CN112392444B - Electric lead screw rodless oil extraction device with closed power mechanism - Google Patents

Abstract

The present invention provides an electric lead screw rodless oil production device with a closed power mechanism, which includes a closed power mechanism and a first plunger pump connected under the closed power mechanism, wherein the closed power mechanism includes: a cylinder body, in which A motor is installed; the transmission structure is located in the cylinder and connected with the motor. The transmission structure has a first screw pair and a second screw pair, a first polished rod and a second polished rod, both of which are dynamic and sealed with the cylinder body, and the first polished rod Connect with one end of the drive shaft of the motor through the first lead screw pair, and connect the second polished rod with the other end of the drive shaft of the motor through the second lead screw pair; The incoming and outgoing volumes of the polished rod relative to the cylinder body are the same. The invention overcomes the problems of low oil pumping efficiency of the conventional pumping unit through the sucker rod, poor reliability of other oil production devices using the principle of electric screw rods, and failure of screw lubrication caused by the open structure.

Description

Electric screw rodless oil production device with closed power mechanism

technical field

The invention relates to the technical field of oil and gas field exploitation, in particular to an electric screw rodless oil production device with a closed power mechanism.

Background technique

In the process of oil and natural gas extraction, when the reservoir pressure is not enough to allow crude oil to flow to the ground or gas wells accumulate liquid, it is necessary to use mechanical oil recovery to lift the oil and gas layer production fluid to the ground. More than 95% of oil wells in my country are mechanical oil recovery wells, and the main mechanical oil recovery methods include beam pumping units, electric submersible pumps, and screw pumps.

In recent years, the development of unconventional oil and gas fields such as low permeability, tight oil, and shale oil has dominated the development. "Multiple wells and low production" have become a reality. The requirements for energy conservation and emission reduction are getting higher and higher. Traditional mechanical oil recovery methods have encountered great challenges. Rod lifting methods such as pumping units and ground-driven screw pumps, due to the long transmission chain, the rod and pipe have high eccentric wear resistance, high accident rate, high waste work, low system efficiency, and high energy consumption; electric submersible pumps are more suitable for high-production Liquid oil wells, but most of the more than 200,000 oil wells in my country have a daily liquid production volume of only a few cubic meters or even hundreds of liters.

In order to meet the needs, rodless lifting methods such as submersible plunger pumps and submersible screw pumps have been explored in recent years. The submersible plunger pump drives the plunger to reciprocate up and down through a permanent magnet linear motor. The lifting force is determined by the volume of the magnet. Due to the small gap between the polished rod and the magnet, the wear is relatively large and the accident rate is high. The submersible screw pump of Baker Hughes adopts the method of "conventional three-phase asynchronous motor + reducer + screw pump", which has the problems of long transmission chain, low efficiency and high accident rate of reducer; the submersible underground direct drive screw invented by my country The pump adopts a relatively expensive low-speed permanent magnet synchronous motor, but the low-speed permanent magnet synchronous motor is limited by the small wellbore space, speed, lifting head and displacement, and due to the characteristics of the screw pump itself, the coupling life is short, so it is still It cannot meet the lifting needs of deep wells and low-production oil wells.

Contents of the invention

The object of the present invention is to provide an electric screw rodless oil production device with a closed power mechanism, which overcomes the disadvantages of low energy efficiency of conventional pumping units through sucker rod transmission, and can realize wide displacement range, high head, long Long life, low cost downhole rodless production.

Above-mentioned purpose of the present invention can adopt following technical scheme to realize:

The invention provides an electric lead screw rodless oil production device with a closed power mechanism, which includes a closed power mechanism installed in the downhole oil pipe and a first plunger pump connected under the closed power mechanism, wherein the closed Power mechanism includes:

A cylinder body, in which an electric motor is installed;

The transmission structure is located in the cylinder and connected with the motor, the transmission structure has a first screw pair located below the motor and a second screw pair located above the motor, the first screw pair The rod pair is connected to one end of the drive shaft of the motor, and the second lead screw pair is connected to the other end of the drive shaft of the motor;

The first polished rod and the second polished rod, both of the first polished rod and the second polished rod are in dynamic sealing cooperation with the cylinder body, and the first polished rod passes through the connection between the first lead screw pair and the drive shaft of the motor One end is connected, and the second polished rod is connected with the other end of the drive shaft of the motor through the second screw pair;

Wherein, when the motor rotates to drive the transmission structure to operate, the volume of the first polished rod moving in and out of the cylinder is the same as the volume of the second polished rod moving in and out of the cylinder.

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, the One end of the drive shaft is connected with the first 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 motor The other end of the drive shaft is connected with the second screw nut.

In an embodiment of the present invention, a first guiding and stabilizing structure is provided between the inner wall of the cylinder body and the first screw pair, and the first guiding and stabilizing structure includes a first guiding groove and a first guiding key, The first guide key can move linearly in the first guide groove.

In an embodiment of the present invention, a second guiding and stabilizing structure is provided between the inner wall of the cylinder body and the second screw pair, and the second guiding and stabilizing structure includes a second guiding groove and a second guiding key, The second guide key can move linearly in the second guide groove.

In an embodiment of the present invention, when one end of the drive shaft of the motor is connected to the first screw rod, an upper limit sensor and a lower limit sensor are connected to the first screw rod.

In an embodiment of the present invention, a first upper displacement sensor and a first lower displacement sensor are connected to the first screw nut.

