A device for centering the polished rod when replacing packing.

Abstract

A device for centering a polished rod during packing replacement includes: an annular fixing assembly, a pressure handle, and a locking plate. A centering pulley is installed inside the pressure handle head. In use, the pressure handle head is rotatably connected to the top of a protrusion on the annular fixing assembly. The polished rod to be centered passes through the hole formed by the opening of the pressure handle head and the centering pulley. Pressing down the pressure handle allows the centering pulley to further press and push the polished rod to complete the centering. The locking plate can be inserted into the gap between the polished rod and the protrusion when the polished rod is centered. The contact points between the device and the polished rod are all designed with arc surfaces, increasing the contact area and providing effective protection for the polished rod. In addition, the present invention does not apply all the force to the polished rod during the polished rod centering process, but designs the force points separately on the polished rod and the wellhead Christmas tree, which can effectively avoid large deformation and damage to the polished rod and the centering device due to excessive force.

Description

Technical fields:

[0001] This invention relates to the field of mechanical oil extraction technology, and in particular to a device for centering the polished rod when replacing packing. Background technology:

[0002] The most common mechanical oil extraction method currently used in crude oil production is the "three-pronged" extraction system: pumping unit, sucker rod, and pump. The pumping unit provides power, the sucker rod transmits power, and the pump draws crude oil to the surface. The polished rod is the uppermost member of the sucker rod; its upper end is connected to the pumping unit via a suspension cable, and its lower end is connected to the sucker rod via threads. The lower end of the sucker rod is connected to the pump piston via a tie rod. During operation, the polished rod is sealed to the outside environment by the sealing packing in the packing box, preventing oil, gas, and water from leaking out during the reciprocating motion of the polished rod. During production, due to the effects of well operations and the natural environment, the pumping unit foundation continuously subsides. Combined with the thermal expansion and contraction of metal equipment, this causes wellhead (packing box) misalignment. Existing methods for adjusting the pumping unit's central axis cannot achieve wellhead alignment. The constant up-and-down movement of the polished rod accelerates wellhead misalignment, thus requiring frequent packing replacement. Because the packing filler fits very tightly in the packing box, it is very difficult to remove and add it. Furthermore, the misalignment between the bare rod and the packing box further increases the difficulty of replacing the packing.

[0003] Currently, packing replacement operations suffer from problems such as high workload, low efficiency, and potential hazards. Specifically, each packing replacement requires shutting down the well, having operators climb into the wellhouse and push the polished rod in the opposite direction for alignment. In severe cases, methods such as wire binding or vehicle towing are necessary for correction. When space is limited, the wellhouse must be hoisted away for alignment, and 360° alignment is not possible without blind spots. Each packing replacement takes at least two hours. For sand and heavy oil wells, prolonged shutdown increases the risk of well sticking, posing a threat to subsequent production.

[0004] Utility model patent CN207686623U discloses a polished rod adjustment device for a pumping unit, which consists of three parts: a fixing sleeve, a support frame, and a straightening component. When the fixing sleeve is fitted onto the polished rod of the pumping unit, the U-shaped frame of the straightening component surrounds the polished rod, and the screw moves along the opening direction of the U-shaped frame to adjust the length of the screw extending out of the U-shaped frame, so as to abut against the polished rod and apply force to straighten the polished rod, thereby correcting the deviation of the polished rod when replacing packing. However, the device still has the following defects: 1) The structure is relatively complex; 2) The connection points between the fixed sleeve and the support frame, as well as between the support frame and the straightening component, are stress concentration points of the structural components. These weld points are also weak links of the metal structure, so the possibility of cracking and damage is very high; 3) Both force points of the tool are located on the optical rod. Due to the limitation of the tool size, the distance between the two action points is small. Therefore, the force required to straighten the optical rod is large. Assuming the offset during correction is L, the corresponding deformation is borne entirely by the optical rod, which causes greater damage to the optical rod and the various slender and thin parts of the tool are prone to deformation and damage; 4) When the U-shaped frame pushes the optical rod, the contact point with it is a straight edge. The pressure at the contact point is strong, which makes it easier to deform the hollow electrically heated optical rod. Summary of the Invention:

[0005] The purpose of this invention is to provide a relatively simple, robust and durable optical rod alignment device. With the help of this device, optical rod alignment can be completed quickly and accurately when replacing packing, so as to facilitate packing replacement, and damage to the optical rod and the device itself can be significantly reduced during the alignment process.

