Disclosure of Invention
The invention aims to provide an electric lead screw rodless oil extraction device with a closed power mechanism, which overcomes the defect of low oil extraction efficiency of a conventional oil extractor through the transmission of a sucker rod, and can realize underground rodless oil extraction with wide discharge range, high lift, long service life and low cost.
The above object of the present invention can be achieved by the following technical solutions:
the invention provides an electric lead screw rodless oil extraction device with a closed power mechanism, which comprises the closed power mechanism arranged in an underground oil pipe and a first plunger pump connected below the closed power mechanism, wherein the closed power mechanism comprises:
a cylinder body in which a motor is installed;
the transmission structure is positioned in the cylinder body and connected with the motor, the transmission structure is provided with a first lead screw pair positioned below the motor and a second lead screw pair positioned above the motor, the first lead screw pair is connected to one end of a driving shaft of the motor, and the second lead screw pair is connected to the other end of the driving shaft of the motor;
the first polish rod and the second polish rod are in dynamic sealing fit with the cylinder body, the first polish rod is connected with one end of a driving shaft of the motor through the first lead screw pair, and the second polish rod is connected with the other end of the driving shaft of the motor through the second lead screw pair;
when the motor rotates to drive the transmission structure to operate, the volume of the first polished rod entering and exiting the cylinder body is the same as the volume of the second polished rod entering and exiting the cylinder body.
In an embodiment of the present invention, the first lead screw pair has a first lead screw and a first lead screw nut, and one end of the drive shaft of the motor is connected to the first lead screw, or one end of the drive shaft of the motor is connected to the first lead screw nut.
In an embodiment of the present invention, the second screw pair has a second screw and a second screw nut, and the other end of the drive shaft of the motor is connected to the second screw, or the other end of the drive shaft of the motor is connected to the second screw nut.
In an embodiment of the invention, a first guide righting structure is arranged between the inner wall of the cylinder body and the first lead screw pair, the first guide righting structure comprises a first guide groove and a first guide key, and the first guide key can move linearly in the first guide groove.
In an embodiment of the present invention, a second guiding and centering structure is disposed between an inner wall of the cylinder and the second screw pair, and the second guiding and centering structure includes a second guiding groove and a second guiding key, and the second guiding key can move linearly in the second guiding groove.
In an embodiment of the present invention, an upper limit sensor and a lower limit sensor are connected to the first screw in a state where one end of a drive shaft of the motor is connected to the first screw.
In an embodiment of the present invention, a first upper displacement sensor and a first lower displacement sensor are connected to the first lead screw nut.
In an embodiment of the present invention, a second upper displacement sensor and a second lower displacement sensor are connected to the second lead screw nut in a state where the other end of the drive shaft of the motor is connected to the second lead screw.
In an embodiment of the present invention, a second upper displacement sensor and a second lower displacement sensor are connected to the second lead screw in a state where the other end of the drive shaft of the motor is connected to the second lead screw nut.
In an embodiment of the present invention, the cylinder block is filled with a lubricating liquid.
In an embodiment of the present invention, the electric lead screw rodless oil extraction device with the sealed power mechanism further includes a second plunger pump, the second plunger pump is located above the sealed power mechanism, and a second polish rod of the sealed power mechanism is connected to the second plunger pump.
In an embodiment of the present invention, the electric lead screw rodless oil extraction device with the sealed power mechanism further includes a ground control cabinet, the ground control cabinet is electrically connected to the motor of the sealed power mechanism through a cable, and the cable is disposed in the oil pipe, or the cable is disposed in an oil jacket annulus.
In an embodiment of the present invention, the first lead screw and the second lead screw are both common lead screws with rectangular or trapezoidal threads, or both the first lead screw and the second lead screw are ball screws.
The invention has the characteristics and advantages that:
the electric lead screw rodless oil extraction device with the closed power mechanism overcomes the defect of low energy efficiency of a conventional oil pumping unit and realizes underground rodless oil extraction. The invention can adopt various rotating motors, including mature, reliable and low-cost conventional high-speed rotating three-phase asynchronous motors, is connected with the existing plunger pump, has small investment and strong reliability, and can realize low stroke frequency, low discharge capacity and high-lift lifting. Meanwhile, the invention has simple structure, the key nodes are convenient to monitor, and the intelligent parameter adjustment is easy. The invention can meet the requirements of lifting, water drainage and gas production of complex oil and gas wells such as low yield wells, deep wells, inclined wells, horizontal wells and the like.
