Plunger type oil well pump for oil field exploitation

Abstract

The invention relates to the technical field of oil well pumps, in particular to a plunger type oil well pump for oil field exploitation. Comprising a pump cylinder, a fixed valve seat is detachably connected to the lower end of the pump cylinder, a fixed valve is placed in the fixed valve seat, a traveling valve seat is slidably connected to the interior of the pump cylinder in a sealed mode, a traveling valve is placed in the traveling valve seat, an installation cylinder is slidably connected to the interior of the traveling valve seat, and a lower positioning frame is fixedly connected to the inner side of the installation cylinder; the lower positioning frame makes contact with the lower portion of the traveling valve, and the mounting cylinder drives the traveling valve to move through the lower positioning frame. The installation cylinder actively controls the traveling valve to move and controls the traveling valve to actively relieve blocking of the traveling valve seat in the down-stroke period, so that when crude oil containing natural gas is extracted, the pressure difference needed by opening of the traveling valve seat is reduced, the invalid stroke generated due to gas compression is shortened, the effective liquid drainage stroke length of the plunger is prolonged, and the safety performance of the plunger is improved. And the fullness coefficient and the oil pumping efficiency of the pump are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil well pumps, and particularly relates to a plunger type oil well pump for oil field development. BACKGROUND

[0002] As a core equipment for lifting well fluid in the process of oil and gas development, the oil well pump is usually composed of a reciprocating plunger (also known as a pump body) and a pump seat fixedly installed at the bottom of the oil pipe. The plunger is assembled with a traveling valve, and the pump seat contains a pump barrel and a fixed valve, which cooperatively complete the functions of inhaling and lifting liquid. In the upstroke, the plunger moves upward, the traveling valve is closed, the pressure in the pump cavity is lowered, the fixed valve is opened under the action of the pressure difference, and the formation fluid is sucked into the pump cavity; in the downstroke, the plunger moves downward, the pressure in the pump cavity rises, the fixed valve is closed and the traveling valve is opened, and the liquid is pushed into the oil pipe above the plunger, so that periodic lifting is realized.

[0003] However, in actual production, the natural gas dissolved in crude oil will affect the efficiency of the oil well pump; the gas entering the pump along with the crude oil will occupy part of the pump cavity volume due to compressibility, reducing the amount of liquid entering; at the same time, the gas responds slowly to pressure changes, which will delay the timely opening and closing of the fixed valve and the traveling valve, reduce the fullness of the pump cavity, and further lead to a decrease in the efficiency of oil pumping. SUMMARY

[0004] The present application provides a plunger type oil well pump for oil field development to overcome the shortcoming of the oil well pump in the prior art, i.e., the efficiency of oil pumping is reduced due to the influence of gas when the oil well pump pumps crude oil containing natural gas.

[0005] The technical scheme is as follows: a plunger type oil well pump for oil field development, comprising: a pump barrel, a fixed valve seat being detachably connected to the lower end of the pump barrel, a fixed valve being placed in the fixed valve seat, a traveling valve seat being sealingly and slidably connected in the pump barrel, a traveling valve being placed in the traveling valve seat, an installation cylinder being slidably connected in the traveling valve seat, a lower positioning frame being fixedly connected to the inner side of the installation cylinder, the lower positioning frame being in contact with the lower part of the traveling valve, the installation cylinder driving the traveling valve to move through the lower positioning frame, so as to control the sealing state of the traveling valve to the traveling valve seat, the traveling valve seat being provided with a containing hole, and a detection mechanism being arranged in the containing hole and used for detecting the pressure on both sides of the traveling valve seat and providing power for the sliding of the installation cylinder.