[0006] The technical solution of this invention is as follows:

[0007] A device for centering the polished rod when replacing packing, characterized in that it includes: an annular fixing assembly for fixing it to the packing box at the wellhead, as well as a pressure handle and a locking plate;

[0008] The pressure handle has a U-shaped forked head and a rod-shaped handle integrally connected to the head. The U-shaped opening of the head faces away from the handle. A pressure-adjusting pulley is installed inside the U-shaped opening of the head, and the axis of rotation of the pressure-adjusting pulley is perpendicular to the axis of the pressure handle. The upper end of the annular fixing assembly has a protrusion.

[0009] In the working state, the pressure handle clamps the top of the protrusion through the U-shaped opening of the handle head and is rotatably connected to the protrusion, allowing the pressure handle to rotate in the vertical plane with the connection point between the handle head and the protrusion as the center. At the same time, the optical rod to be aligned passes through the hole formed by the U-shaped opening of the handle head and the pressure pulley. The pressure pulley is close to the optical rod to be aligned, and the handle of the pressure handle is in an inclined upward state, so that before the handle is pressed down to a horizontal state, the pressure pulley can further press and push the optical rod. The locking piece can be inserted into the gap between the optical rod and the protrusion when the optical rod is in the aligned state, and forms a tight contact with both the optical rod and the protrusion.

[0010] Furthermore, the surface of the protrusion that contacts the locking plate is provided with a positive step, and the surface of the locking plate that contacts the protrusion is provided with an inverted step that can cooperate with the positive step; the surface of the locking plate that contacts the guide rod is a concave arc surface that can fit tightly against the surface of the guide rod.

[0011] Furthermore, the pressure pulley is a grooved pulley, with the arc-shaped groove on its side circumference matching the curvature of the surface of the smooth rod that it contacts.

[0012] Furthermore, the annular fixing assembly is composed of clamps and grips, both of which are semi-annular in shape, joined together. Bolt holes of completely corresponding size and position are opened on the mating surfaces of the clamps and grips. In the mating state, a fastening bolt passes through each pair of bolt holes to form a fixed connection.

[0013] Furthermore, the clamp and the gripper are provided with threaded holes facing the packing box at half the arc length; the protrusion is provided on the upper end face of the clamp or gripper at half the arc length; in the working state, a positioning bolt passes through each threaded hole, and the front end of the positioning bolt is tightly pressed against the surface of the packing box.

[0014] Furthermore, the top of the protrusion is provided with a vertically upward connecting part; in the connected state, the U-shaped opening of the pressure handle head is clamped on the connecting part, and the handle head and the connecting part are fixed by a pin through the area forming the clamping structure.

[0015] Based on this, the present invention provides a method for centering the optical rod using the aforementioned centering optical rod device when replacing packing, comprising the following steps:

[0016] 1) Fix the annular fixing component of the device to the outside of the wellhead packing box, and at the same time make the connecting part of the annular fixing component for connecting the pressure handle head on the circumference of the packing box the side closest to the polished rod and the packing box.

[0017] 2) Connect the pressure handle head to the protrusion of the annular fixing assembly, and at the same time make the light rod pass through the hole formed by the U-shaped opening of the handle head and the pressure pulley, with the pressure pulley close to the light rod. At this time, the handle of the pressure handle is in an inclined upward state.

[0018] 3) Press down the handle to make the pressure pulley press further against and push the guide rod, so that the guide rod is gradually centered;

[0019] 4) When the optical rod is aligned, insert the locking piece into the gap between the optical rod and the protrusion.