The electric lead screw rodless oil extraction device with the closed power mechanism disclosed by the invention has the advantages that the motor, the lead screw, the first polished rod and the second polished rod are closed in the cylinder body by the closed power mechanism, the first lead screw and the second lead screw are linked with the first polished rod and the second polished rod to synchronously enter and exit the cylinder body when the motor rotates, the volume in the cylinder body is kept constant, the pressure is kept unchanged, the integral sealing of the cylinder body is realized, the lead screw is ensured to be well lubricated, and the scale formation is prevented.
The electric lead screw rodless oil extraction device with the closed power mechanism has the advantages of wide application range, strong reliability, high mechanical efficiency and high intelligent degree, can greatly reduce the cost, and meets the development requirements of 'multi-well low-yield' oil fields in China.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Where adjective or adverbial modifiers "upper" and "lower", "top" and "bottom", "inner" and "outer" are used merely to facilitate relative reference between groups of terms, and do not describe any particular directional limitation on the modified terms. In the description of the present invention, "a plurality" means two or more and "at least one" means one or more unless otherwise specified.
As shown in fig. 1 to 2, the present invention provides an electric lead screw rodless oil production device with a sealed power mechanism, which includes a sealed power mechanism 10 installed in a downhole oil pipe 6, and a first plunger pump 8 connected below the sealed power mechanism 10, wherein the sealed power mechanism 10 includes a cylinder body 1, a transmission structure 2, a first polish rod 21, and a second polish rod 22, wherein: the cylinder body 1 is internally provided with a motor 3; the transmission structure 2 is positioned in the cylinder body 1 and connected with the motor 3, the transmission structure 2 is provided with a first lead screw pair 23 positioned below the motor 3 and a second lead screw pair 24 positioned above the motor 3, the first lead screw pair 23 is connected with one end 32 of a driving shaft of the motor 3, and the second lead screw pair 24 is connected with the other end 33 of the driving shaft of the motor 3; the first polish rod 21 and the second polish rod 22 are in dynamic sealing fit with the cylinder body 1, the first polish rod 21 is connected with one end 32 of a driving shaft of the motor 3 through the first lead screw pair 23, and the second polish rod 22 is connected with the other end 33 of the driving shaft of the motor 3 through the second lead screw pair 24; when the motor 3 rotates to drive the transmission structure 2 to operate, the volume of the first polish rod 21 entering and exiting the cylinder 1 is the same as the volume of the second polish rod 22 entering and exiting the cylinder 1.
The electric lead screw rodless oil extraction device with the closed power mechanism overcomes the defect of low energy efficiency of the conventional oil pumping unit, and realizes underground rodless oil extraction. The invention can adopt various rotating motors, including mature, reliable and low-cost conventional high-speed rotating three-phase asynchronous motors, is connected with the existing plunger pump, has small investment and strong reliability, and can realize high-efficiency and reliable pumping. Meanwhile, the invention has simple structure, the key nodes are convenient to monitor, and the intelligent parameter adjustment is easy. The invention can meet the requirements of lifting, water drainage and gas production of complex oil and gas wells such as low yield wells, deep wells, inclined wells, horizontal wells and the like.
In addition, the closed power mechanism has a simple structure, and overcomes the defect of low oil pumping efficiency of the conventional oil pumping unit. The closed power mechanism seals the motor 3, the first polish rod 21 and the second polish rod 22 in the cylinder body 1, and solves the polish rod eccentric wear problem possibly existing in the motion conversion and energy transfer processes. The invention can realize the synchronous in-and-out of the cylinder body 1 of the first polish rod 21 and the second polish rod 22 through the linkage of the motor 3, can keep the volume in the cylinder body 1 constant and the pressure in the cylinder body 1 constant, and ensures the whole sealing performance of the cylinder body 1.
