CN204371621U - A sealing device for electric submersible reciprocating pump oil production system - Google Patents

Abstract

The utility model relates to a sealing device for electronic oily reciprocating pump oil recovery system that dives, including electronic oily reciprocating pump barrel that dives, the oil-well pump pull rod, still include linear electric motor, linear electric motor's upper and lower end is enclosed by last bellows and bellows seal down respectively, it sets up bellows protecting tube and bellows protecting tube down respectively to go up the bellows and bellows outside of tubes down, adopt high elasticity corrosion resistant rubber bellows, realized diving oily linear electric motor motion part and well liquid's thorough isolation, be full of lubricating oil in the bellows simultaneously, make the rotor shaft be in good lubricated state all the time, the trouble-free operating time of electronic oily reciprocating pump oil recovery system that dives has been guaranteed.

Description

A sealing device for electric submersible reciprocating pump oil production system

technical field

The utility model belongs to the technical field of downhole operation tools in the petroleum and natural gas industry, and in particular relates to a sealing device for an electric submersible reciprocating pump oil production system, which is a sealing device designed for an electric submersible reciprocating pump oil production system in an oil field, and is suitable for using a submersible reciprocating pump. The oil linear motor is connected to the reciprocating pump to lift the crude oil production well.

Background technique

The electric submersible reciprocating pump oil production system is to place the submersible linear motor downhole, and convert the electric energy into linear reciprocating mechanical energy through magnetic excitation, without any transmission device of an intermediate conversion mechanism, so as to directly drive the oil well pump to realize reciprocating motion, lifting pump oil.

For example, Chinese patent CN103557145A discloses an electric submersible reciprocating pump, including three parts of a linear motor, an oil well pump and a ground control cabinet. There is a centralizer at the bottom; the oil well pump includes an outer cylinder, an inner cylinder and a plunger. The interior of the oil well pump is sequentially connected collar, push rod, liquid inlet screen, plunger, swimming ball, swimming Springs, fixed balls, fixed springs, elevator positions and connecting hoops. The linear motor mover is composed of a permanent magnet, a magnetic stack, and a central rod; the permanent magnet is sealed with an anti-corrosion alloy material; the magnetic stack and the central rod are made of stainless steel; the linear motor stator is composed of a winding iron core, an inner cylinder and an outer shell; There is no bearing between the stator and the mover; the outer surface of the iron ring of the mover and the stator support guide sleeve form a friction pair; the lead-out cable of the linear motor is protected by a stainless steel tube, and the outer wall of the stainless steel tube is welded to the stator assembly at the outlet; the lead-out cable Mates with the small flat cable inside the junction barrel. The liquid inlet screen is sleeved on the push rod, and the upper end of the liquid inlet screen is equipped with a multi-blade sand scraper, which is closely matched with the push rod. The outside of the plunger is covered with a sleeve. The upper end of the fixed ball is equipped with a spring return pilot valve. The annular space between the inner cylinder and the outer cylinder is a grit chamber. The fixed ball is located at the upper end of the pump cavity. When the plunger travels to the top dead center, the distance between the plunger and the fixed ball seat is less than 10mm, and the lower end of the liquid inlet screen 11 is equipped with a sand scraping cup.

The well fluid flows from the bottom to the top (vertical well) to the oil pump through the outer wall of the linear motor. The motor dissipates heat through the well fluid, and at the same time warms the well fluid to enhance the fluidity of the well fluid. The alternating traveling wave magnetic field of the motor stator has a dilution effect on the well fluid. When the motor stator goes up, the well fluid is sucked into the motor balance chamber through the liquid inlet hole of the balance chamber within 1 second; when the motor stator goes down, the well fluid in the balance chamber is squeezed out by the rotor within 1 second. Repeatedly, it continuously produces local impact on the oil layer, and can also increase the fluidity of the oil, effectively solve the problem of plugging, and is suitable for the production of vertical wells, inclined wells, and horizontal wells.