[0020] The polished rod alignment device of this invention features a simple, robust, and durable structure with virtually no weld points, avoiding the impact of high-temperature welding on material properties. More importantly, the contact points (such as locking plates and other stress points) between the device and the polished rod are all arc-shaped, increasing the contact area and effectively protecting the polished rod. Furthermore, it limits lateral displacement of the polished rod during alignment, enabling rapid and accurate alignment. Additionally, this invention does not apply all stress to the polished rod during alignment; instead, stress points are designed on both the polished rod and the wellhead Christmas tree. Assuming the total offset of the polished rod relative to the Christmas tree during alignment is L, this invention requires only an offset of L / 2 for both the polished rod and the Christmas tree. Since the polished rod and tie rod are typically hundreds of meters long, reducing the offset or deformation by half significantly reduces the corresponding stress, effectively preventing excessive deformation and damage to the polished rod and alignment device caused by excessive stress. Attached image description:

[0021] Figure 1 This is a side view of the overall structure of the optical rod centering device of the present invention in use.

[0022] Figure 2 This is a three-dimensional structural schematic diagram of the optical rod centering device of the present invention.

[0023] Figure 3 This is a top view of the handle.

[0024] Figure 4 This is a three-dimensional structural diagram of the ring-shaped fixing component.

[0025] Figure 5 This is a front view with the concave arc side of the clamp facing forward.

[0026] Figure 6 This is a front view with the convex arc side of the clamp as the front.

[0027] Figure 7 This is a schematic diagram of the three-dimensional structure of the locking plate.

[0028] Figure 8 This is a side view of the lock plate.

[0029] Figure 9 This is a top view of the locking plate.

[0030] The reference numerals in the figure represent the following components:

[0031] 1. Positioning bolt, 2. Clamp, 3. Smooth rod, 4. Pressure handle, 41. Handle head, 42. Handle handle, 5. Pressure pulley, 6. Pin, 7. Locking plate, 71. Inverted step, 72. Arc surface, 8. Fastening bolt, 9. Clamp, 10. Packing box, 11. Protrusion, 111. Positive step, 12. Connecting part, 13. Bolt hole, 14. Threaded hole. Detailed implementation method:

[0032] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0033] like Figures 1-3 As shown, the device for centering the polished rod when replacing packing is characterized by comprising: an annular fixing assembly for fixedly connecting to the packing box at the wellhead, and a pressure handle 4 and a locking plate 7; the pressure handle 4 has a U-shaped forked head 41 and a rod-shaped handle 42 integrally connected to the head, the U-shaped opening of the head 41 being opposite to the handle 42; a pressure-aligning pulley 5 (fixed pulley) is installed inside the U-shaped opening of the head 41, and the axis of rotation of the pressure-aligning pulley 5 is perpendicular to the axis of the pressure handle 4;

[0034] like Figures 4-6 As shown, the annular fixing assembly is composed of clamps 2 and clamps 9, both of which are semi-annular in shape, joined together. Bolt holes 13 of completely corresponding size and position are opened on the mating surfaces of the clamps 2 and clamps 9. In the mating state, fastening bolts 8 pass through each pair of bolt holes 13 to form a fixed connection.

[0035] Both the clamp 2 and the clamp 9 have threaded holes 14 facing the packing box 10 at half their arc length, so that the annular fixing assembly formed by the clamp 2 and the clamp 9 has a pair of opposing threaded holes 14 on its circumference. The protrusion 11 is provided on the upper end face of the clamp 2 or the clamp 9 at half its arc length. In this specific embodiment, the protrusion 11 is provided on the clamp 9, and the threaded holes 14 on the clamp 9 are located directly below the protrusion 11. In the working state, a positioning bolt 1 passes through each threaded hole 14, and the front end of the positioning bolt 1 is tightly pressed against the surface of the packing box 10.

[0036] like Figure 1 As shown, in the usage state, the pressure handle 4 clamps the top of the protrusion 11 through the U-shaped opening of the handle head 41 and is rotatably connected to the protrusion 11, allowing the pressure handle 4 to rotate in a vertical plane with the connection point between the handle head 41 and the protrusion 11 as the center. Simultaneously, the optical rod 3 to be aligned passes through the hole formed by the U-shaped opening of the handle head 41 and the alignment pulley 5. The alignment pulley 5 is close to the optical rod 3 to be aligned, and the handle 42 of the pressure handle 4 is in an upward-tilted state. This allows the alignment pulley 5 to further press and push the optical rod 3 before the handle 42 is pressed down to a horizontal state, thus aligning the optical rod 3. Figure 3 As shown, the pressure pulley 5 is a grooved pulley, and the arc-shaped groove on its side circumference matches the arc of the side surface of the light rod 3 that it contacts.