Specifically, the cylinder body 1 is substantially cylindrical and cylindrical, and the interior thereof is filled with a lubricating liquid which can lubricate and cool components in the cylinder body 1; the motor 3 is fixedly connected to the inner wall of the cylinder 1, and the motor 3 may be a rotary motor including a conventional three-phase asynchronous motor, a permanent magnet synchronous motor, and the like. In this embodiment, the motor 3 is connected to the inner wall of the cylinder 1 through the connecting bracket 31, the connecting bracket 31 has a plurality of through holes 311, the through holes 311 are separately disposed around the motor 3, and the through holes 311 are disposed to enable the lubricating fluid above the motor 3 and below the motor 3 to flow smoothly, so as to achieve the purpose of cooling the motor 3 and ensure that the first and second polish rods 21 and 22 are not obstructed by the pressure of the lubricating fluid in the cylinder 1.
The first polish rod 21 and the second polish rod 22 are respectively arranged at the two opposite ends of the cylinder body 1, in the embodiment, the first polish rod 21 is arranged at the lower part in the cylinder body 1 and can extend out from the lower end of the cylinder body 1, and a first dynamic sealing structure 211 is arranged between the first polish rod 21 and the cylinder body 1; the second polish rod 22 is disposed at the upper portion inside the cylinder 1 and can protrude from the upper end of the cylinder 1, and a second dynamic sealing structure 221 is disposed between the second polish rod 22 and the cylinder 1. The first dynamic sealing structure 211 and the second dynamic sealing structure 221 are adopted in the invention, so that the first polish rod 21 and the second polish rod 22 can be ensured to be in a sealing state all the time in the motion process relative to the cylinder body 1, on one hand, the lubricating liquid in the cylinder body 1 can be ensured not to leak, the sealing performance of the cylinder body 1 can be ensured, and on the other hand, the first polish rod 21 and the second polish rod 22 can be ensured to move smoothly relative to the cylinder body 1. In the present embodiment, the first dynamic seal structure 211 and the second dynamic seal structure 221 may adopt a labyrinth seal structure or a rubber ring seal structure, which are known in the art, and are not limited herein.
According to one embodiment of the invention, the first spindle assembly 23 of the transmission 2 has a first spindle 231 and a first spindle nut 232 which meshes therewith, and one end 32 of the drive shaft of the electric motor 3 is connected to the first spindle 231, or one end 32 of the drive shaft of the electric motor 3 is connected to the first spindle nut 232.
Further, in the present invention, the second screw pair 24 has a second screw 241 and a second screw nut 242 engaged therewith, and the other end 33 of the driving shaft of the motor 3 is connected to the second screw 241 or the other end 33 of the driving shaft of the motor 3 is connected to the second screw nut 242.
The other end 33 of the driving shaft and one end 32 of the driving shaft belong to the upper end and the lower end of the driving shaft of the motor 3, are respectively connected with the first screw pair 23 and the second screw pair 24, and are symmetrically arranged in the cylinder body 1 relative to the motor 3.
As shown in fig. 3, in one possible embodiment of the hermetic power mechanism 10 of the present invention, one end 32 of the driving shaft of the motor 3 is connected to one end of the first lead screw 231, one end of the first lead screw nut 232 is formed with an internal thread, the other end thereof is a closed end, the first lead screw nut 232 is engaged with the first lead screw 231 through the internal thread thereof, and the closed end of the first lead screw nut 232 is connected to the first polished rod 21.
In this embodiment, the other end 33 of the driving shaft of the motor 3 is connected to the second lead screw 241, one end of the second lead screw nut 242 is formed with an internal thread, the other end is a closed end, the second lead screw nut 242 is engaged with the second lead screw 241 through the internal thread, and the closed end of the second lead screw nut 242 is connected to the second polished rod 22.