In an embodiment of the present invention, when the other end of the drive shaft of the motor is connected to the second screw, the second screw nut is connected with a second upper displacement sensor and a second lower displacement sensor. sensor.

In an embodiment of the present invention, when the other end of the drive shaft of the motor is connected to the second screw nut, a second upper displacement sensor and a second lower displacement sensor are connected to the second screw nut. sensor.

In an embodiment of the present invention, the cylinder is filled with lubricating liquid.

In an embodiment of the present invention, the electric screw rodless oil production device with a sealed power mechanism further includes a second plunger pump, the second plunger pump is located above the sealed power mechanism, and the sealed power mechanism The second polished rod of the mechanism is connected with the second plunger pump.

In an embodiment of the present invention, the electric lead screw rodless oil production device with a closed power mechanism further includes a ground control cabinet, the ground control cabinet is electrically connected to the motor of the closed power mechanism through a cable, and the cable is set In the oil pipe, alternatively, the cable is arranged in the oil jacket annulus.

In an embodiment of the present invention, both the first screw rod and the second screw rod are ordinary screw screws with rectangular or trapezoidal threads, or both the first screw rod and the second screw rod are ball bearings. lead screw.

Features and advantages of the present invention are:

1. The electric lead screw rodless oil production device with a closed power mechanism of the present invention overcomes the disadvantage of low energy efficiency of conventional pumping units and realizes downhole rodless oil production. The present invention can adopt various rotating motors, including mature, reliable and low-cost conventional high-speed rotating three-phase asynchronous motors, connected to existing plunger pumps, with small investment and strong reliability, and can realize low stroke times, low displacement and high head lift. Simultaneously, the present invention has a simple structure, and key nodes are easy to monitor, and are easy to intelligently adjust parameters. The invention can meet the needs of lifting and draining gas recovery of low-yield, deep wells, inclined wells, horizontal wells and other complex oil and gas wells.

2. The electric lead screw rodless oil production device with a closed power mechanism of the present invention, the closed power mechanism seals the motor, the lead screw, the first polished rod and the second polished rod in the cylinder body. When the motor rotates, the first screw rod, the second polished rod The first polished rod and the second polished rod are synchronously entered and exited from the cylinder by the linkage of two screw rods to keep the volume and pressure constant in the cylinder, so as to realize the overall airtightness of the cylinder, ensure good lubrication of the screw and prevent fouling.

3. The electric lead screw rodless oil production device with a closed power mechanism of the present invention has wide application range, strong reliability, high mechanical efficiency, and high degree of intelligence, which can greatly reduce costs and meet the development needs of my country's "multiple wells and low production" oilfields .

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

Fig. 1 is a structural schematic diagram of an electric screw rodless oil production device with a closed power mechanism according to the present invention.

Fig. 2 is a structural schematic diagram of another embodiment of the electric screw rodless oil production device with a closed power mechanism of the present invention.

Fig. 3 is a schematic structural view of the first embodiment of the sealed power mechanism of the present invention.

Fig. 4 is a schematic structural view of the second embodiment of the sealed power mechanism of the present invention.

Fig. 5 is a schematic structural view of a third embodiment of the sealed power mechanism of the present invention.

Fig. 6 is a schematic structural view of the fourth embodiment of the sealed power mechanism of the present invention.

Reference signs and description:

1. Cylinder body; 2. Transmission structure; 21. The first polished rod; 211. The first dynamic sealing structure; 22. The second polished rod; 221. The second dynamic sealing structure; 23. The first screw pair; 231. The first Screw rod; 232, the first screw nut; 2321, perforation; 233, the upper limit sensor; 234, the lower limit sensor; 235, the first upper displacement sensor; 236, the first lower displacement sensor; 24, the second leading screw Vice; 241, the second screw mandrel; 242, the second screw mandrel nut; 2421, perforation; 243, the second upper displacement sensor; 244, the second lower displacement sensor; 3, motor; 31, connecting bracket; 311, through flow Hole; 32, one end of the drive shaft; 33, the other end of the drive shaft; 4, the first guide and righting structure; 41, the first guide slot; 42, the first guide key; 5, the second guide and righting structure; 51, the first guide Two guide grooves; 52, second guide key; 6, tubing; 7, downhole casing; 8, first plunger pump; 81, first piston; 9, second plunger pump; 10, sealed power mechanism; 11 , Ground control cabinet; 12, cable; 13, oil reservoir.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Wherein, the use of adjective or adverbial modifiers "upper" and "lower", "top" and "bottom", "inner" and "outer" is only for relative reference between groups of terms and is not descriptive. Any specific directional constraints on the modified term. In the description of the present invention, unless otherwise specified, "plurality" means two or more, and "at least one" means one or more.

