Anti-sanding oil well pump for oil extraction

Abstract

The invention relates to the technical field of oil well pumps, in particular to an anti-sanding oil well pump for oil extraction. When a plunger of the oil well pump reciprocates in a pump cylinder, gravels in crude oil can enter the space between the plunger and the pump cylinder and scratch the surfaces of the plunger and the pump cylinder, and therefore the working efficiency of the oil well pump is reduced. Comprising a pump cylinder; the fixed valve cover is in threaded connection with the pump cylinder; the sliding valve cover is connected into the pump cylinder in a sliding mode, the sliding valve cover is fixedly connected with a sucker rod, a traveling valve is arranged in the sliding valve cover, a fixed valve is arranged in the fixed valve cover, and guide grooves distributed in the circumferential direction at intervals are formed in the lower portion of the sliding valve cover. The guide groove is matched with the temporary storage cavity, the flowing state of sand-containing crude oil is optimized according to the Poiseuille law principle, gravel near the sliding valve cover and the pump cylinder tends to flow along the guide groove in the oil extraction process, the probability that the gravel enters gaps is reduced, abrasion is reduced, and the service life of the sliding valve cover and the service life of the pump cylinder are prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of oil well pumps, in particular to an anti-sand wear oil well pump for oil production. Background Art

[0002] In the process of oilfield exploitation, the oil well pump is the core lifting equipment, and its operating efficiency directly affects the crude oil exploitation effect. However, during drilling and oil pumping operations, due to the unstable formation structure or the failure of the exploitation equipment to effectively prevent the entry of gravel, the gravel will be brought into the oil well pump along with the crude oil. Once the gravel enters the oil well pump, it will cause wear on the parts of the equipment, among which the most serious is the wear between the plunger assembly and the pump barrel: Specifically, when the plunger of the oil well pump reciprocates in the pump barrel, the sand will inevitably enter the tiny gap between the plunger and the pump barrel. These sand particles will scratch the surface of the plunger and the pump barrel during the movement, causing material peeling, and then gradually widening the gap between the two. The expansion of the gap will not only reduce the working efficiency of the oil well pump, but also increase the operating load of the equipment. When the wear is more serious, the oil well pump needs to be shut down for maintenance, which will affect the normal exploitation progress and economic benefits of the oil field. Summary of the invention

[0003] In order to overcome the problems in the above-mentioned background technology, the present invention provides an anti-sanding oil pump for oil production.

[0004] The technical solution of the present invention is: an anti-sand wear oil pump for oil production, comprising: Pump barrel; A fixed valve cover, threadedly connected to the pump barrel; A sliding valve cover is slidably connected in the pump barrel, the sliding valve cover is fixedly connected to a sucker rod, a movable valve is arranged in the sliding valve cover, a fixed valve is arranged in the fixed valve cover, a circumferentially spaced guide grooves are arranged at a lower portion of the outer side of the sliding valve cover, a circumferentially arrayed inclined surface is arranged on a side of the sliding valve cover away from the sucker rod, the inclined surface of the sliding valve cover is located at the lower side of an adjacent guide groove, and a single inclined surface is connected to an adjacent guide groove.

[0005] Preferably, the guide groove is a spiral groove and is distributed in a circumferential array on the outer side of the sliding valve cover.

[0006] Preferably, the guide grooves distributed in the circumferential array are connected end to end in the horizontal projection to form a ring.

[0007] Preferably, the inclined surfaces distributed in a circumferential array on the sliding valve cover are connected end to end in a horizontal projection to form a ring.

[0008] Preferably, a temporary storage cavity is formed between the sliding valve cover and the pump barrel, the guide groove is communicated with the temporary storage cavity, and a sliding ring is slidably connected in the temporary storage cavity.