The operation of the closed power mechanism 10 in this embodiment is as follows:
starting the motor 3, the driving shaft of the motor 3 rotates, one end 32 of the driving shaft drives the first lead screw 231 to rotate, and at this time, the first lead screw nut 232 moves upwards along the axial direction of the cylinder body 1 and drives the first polished rod 21 to move upwards (i.e. move towards the direction in the cylinder body 1); at the same time, the other end 33 of the driving shaft drives the second lead screw 241 to rotate, and at this time, the second lead screw nut 242 moves upward along the axial direction of the cylinder 1, and drives the second polished rod 22 to move upward (i.e., to move in the direction out of the cylinder 1). When the driving shaft of the motor 3 rotates in the other direction, the first polish rod 21 moves downward (i.e., moves in the direction out of the cylinder 1), and the second polish rod 22 also moves downward (i.e., moves in the direction into the cylinder 1) in synchronization. In the process of such movement, the volume of the first polish rod 21 entering and exiting the cylinder 1 is always equal to the volume of the second polish rod 22 entering and exiting the cylinder 1, and the lubricating liquid in the cylinder 1 flows in the cylinder 1 through the plurality of flow-through holes 311 on the connecting bracket 31, so as to keep the pressure in the cylinder 1 unchanged.
As shown in fig. 4, in another possible embodiment of the present invention, one end 32 of the driving shaft of the motor 3 is connected to the first lead screw nut 232, the first lead screw nut 232 is engaged with the first lead screw 231, and the other end of the first lead screw 231 is connected to the first polished rod 21.
In this embodiment, the other end 33 of the driving shaft of the motor 3 is connected to the second lead screw 241, the second lead screw 241 is engaged with the second lead screw nut 242, and the closed end of the second lead screw nut 242 is connected to the second polished rod 22.
The operation of the closed power mechanism 10 in this embodiment is as follows:
starting the motor 3, wherein a driving shaft of the motor 3 rotates, and one end 32 of the driving shaft drives the first lead screw nut 232 to rotate, and at this time, the first lead screw 231 moves upward along the axial direction of the cylinder body 1 and drives the first polished rod 21 to move upward (i.e. move toward the direction inside the cylinder body 1); at the same time, the other end 33 of the driving shaft drives the second lead screw 241 to rotate, and at this time, the second lead screw nut 242 moves upward along the axial direction of the cylinder 1, and drives the second polished rod 22 to move upward (i.e., to move in the direction out of the cylinder 1). When the driving shaft of the motor 3 rotates in the other direction, the first polish rod 21 moves downward (i.e., moves in the direction out of the cylinder 1), and the second polish rod 22 also moves downward (i.e., moves in the direction into the cylinder 1) in synchronization. In the process of such movement, the volume of the first polish rod 21 entering and exiting the cylinder 1 is always equal to the volume of the second polish rod 22 entering and exiting the cylinder 1, and the lubricating liquid in the cylinder 1 flows in the cylinder 1 through the plurality of flow-through holes 311 on the connecting bracket 31, so as to keep the pressure in the cylinder 1 unchanged.
As shown in fig. 5, in a third possible embodiment of the present invention, one end 32 of the driving shaft of the motor 3 is connected to the closed end of the first lead screw nut 232, the first lead screw nut 232 is engaged with the first lead screw 231, and the other end of the first lead screw 231 is connected to the first polished rod 21.
In this embodiment, the other end 33 of the driving shaft of the motor 3 is connected to the closed end of the second lead screw nut 242, the second lead screw nut 242 is engaged with the second lead screw 241, and the other end of the second lead screw 241 is connected to the second polished rod 22.
The operation of the closed power mechanism 10 in this embodiment is as follows:
starting the motor 3, wherein a driving shaft of the motor 3 rotates, and one end 32 of the driving shaft drives the first lead screw nut 232 to rotate, and at this time, the first lead screw 231 moves upward along the axial direction of the cylinder body 1 and drives the first polished rod 21 to move upward (i.e. move toward the direction inside the cylinder body 1); at the same time, the other end 33 of the driving shaft drives the second lead screw nut 242 to rotate, and at this time, the second lead screw 241 moves upward along the axial direction of the cylinder 1, and drives the second polished rod 22 to move upward (i.e., to move in the direction out of the cylinder 1). When the one end 32 of the driving shaft of the motor 3 and the other end 33 of the driving shaft rotate in the other direction together, the first polish rod 21 moves downward (i.e., moves in the direction out of the cylinder 1), and the second polish rod 22 also moves downward (i.e., moves in the direction into the cylinder 1) in synchronization. In the process of such movement, the volume of the first polish rod 21 entering and exiting the cylinder 1 is always equal to the volume of the second polish rod 22 entering and exiting the cylinder 1, and the lubricating liquid in the cylinder 1 flows in the cylinder 1 through the plurality of flow-through holes 311 on the connecting bracket 31, so as to keep the pressure in the cylinder 1 unchanged.