As shown in Figures 1 to 2, the present invention provides an electric lead screw rodless oil recovery device with a closed power mechanism, including a closed power mechanism 10 installed in the downhole oil pipe 6, and a closed power mechanism 10 connected to the The first plunger pump 8 below, wherein, the airtight power mechanism 10 includes a cylinder body 1, a transmission structure 2, a first polished rod 21 and a second polished rod 22, wherein: a motor 3 is installed in the cylinder body 1; the transmission structure 2 Located in the cylinder body 1 and connected to the motor 3, the transmission structure 2 has a first screw pair 23 below the motor 3 and a second screw pair 24 above the motor 3, so The first lead screw pair 23 is connected to one end 32 of the drive shaft of the motor 3, and the second lead screw pair 24 is connected to the other end 33 of the drive shaft of the motor 3; The second polished rods 22 are all in dynamic sealing cooperation with the cylinder body 1, the first polished rods 21 are connected to one end 32 of the drive shaft of the motor 3 through the first lead screw pair 23, and the second polished rods 22 The other end 33 of the drive shaft of the motor 3 is connected through the second lead screw pair 24; wherein, when the motor 3 rotates to drive the transmission structure 2 to run, the first polished rod 21 is opposite to the cylinder The entry and exit volume of the body 1 is the same as the entry and exit volume of the second polished rod 22 relative to the cylinder body 1 .

The electric lead screw rodless oil production device with a closed power mechanism of the present invention overcomes the shortcoming of low energy efficiency of conventional pumping units, and realizes downhole rodless oil production. The invention can adopt various rotating motors, including mature, reliable and low-cost conventional high-speed rotating three-phase asynchronous motors, and connects existing plunger pumps with small investment and high reliability, and can realize efficient and reliable pumping. Simultaneously, the present invention has a simple structure, and key nodes are easy to monitor, and are easy to intelligently adjust parameters. The invention can meet the needs of lifting and draining gas recovery of low-yield, deep wells, inclined wells, horizontal wells and other complex oil and gas wells.

In addition, the closed power mechanism has a simple structure and overcomes the disadvantage of low pumping energy efficiency of conventional pumping units. The closed power mechanism seals the motor 3, the first polished rod 21 and the second polished rod 22 in the cylinder body 1, which solves the problem of eccentric wear of the polished rods that may exist in the process of motion conversion and energy transmission. The present invention realizes that the first polished rod 21 and the second polished rod 22 enter and exit the cylinder body 1 synchronously through the linkage of the motor 3 , and can keep the internal volume of the cylinder body 1 constant and the pressure inside the cylinder body 1 constant, so as to ensure the overall airtightness of the cylinder body 1 .

Specifically, the cylinder body 1 is generally in the shape of a cylinder, and its interior is filled with lubricating fluid, which can lubricate and cool the components in the cylinder body 1; the motor 3 is fixedly connected to the inner wall of the cylinder body 1, and the motor 3 It can be a rotating 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 body 1 through a connecting bracket 31. The connecting bracket 31 has a plurality of through-flow holes 311, and these through-flow holes 311 are arranged around the motor 3. The setting of the flow hole 311 can make the lubricating fluid above the motor 3 and below the motor 3 flow smoothly. On the one hand, it can achieve the purpose of cooling the motor 3, and on the other hand, it can ensure the first polished rod 21 and the second polished rod 22. The activities in the cylinder body 1 are not hindered by the pressure of the lubricating fluid in the cylinder body 1 .

The first polished rod 21 and the second polished rod 22 are respectively arranged at opposite ends of the cylinder body 1. In this embodiment, the first polished rod 21 is arranged at the lower part of the cylinder body 1 and can protrude from the lower end of the cylinder body 1. A first dynamic sealing structure 211 is arranged between a polished rod 21 and the cylinder body 1; the second polished rod 22 is arranged on the top in the cylinder body 1 and can stretch out from the upper end of the cylinder body 1, and the second polished rod 22 and the cylinder body 1 is provided with a second dynamic sealing structure 221. The present invention adopts the first dynamic sealing structure 211 and the second dynamic sealing structure 221, which can ensure that the movement process of the first polished rod 21 and the second polished rod 22 relative to the cylinder body 1 is always in a sealed state, on the one hand, it can ensure the lubrication inside the cylinder body 1 The liquid does not leak out to ensure the tightness of the cylinder body 1. On the other hand, it can ensure that the first polished rod 21 and the second polished rod 22 can move smoothly relative to the cylinder body 1. In this embodiment, the first dynamic sealing structure 211 and the second dynamic sealing structure 221 may adopt a known labyrinth sealing structure or rubber ring sealing structure, which is not limited here.

According to one embodiment of the present invention, the first lead screw pair 23 of the transmission structure 2 has a first lead screw 231 and a first lead screw nut 232 engaged therewith, and one end 32 of the driving shaft of the motor 3 is connected to the first lead screw. The rod 231 is connected, or one end 32 of the drive shaft of the motor 3 is connected with the first screw nut 232 .

Further, in the present invention, the second lead screw pair 24 has a second lead screw 241 and a second lead screw nut 242 engaged therewith, and the other end 33 of the drive shaft of the motor 3 is connected to the second lead screw 241 , or, the other end 33 of the drive shaft of the motor 3 is connected to the second screw nut 242 .

The other end 33 of the drive shaft of the present invention and one end 32 of the drive shaft belong to the upper and lower ends of the drive shaft of the motor 3, are respectively connected to the first lead screw pair 23 and the second lead screw pair 24, and are symmetrically arranged on the cylinder body relative to the motor 3 within 1.

As shown in Figure 3, in a possible embodiment of the airtight power mechanism 10 of the present invention, one end 32 of the drive shaft of the motor 3 is connected to one end of the first screw 231, and one end of the first screw nut 232 is formed with an inner Thread, the other end of which is a closed end, the first screw nut 232 engages with the first screw 231 through its internal thread, the closed end of the first screw nut 232 is connected with the first polished rod 21, in the present invention, The first screw nut 232 and the first polished rod 21 can be processed as one body, or can be processed separately and connected mechanically, such as by welding, screw connection or interference plug connection, etc., which is not limited here.