[0006] Further, the detection mechanism comprises an upper sliding column and a lower sliding column, both of which are sealingly and slidably connected in the accommodating hole, two positioning rings are fixedly connected in the accommodating hole, both of which are located between the upper sliding column and the lower sliding column, and both of the two positioning rings are used for limiting the limit positions of the upper sliding column and the lower sliding column, the accommodating hole, the upper sliding column and the lower sliding column jointly form an accommodating cavity, the accommodating cavity stores damping liquid, the upper sliding column and the lower sliding column are sealingly and slidably connected with a connecting rod, the connecting rod is fixedly connected with the mounting cylinder through a connecting rod, the connecting rod is fixedly connected with a connecting disc, the connecting disc is located between the upper sliding column and the lower sliding column, the connecting disc is provided with a flow hole for the flow of damping liquid, the upper sliding column is provided with a second elastic member, the end of the second elastic member is fixedly connected with the connecting disc, and the second elastic member is used for providing power for the movement of the floating valve relative to the floating valve seat.

[0007] Further, the first rotating rod of the lower positioning ring is fixedly connected with a first elastic member, the end of the first elastic member is fixedly connected with the lower sliding column, and the first elastic member is used for pulling the lower sliding column to move.

[0008] Further, the mounting frame is fixedly connected with the position close to the upper sliding column of the floating valve seat, the mounting frame is rotatably connected with a swing block, the swing block is used for limiting the connecting rod, the torsional spring is fixedly connected between the swing block and the mounting frame, the top block is fixedly connected with the position corresponding to the swing block on the upper side of the upper sliding column, and the top block is used for pressing the swing block to swing.

[0009] Further, the connecting rod is slidably connected with a transmission rod, the transmission rod is fixedly connected with a damping disc, the damping disc is sleeved on the outer side of the connecting rod, the damping disc is rotatably connected with a second rotating rod, the second rotating rod of the damping disc is fixedly connected with the second elastic member, and the end of the second elastic member is fixedly connected with the connecting disc.

[0010] Further, the connecting rod is fixedly connected with two symmetrically distributed elastic sheets close to the upper sliding column, the elastic sheets are used for abutting against the upper sliding column and limiting the connecting rod, the transmission rod is fixedly connected with a convex point close to the two elastic sheets, and the convex point is used for pressing the corresponding elastic sheet.

[0011] Further, the upper parts of the opposite sides of the two elastic sheets are provided with arc surfaces, and the convex points are semispherical protrusions.

[0012] Further, the maximum distance between the two convex points is greater than the minimum distance between the two elastic sheets.

[0013] Further, the inner side of the mounting cylinder is fixed with an upper positioning frame, which is above the center of the floating valve ball.

[0014] Further, the lower positioning frame and the upper positioning frame are of the same shape, and the distance between the lower positioning frame and the center of the floating valve ball is not equal to the distance between the upper positioning frame and the center of the floating valve ball in the axial direction of the pump cylinder.

[0015] In general, compared with the prior art, the above technical scheme of the present application can achieve the following beneficial effects: the present application actively controls the movement of the floating valve through the mounting cylinder, actively releases the blockage of the floating valve seat during the downstroke, thereby reducing the pressure difference required for opening the floating valve seat when extracting crude oil containing natural gas, shortening the invalid stroke caused by gas compression, prolonging the effective displacement stroke length of the plunger, and improving the fullness coefficient and oil extraction efficiency of the pump.

[0016] During the downstroke, the proportion of gas in the pump cavity is determined according to the pressure difference change rate on both sides of the floating valve seat, so as to control the movement distance of the connecting rod, i.e. the size of the flow area between the floating valve and the floating valve seat after the floating valve releases the blockage of the floating valve seat. Thus, for crude oil with high gas content, the flow area between the floating valve and the floating valve seat is reduced to reduce the impact and vibration caused by the violent flow of gas-liquid mixture, which is beneficial to the stable operation of the equipment.

[0017] The upper positioning frame limits the movement of the floating valve, and then keeps the flow area between the floating valve and the floating valve seat stable after the floating valve releases the limit of the floating valve seat, preventing the floating valve from moving due to the fluid drag generated by the flow of gas-liquid mixture, which is beneficial to the stable operation of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the present application; Figure 2 It is a schematic diagram of the three-dimensional structure of the mounting cylinder and the positioning ring of the present application; Figure 3 It is a schematic diagram of the three-dimensional structure of the lower positioning frame and the connecting rod of the present application; Figure 4 It is a schematic diagram of the three-dimensional structure of the connecting disc and the damping disc of the present application; Figure 5 It is a schematic diagram of the three-dimensional structure of the mounting frame and the swing block of the present application; Figure 6 It is a schematic diagram of the three-dimensional structure of the connecting rod and the damping disc of the present application; Figure 7 It is a schematic diagram of the three-dimensional structure of the transmission rod and the elastic sheet of the present application.