As shown in fig. 6, in a fourth possible embodiment of the present invention, one end 32 of the driving shaft of the motor 3 is connected to one end of the first lead screw 231, one end of the first lead screw nut 232 is formed with an internal thread, the other end thereof is a closed end, the first lead screw nut 232 is engaged with the first lead screw 231 through the internal thread thereof, and the closed end of the first lead screw nut 232 is connected to the first polish rod 21.
In this embodiment, the other end 33 of the driving shaft of the motor 3 is connected to the second lead screw nut 242, one end of the second lead screw nut 242 is formed with an internal thread, the other end thereof is a closed end, the second lead screw 241 is engaged with the second lead screw nut 242, and the other end of the second lead screw 241 is connected to the second polished rod 22.
The operation of the closed power mechanism 10 in this embodiment is as follows:
starting the motor 3, the driving shaft of the motor 3 rotates, one end 32 of the driving shaft drives the first lead screw 231 to rotate, and at this time, the first lead screw nut 232 moves upwards along the axial direction of the cylinder body 1 and drives the first polished rod 21 to move upwards (i.e. move towards the direction in the cylinder body 1); at the same time, the other end 33 of the driving shaft drives the second lead screw nut 242 to rotate, and at this time, the second lead screw 241 moves upward along the axial direction of the cylinder 1, and drives the second polished rod 22 to move upward (i.e., to move in the direction out of the cylinder 1). When the driving shaft of the motor 3 rotates in the other direction, the first polish rod 21 moves downward (i.e., moves in the direction out of the cylinder 1), and the second polish rod 22 also moves downward (i.e., moves in the direction into the cylinder 1) in synchronization. In the process of such movement, the volume of the first polish rod 21 entering and exiting the cylinder 1 is always equal to the volume of the second polish rod 22 entering and exiting the cylinder 1, and the lubricating liquid in the cylinder 1 flows in the cylinder 1 through the plurality of flow-through holes 311 on the connecting bracket 31, so as to keep the pressure in the cylinder 1 unchanged.
According to an embodiment of the present invention, as shown in fig. 3 to 6, a first guide righting structure 4 is connected between the inner wall of the cylinder body 1 and the first lead screw pair 23, and the first guide righting structure 4 can play a role in guiding the first lead screw 231 or the first lead screw nut 232 of the first lead screw pair 23 to move linearly along the axial direction of the cylinder body 1, limiting the rotation of the first lead screw 231 or the first lead screw nut 232, so as to achieve the purpose of guiding the first polished rod 21 to move linearly along the axial direction of the cylinder body 1, limiting the rotation of the first polished rod 21, and playing a role in righting the first lead screw 231 or the first lead screw nut 232, so as to prevent the first polished rod 21 from deflecting during the axial movement.
In a possible embodiment, a first guide groove 41 is provided on the inner wall of the cylinder 1, and a first guide key 42 is connected to the first screw pair 23, and the first guide key 42 can move linearly in the first guide groove 41. In this embodiment, in a state where the first polish rod 21 is coupled to the first lead screw nut 232 of the first lead screw pair 23, as shown in fig. 3 and 6, the first guide key 42 is coupled to the first lead screw nut 232; as shown in fig. 4 and 5, in a state where the first polish rod 21 is coupled to the first lead screw 231 of the first lead screw pair 23, the first guide key 42 is coupled to the first lead screw 231.
In another possible embodiment, a first guide key 42 is connected to the inner wall of the cylinder 1, and a first guide groove 41 is formed on the first screw pair 23, and the first guide key 42 can move linearly in the first guide groove 41. In this embodiment, in a state where the first polish rod 21 is connected to the first lead screw nut 232 of the first lead screw pair 23, the first guide groove 41 is opened on an outer wall of the first lead screw nut 232 (no drawing is provided); the first guide groove 41 is opened on the first lead screw 231 (not shown) in a state where the first polish rod 21 is connected to the first lead screw 231 of the first lead screw pair 23.