In this embodiment, the other end 33 of the drive shaft of the motor 3 is connected to the second screw nut 241, and one end of the second screw nut 242 is formed with an internal thread, and the other end is a closed end. The second screw nut 242 Engage with the second screw rod 241 through its internal thread, the closed end of the second screw nut 242 is connected with the second polished rod 22, in the present invention, the second screw nut 242 and the second polished rod 22 can be processed into one, They can also be processed separately and connected mechanically, for example, by welding or screw connection or interference plug connection, etc., and there is no limitation here.

The mode of operation of the airtight power mechanism 10 in this embodiment is as follows:

Start the motor 3, the drive shaft of the motor 3 rotates, and one end 32 of the drive shaft drives the first screw rod 231 to rotate. At this time, the first screw nut 232 moves upward along the axial direction of the cylinder body 1, and drives the first polished rod 21 upward. At the same time, the other end 33 of the drive shaft drives the second screw 241 to rotate, and now the second screw nut 242 moves upward along the axial direction of the cylinder 1, And drive the second polished rod 22 to move upwards (that is, to move toward the outside of the cylinder body 1). When the driving shaft of the motor 3 rotates in another direction, the first polished rod 21 moves downwards (that is, moves toward the outside of the cylinder body 1), and the second polished rod 22 also moves downwards synchronously (that is, moves toward the inside of the cylinder body 1). direction of movement). During such a movement, the volume of the first polished rod 21 entering and exiting the cylinder 1 is always equal to the volume of the second polished rod 22 entering and exiting the cylinder 1, and the lubricating fluid in the cylinder 1 passes through a plurality of flow holes 311 on the connecting bracket 31 It flows in the cylinder 1 and keeps the pressure in the cylinder 1 constant.

As shown in Figure 4, in another feasible embodiment of the present invention, one end 32 of the drive shaft of the motor 3 is connected with the first screw nut 232, and the first screw nut 232 is engaged with the first screw mandrel 231, the second The other end of the threaded rod 231 is connected to the first polished rod 21. In the present invention, the first threaded rod 231 and the first polished rod 21 can be processed into one body, or can be processed separately and connected mechanically, such as by welding or threading. Connections or interference plug connections, etc., are not limited here.

In this embodiment, the other end 33 of the drive shaft of the motor 3 is connected with the second screw mandrel 241, and the second screw mandrel 241 is engaged with the second screw mandrel nut 242, and the closed end of the second screw mandrel nut 242 is connected with the second polished rod. 22 connected, in the present invention, the second screw nut 242 and the second polished rod 22 can be processed into one body, or can be processed separately and connected mechanically, such as by welding or threaded connection or interference plug connection, etc., in This is not limited.

The mode of operation of the airtight power mechanism 10 in this embodiment is as follows:

Start the motor 3, the drive shaft of the motor 3 rotates, and one end 32 of the drive shaft drives the first screw nut 232 to rotate. At this time, the first screw rod 231 moves upward along the axial direction of the cylinder body 1, and drives the first polished rod 21 upward. At the same time, the other end 33 of the drive shaft drives the second screw 241 to rotate, and now the second screw nut 242 moves upward along the axial direction of the cylinder 1, And drive the second polished rod 22 to move upwards (that is, to move toward the outside of the cylinder body 1). When the driving shaft of the motor 3 rotates in another direction, the first polished rod 21 moves downwards (that is, moves toward the outside of the cylinder body 1), and the second polished rod 22 also moves downwards synchronously (that is, moves toward the inside of the cylinder body 1). direction of movement). During such a movement, the volume of the first polished rod 21 entering and exiting the cylinder 1 is always equal to the volume of the second polished rod 22 entering and exiting the cylinder 1, and the lubricating fluid in the cylinder 1 passes through a plurality of flow holes 311 on the connecting bracket 31 It flows in the cylinder 1 and keeps the pressure in the cylinder 1 constant.

As shown in Figure 5, in the third feasible embodiment of the present invention, one end 32 of the drive shaft of the motor 3 is connected with the closed end of the first screw nut 232, and the first screw nut 232 is engaged with the first screw rod 231 , the other end of the first threaded rod 231 is connected to the first polished rod 21. In the present invention, the first threaded rod 231 and the first polished rod 21 can be processed into one body, or processed separately and connected mechanically, for example, by Welding or screw connection or interference plug connection, etc., are not limited here.

In this embodiment, the other end 33 of the drive shaft of the motor 3 is connected to the closed end of the second screw nut 242, and the second screw nut 242 is engaged with the second screw rod 241, and the other end of the second screw rod 241 It is connected with the second polished rod 22. In the present invention, the second threaded rod 241 and the second polished rod 22 can be processed as a whole, or they can be processed separately and connected mechanically, such as by welding or threaded connection or interference plug connection. etc., no limitation here.