[0009] As a preference, it also includes: A rotating plate is slidably connected in the sliding ring. The sliding ring and the rotating plate are both provided with circumferentially spaced through holes, and the circumferentially spaced through holes on the two correspond to each other one by one. The sliding valve cover is provided with exhaust holes which are spaced apart and used to connect the temporary storage chamber with the pump barrel on the upper side of the sliding valve cover. A one-way pressure valve is provided in the exhaust hole.

[0010] Preferably, the through holes distributed circumferentially at intervals on the sliding ring correspond one to one with the guide grooves distributed circumferentially at intervals.

[0011] As a preference, it also includes: An expansion bag is fixedly connected in the sliding ring, and the expansion bag is fixedly connected to the rotating plate; The communicating pipe is fixedly connected to the sliding valve cover. An annular cavity is arranged inside the sliding valve cover. The expansion bag and the annular cavity are communicated through the communicating pipe.

[0012] As a preference, it also includes: The fixed shells are provided with a plurality of fixed shells, which are fixedly connected in the sliding valve cover and are circumferentially spaced in the sliding valve cover. A piston rod is sealingly and slidingly connected in the fixed shell. A tension spring is provided between the fixed shell and the piston rod. The fixed shell is connected with the annular cavity through a pipeline.

[0013] Beneficial effects: The present invention optimizes the flow state of sand-containing crude oil according to the principle of Poiseuille's law by cooperating with the guide groove and the temporary storage chamber, so that the sand and gravel near the sliding valve cover and the pump barrel are more inclined to flow along the guide groove during oil production, reducing the probability of sand and gravel entering the gap, thereby reducing wear and extending the service life of the sliding valve cover and the pump barrel; during the oil pressure process, if gas lock occurs, the temporary storage chamber is connected to the lower side of the sliding valve cover through the guide groove, so that the gas pressure gradually increases and is discharged through the one-way valve in the exhaust hole. This design can maintain the gas pressure on the lower side of the sliding valve cover stable, reduce the probability of abnormal vibration of the sucker rod caused by instantaneous release of gas pressure, and thus reduce the possibility of equipment damage due to gas lock. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a three-dimensional structural schematic diagram of the internal structure of the pump barrel and the fixed valve cover of the present invention; Figure 3 It is a three-dimensional structural schematic diagram of the sliding valve cover and the movable valve of the present invention; Figure 4 It is a schematic diagram of the three-dimensional structure of the sliding valve cover and the sliding ring of the present invention; Figure 5 It is a three-dimensional structural cross-sectional view of the pump barrel and the sliding valve cover of the present invention; Figure 6 It is a schematic diagram of the three-dimensional structure of the rotating plate and the expansion bag of the present invention; Figure 7 An exploded view of the sliding ring and the rotating plate of the present invention; Figure 8 It is a three-dimensional structural cross-sectional view of the sliding valve cover and the movable valve of the present invention; Fig. 9 For the present invention Figure 8 Enlarged view of point A in the middle.

[0015] Markings in the figure are: 1-pump barrel, 2-fixed valve cover, 3-sliding valve cover, 4-sucker rod, 5-moving valve, 6-fixed valve, 7-guide groove, 8-temporary storage chamber, 9-sliding ring, 10-rotating plate, 11-exhaust hole, 12-expansion bag, 13-connecting pipe, 14-annular chamber, 15-fixed shell, 16-piston rod, 17-tension spring. DETAILED DESCRIPTION

[0016] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention.