According to another embodiment of the present invention, a second guide and centering structure 5 is connected between the inner wall of the cylinder body 1 and the second lead screw pair 24, and the second guide and centering structure 5 can play a role in guiding the second lead screw 241 or the second lead screw nut 242 of the second lead screw pair 24 to move linearly along the axial direction of the cylinder body 1, and limiting the rotation of the second lead screw 241 or the second lead screw nut 242, so as to achieve the purpose of guiding the second polish rod 22 to move linearly along the axial direction of the cylinder body 1, and limiting the rotation of the second polish rod 22, and at the same time, play a role in centering the second lead screw 241 or the second lead screw nut 242, and prevent the second polish rod 22 from deflecting during the movement.
In a possible embodiment, a second guide groove 51 is provided on the inner wall of the cylinder 1, and a second guide key 52 is connected to the second screw pair 24, and the second guide key 52 is axially movably disposed in the second guide groove 51. In this embodiment, in a state where the second polish rod 22 is coupled to the second lead screw nut 242 of the second lead screw pair 24, as shown in fig. 3 and 4, the second guide key 52 is coupled to the second lead screw nut 242; as shown in fig. 5 and 6, in a state where the second polish rod 22 is coupled to the second lead screw 241 of the second lead screw pair 24, the second guide key 52 is coupled to the second lead screw 241.
In another possible embodiment, a second guide key 52 is connected to the inner wall of the cylinder 1, and a second guide groove 51 is provided on the second screw pair 24, and the second guide key 52 is axially movably disposed in the second guide groove 51. In this embodiment, in a state where the second polish rod 22 is connected to the second lead screw nut 242 of the second lead screw pair 24, the second guide groove 51 is opened on the outer wall of the second lead screw nut 242 (not shown); when the second polish rod 22 is connected to the second lead screw 241 of the second lead screw pair 24, the second guide groove 51 is opened on the second lead screw 241 (not shown).
According to an embodiment of the present invention, an upper limit sensor 233 and a lower limit sensor 234 are connected to the first screw 231 in a state where one end 32 of the driving shaft of the motor 3 is connected to the first screw 231. Specifically, the upper limit sensor 233 is disposed near the motor 3, and the lower limit sensor 234 is disposed near the first polish rod 21.
As shown in fig. 3 and 6, when the first lead screw nut 232 moves upward to the upper limit sensor 233 located at the top of the first lead screw 231, or when the first lead screw nut 232 moves downward to the lower limit sensor 234 located at the bottom of the first lead screw 231, the upper limit sensor 233 and/or the lower limit sensor 234 may send a signal command to an external control system, and the external control system may control the driving shaft of the motor 3 to switch the rotation direction and thus control the first lead screw 231 to rotate reversely after receiving the signal command.
The upper limit sensor 233 and the lower limit sensor 234 are provided to sense the displacement of the first lead screw nut 232 and the time when it travels to the upper portion of the first lead screw 231 or the lower portion of the first lead screw 231.
Further, a first upper displacement sensor 235 and a first lower displacement sensor 236 are connected to the first lead screw nut 232. Specifically, the first upper displacement sensor 235 is disposed near the motor 3, and the first lower displacement sensor 236 is disposed near the first polish rod 21. As shown in fig. 3 and 6, the movement speed and position of the first lead screw nut 232 can be transmitted to an external control system through the first upper displacement sensor 235 and the first lower displacement sensor 236, and after receiving the instruction, the external control system can determine the working condition of the sealed power mechanism 10 according to the movement speed and position of the first lead screw nut 232, thereby determining the forward and reverse rotation timing and the forward and reverse rotation switching frequency of the motor 3, and further adjusting parameters such as stroke and stroke frequency of the first plunger pump 8 connected to the first polish rod 21.
According to a possible embodiment of the present invention, a second upper displacement sensor 243 and a second lower displacement sensor 244 are connected to the second lead screw nut 242 in a state where the other end 33 of the driving shaft of the motor 3 is connected to the second lead screw 241. Specifically, the second upper displacement sensor 243 is disposed near the second polished rod 22, and the second lower displacement sensor 244 is disposed near the motor 3.
As shown in fig. 3 and 4, the moving speed and the position of the second lead screw nut 242 may be transmitted to an external control system through a second upper displacement sensor 243 and a second lower displacement sensor 244, and then the operating condition of the hermetic power mechanism 10 may be determined according to the moving speed and the position of the second lead screw nut 242, so as to determine the forward and reverse rotation timing and the forward and reverse rotation switching frequency of the motor 3, and further adjust parameters such as the stroke and the frequency of the plunger pump connected to the second polish rod 22.