The mode of operation of the airtight power mechanism 10 in this embodiment is as follows:

Start the motor 3, the drive shaft of the motor 3 rotates, and one end 32 of the drive shaft drives the first screw nut 232 to rotate. At this time, the first screw rod 231 moves upward along the axial direction of the cylinder body 1, and drives the first polished rod 21 upward. At the same time, the other end 33 of the drive shaft drives the second screw nut 242 to rotate, and now the second screw 241 moves upward along the axial direction of the cylinder 1, And drive the second polished rod 22 to move upwards (that is, to move toward the outside of the cylinder body 1). When one end 32 of the drive shaft of the motor 3 and the other end 33 of the drive shaft rotate in the other direction, the first polished rod 21 moves downward (that is, moves to the direction outside the cylinder body 1), and the second polished rod 22 is also synchronized Downward movement (that is, movement in the direction of cylinder 1). During such a movement, the volume of the first polished rod 21 entering and exiting the cylinder 1 is always equal to the volume of the second polished rod 22 entering and exiting the cylinder 1, and the lubricating fluid in the cylinder 1 passes through a plurality of flow holes 311 on the connecting bracket 31 It flows in the cylinder 1 and keeps the pressure in the cylinder 1 constant.

As shown in Figure 6, in the fourth feasible embodiment of the present invention, one end 32 of the drive shaft of the motor 3 is connected with one end of the first screw mandrel 231, and one end of the first screw mandrel nut 232 is formed with internal thread, and its other One end is a closed end, and the first screw nut 232 is engaged with the first screw mandrel 231 by its internal thread, and the closed end of the first screw nut 232 is connected with the first polished rod 21. In the present invention, the first screw mandrel The nut 232 and the first polished rod 21 can be processed into one body, or can be processed separately and connected mechanically, for example, by welding, screw connection or interference plug connection, etc., which is not limited here.

In this embodiment, the other end 33 of the drive shaft of the motor 3 is connected with the second screw nut 242, and one end of the second screw nut 242 is formed with an internal thread, and the other end is a closed end. The second screw nut 241 Mesh with the second screw nut 242, and the other end of the second screw rod 241 is connected with the second polished rod 22. In the present invention, the second screw rod 241 and the second polished rod 22 can be processed as one or separately And be connected by mechanical means, such as welding or screw connection or interference plug connection, etc., which is not limited here.

The mode of operation of the airtight power mechanism 10 in this embodiment is as follows:

Start the motor 3, the drive shaft of the motor 3 rotates, and one end 32 of the drive shaft drives the first screw rod 231 to rotate. At this time, the first screw nut 232 moves upward along the axial direction of the cylinder body 1, and drives the first polished rod 21 upward. At the same time, the other end 33 of the drive shaft drives the second screw nut 242 to rotate, and now the second screw 241 moves upward along the axial direction of the cylinder 1, And drive the second polished rod 22 to move upwards (that is, to move toward the outside of the cylinder body 1). When the driving shaft of the motor 3 rotates in another direction, the first polished rod 21 moves downwards (that is, moves toward the outside of the cylinder body 1), and the second polished rod 22 also moves downwards synchronously (that is, moves toward the inside of the cylinder body 1). direction of movement). During such a movement, the volume of the first polished rod 21 entering and exiting the cylinder 1 is always equal to the volume of the second polished rod 22 entering and exiting the cylinder 1, and the lubricating fluid in the cylinder 1 passes through a plurality of flow holes 311 on the connecting bracket 31 It flows in the cylinder 1 and keeps the pressure in the cylinder 1 constant.

According to one embodiment of the present invention, as shown in Fig. 3 to Fig. 6, a first guiding and centralizing structure 4 is connected between the inner wall of the cylinder body 1 and the first lead screw pair 23, and the first guiding and centralizing structure 4 can act as The first lead screw 231 or the first lead screw nut 232 that guides the first lead screw pair 23 moves linearly along the axial direction of the cylinder body 1 to limit the rotation of the first lead screw 231 or the first lead screw nut 232 to realize the guiding The first polished rod 21 moves linearly along the axial direction of the cylinder body 1 to limit the rotation of the first polished rod 21. At the same time, it can also play a role in righting the first screw rod 231 or the first screw nut 232 to prevent the first polished rod from 21 is deflected during the axial movement.

In a feasible embodiment, a first guide groove 41 is provided on the inner wall of the cylinder body 1, and a first guide key 42 is connected to the first lead screw pair 23, and the first guide key 42 can be positioned in the first guide groove. 41 to move in a straight line. In this embodiment, when the first polished rod 21 is connected to the first screw nut 232 of the first screw pair 23, as shown in Figure 3 and Figure 6, the first guide key 42 is connected to the first screw nut 232. On the rod nut 232; as shown in Figure 4 and Figure 5, when the first polished rod 21 is connected to the first screw rod 231 of the first screw pair 23, the first guide key 42 is connected to the first screw rod 231 superior.

In another feasible embodiment, a first guide key 42 is connected to the inner wall of the cylinder body 1, and the first screw pair 23 is provided with a first guide groove 41, and the first guide key 42 can Move linearly in the groove 41. In this embodiment, when the first polished rod 21 is connected to the first screw nut 232 of the first screw pair 23, the first guide groove 41 is opened on the outer wall of the first screw nut 232 (not provided Accompanying drawing); When the state that the first polished rod 21 is connected with the first screw mandrel 231 of the first lead screw pair 23, the first guide groove 41 is offered on the first screw mandrel 231 (the accompanying drawings are not provided).