[0019] In the above drawings: 1, pump barrel, 2, fixed valve seat, 3, fixed valve, 4, movable valve seat, 401, accommodating hole, 402, accommodating cavity, 5, movable valve, 6, mounting cylinder, 7, lower positioning frame, 8, upper sliding column, 9, lower sliding column, 10, positioning ring, 11, connecting rod, 12, connecting disc, 121, flow-through hole, 13, first elastic member, 14, mounting frame, 15, swing block, 16, top block, 17, transmission rod, 18, damping disc, 19, second elastic member, 20, elastic sheet, 21, protruding point, 22, upper positioning frame. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application.

[0021] Examples of the described embodiments are shown in the drawings, in which the same or similar notations are used to denote the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application. Embodiment 1

[0022] The present embodiment discloses a plunger type oil pumping pump for oil field development, which is used to solve the problem of reduced oil pumping efficiency due to the influence of gas when the oil pumping pump extracts crude oil containing natural gas in the prior art.

[0023] It should be understood that the state of each part in the drawings is shown when the upper stroke is performed; the apparent weight in this document refers to the sum of the vectors of the weight and the buoyancy of the corresponding part in the crude oil.

[0024] Referring to Figures 1 to 3The utility model provides a kind of plunger type oil well pump for oil field exploitation, comprising: pump barrel 1, the lower end of pump barrel 1 is detachably connected with fixed valve seat 2, fixed valve seat 2 is placed with fixed valve 3, pump barrel 1 is sealed slidingly connected with movable valve seat 4, movable valve seat 4 is placed with movable valve 5, pump barrel 1, fixed valve seat 2, fixed valve 3 and movable valve 5 are existing parts, not additional show in drawing, and the surface of pump barrel 1, fixed valve seat 2, fixed valve 3 and movable valve 5 is provided with polyaryletherketone coating, to enhance the corrosion resistance of the device;Movable valve seat 4 is slidingly connected with mounting cylinder 6, the inner diameter of mounting cylinder 6 is greater than the outer diameter of movable valve 5, the inner side of mounting cylinder 6 is fixedly connected with lower positioning frame 7, lower positioning frame 7 is in contact with the lower part of movable valve 5, mounting cylinder 6 moves movable valve 5 by lower positioning frame 7, to control the plugging state of movable valve 5 to movable valve seat 4, movable valve seat 4 is provided with accommodating hole 401, accommodating hole 401 can be multiple annular distribution, to provide circumferentially uniform force for mounting cylinder 6, accommodating hole 401 is provided with detection mechanism for detecting the pressure on the upper and lower sides of movable valve seat 4 and providing power for the sliding of mounting cylinder 6.

[0025] The above setting can realize that movable valve 5 is actively controlled to move by mounting cylinder 6, movable valve 5 actively releases the plugging of movable valve seat 4 during lower stroke, so that when extracting crude oil containing natural gas, the pressure difference required for the opening of movable valve seat 4 is reduced, the invalid stroke generated due to gas compression is shortened, the effective liquid discharge stroke length of plunger is prolonged, and the fullness coefficient and oil pumping efficiency of the pump are improved.