According to another possible embodiment of the present invention, a second upper displacement sensor 243 and a second lower displacement sensor 244 are connected to the second lead screw 241 in a state where the other end 33 of the driving shaft of the motor 3 is connected to the second lead screw nut 242.
As shown in fig. 5 and 6, the moving speed and position of the second lead screw 241 can be transmitted to an external control system through the second upper displacement sensor 243 and the second lower displacement sensor 244, and the working condition of the present invention can be determined according to the moving speed and position of the second lead screw 241, so that the forward and reverse rotation timing and the forward and reverse rotation switching frequency of the motor 3 can be determined, and further parameters such as stroke and stroke frequency of the plunger pump connected to the second polished rod 22 can be adjusted.
In the present invention, in the embodiments of fig. 3 to 6, the first lead screw 231, the first lead screw nut 232, the second lead screw 241, and the second lead screw nut 242 may be optimally designed and arranged according to the lifting force, stroke frequency, and reduction ratio of the oil pump, based on the material, thread type, inner and outer diameters, lead screw thread lead, and other parameters. In addition, the first lead screw 231, the first lead screw nut 232, the second lead screw 241, the second lead screw nut 242, the first polish rod 21 and the second polish rod 22 may be integrally manufactured, or may be separately designed and manufactured, and may be connected and assembled when used. The first lead screw 231, the first lead screw nut 232, the second lead screw 241 and the second lead screw nut 242 may be ball screws, ordinary lead screws or other specially designed lead screws, wherein the thread in the ordinary lead screw may be a trapezoidal thread or a rectangular thread, etc. Furthermore, the first lead screw nut 232 and the second lead screw nut 242 have a through hole 2321 and a through hole 2421 on the peripheral wall thereof, so that the lubricating fluid in the cylinder 1 can flow into the first lead screw nut 232 and the second lead screw nut 242, thereby achieving the purpose of lubricating the first lead screw 231 and the second lead screw 241.
When the first polish rod 21 is connected with the first plunger pump 8, the second polish rod 22 positioned at the upper part of the closed power mechanism 10 can play a role in volume compensation for the cylinder body 1 of the closed power mechanism 10; on the contrary, when the second polish rod 22 is connected with the second plunger pump 9, the first polish rod 21 located at the lower portion may also perform a volume compensation function for the cylinder 1 of the hermetic actuating mechanism 10. The diameters of the first and second polish rods 21 and 22 and the leads and sizes of the first and second lead screws 231 and 241 may be the same or different, but the volumes of the polish rods respectively entering the cylinder 1 are the same as the volumes of the polish rods extending out of the cylinder 1, so as to ensure that the pressure in the cylinder is constant.
As shown in fig. 1 to 2, the electric lead screw rodless oil production device with a sealed power mechanism of the present invention further includes a ground control cabinet 11, the ground control cabinet 11 is disposed on the ground, the ground control cabinet 11 is electrically connected to the motor 3 of the sealed power mechanism 10 located downhole through a cable 12, wherein the cable 12 includes a power cable and a data cable, and the upper limit sensor 233, the lower limit sensor 234, the first upper displacement sensor 235, the first lower displacement sensor 236, the second upper displacement sensor 243, and the second lower displacement sensor 244 of the sealed power mechanism 10 are all in communication with the data cable; the power cable is electrically connected to the motor 3 of the sealed power mechanism 10. In the present invention, the power of the motor 3 may be determined based on the displacement volume and the head of the first plunger pump 8.
