, the liquid inside the pump barrel 4 cannot enter the plunger 15 downward.

[0043] When the sucker rod drives the pump barrel 4 upward, the pressure inside the pump barrel 4 decreases. The liquid inside the plunger 15 pushes the second valve ball inside the second valve seat 9 upward, causing it to move away from the second inner hole. After the second inner hole opens, the liquid inside the plunger 15 enters the pump barrel 4 through the second inner hole.

[0044] In this invention, a fixed valve cover 18 is provided at the top of the second valve seat 9, and an outlet is provided on the side wall of the fixed valve cover 18.

[0045] In this embodiment of the invention, the second valve ball 8 is located inside the fixed valve cover 18, which prevents the second valve ball 8 from entering the pump barrel 4 upwards. When the sucker rod drives the pump barrel 4 upwards, the liquid inside the plunger 15 passes through the second inner hole and then enters the pump barrel 4 through the outlet on the fixed valve cover 18.

[0046] In this invention, the bottom end of the plunger 15 is connected to the plunger connector 14, the plunger connector 14 is connected to one end of the connecting pipe 13, and the other end of the connecting pipe 13 is connected to the sealing connection mechanism.

[0047] In this embodiment of the invention, when the sucker rod drives the pump barrel 4 to move upward, the pressure inside the pump barrel 4 decreases, and the liquid in the oil pipe below the sealing connection mechanism moves upward through the sealing connection mechanism, the connecting pipe 13 and the plunger joint 14 and then enters the interior of the plunger 15.

[0048] In this invention, the sealing connection mechanism includes: a support mandrel 12, a support cup 19, a locking anchor 6, and a sealing assembly; the top end of the support mandrel 12 is connected to the connecting pipe 13, and the bottom end of the support mandrel 12 is connected to the locking anchor 6; the support cup 19 is sleeved on the outside of the support mandrel 12; both ends of the sealing assembly are respectively connected to oil pipes, and during connection, the support mandrel 12 is inserted into the sealing assembly and engages with the sealing assembly.

[0049] In this invention, the supporting cup 19 is fixed to the outside of the supporting spindle 12 by the cup seat ring and the cup pressure cap.

[0050] In this embodiment of the invention, the top end of the support spindle 12 is connected to the bottom end of the connecting pipe 13 via a pump barrel lower connector, and the bottom end of the support spindle 12 is connected to the top end of the locking anchor 6. The support cup 19 is fixed to the outside of the support spindle 12 by a cup seat ring and a cup pressure cap. A support seat ring 7 is provided on the outside of the upper end of the locking anchor 6.

[0051] The support cup 19 serves to support and seal the pump barrel 4 and plunger 15, keeping them in the middle position inside the oil pipe and maintaining a certain gap between the pump barrel 4 and the outer wall of the oil pipe. The cup seat, cup cap, and support seat 7 are used to fix the support cup 19 to the support spindle 12.

[0052] The locking anchor 6 is also fitted with several sealing rings on its outside.

[0053] During wellheading, the pump barrel 4, plunger 15, support mandrel 12, and locking anchor 6 are lowered into the well via the sucker rod. When the bottom of the locking anchor 6 reaches the sealing assembly, it is lowered further, allowing the locking anchor 6 and support mandrel 12 to insert into the sealing assembly. Corresponding snap-fit ​​structures are provided inside the sealing assembly for locking the locking anchor 6 and the sealing assembly. Sealing is achieved by the sealing ring on the outside of the locking anchor 6 and the support cup 19 on the outside of the support mandrel 12 fitting against the inner wall of the sealing assembly.

[0054] During oil extraction, the liquid in the oil pipe below the sealing assembly enters the plunger 15 through the hollow interior of the support assembly, locking anchor 6, support spindle 12, and connecting pipe 13.

[0055] When pump barrel 4 and plunger 15 require maintenance or component replacement, i.e., when pump barrel 4 and plunger 15 need to be removed, the pump barrel 4 is moved upward by the sucker rod. When the pump barrel 4 moves upward to its maximum limit, because the pump barrel 4 and plunger 15 have a mutually cooperating limit suspension structure, the pump barrel 4 will not disengage from the plunger 15, thus applying an upward pulling force to the plunger 15 through the pump barrel 4. When this pulling force exceeds a predetermined value, the locking anchor 6 disengages from the sealing assembly, and the sucker rod moves the pump barrel 4 and plunger 15 upward to the surface. For reuse, the pump barrel 4 and plunger 15 are lowered back into the well via the sucker rod, and the locking anchor 6 is inserted into the sealing assembly to complete the locking.