[0026] Referring to Figures 2 to 4 The detection mechanism comprises: upper sliding column 8 and lower sliding column 9, which are sealingly and slidingly connected to the upper and lower positions in accommodating hole 401, respectively, two positioning rings 10 are fixedly connected in accommodating hole 401, and the two positioning rings 10 are located between upper sliding column 8 and lower sliding column 9, the upper positioning ring 10 is used to limit the lower limit position of upper sliding column 8, and the lower positioning ring 10 is used to limit the upper limit position of lower sliding column 9; accommodating hole 401, upper sliding column 8 and lower sliding column 9 jointly form accommodating cavity 402, damping liquid is stored in accommodating cavity 402, and the damping liquid can be selected from silicone oil or hydraulic oil damping medium; upper sliding column 8 and lower sliding column 9 are sealingly and slidingly connected with connecting rod 11, connecting rod 11 is fixedly connected with mounting cylinder 6 through connecting rod, connecting rod 11 is fixedly connected with connecting disc 12, connecting disc 12 is located between upper sliding column 8 and lower sliding column 9, connecting disc 12 is provided with flow-through hole 121, flow-through hole 121 is used to flow damping liquid, so that connecting disc 12 has small resistance during movement in accommodating cavity 402; upper sliding column 8 is provided with second elastic member 19, second elastic member 19 is selected from constant force spring, the end of second elastic member 19 is fixedly connected with connecting disc 12, and second elastic member 19 is used to provide power for the movement of movable valve 5 relative to movable valve seat 4.

[0027] The above arrangement can be realized by penetrating the traveling valve seat 4 through the accommodating hole 401, so that the pressure difference on both sides of the traveling valve seat 4 is reflected on the positions of the upper and lower sliding columns 8 and 9 in the accommodating hole 401, and then during the downstroke, when the upper and lower sliding columns 8 and 9 sense that the pressure difference on both sides of the traveling valve seat 4 approaches zero, the traveling valve 5 is controlled to move upward to open the traveling valve seat 4, so that the traveling valve seat 4 can be opened in advance and stably, reducing the alternating load and prolonging the effective liquid discharge stroke length.

[0028] Referring to Figure 4 , the lower positioning ring 10 is rotatably connected with a first rotating rod, the first rotating rod is fixedly connected with a first elastic member 13, the end of the first elastic member 13 is fixedly connected with the lower sliding column 9, and the first elastic member 13 is used to pull the lower sliding column 9 to move. The first elastic member 13 is selected as a constant force spring, and the first elastic member 13 shown in the figure is in a state of stretching force storage, which is used to reduce the interference force (here, the interference force means the apparent weight of the upper and lower sliding columns 8 and 9, and the elastic force of the second elastic member 19) when the upper and lower sliding columns 8 and 9 sense the pressure difference on both sides of the traveling valve seat 4. The pulling force provided by the first elastic member 13 is equal to the sum of the apparent weight of the upper and lower sliding columns 8 and 9 and the pulling force provided by the second elastic member 19, so that the movement of the upper and lower sliding columns 8 and 9 in the accommodating hole 401 is only affected by the pressure difference on both sides of the traveling valve seat 4.

[0029] It should be noted that in the embodiment, the arrangement relationship between the upper sliding column 8 and the second elastic member 19 can be regarded as that the upper sliding column 8 is rotatably connected with a second rotating rod, and the second rotating rod is fixedly connected with the second elastic member 19.

[0030] Referring to Figures 3 to 5 , the position close to the upper sliding column 8 of the traveling valve seat 4 is fixedly connected with a mounting frame 14, the mounting frame 14 is rotatably connected with two symmetrical swing blocks 15, the two swing blocks 15 are respectively located on both sides of the connecting rod 11, a torsional spring is fixedly connected between the swing block 15 and the mounting frame 14, the swing block 15 is composed of a cylindrical part, a square block part and a rotating shaft, initially, the cylindrical part of the swing block 15 abuts against the connecting rod 11, and the connecting rod 11 is unidirectionally limited by the friction force between them, limiting the upward movement of the connecting rod 11, the upper side of the upper sliding column 8 is fixedly connected with a top block 16 corresponding to the swing block 15, and the top block 16 is used to press the square block part of the swing block 15 to swing the swing block 15, so as to control the limiting state of the swing block 15 to the connecting rod 11.

[0031] The above arrangement can achieve that the position of the connecting rod 11 is limited by the swing block 15, so that the position of the connecting rod 11 is stable during the movement of the upper sliding column 8 and the lower sliding column 9, until the upper sliding column 8 and the lower sliding column 9 move to the limit position, then the swing block 15 releases the limitation on the connecting rod 11, so that the connecting rod 11 drives the floating valve 5 to move upward to open the floating valve seat 4.

[0032] Workflow: the relative position relationship of all parts in the floating valve seat 4 during the upstroke is shown in the figure, and the subsequent action after the upstroke is completed and the downstroke begins is described.