[0037] like Figure 1As shown, the locking piece 7 can be inserted into the gap between the light rod 3 and the protrusion 11 when the light rod 3 is in the centering state, and forms a tight contact with the light rod 3 and the protrusion 11 respectively.

[0038] like Figures 7-9 As shown, the surface of the protrusion 11 that contacts the locking plate 7 has a positive step 111, and the surface of the locking plate 7 that contacts the protrusion 11 has an inverted step 71 that can cooperate with the positive step 111. When the locking plate 7 and the protrusion 11 are tightly fitted, the inverted step 71 on the locking plate 7 presses against the positive step 111 of the protrusion 11. The surface of the locking plate 7 that contacts the guide rod 3 is a concave arc surface 72 that can be tightly fitted to the surface of the guide rod. The above design can form a more tightly fitted and relatively stable structure between the guide rod 3, the locking plate 7, and the protrusion 11. The arc surface design of the contact surface between the locking plate 7 and the guide rod 3 increases the contact area and effectively protects the guide rod, while also limiting the lateral displacement of the guide rod during the straightening process.

[0039] The locking plate 7 should be designed to fit precisely into the gap between the guide rod 3 and the protrusion 11 after the guide rod 3 is aligned, and to form a tight contact between the locking plate 7 and both sides of the guide rod 3 and the protrusion 11. For packing boxes of different sizes, the gap between the guide rod 3 and the protrusion 11 in the aligned state can be measured in advance, and a locking plate with a thickness that meets the requirements can be designed based on this size.

[0040] In this specific embodiment, the movable connection between the protrusion 11 and the handle 4 is as follows: the top of the protrusion 11 is provided with a vertically upward connecting part 12; in the connected state, the U-shaped opening of the handle head 41 is clamped on the connecting part 12, and the handle head 41 and the connecting part 12 are fixed by a pin 6 through the area forming the clamping structure.

[0041] The method of using the optical rod alignment device of the present invention specifically includes the following steps:

[0042] 1) Fix the annular fixing component of the device to the outside of the wellhead packing box, and at the same time, make the connecting part of the annular fixing component for connecting the pressure handle head on the circumference of the packing box the side closest to the polished rod and the packing box.

[0043] Specifically, the clamps 2 and 9, both semi-circular in shape, are joined together (forming a ring-shaped fixing assembly) and fixed to the outside of the packing box 10. Bolt holes 13 of completely corresponding size and position are opened on the mating surfaces of the clamps 2 and 9. Each pair of bolt holes 13 is filled with a fastening bolt 8 to form a fixed connection. When fixing the connection, the position of the clasp 9 (protrusion 11) on the circumference of the packing box is adjusted so that the connecting part 12 on the protrusion 11 is on the side of the circumference closest to the bare rod 3 and the packing box 10. After adjusting the position, two positioning bolts 1 are taken. One is inserted into the threaded hole 14 of the clamp 2 and tightened, and the other is inserted into the threaded hole 14 of the clasp 9 and tightened. The tops of the two positioning bolts 1 rest on the packing box and are positioned opposite each other, thereby fixing the ring-shaped fixing assembly to the packing box 10.

[0044] 2) Connect the handle head 41 of the pressure handle 4 to the protrusion 11 of the annular fixing assembly. When connecting, the U-shaped opening of the handle head 41 is clamped on the connecting part 12. The area forming the clamping structure is penetrated and fixed by the pin 6. At the same time as connecting, the light rod 3 passes through the hole formed by the U-shaped opening of the handle head 41 and the pressure pulley 5 and the pressure pulley 5 is close to the light rod 3. At this time, the handle 42 of the pressure handle 4 is in an inclined upward state.