[0017] Embodiment 1: A sand-proof oil well pump for oil production, such as Figure 1-Figure 4 As shown, it includes: a pump barrel 1; a fixed valve cover 2, which is threadedly connected to the pump barrel 1; a sliding valve cover 3, which is slidably connected in the pump barrel 1, the sliding valve cover 3 is fixedly connected to the sucker rod 4, a floating valve 5 is arranged in the sliding valve cover 3, and a fixed valve 6 is arranged in the fixed valve cover 2, and a guide groove 7 distributed at intervals in the circumferential direction is arranged at the lower part of the outer side of the sliding valve cover 3; the guide groove 7 is a spiral groove, and is distributed in a circumferential array on the outer side of the sliding valve cover 3; the guide grooves 7 distributed in the circumferential array are connected end to end in the horizontal projection to form a ring; the side of the sliding valve cover 3 away from the sucker rod 4 is provided with inclined surfaces distributed in the circumferential array, the inclined surfaces of the sliding valve cover 3 are located at the lower side of the adjacent guide grooves 7, and a single inclined surface is connected with the adjacent guide grooves 7; the inclined surfaces distributed in the circumferential array on the sliding valve cover 3 are connected end to end in the horizontal projection to form a ring; a temporary storage chamber 8 is formed between the sliding valve cover 3 and the pump barrel 1, the guide groove 7 is connected to the temporary storage chamber 8, and a sliding ring 9 is slidably connected in the temporary storage chamber 8.

[0018] In the above scheme, the number of guide grooves 7 can be set according to demand. In the figure, the number of guide grooves 7 is ten uniformly distributed in the circumferential direction, which is used to ensure that the sliding valve cover 3 is uniformly stressed during oil production. The inclined surfaces distributed in the circumferential array on the sliding valve cover 3 are all located on the lower side thereof. When encountering gravel in the crude oil, the gravel enters the guide groove 7 under the guidance of the inclined surface on the sliding valve cover 3. Through the inclined design, the impact force between the gravel and the inclined surface and the guide groove 7 on the sliding valve cover 3 is reduced, thereby extending the service life. The guide grooves 7 distributed in the circumferential array are connected end to end in the vertical projection to form a ring. In this way, during the oil production process (that is, during the up and down reciprocating movement of the sliding valve cover 3), the crude oil in the guide groove 7 is in the Poiseuille shape in fluid mechanics. The law (under the same pressure difference, the wider the flow channel, the smaller the flow resistance, the easier the fluid passes, and the crude oil actively carries the gravel to flow into the guide groove 7) forms a "self-cleaning" oil film near the guide groove 7 on the sliding valve cover 3 to reduce the probability of gravel intrusion. At the same time, the alternation of new and old oil films can assist the discharge of gravel. The temporary storage chamber 8 is filled with gas on the upper side of the sliding ring 9, and the sliding valve cover 3 and the pump barrel 1 and the sliding ring 9 are all sealed and sliding. The inclined surfaces distributed in the circumferential array on the sliding valve cover 3 are connected end to end in the horizontal projection to form a ring, so that the crude oil and the gravel in it that contact the lower side of the sliding valve cover 3 will be guided, thereby reducing the probability of the gravel being hard squeezed between the sliding valve cover 3 and the pump barrel 1 when they slide relative to each other.

[0019] Specific working principle: When using this device to produce oil in an oil field, the user first connects this device to external devices (such as sand control cylinder, pumping unit, stabilizer, etc.) and installs it in the oil field, then starts the pumping unit, and the pumping unit drives the sucker rod 4 to move back and forth up and down, and the sucker rod 4 drives the sliding valve cover 3 to move back and forth up and down. When the sucker rod 4 drives the sliding valve cover 3 to move upward, the sliding valve cover 3 drives the floating valve 5 to move upward, and the distance between the floating valve 5 and the fixed valve 6 gradually increases. The floating valve 5 remains sealed with the sliding valve cover 3 under the pressure of the crude oil on its upper side. Under the action of pressure, the crude oil in the oil field passes through the sand control cylinder to lift the fixed valve 6 upward, and the crude oil on the lower side of the sliding valve cover 3 and the crude oil on the lower side of the fixed valve 6 move upward at the same time. This is the oil pumping process.