[0033] Downstroke: the floating valve seat 4 moves downward, and the fixed valve 3 moves downward under the action of gravity and blocks the fixed valve seat 2. During this process, the pressure in the pump cavity (the pump cavity refers to the chamber between the fixed valve seat 2 and the floating valve seat 4) gradually increases, so that the pressure difference between the upper and lower sides of the floating valve seat 4 gradually decreases. At this time, the upper sliding column 8 and the lower sliding column 9 are subjected to the force provided by the pressure difference (the first force, which is downward at the beginning of the downstroke), the tension of the first elastic member 13 (the second force), the tension of the second elastic member 19 (the third force), and the apparent weight of the upper sliding column 8 and the lower sliding column 9 (the fourth force). However, the second force, the third force, and the fourth force will be offset to zero during the movement of the upper sliding column 8 and the lower sliding column 9 relative to the floating valve seat 4.

[0034] After the pressure on the lower side of the floating valve seat 4 begins to be greater than that on the upper side (this paragraph describes the action of the parts with the floating valve seat 4 as the reference), the upper sliding column 8 and the lower sliding column 9 move upward. During the upward movement, the upper sliding column 8 stretches the second elastic member 19. At this time, the connecting rod 11 is limited by the swing block 15, and the second elastic member 19 is stretched. At the same time, the upper sliding column 8 drives the top block 16 to move upward, so that the distance between the top block 16 and the corresponding swing block 15 gradually decreases. Finally, when the lower sliding column 9 contacts the lower positioning ring 10, the upper sliding column 8 moves to the upper limit position. At this time, the top block 16 pushes the corresponding swing block 15 to swing, so that the swing block 15 loses contact with the connecting rod 11 and releases the limitation on the connecting rod 11. The connecting rod 11 moves upward under the action of the tension of the second elastic member 19. The connecting rod 11 drives the installation cylinder 6, the lower positioning frame 7, and the floating valve 5 to move upward together, so that the floating valve 5 releases the blockage of the floating valve seat 4. In this way, during the downstroke, when the pressure on the lower side of the floating valve seat 4 begins to be greater than that on the upper side, the floating valve seat 4 is opened, without waiting for the pressure difference between the two sides of the floating valve seat 4 to increase to a sufficient degree to push the floating valve 5 to move upward, so that the floating valve seat 4 can be opened in advance, thereby prolonging the effective liquid discharge stroke length.

[0035] At the end of the downstroke, the pressure difference on both sides of the traveling valve seat 4 is zero, the traveling valve 5 moves down under the action of gravity, and the traveling valve 5 drives the connecting rod 11 to move down through the lower positioning frame 7 and the mounting cylinder 6, the connecting rod 11 drives the upper sliding column 8 to move down through the connecting disc 12 and the second elastic element 19, the first elastic element 13 is stretched, the upper sliding column 8 drives the top block 16 to release the extrusion of the swing block 15, and the swing block 15 re-contacts the connecting rod 11 under the action of the torsional spring. Finally, all parts in the traveling valve seat 4 return to the state shown in the drawing. Example 2

[0036] This embodiment is further optimized on the basis of example 1.

[0037] When oil production operation is performed on an oil well with high gas content, due to the presence of gas, the gas is compressed during the downstroke, and when the traveling valve is opened, the gas-liquid mixture flows rapidly, which can cause liquid impact on the traveling valve, the tubing, the polished rod and other parts and cause vibration, thereby causing additional damage.

[0038] Referring to Figures 2 to 4 and Figure 6 , the connecting rod 11 is slidably connected with a transmission rod 17, the transmission rod 17 is of elastic metal material, which facilitates embedding the transmission rod 17 into the connecting rod 11; the transmission rod 17 is fixedly connected with a damping disc 18, the damping disc 18 is sleeved outside the connecting rod 11, the inner diameter of the damping disc 18 is larger than the outer diameter of the connecting rod 11, that is, there is an annular gap between the damping disc 18 and the connecting rod 11 for the damping liquid to flow; the damping disc 18 is rotationally connected with a second rotating rod, and the second rotating rod is fixedly connected with a second elastic element 19.