[0056] In this invention, the sealing assembly includes: a cup support joint 21 and a locking support joint 23; the top end of the cup support joint 21 is connected to an oil pipe, and the bottom end of the cup support joint 21 is connected to the locking support joint 23; the locking support joint 23 is used to engage with the locking anchor 6.

[0057] In embodiments of the present invention, such as Figure 2 As shown, one end of the cup support joint 21 is connected to the upper oil pipe via the first oil pipe coupling 20, and the other end is connected to the locking support joint 23 via the second oil pipe coupling 22. The two ends of the cup support joint 21 are respectively located inside the first oil pipe coupling 20 and the second oil pipe coupling 22. One end of the locking support joint 23 is located inside the second oil pipe coupling 22, and the other end is connected to the lower oil pipe.

[0058] During connection, the sucker rod drives the pump barrel 4, plunger 15, support mandrel 12, and locking anchor 6 downwards. When the locking anchor 6 reaches the first tubing coupling 20, it inserts downwards into the cup support joint 21 and locking support joint 23 through the first tubing coupling 20. At this time, the support cup 19 outside the support mandrel 12 is inside the cup support joint 21, and the lower part of the locking anchor 6 is inside the locking support joint 23. When the sucker rod continues to drive the pump barrel 4 downwards to the lowest limit, the bottom end of the pump barrel 4 is engaged at the second protrusion 17 at the top of the support mandrel 12. The sucker rod pushes the support mandrel 12 and locking anchor 6 downwards through the pump barrel 4. When the locking anchor 6 is fully inserted into the locking support joint 23, the locking anchor 6 and the locking support joint 23 engage and lock. The support cup 19 contacts and seals with the inner wall of the cup support joint 21; the outer sealing ring of the locking anchor 6 fits and seals with the inner wall of the locking support joint 23, thereby achieving the purpose of lifting the liquid.

[0059] When it is necessary to remove the pump barrel 4 and the plunger 15, the pump barrel 4 is moved upward by the sucker rod. The pump barrel 4 applies an upward pulling force to the plunger 15, the support spindle 12 and the locking anchor 6, so that the locking anchor 6 is disengaged from the locking support joint 23, and the disassembly is completed.

[0060] In this invention, the locking anchor 6 is a claw-type connector, and the outer side wall of the locking anchor 6 is provided with a first protrusion 5; the locking support connector 23 is provided with a second protrusion 17 that engages with the first protrusion 5.

[0061] In this embodiment of the invention, there is a certain gap between each claw of the locking anchor 6; the top and bottom surfaces of the second protrusion 17 inside the locking support joint 23 are both inclined surfaces. During connection, the bottom end of the locking anchor 6 is inserted into the locking support joint 23. When the first protrusion 5 on the outside of the locking anchor 6 reaches the annular second protrusion 17 inside the locking support joint 23, a downward thrust is applied by the sucker rod and the pump barrel 4, causing the claw-shaped parts at the bottom of the locking anchor 6 to converge towards the center, thereby reducing the overall diameter of the locking anchor 6. As it continues downward, the first protrusion 5 passes over the second protrusion 17. When it reaches below the second protrusion 17, the first protrusion 5 and the second protrusion 17 cooperate to lock the locking anchor 6 inside the locking support joint 23, preventing it from moving upward. During the oil extraction process, when the sucker rod drives the pump barrel 4 to move, it will not apply excessive tension to the plunger 15 and the locking anchor 6, so the locking anchor 6 will not come out, thereby achieving the positioning of the plunger 15.

[0062] When it is necessary to remove the pump barrel 4 and the plunger 15, the pump barrel 4 is driven upward by the sucker rod. The pump barrel 4 applies a pulling force to the plunger 15, the support spindle 12 and the locking anchor 6. When the first protrusion 5 of the locking anchor 6 reaches below the second protrusion 17, its claw-shaped parts converge towards the center, thereby reducing the overall diameter of the locking anchor 6. As it continues to move upward, the first protrusion 5 passes over the second protrusion 17, thereby causing the locking anchor 6 to disengage from the locking support joint 23, completing the disassembly.

[0063] In this embodiment of the invention, the oil pump consisting of the oil outlet valve 1, oil inlet valve 2, double-threaded pipe, pump barrel 4, and pump barrel lower connector has a maximum outer diameter of Φ68mm, and the gap between the pump barrel 4 and the Φ76mm oil pipe is 4mm. The 4mm gap effectively prevents scale from falling off and entering the pump barrel 4 when the pump barrel 4 is lifting by the impact of the liquid flow.