[0020] When the sliding valve cover 3 stops moving upward and starts to move downward driven by the sucker rod 4, the sliding valve cover 3 drives the floating valve 5 to move downward, and the distance between the floating valve 5 and the fixed valve 6 gradually decreases. Under the action of pressure, the floating valve 5 moves upward relative to the sliding valve cover 3, so that the floating valve 5 and the sliding valve cover 3 lose the seal. At the same time, the fixed valve 6 moves downward and resets, so that the seal between the fixed valve 6 and the fixed valve cover 2 is restored, and the crude oil on the lower side of the sliding valve cover 3 moves upward through the sliding valve cover 3 to the upper side of the floating valve 5, thereby squeezing the crude oil between the floating valve 5 and the fixed valve 6 to the upper side of the floating valve 5. This is the oil compression process. Subsequently, the above-mentioned oil pumping process and oil compression process are repeated to gradually pump the crude oil in the oil field to the outside world. This is the use process of this device.

[0021] During the up and down reciprocating movement of the sliding valve cover 3, if the sand content in the crude oil increases due to damage to the sand prevention tube or other reasons, thereby affecting the normal operation of the device (i.e., under this sand content, the device continues to wear), during the oil pumping process, the sand-containing crude oil moves upward through the fixed valve 6 to between the fixed valve 6 and the floating valve 5. During the oil pressing process, the sliding valve cover 3 moves downward, and most of the gravel moves upward through the sliding valve cover 3 to the upper side of the floating valve 5 driven by the crude oil. A small amount of gravel and crude oil contact the lower inclined surface of the sliding valve cover 3 and enter the guide groove 7 adjacent to the lower inclined surface of the sliding valve cover 3 under its guidance. The crude oil and gravel enter the temporary storage chamber 8 through the guide groove 7. The sand-containing crude oil squeezes the sliding ring 9 to move upward and compresses the gas between the sliding ring 9 and the sliding valve cover 3, so that the sliding ring 9 gradually moves upward relative to the sliding valve cover 3, thereby partially releasing the sand during the oil pressing process. The sandy crude oil is temporarily stored between the lower side of the sliding ring 9 and the sliding valve cover 3, i.e., the probability of some sand and gravel in the crude oil entering between the sliding valve cover 3 and the pump barrel 1 under the pressure during the oil pressing process is reduced. When the oil pressing process is completed and the next round of oil pumping is carried out, the compressed gas between the sliding ring 9 and the sliding valve cover 3 squeezes and drives the sliding ring 9 to reset, and the sliding ring 9 squeezes and discharges the sandy crude oil on its lower side downward through the guide groove 7, i.e., preventing the sandy crude oil from staying in the temporary storage chamber 8 for a long time. The guide groove 7 cooperates with the temporary storage chamber 8 to optimize the flow state of the sandy crude oil according to Poiseuille's law, so that the sand and gravel near the sliding valve cover 3 and the pump barrel 1 are more inclined to flow along the guide groove 7 during the oil production process, reducing the probability of sand and gravel entering the gap, thereby reducing wear and extending the service life of the sliding valve cover 3 and the pump barrel 1. After the crude oil in the oil field is produced, the device is removed from the oil field, and the use of the device is completed at this time.

[0022] Embodiment 2: Based on embodiment 1, Figure 2 and Figure 5-Figure 7As shown, it also includes: a rotating plate 10, which is slidably connected in the sliding ring 9, and the sliding ring 9 and the rotating plate 10 are both provided with circumferentially spaced through holes, and the circumferentially spaced through holes of the two correspond one to one, and the sliding valve cover 3 is provided with exhaust holes 11 that are spaced and used to connect the temporary storage chamber 8 with the pump barrel 1 on the upper side of the sliding valve cover 3, and a one-way pressure valve is arranged in the exhaust hole 11, and the circumferentially spaced through holes on the sliding ring 9 correspond one to one with the circumferentially spaced guide grooves 7.