Specifically, as shown in fig. 1, the sealed power mechanism 10 and the first plunger pump 8 are sequentially placed in the downhole fluid from top to bottom, and power is supplied to the sealed power mechanism 10 downhole through the power supply of the ground control cabinet 11 and the cable 12, at this time, the motor 3 rotates in the forward direction, the first polish rod 21 of the sealed power mechanism 10 moves upward, and drives the first plunger pump 8 to move upward to discharge the fluid. When the ground control cabinet 11 detects the signal transmitted by the upper limit sensor 233, the motor 3 rotates in the reverse direction, and the first polish rod 21 of the airtight power mechanism 10 moves downward and drives the first plunger pump 8 to suck liquid downward. When the ground control cabinet 11 detects the signal transmitted by the lower limit sensor 234, the motor 3 rotates in the forward direction, and at this time, the first polish rod 21 of the airtight power mechanism 10 moves upward and drives the first plunger pump 8 to discharge liquid. Thus, a pumping stroke is completed, and the steps are circulated repeatedly, so that the purpose of pumping the liquid in the underground oil reservoir 13 can be achieved.
In the embodiment of fig. 1, only the first polish rod 21 closing the lower part of the power mechanism 10 is connected with the first plunger pump 8 for the purpose of pumping the crude oil downhole; in this case, the length of the cylinder 1 in the axial direction can be shortened by changing parameters such as the diameter of the second polish rod 22, the lead of the second lead screw 241 or the second lead screw nut 242 of the second lead screw pair 24, and the like, so that the total length of the entire hermetic power mechanism 10 is shortened, and the purpose of reducing the overall size of the hermetic power mechanism 10 is achieved.
According to one embodiment of the present invention, as shown in fig. 2, the rodless oil recovery device further includes a second plunger pump 9, the second plunger pump 9 is located above the airtight power mechanism 10, and the second polish rod 22 of the airtight power mechanism 10 is connected to the second piston rod of the second plunger pump 9. In the embodiment, the first plunger pump 8 and the second plunger pump 9 are connected to the closed power mechanism 10, so that double-pump pumping is realized, and the efficiency of underground oil extraction is improved.
Specifically, as shown in fig. 2, the second plunger pump 9, the airtight power mechanism 10 and the first plunger pump 8 are sequentially placed in the downhole fluid from top to bottom, and power is supplied to the downhole airtight power mechanism 10 through the power supply of the ground control cabinet 11 and the cable 12, at this time, the motor 3 rotates in the forward direction, the first polish rod 21 of the airtight power mechanism 10 moves upward and drives the first piston 81 of the first plunger pump 8 to move upward for discharging liquid, and simultaneously, the second polish rod 22 moves upward and drives the second plunger pump 9 to move upward for sucking liquid. When the ground control cabinet 11 detects the signal transmitted by the upper limit sensor 233, the motor 3 rotates in the reverse direction, and at this time, the first polish rod 21 of the airtight power mechanism 10 moves downward to drive the first plunger pump 8 to suck liquid, and simultaneously, the second polish rod 22 moves downward to drive the second plunger pump 9 to discharge liquid. When the ground control cabinet 11 detects the signal transmitted by the lower limit sensor 234, the driving motor 3 rotates in the forward direction, and at this time, the first polish rod 21 of the airtight power mechanism 10 moves upward to drive the first plunger pump 8 to discharge liquid, and the second polish rod 22 of the airtight power mechanism 10 moves upward to drive the second plunger pump 9 to suck liquid. Thus, a pumping stroke is completed, and the steps are repeatedly circulated, so that the purpose of pumping the liquid in the oil reservoir 13 can be achieved.
According to the electric lead screw rodless oil extraction device with the closed power mechanism, the ground control cabinet 11 can intelligently adjust the forward and reverse rotation direction and the rotating speed of the motor 3, the stroke and the working condition of the first lead screw 231, the first lead screw nut 232, the second lead screw 241 or the second lead screw nut 242 and the like according to the running conditions of the first lead screw 231, the first lead screw nut 232, the second lead screw 241 and the second lead screw nut 242, so that the stroke, the stroke frequency or the emergency start and stop of the first plunger pump 8 and/or the second plunger pump 9 are optimally adjusted. The invention can meet the requirements of lifting, draining and gas production of complex oil and gas wells such as low yield wells, deep wells, inclined wells, horizontal wells and the like, and particularly meets the urgent requirements of energy conservation, consumption reduction and benefit improvement of more than 20 and ten thousand low-yield oil wells with only several square or even hundreds of liters per day in China.
The above are only a few embodiments of the present invention, and those skilled in the art can make various changes or modifications to the embodiments of the present invention according to the disclosure of the application document without departing from the spirit and scope of the present invention.