[0064] The lower part of the plunger 15, which consists of locking anchor 6, support seat ring 7, support cup 19, cup reducer, cup pressure cap, cup seat ring, support cup 19, and support cup 19 mandrel, has a maximum outer diameter of Φ57mm. It is sealed to the sealing assembly to ensure the oil pipe is sealed and pressure-bearing.

[0065] The plunger connector 14, plunger 15, double-threaded, φ45 valve ball and seat (first valve ball and first valve seat 10), fixed valve cover 18, and φ35 valve ball and seat (second valve ball and second valve seat 9) constitute the upper part of the plunger 15 and connect it to the pump barrel 4. The total length of the plunger 15 and the connecting pipe 13 is designed according to the maximum stroke of the pumping unit.

[0066] Experimental application was conducted on pumping wells in ternary composite blocks exhibiting scale buildup issues such as scale jamming, rod lag, and piston scoring. These wells underwent pump inspections due to scale buildup, with an inspection cycle of less than 300 days. The downhole setup consisted of φ76mm tubing and φ22mm / φ25mm sucker rods. The pump depth was 20-50m above the perforated section, and the pumping unit's stroke parameters did not exceed 5.5m. During pump inspections, the scale-resistant rod-type pumping unit of this invention was replaced. It was lowered to the predetermined depth according to the oil production engineering design. After the scale-resistant rod-type pumping unit was lowered to the designed depth along with the sucker rod, it was raised 1-2 sucker rod heights and then quickly lowered. The lower end anchoring device (locking anchor 6) of the scale-resistant rod-type pumping unit was connected to the locking support joint 23 of the sealing assembly. After adjusting the anti-blowout distance according to the stroke, a pressure test was performed. If the wellhead pressure rose above 3MPa and remained stable for more than 5 minutes, it was considered normal pressure holding, and the pumping unit was started for production. If the pressure is not normal, repeatedly connect and tighten the locking anchor 6 and the locking support joint 23 until the pressure is qualified.

[0067] During pumping, the floating valve closes and the fixed valve opens during the upstroke, allowing fluid to enter the plunger 15 and pump barrel 4 from the casing. Because the floating valve is closed during the upstroke, scale from the tubing cannot enter the pump barrel 4. During the downstroke, the floating valve opens and the fixed valve closes, allowing fluid to enter the tubing from the pump barrel 4. During the downstroke, fluid enters the tubing from the floating valve, which is a drainage state. Scale flakes are unable to enter the pump barrel 4 due to the impact of the fluid flow and fall to the bottom of the well. This pump effectively prevents scale flakes from entering the gap between the pump barrel 4 and the plunger 15 during both the upstroke and downstroke, significantly reducing the chance of pump jamming due to scale. During pump inspection, simply lifting the sucker rod disengages it from the tubing, allowing for pump replacement without moving the tubing.

[0068] The invention was tested in 60 wells. All wells operated normally after being run into the wells, with an average pump efficiency of 51.2%, which is 9.4 percentage points higher than that of ordinary oil pumps. The average pump inspection cycle was 612 days, which is 337 days longer than that of ordinary oil pumps, achieving a better scale prevention effect.

[0069] It is understood that the various embodiments mentioned above in this invention can be combined with each other to form combined embodiments without violating the principle and logic. Due to space limitations, this invention will not elaborate further.

[0070] In response to the severe scaling in mechanically operated wells in ternary composite oil displacement blocks, where scale flakes easily fall off the tubing and into the pump barrel 4, causing rod lag, piston damage, and pump jamming, this invention conducts research on the moving barrel rod type anti-scaling pump technology. The specific innovations are mainly reflected in the following aspects: (1) Design of fixed plunger 15: The sealing assembly is designed to be connected to the bottom of the tubing, and the lower part of the plunger 15 is designed with a snap ring structure (locking anchor 6) and a locking support joint 23 for detachable connection. (2) Design of inverted structure: The plunger 15 is fixed inside the tubing, and the sucker rod drives the pump barrel 4 to move up and down to lift it. Through the impact of the liquid flow, it can effectively prevent scale flakes from falling into the pump barrel 4. This can prevent scale flakes from falling into the pump barrel 4 in ternary composite scaled wells, thus extending the pump inspection cycle and saving construction costs.