[0039] The above arrangement can realize that, during the downstroke, the proportion of gas in the pump cavity is judged according to the change speed of the pressure difference on both sides of the traveling valve seat 4, so as to control the moving distance of the connecting rod 11, that is, to control the size of the flow area between the traveling valve 5 and the traveling valve seat 4 after the traveling valve 5 unblocks the traveling valve seat 4. In this way, for crude oil with high gas content, the flow area between the traveling valve 5 and the traveling valve seat 4 is reduced, so as to reduce the impact and vibration caused by the violent flow of the gas-liquid mixture, which is beneficial to the stable operation of the equipment.

[0040] Work flow: during the upstroke, the upper sliding column 8 and the lower sliding column 9 are both at the lower limit position, and are subjected to the first force brought by the pressure difference, the second force provided by the first elastic element 13, the third force provided by the second elastic element 19 (at this time, the force is zero), and the fourth force brought by the weight. Since the first force downward is greater than the second force upward, the upper sliding column 8 and the lower sliding column 9 remain stationary at the lower limit position.

[0041] During the downstroke (the movement of the parts will be described with reference to the traveling valve seat 4), the first force gradually changes from downward to upward, causing the upper sliding column 8 and the lower sliding column 9 to move upward (during this process, the second, third, and fourth forces cancel each other out). The damping fluid in the accommodating cavity 402 moves upward as a whole. The damping fluid located below the damping disk 18 in the accommodating cavity 402 needs to pass through the annular gap between the damping disk 18 and the connecting rod 11 to flow to the upper side of the damping disk 18. During this process, a portion of the damping fluid passes through the damping disk 18 and moves to the upper side of the damping disk 18, while the remaining damping fluid pushes the damping disk 18 upward, increasing the distance between the damping disk 18 and the connecting disk 12, stretching the second elastic element 19 and storing its force.

[0042] During the downward movement of the traveling valve seat 4, if the gas content in the pump chamber is high, the overall compressibility of the gas-liquid mixture in the pump chamber is high. Therefore, the pressure rise rate in the pump chamber is slower during the downward movement of the traveling valve seat 4, meaning the pressure difference between the two sides of the traveling valve seat 4 increases more slowly. This results in the upper sliding column 8 and the lower sliding column 9 having smaller accelerations compared to the moving traveling valve seat 4. Consequently, the time required for the upper sliding column 8 and the lower sliding column 9 to move from the lower limit position to the upper limit position is longer. Meanwhile, the force stored in the second elastic element 19 is transferred to the swing block. The longer the time between the release of the limiting position of the connecting rod 11, the shorter the total upward movement distance of the damping disc 18. Consequently, after the connecting rod 11 is released from its limiting position and begins to move, the movement distance of the connecting rod 11 is shorter. This results in a shorter movement distance of the moving valve 5 and a smaller flow area between the moving valve seat 4 and the moving valve 5. Thus, for gas-liquid mixtures with high gas content, when the moving valve seat 4 is opened, the flow area between the moving valve seat 4 and the moving valve 5 is actively reduced, thereby reducing the impact and vibration caused by the flow of the gas-liquid mixture. Example 3

[0043] This embodiment is a further optimization based on embodiment 2.

[0044] See Figure 6 and Figure 7 Two symmetrically distributed elastic plates 20 are fixed to the upper part of the connecting rod 11. The upper sides of the two elastic plates 20 are provided with arc surfaces. The elastic plates 20 are used to abut against the upper sliding column 8 and limit the connecting rod 11. The upper left and right sides of the transmission rod 17 are fixed with protrusions 21. The protrusions 21 are hemispherical protrusions. The protrusions 21 are used to squeeze the corresponding elastic plates 20. The maximum distance between the two protrusions 21 is greater than the minimum distance between the two elastic plates 20.

[0045] See Figure 3 An upper positioning frame 22 is fixedly connected to the inner side of the mounting cylinder 6. The upper positioning frame 22 is located above the center of the moving valve 5. The lower positioning frame 7 and the upper positioning frame 22 are used together to limit the position of the moving valve 5.