According to another embodiment of the present invention, a second guiding and centralizing structure 5 is connected between the inner wall of the cylinder body 1 and the second screw pair 24 , and the second guiding and centralizing structure 5 can guide the second screw pair 24 The second screw 241 or the second screw nut 242 moves linearly along the axial direction of the cylinder body 1, restricting the rotation of the second screw rod 241 or the second screw nut 242, so as to guide the second polished rod 22 along the cylinder body 1 Linear movement in the axial direction of the second polished rod 22, the purpose of restricting the rotation of the second polished rod 22, and at the same time, it can also play a role in righting the second screw rod 241 or the second screw nut 242, preventing the second polished rod 22 from deflecting during the moving process .

In a feasible embodiment, a second guide groove 51 is provided on the inner wall of the cylinder body 1, and a second guide key 52 is connected to the second lead screw pair 24, and the second guide key 52 is arranged axially movable. in the second guide groove 51 . In this embodiment, when the second polished rod 22 is connected to the second screw nut 242 of the second lead screw pair 24, as shown in Figures 3 and 4, the second guide key 52 is connected to the second lead screw On the rod nut 242; as shown in Figure 5 and Figure 6, when the second polished rod 22 is connected to the second screw rod 241 of the second screw pair 24, the second guide key 52 is connected to the second screw rod 241 superior.

In another feasible embodiment, a second guide key 52 is connected to the inner wall of the cylinder body 1, and the second screw pair 24 is provided with a second guide groove 51, and the second guide key 52 can move axially. It is arranged in the second guide groove 51 . In this embodiment, when the second polished rod 22 is connected to the second screw nut 242 of the second screw pair 24, the second guide groove 51 is opened on the outer wall of the second screw nut 242 (not provided Accompanying drawing); Under the state that the second polished rod 22 is connected with the second screw mandrel 241 of the second lead screw pair 24, the second guide groove 51 is offered on the second screw mandrel 241 (the accompanying drawings are not provided).

According to one embodiment of the present invention, in a state where one end 32 of the drive shaft of the motor 3 is connected to the first screw rod 231 , an upper limit sensor 233 and a lower limit sensor 234 are connected to the first screw rod 231 . Specifically, the upper limit sensor 233 is disposed close to the motor 3 , and the lower limit sensor 234 is disposed close to the first polished rod 21 .

As shown in Fig. 3 and Fig. 6, when the first screw nut 232 moves upwards to the upper limit sensor 233 at the top of the first screw mandrel 231, or, when the first screw nut 232 moves down to the upper limit sensor 233 at the first When the lower limit sensor 234 is on the bottom of the screw mandrel 231, the upper limit sensor 233 and/or the lower limit sensor 234 can send a signal command to the external control system. After the external control system receives the command, it can control the drive shaft of the motor 3 to convert the direction of rotation. Further, the first threaded mandrel 231 is controlled to rotate in reverse.

The setting of the upper limit sensor 233 and the lower limit sensor 234 is used to sense the displacement of the first lead screw nut 232 and the time when it moves to the upper part of the first lead screw 231 or the lower part of the first lead screw 231 .

Further, the first screw nut 232 is connected with a first upper displacement sensor 235 and a first lower displacement sensor 236 . Specifically, the first upper displacement sensor 235 is disposed close to the motor 3 , and the first lower displacement sensor 236 is disposed close to the first polished rod 21 . As shown in Figure 3 and Figure 6, the movement speed and position of the first screw nut 232 can be transmitted to the external control system through the first upper displacement sensor 235 and the first lower displacement sensor 236, after the external control system receives the instruction, it can Determine the working condition of the airtight power mechanism 10 according to the movement speed and position of the first screw nut 232, thereby determine the forward and reverse timing and forward and reverse switching frequency of the motor 3, and then adjust the first plunger connected to the first polished rod 21 Parameters such as the stroke and stroke times of the pump 8.

According to a feasible embodiment of the present invention, in the state where the other end 33 of the drive shaft of the motor 3 is connected to the second screw 241 , the second screw nut 242 is connected with a second upper displacement sensor 243 and a second screw nut 242 . Two lower displacement sensors 244. Specifically, the second upper displacement sensor 243 is disposed close to the second polished rod 22 , and the second lower displacement sensor 244 is disposed close to the motor 3 .

As shown in FIGS. 3 and 4 , the movement speed and position of the second screw nut 242 can be transmitted to the external control system through the second upper displacement sensor 243 and the second lower displacement sensor 244 , and then can be transmitted according to the second screw nut 242 The speed and position of the movement determine the working condition of the airtight power mechanism 10, thereby determining the forward and reverse timing of the motor 3, the forward and reverse switching frequency, and then adjusting the parameters such as the stroke and stroke times of the plunger pump connected to the second polished rod 22.

According to another feasible embodiment of the present invention, in the state where the other end 33 of the drive shaft of the motor 3 is connected to the second screw nut 242, the second screw rod 241 is connected with a second upper displacement sensor 243 and The second lower displacement sensor 244 .

As shown in Figures 5 and 6, the movement speed and position of the second screw rod 241 can be transmitted to the external control system through the second upper displacement sensor 243 and the second lower displacement sensor 244, and then can be controlled according to the movement of the second screw rod 241 The speed and position determine the working conditions of the present invention, thereby determining the forward and reverse timing and forward and reverse switching frequency of the motor 3, and then adjusting the parameters such as the stroke and stroke times of the plunger pump connected to the second polished rod 22.