[0045] 3) Press down the handle 42 of the pressure handle 4 so that the pressure handle 4 gradually becomes horizontal from the tilt. This process also causes the pressure pulley 5 to press further and push the light rod 3, so that the position of the light rod 3 gradually becomes centered.

[0046] 4) When the guide rod 3 is aligned, insert the locking piece 7 into the gap between the guide rod 3 and the protrusion 11. At this time, the locking piece forms a tight contact with the guide rod and the protrusion on both sides, which makes it easy to replace the packing.

[0047] The above-described specific embodiments are only used to illustrate the present invention. Any equivalent modifications made based on the technical solutions of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. A device for centering the polished rod when replacing packing, characterized in that... include: An annular fixing assembly, pressure handle, and locking plate are used to securely connect to the wellhead packing box. The pressure handle has a U-shaped forked head and a rod-shaped handle integrally connected to the head. The U-shaped opening of the head faces away from the handle. A pressure-adjusting pulley is installed inside the U-shaped opening of the head, and the axis of rotation of the pressure-adjusting pulley is perpendicular to the axis of the pressure handle. The upper end of the annular fixing assembly has a protrusion. The ring-shaped fixing assembly is composed of clamps and grips, both of which are semi-circular in shape, joined together. Bolt holes of completely corresponding size and position are opened on the mating surfaces of the clamps and grips. In the mating state, a fastening bolt passes through each pair of bolt holes to form a fixed connection. In the working state, the pressure handle clamps the top of the protrusion through the U-shaped opening of the handle head and is rotatably connected to the protrusion, allowing the pressure handle to rotate in the vertical plane with the connection point between the handle head and the protrusion as the center. At the same time, the optical rod to be aligned passes through the hole formed by the U-shaped opening of the handle head and the pressure pulley. The pressure pulley is close to the optical rod to be aligned, and the handle of the pressure handle is in an inclined upward state, so that before the handle is pressed down to a horizontal state, the pressure pulley can further press and push the optical rod. The locking piece can be inserted into the gap between the optical rod and the protrusion when the optical rod is in the aligned state, and forms a tight contact with both the optical rod and the protrusion.

2. The device for centering the optical rod according to claim 1, characterized in that: The surface of the protrusion that contacts the locking plate is provided with a positive step, and the surface of the locking plate that contacts the protrusion is provided with an inverted step that can cooperate with the positive step; the surface of the locking plate that contacts the guide rod is a concave arc surface that can fit tightly against the surface of the guide rod.

3. The device for centering the optical rod according to claim 1 or 2, characterized in that: The pressure pulley is a grooved pulley, with the arc-shaped groove on its side circumference matching the arc of the smooth rod surface it contacts.

4. The device for centering the optical rod according to claim 3, characterized in that: Both the clamp and the gripper have threaded holes facing the packing box at half the arc length; the protrusion is located on the upper end face of the clamp or gripper at half the arc length; in the working state, a positioning bolt passes through each threaded hole, and the front end of the positioning bolt is tightly pressed against the surface of the packing box.

5. The device for centering the optical rod according to claim 4, characterized in that: The top of the protrusion is provided with a vertically upward connecting part; in the connected state, the U-shaped opening of the pressure handle head is clamped on the connecting part, and the handle head and the connecting part are fixed by a pin through the area forming the clamping structure.

6. A method for aligning a light rod using the light rod alignment device according to claim 1, characterized in that... Includes the following steps: 1) Fix the annular fixing component of the device to the outside of the wellhead packing box, and at the same time, make the connecting part of the annular fixing component for connecting the pressure handle head on the circumference of the packing box the side closest to the polished rod and the packing box. 2) Connect the pressure handle head to the protrusion of the annular fixing assembly, and at the same time make the light rod pass through the hole formed by the U-shaped opening of the handle head and the pressure pulley, with the pressure pulley close to the light rod. At this time, the handle of the pressure handle is in an inclined upward state. 3) Press down the handle to make the pressure pulley press further against and push the guide rod, so that the guide rod is gradually centered; 4) When the optical rod is aligned, insert the locking piece into the gap between the optical rod and the protrusion.

Images