[0046] The above settings can restrict the movement of the movable valve 5 by relying on the upper positioning frame 22, and thus maintain the stability of the flow area between the movable valve 5 and the movable valve seat 4 after the movable valve 5 releases its restriction on the movable valve seat 4, preventing the movable valve 5 from moving due to the fluid drag generated by the flow of the gas-liquid mixture, which is conducive to the stable operation of the equipment.

[0047] See Figure 3 The lower positioning frame 7 and the upper positioning frame 22 have the same shape. In the axial direction of the pump cylinder 1, the distance between the lower positioning frame 7 and the center of the floating valve 5 is not equal to the distance between the upper positioning frame 22 and the center of the floating valve 5. This allows the floating valve 5 to wobble and roll slightly between the lower positioning frame 7 and the upper positioning frame 22, thus avoiding the floating valve 5 from contacting the floating valve seat 4 at the same position and maintaining the effective number of times the floating valve 5 seals the floating valve seat 4.

[0048] Work process: Repeat the process of embodiment 2. When the damping disk 18 moves upward, the damping disk 18 drives the protrusion 21 to move upward through the transmission rod 17. The protrusion 21 loses contact with the elastic plate 20. The elastic plate 20 swings under its own elasticity and loses contact with the upper sliding column 8.

[0049] When the swing block 15 releases the restriction on the connecting rod 11, the second elastic element 19 drives the connecting rod 11, the connecting plate 12 and the elastic plate 20 to move upward, while the damping plate 18 remains stationary under the action of fluid damping, so that the distance between the damping plate 18 and the connecting plate 12 decreases until the distance between the damping plate 18 and the connecting plate 12 decreases to the initial distance. Then, the elastic plate 20 re-contacts the corresponding protrusion 21 and is squeezed by the protrusion 21 to re-contact the upper sliding column 8. In this way, the friction between the elastic plate 20 and the upper sliding column 8 restricts the upward movement of the connecting rod 11.

[0050] When the traveling valve seat 4 opens, as the gas-liquid mixture flows (the gas in the pump chamber is located at the top of the pump chamber due to buoyancy), the proportion of gas in the pump chamber gradually decreases. Eventually, all the gas-liquid mixture located at the top of the pump chamber is discharged. Subsequently, the traveling valve seat 4 continues to move downward, and the crude oil in the pump chamber flows out through the gap between the traveling valve seat 4 and the traveling valve 5. The crude oil is a pure liquid, and its fluid drag force is greater than that of the gas-liquid mixture. In this case, the fluid drag force drives the traveling valve 5 to move upward, increasing the flow area between the traveling valve seat 4 and the traveling valve 5. The traveling valve 5 drives the connecting rod 11 to move upward through the mounting cylinder 6 and the upper positioning frame 22. The connecting rod 11 drives the elastic plate 20, the protrusion 21, the transmission rod 17, the connecting plate 12, and the damping plate 18 to gradually move upward. Thus, after the gas-liquid mixture in the pump chamber is emptied, the fluid drag force overcomes the friction between the elastic plate 20 and the upper sliding column 8, increasing the flow area between the traveling valve seat 4 and the traveling valve 5.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A plunger-type oil pump for oilfield development, comprising: A pump cylinder (1) is detachably connected to a fixed valve seat (2) at its lower end. A fixed valve (3) is placed inside the fixed valve seat (2). A sliding valve seat (4) is slidably connected inside the pump cylinder (1). A sliding valve (5) is placed inside the sliding valve seat (4). The feature is that an installation cylinder (6) is slidably connected inside the sliding valve seat (4). A lower positioning frame (7) is fixedly connected to the inner side of the installation cylinder (6). The lower positioning frame (7) contacts the lower part of the sliding valve (5). The installation cylinder (6) drives the sliding valve (5) to move through the lower positioning frame (7) to control the blocking state of the sliding valve seat (4) by the sliding valve (5). The sliding valve seat (4) is provided with a receiving hole (401). A detection mechanism is provided inside the receiving hole (401) for detecting the pressure on the upper and lower sides of the sliding valve seat (4) and providing power for the sliding of the installation cylinder (6).