In the present invention, in the above-mentioned implementations of FIGS. , screw thread lead and other parameters can be optimally designed and configured according to the lifting force, stroke and stroke times, and reduction ratio of the oil well pump. In addition, the first screw rod 231, the first screw nut 232, the second screw rod 241, the second screw nut 242, the first polished rod 21 and the second polished rod 22 can be manufactured integrally, or can be designed and manufactured separately. Just connect and assemble. The first lead screw 231, the first lead screw nut 232, the second lead screw 241 and the second lead screw nut 242 can be ball screws, ordinary lead screws or other specially designed lead screws, wherein the threads in the ordinary lead screws can be For trapezoidal thread or rectangular thread, etc. Furthermore, perforations 2321 and 2421 are provided on the peripheral walls of the first screw nut 232 and the second screw nut 242, so that the lubricating liquid in the cylinder body 1 can flow into the first screw nut 232 and the second screw nut. 242 to achieve the purpose of lubricating the first screw mandrel 231 and the second screw mandrel 241.

In this airtight power mechanism 10, when the first polished rod 21 is connected to the first plunger pump 8, the second polished rod 22 on the upper part can play a role of volume compensation for the cylinder body 1 of the airtight power mechanism 10; on the contrary, when the second polished rod 22 is connected with the second plunger pump 9, the first polished rod 21 located at the lower part can also play a role of volume compensation for the cylinder body 1 of the airtight power mechanism 10. The diameter of the first polished rod 21 and the second polished rod 22, the lead and the size of the first screw mandrel 231 and the second screw mandrel 241 can be the same or different, but the volume of the polished rods entering the cylinder body 1 and extending out of the cylinder body 1 respectively The volume of the polished rods is the same, so as to ensure that the pressure in the cylinder remains unchanged.

As shown in Figures 1 to 2, the electric lead screw rodless oil production device with a closed power mechanism of the present invention also includes a ground control cabinet 11, which is placed on the ground, and the ground control cabinet 11 is connected to the ground through a cable 12. The motor 3 of the closed power mechanism 10 located in the downhole is electrically connected, wherein the cable 12 includes a power cable and a data cable, the upper limit sensor 233, the lower limit sensor 234, the first upper displacement sensor 235, the first lower limit sensor 234 of the closed power mechanism 10. The partial displacement sensor 236 , the second upper displacement sensor 243 and the second lower displacement sensor 244 are all in communication with the data cable; the power cable is electrically connected with the motor 3 of the airtight power mechanism 10 . In the present invention, the power of the motor 3 can be determined according to the displacement and head of the first plunger pump 8 .

Specifically, as shown in Fig. 1, the airtight power mechanism 10 and the first plunger pump 8 are placed in the downhole liquid sequentially from top to bottom, through the power supply of the ground control cabinet 11, and through the cable 12 to the airtight power mechanism 10 downhole. Power is supplied, and at this time, the motor 3 rotates in the forward direction, and the first polished rod 21 of the airtight power mechanism 10 moves upwards, and drives the first plunger pump 8 to move upwards to discharge liquid. When the ground control cabinet 11 detects the signal transmitted by the upper limit sensor 233, the motor 3 reversely rotates, and at this moment, the first polished 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. At this time, the first polished rod 21 of the airtight power mechanism 10 moves upward, and drives the first plunger pump 8 to discharge liquid. In this way, one suction stroke is completed, and the above steps are reciprocated to achieve the purpose of pumping the liquid in the downhole reservoir 13 .

In the embodiment of Fig. 1, only the first polished rod 21 at the bottom of the airtight power mechanism 10 is connected with the first plunger pump 8 to realize the purpose of pumping downhole crude oil; and the second polished rod 22 at the top of the airtight power mechanism 10 Not connected to the plunger pump, the second polished rod 22 can play a role in volume compensation for the cylinder body 1 of the airtight power mechanism 10. In this case, the diameter of the second polished rod 22 and the Parameters such as the lead of the second screw mandrel 241 or the second screw nut 242 shorten the length of the axial direction of the cylinder body 1, thereby shortening the total length of the entire airtight power mechanism 10, reaching the purpose of reducing the overall size of the airtight power mechanism 10. Purpose.

According to an embodiment of the present invention, as shown in FIG. 2 , the rodless oil production device further includes a second plunger pump 9, and the second plunger pump 9 is located above the sealed power mechanism 10. The first piston pump of the sealed power mechanism 10 is The second polished rod 22 links to each other with the second piston rod of the second plunger pump 9 . In this embodiment, the first plunger pump 8 and the second plunger pump 9 are connected to the airtight power mechanism 10 to realize double-pump suction and improve the efficiency of downhole oil recovery.

Specifically, as shown in Figure 2, the second plunger pump 9, the sealed power mechanism 10 and the first plunger pump 8 are sequentially placed in the downhole fluid from top to bottom, through the power supply of the ground control cabinet 11, and through the cable 12 Power is supplied to the closed power mechanism 10 in the well. At this time, the motor 3 rotates in the forward direction, and the first polished rod 21 of the closed power mechanism 10 moves upward, and drives the first piston 81 of the first plunger pump 8 to move upward for liquid discharge , and at the same time the second polished rod 22 moves upwards, and drives the second plunger pump 9 to move upwards to absorb liquid. After the ground control cabinet 11 detects the signal transmitted by the upper limit sensor 233, the motor 3 rotates in the opposite direction. At this time, the first polished rod 21 of the airtight power mechanism 10 moves downward, driving the first plunger pump 8 to absorb liquid, and at the same time the second The polished rod 22 moves downward, and drives 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 drive motor 3 rotates in the forward direction. The second polished rod 22 of the mechanism 10 moves upwards and drives the second plunger pump 9 to absorb liquid. In this way, one suction stroke is completed, and the above steps are reciprocated to achieve the purpose of pumping the liquid in the oil reservoir 13 .