[0023] In the above scheme, the through holes on the sliding ring 9 and the rotating plate 10 are in one-to-one correspondence, and when the adjacent through holes of the two are connected, the upper and lower sides of the temporary storage chamber 8 separated by the sliding ring 9 are connected, and when the adjacent through holes of the two are staggered, the upper and lower sides of the temporary storage chamber 8 separated by the sliding ring 9 are not connected, the one-way pressure valve in the exhaust hole 11 has an initial starting pressure, and the initial starting pressure of the one-way pressure valve in the exhaust hole 11 is less than the triggering pressure of the floating valve 5 (that is, the pressure when the floating valve 5 and the sliding valve cover 3 lose the seal), when the sliding ring 9 compresses the gas on its upper side, the one-way pressure valve in the exhaust hole 11 is never triggered, and the lower side inclined surface of the sliding ring 9 gradually tilts toward its axis from top to bottom.

[0024] like Figure 5-Figure 9 As shown, it also includes: an expansion bag 12, which is fixed in the sliding ring 9, and the expansion bag 12 is fixed to the rotating plate 10; a connecting pipe 13, which is fixed to the sliding valve cover 3, and an annular cavity 14 is arranged in the sliding valve cover 3, and the expansion bag 12 and the annular cavity 14 are connected through the connecting pipe 13; it also includes: a fixed shell 15, which has a plurality of fixed shells, which are fixed in the sliding valve cover 3 and are circumferentially spaced in the sliding valve cover 3, and a piston rod 16 is sealed and slidably connected in the fixed shell 15, and a tension spring 17 is arranged between the fixed shell 15 and the piston rod 16, and the fixed shell 15 is connected with the annular cavity 14 through a pipeline.

[0025] In the above scheme, the expansion bag 12, the connecting pipe 13, the annular cavity 14 and the fixed shell 15 are all filled with a transmission medium, which can be hydraulic oil or other difficult-to-compress fluid. Figure 6 For example, only the right part of the expansion bag 12 is fixedly connected to the sliding ring 9, the connecting pipe 13 is a soft pipe, and the number of fixed shells 15 can be changed according to needs. In this solution, there are four fixed shells 15 distributed in a circumferential array. During the oil pressure process, the piston rod 16 is in an extended state, and the pressure of the crude oil on it is a wrapping pressure. In addition, its cross-sectional area is small, and it is difficult for the crude oil to squeeze the piston rod 16 into the fixed shell 15. The tension spring 17 is initially in a stretched state.

[0026] Specific working principle: If air lock occurs during the above-mentioned oil pressure process, as the sliding valve cover 3 gradually moves downward, the sliding ring 9 is connected with the through hole on the rotating plate 10, and the temporary storage chamber 8 is connected with the pump barrel 1 at the lower part of the sliding valve cover 3 through the guide groove 7. As the sliding valve cover 3 continues to move downward, the gas pressure in the temporary storage chamber 8 gradually increases until the pressure is higher than the starting pressure of the one-way pressure valve on the exhaust hole 11. The compressed gas is discharged to the upper side of the sliding valve cover 3 through the one-way pressure valve on the exhaust hole 11, so that the gas pressure on the lower side of the sliding valve cover 3 is maintained stable. In the above process, the gas pressure is not enough to squeeze the floating valve 5 upward, thereby reducing the probability of abnormal vibration of the sucker rod caused by the upward movement of the floating valve 5 (i.e., the instantaneous release of air pressure) when the air lock occurs, thereby affecting its service life.

[0027] When the floating valve 5 moves downward until it contacts the crude oil, it moves upward under pressure and loses the squeezing of the piston rod 16. The piston rod 16 moves toward the axial direction of the sliding valve cover 3 driven by the tension spring 17. At the same time, the hydraulic oil in the annular cavity 14 is extracted into the fixed shell 15 through the pipeline. The annular cavity 14 extracts the hydraulic oil in the expansion bag 12 through the connecting pipe 13. The expansion bag 12 contracts and drives the rotating plate 10 to slide in the sliding ring 9 until the through hole on the sliding ring 9 intersects with the through hole on the rotating plate 10. At this time, the rotating plate 10 restores the isolation of the temporary storage chamber 8, and then repeats the above oil compression process. After the oil compression process is completed, if the lower side of the sliding valve cover 3 still extracts some gas during the oil extraction process, repeat the above steps to exhaust the gas, thereby reducing the probability of gas lock.