2. The plunger-type oil pump for oilfield development according to claim 1, characterized in that, The testing institutions include: The upper sliding column (8) and the lower sliding column (9) are both sealed and slidably connected within the receiving hole (401). Two positioning rings (10) are fixedly connected within the receiving hole (401). The two positioning rings (10) are located between the upper sliding column (8) and the lower sliding column (9). The two positioning rings (10) are used to limit the extreme positions of the upper sliding column (8) and the lower sliding column (9), respectively. The receiving hole (401), the upper sliding column (8), and the lower sliding column (9) together form a receiving cavity (402). The receiving cavity (402) contains damping fluid. The upper sliding column (8) and the lower sliding column (9) are sealed together. A connecting rod (11) is slidably connected to the mounting cylinder (6) via a connecting rod. A connecting plate (12) is fixedly connected to the connecting rod (11). The connecting plate (12) is located between the upper sliding column (8) and the lower sliding column (9). The connecting plate (12) is provided with a flow hole (121) for supplying damping fluid. The upper sliding column (8) is provided with a second elastic element (19). The end of the second elastic element (19) is fixedly connected to the connecting plate (12). The second elastic element (19) is used to provide power for the movement of the floating valve (5) relative to the floating valve seat (4).

3. The plunger-type oil pump for oilfield development according to claim 2, characterized in that, A first rotating rod is rotatably connected to the positioning ring (10) on the lower side. The first rotating rod of the positioning ring (10) is fixedly connected to a first elastic element (13). The end of the first elastic element (13) is fixedly connected to the sliding column (9). The first elastic element (13) is used to pull the sliding column (9) to move.

4. A plunger-type oil pump for oilfield development according to claim 2, characterized in that, The moving valve seat (4) is fixedly connected to a mounting bracket (14) near the upper sliding column (8). The mounting bracket (14) is rotatably connected to a swing block (15). The swing block (15) is used to limit the connecting rod (11). A torsion spring is fixedly connected between the swing block (15) and the mounting bracket (14). A top block (16) is fixedly connected to the upper side of the upper sliding column (8) at a position corresponding to the swing block (15). The top block (16) is used to squeeze the swing block (15) so that the swing block (15) swings.

5. A plunger-type oil pump for oilfield development according to claim 4, characterized in that, A transmission rod (17) is slidably connected inside the connecting rod (11). A damping disc (18) is fixedly connected to the transmission rod (17). The damping disc (18) is sleeved on the outside of the connecting rod (11). A second rotating rod is rotatably connected to the damping disc (18). The second rotating rod of the damping disc (18) is fixedly connected to the second elastic element (19). The end of the second elastic element (19) is fixedly connected to the connecting disc (12).

6. A plunger-type oil pump for oilfield development according to claim 4, characterized in that, Two symmetrically distributed elastic plates (20) are fixed to the connecting rod (11) near the upper sliding column (8). The elastic plates (20) are used to abut against the upper sliding column (8) and limit the connecting rod (11). The transmission rod (17) is fixed with protrusions (21) near the two elastic plates (20). The protrusions (21) are used to squeeze the corresponding elastic plates (20).

7. A plunger-type oil pump for oilfield development according to claim 6, characterized in that, Both elastic sheets (20) have an arc surface on their upper parts facing each other, and the protrusion (21) is a hemispherical protrusion.

8. A plunger-type oil pump for oilfield development according to claim 6, characterized in that, The maximum distance between the two protrusions (21) is greater than the minimum distance between the two elastic sheets (20).

9. A plunger-type oil pump for oilfield development according to claim 2, characterized in that, An upper positioning frame (22) is fixedly connected to the inner side of the mounting cylinder (6). The upper positioning frame (22) is located above the center of the movable valve (5). The lower positioning frame (7) and the upper positioning frame (22) are used together to limit the position of the movable valve (5).

10. A plunger-type oil pump for oilfield development according to claim 9, characterized in that, The lower positioning frame (7) has the same shape as the upper positioning frame (22). In the axial direction of the pump cylinder (1), the distance between the lower positioning frame (7) and the center of the floating valve (5) is not equal to the distance between the upper positioning frame (22) and the center of the floating valve (5).

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