In the electric lead screw rodless oil production device with a closed power mechanism of the present invention, the ground control cabinet 11 can be operated according to the operating conditions of the first screw 231 , the first screw nut 232 , the second screw 241 and the second screw nut 242 Intelligently adjust the forward and reverse direction, rotational speed, stroke and working conditions of the first screw 231, the first screw nut 232, the second screw 241 or the second screw nut 242 of the motor 3, thereby optimizing the adjustment of the first column The stroke, stroke times or emergency start and stop of the plunger pump 8 and/or the second plunger pump 9. The invention can meet the needs of low-yield, deep wells, inclined wells, horizontal wells and other complex oil and gas wells for lifting and drainage and gas recovery, especially to meet the urgent need of saving energy, reducing consumption and improving benefits for more than 200,000 low-yielding oil wells in my country with a daily output of only a few square meters or even hundreds of liters need.

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 contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims (13)

1. An electric lead screw rodless oil production device with a closed power mechanism, characterized in that it includes a closed power mechanism installed in the downhole oil pipe and a first plunger pump connected below the closed power mechanism, wherein, The airtight power mechanism includes: A cylinder body, in which an electric motor is installed; The transmission structure is located in the cylinder and connected with the motor, the transmission structure has a first screw pair located below the motor and a second screw pair located above the motor, the first screw pair The rod pair is connected to one end of the drive shaft of the motor, and the second lead screw pair is connected to the other end of the drive shaft of the motor; The first polished rod and the second polished rod, both of the first polished rod and the second polished rod are in dynamic sealing cooperation with the cylinder body, and the first polished rod passes through the connection between the first lead screw pair and the drive shaft of the motor One end is connected, and the second polished rod is connected with the other end of the drive shaft of the motor through the second screw pair; Wherein, when the motor rotates to drive the transmission structure to operate, the volume of the first polished rod moving in and out of the cylinder is the same as the volume of the second polished rod moving in and out of the cylinder. 2. The electric lead screw rodless oil production device with a closed power mechanism as claimed in claim 1, wherein the first lead screw pair has a first lead screw and a first lead screw nut, and the drive of the electric motor One end of the shaft is connected with the first screw, or one end of the drive shaft of the motor is connected with the first screw nut. 3. The electric lead screw rodless oil production device with a closed power mechanism as claimed in claim 2, wherein the second lead screw pair has a second lead screw and a second lead screw nut, and the drive of the electric motor The other end of the shaft is connected with the second screw, or the other end of the drive shaft of the motor is connected with the second screw nut. 4. The electric lead screw rodless oil production device with a closed power mechanism according to claim 1, characterized in that a first guiding and stabilizing structure is provided between the inner wall of the cylinder body and the first lead screw pair, The first guiding and stabilizing structure includes a first guiding slot and a first guiding key, and the first guiding key can move linearly in the first guiding slot. 5. The electric lead screw rodless oil production device with a sealed power mechanism as claimed in claim 4, characterized in that a second guiding and stabilizing structure is arranged between the inner wall of the cylinder body and the second lead screw pair, The second guiding and stabilizing structure includes a second guiding slot and a second guiding key, and the second guiding key can move linearly in the second guiding slot. 6. The electric screw rodless oil production device with a sealed power mechanism according to claim 2, characterized in that, in the state where one end of the drive shaft of the electric motor is connected to the first screw mandrel, the second An upper limit sensor and a lower limit sensor are connected on the threaded rod. 7. The electric lead screw rodless oil production device with a closed power mechanism according to claim 6, wherein a first upper displacement sensor and a first lower displacement sensor are connected to the first screw nut. 8. The electric lead screw rodless oil production device with a closed power mechanism according to claim 3, characterized in that, in the state where the other end of the drive shaft of the electric motor is connected to the second screw mandrel, the A second upper displacement sensor and a second lower displacement sensor are connected to the second screw nut. 9. The electric lead screw rodless oil production device with a sealed power mechanism as claimed in claim 3, wherein, in the state where the other end of the drive shaft of the electric motor is connected to the second screw nut, the A second upper displacement sensor and a second lower displacement sensor are connected to the second screw rod. 10. The electric lead screw rodless oil extraction device with a sealed power mechanism according to claim 1, wherein the cylinder is filled with lubricating fluid. 11. The electric screw rodless oil production device with a closed power mechanism according to claim 1, characterized in that, the electric screw rodless oil production device with a closed power mechanism further comprises a second plunger pump, the The second plunger pump is located above the airtight power mechanism, and the second polished rod of the airtight power mechanism is connected with the second plunger pump. 12. The electric screw rodless oil production device with a closed power mechanism according to claim 1, characterized in that, the electric screw rodless oil production device with a closed power mechanism further includes a ground control cabinet, and the ground control cabinet The cabinet is electrically connected with the motor of the sealed power mechanism through cables, and the cables are arranged in the oil pipe, or the cables are arranged in the oil jacket annulus. 13. The electric screw rodless oil production device with a closed power mechanism according to claim 3, characterized in that, the first screw rod and the second screw rod are ordinary screw screws with rectangular or trapezoidal threads, Alternatively, both the first screw and the second screw are ball screws.

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