[0028] When the above-mentioned movable valve 5 moves upward, some gas still remains on the lower side of the rotating plate 10, thereby providing time for the movement of the sliding ring 9 and the rotating plate 10 to prevent the crude oil from flowing to the upper side of the rotating plate 10 through the through holes on the sliding ring 9 and the rotating plate 10.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A sand-proof oil pump for oil production, characterized in that: include: Pump barrel (1); A fixed valve cover (2) threadedly connected to the pump barrel (1); A sliding valve cover (3) is slidably connected in the pump barrel (1), the sliding valve cover (3) is fixedly connected to a sucker rod (4), a floating valve (5) is arranged in the sliding valve cover (3), a fixed valve (6) is arranged in the fixed valve cover (2), a circumferentially spaced guide grooves (7) are arranged at a lower portion of the outer side of the sliding valve cover (3), a circumferentially arrayed inclined surface is arranged on a side of the sliding valve cover (3) away from the sucker rod (4), the inclined surface of the sliding valve cover (3) is located at the lower side of the adjacent guide groove (7), and a single inclined surface is connected to the adjacent guide groove (7).

2. The sand-proof oil well pump for oil production according to claim 1, characterized in that: The guide grooves (7) are spiral grooves and are distributed in a circumferential array on the outside of the sliding valve cover (3).

3. The sand-proof oil well pump for oil production according to claim 2, characterized in that: The guide grooves (7) distributed in a circumferential array are connected end to end in a horizontal projection to form a ring.

4. The sand-proof oil well pump for oil production according to claim 3, characterized in that: The inclined surfaces distributed in a circumferential array on the sliding valve cover (3) are connected end to end in a horizontal projection to form a ring.

5. The sand-proof oil well pump for oil production according to claim 4, characterized in that: A temporary storage chamber (8) is formed between the sliding valve cover (3) and the pump barrel (1); the guide groove (7) is in communication with the temporary storage chamber (8); and a sliding ring (9) is slidably connected in the temporary storage chamber (8).

6. The sand-proof oil pump for oil production according to claim 5, characterized in that include: A rotating plate (10) is slidably connected in the sliding ring (9); the sliding ring (9) and the rotating plate (10) are both provided with through holes spaced apart in the circumferential direction, and the through holes spaced apart in the circumferential direction on the two plates correspond to each other one by one; the sliding valve cover (3) is provided with exhaust holes (11) spaced apart in the circumferential direction and used for connecting the temporary storage chamber (8) with the pump barrel (1) at the upper side of the sliding valve cover (3); and a one-way pressure valve is provided in the exhaust hole (11).

7. The sand-proof oil well pump for oil production according to claim 6, characterized in that: The through holes distributed at intervals in the circumferential direction on the sliding ring (9) correspond one to one with the guide grooves (7) distributed at intervals in the circumferential direction.

8. The sand-proof oil well pump for oil production according to claim 7, characterized in that include: An expansion bag (12) is fixedly connected inside the sliding ring (9), and the expansion bag (12) is fixedly connected to the rotating plate (10); The connecting pipe (13) is fixedly connected to the sliding valve cover (3). An annular cavity (14) is provided in the sliding valve cover (3). The expansion bag (12) and the annular cavity (14) are connected via the connecting pipe (13).

9. The sand-proof oil well pump for oil production according to claim 8, characterized in that include: A plurality of fixed shells (15) are fixedly connected to the sliding valve cover (3) and are circumferentially spaced apart in the sliding valve cover (3). A piston rod (16) is sealingly and slidably connected to the fixed shell (15). A tension spring (17) is provided between the fixed shell (15) and the piston rod (16). The fixed shell (15) is connected to the annular cavity (14) via a pipeline.

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