[0071] The anti-scaling pump of this invention has a reasonable structure, which can replace the pump without moving the tubing string. During replacement, the sucker rod is lifted to a certain load to disengage the pump from the sealing assembly, the old pump is removed, the new pump is installed and lowered again, and the minor repair work can be completed. This avoids removing the entire well tubing string during replacement, reduces the workload, and improves construction efficiency.

[0072] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A scale-resistant rod-type oil pump, characterized in that, include: Pump cylinder (4), plunger (15) and sealing connection mechanism; The bottom end of the plunger (15) is detachably connected to the sealing connection mechanism, the sealing connection mechanism is connected to the oil pipe, and a fixed valve is provided on the plunger (15); The plunger (15) is located inside the pump barrel (4), the top of the pump barrel (4) is connected to the sucker rod, the pump barrel (4) is located inside the oil pipe, and a floating valve is provided at the upper end of the pump barrel (4). The sucker rod moves up and down, driving the pump barrel (4) to move. When the pump barrel (4) moves downward, the floating valve opens. When the pump barrel (4) moves upward, the floating valve closes. When the pump barrel (4) moves upward, the liquid in the pump pipe enters the pump barrel (4) through the plunger (15) and the fixed valve. The fixed valve is used to prevent the liquid in the pump barrel (4) from entering the plunger (15).

2. The scale-resistant rod-type oil pump according to claim 1, characterized in that: The top of the movable valve is connected to the sucker rod via an oil outlet valve (1).

3. The scale-resistant rod-type oil pump according to claim 2, characterized in that: The top of the movable valve is connected to the oil outlet valve (1) via the oil inlet valve (2).

4. The scale-resistant rod-type oil pump according to claim 1, characterized in that, The movable valve includes: a first valve ball (11) and a first valve seat (10); The first valve seat (10) is connected between the pump barrel (4) and the sucker rod; The first valve seat (10) is provided with a first inner hole, and the first valve ball (11) is located above the first inner hole.

5. The scale-resistant rod-type oil pump according to claim 4, characterized in that: The first valve seat (10) is connected to the pump cylinder (4) via a first double-threaded pipe (3).

6. The scale-resistant rod-type oil pump according to claim 1, characterized in that, The fixed valve includes: a second valve ball (8) and a second valve seat (9); The bottom end of the second valve seat (9) is connected to the top end of the plunger (15); The second valve seat (9) is provided with a second inner hole, and the second valve ball (8) is located above the second inner hole.

7. The scale-resistant rod-type oil pump according to claim 6, characterized in that: The second valve seat (9) is provided with a fixed valve cover (18) at its top, and a liquid outlet is provided on the side wall of the fixed valve cover (18).

8. The scale-resistant rod-type oil pump according to claim 6, characterized in that: The second valve seat (9) is connected to the plunger (15) via a second double-threaded pipe (16).

9. The scale-resistant rod-type oil pump according to claim 1, characterized in that: The bottom end of the plunger (15) is connected to the plunger connector (14), the plunger connector (14) is connected to one end of the connecting pipe (13), and the other end of the connecting pipe (13) is connected to the sealing connection mechanism.

10. The scale-resistant rod-type oil pump according to claim 9, characterized in that, The sealing connection mechanism includes: a support spindle (12), a support cup (19), a locking anchor (6), and a sealing assembly; The top end of the support mandrel (12) is connected to the connecting pipe (13), and the bottom end of the support mandrel (12) is connected to the locking anchor (6). The supporting cup (19) is sleeved on the outside of the supporting mandrel (12); The two ends of the sealing assembly are respectively connected to oil pipes. When connected, the support mandrel (12) is inserted into the sealing assembly and engages with the sealing assembly.

11. The scale-resistant rod-type oil pump according to claim 10, characterized in that, The sealing assembly includes: a cup support joint (21) and a locking support joint (23); The top end of the cup support joint (21) is connected to the oil pipe, and the bottom end of the cup support joint (21) is connected to the locking support joint (23). The locking support joint (23) is used to engage with the locking anchor (6).

12. The scale-resistant rod-type oil pump according to claim 11, characterized in that: The locking anchor (6) is a claw-type connector, and the outer side wall of the locking anchor (6) is provided with a first protrusion (5). The locking support joint (23) is provided with a second protrusion (17) that engages with the first protrusion (5).

13. The scale-resistant rod-type oil pump according to any one of claims 10-12, characterized in that: The support cup (19) is fixed to the outside of the support spindle (12) by the cup seat ring and the cup pressure cap.

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