Another example is the Chinese patent CN202900189U, which discloses a process string for an electric submersible pump, which includes a string assembly and an electric submersible pump assembly loaded into the string assembly, and the string assembly It includes the oil pipe inserted into the casing, the front end of the oil pipe is provided with a snubbing switch, the electric submersible pump assembly includes the electric submersible pump and the snubbing switch operating rod installed at the front end of the pump, the electric submersible pump is installed Inside the tubing, the snubbing switch operating rod is located above the snubbing switch. A pump connection seat is also provided between the oil pipe and the snubbing switch, and a locking claw is installed on the electric submersible pump and engaged with the locking claw on the pump connection seat; There is a sealing ring; the position where the front end of the electric submersible pump is connected to the snubbing switch operating rod is also provided with a suction port; the rear end of the electric submersible pump is connected to a cable, and the cable is sealed in a coiled tubing; the oil pipe is divided into Two sections of oil pipes with different diameters are connected to each other. An electric submersible pump is installed in the oil pipe with a large diameter, and a packer and an exhaust valve are installed between the outer wall of the oil pipe with a small diameter and the casing; the casing is a 7in casing, The oil pipes are 4in oil pipe and 5in oil pipe respectively.

The tubing string adopts a combination of two-stage tubing that is thinner at the top and thicker at the bottom. A non-casing packer is installed outside the upper tubing, and a plug-in electric submersible pump connection seat and a one-way snubbing switch are installed at the bottom of the lower tubing. The whole set of pipe string and tool combination is installed downhole for a long time as a standing pipe string. The plug-in electric submersible pump with a lower suction port is transported downhole by coiled tubing, inserted into the pump connection seat to lock and seal, and at the same time, the snubbing switch operating lever opens the snubbing switch to open the tubing channel, and the formation fluid is lifted by the electric submersible pump. The rising edge produces ground in the annulus between the coiled tubing and the tubing. When the electric submersible pump is pulled out, the snubbing switch is automatically closed to block the tubing passage. Use simple downhole tools to realize pump inspection of electric submersible pump without snubbing operation, simplify the operation process, shorten the operation time, save the operation platform, and save operation costs; there is no need to kill the well during pump inspection, reducing reservoir damage and protecting reservoir productivity.

It can be seen from the above two patents that, compared with the rod pump oil production system of the pumping unit, the electric submersible reciprocating pump oil production system eliminates the stroke loss because it does not require the sucker rod, and improves the pump efficiency of the oil well pump and the operating efficiency of the system. Reduce energy consumption, and fundamentally solve the problem of eccentric wear of rods and tubes that is common in directional wells.

However, domestic and foreign investigations have found that the failure of the dynamic seal of the motor has become a major obstacle restricting the popularization and application of the system. Once the dynamic seal fails, the well fluid with impurities will enter the inside of the motor, causing corrosion of the mover magnetic steel, abrasion of the inner hole of the stator, and even burning of the motor, which seriously affects the service life of the oil production system. Therefore, it is necessary to redesign the dynamic sealing device of the system to meet the production needs of the oil well.

Utility model content

The purpose of this utility model is to overcome the failure of the dynamic seal of the current motor. After the seal fails, the well fluid with impurities will enter the interior of the motor, causing the corrosion of the mover magnet, the wear of the inner hole of the stator, and even the burning of the motor, which seriously affects the motor. The problem of the service life of the oil production system.

For this reason, the utility model provides a sealing device for an electric submersible reciprocating pump oil production system, including an electric submersible reciprocating pump barrel, an oil pump pull rod inside the electric submersible reciprocating pump barrel, and a linear motor, The lower end of the pull rod of the oil pump is connected to the upper end of the upper pull rod of the linear motor, and the lower end of the motor outer cylinder of the linear motor is connected with a plug;

The outer wall of the upper part of the upper tie rod is covered with an upper bellows, and an upper bellows protective pipe is arranged outside the upper bellows. The upper end of the upper bellows is connected to the connection between the pull rod of the oil well pump and the upper tie rod, and the lower end of the upper bellows is connected to the upper end of the outer cylinder of the motor. , the upper and lower ends of the upper bellows protection pipe are respectively connected to the lower end of the electric submersible reciprocating pump cylinder and the upper end of the motor outer cylinder;

The outer wall of the lower part of the lower rod of the linear motor is covered with a lower bellows, and the lower bellows is provided with a lower bellows protection tube. The upper end of the lower bellows is connected to the lower end of the motor tail pipe of the linear motor, and the lower end of the lower bellows is connected to the lower end of the lower rod The upper and lower ends of the lower bellows protection pipe are respectively connected to the lower end of the motor tail pipe and the upper end of the plug.

The connection between the pull rod of the oil well pump and the upper pull rod is provided with a first flange, the upper end of the motor outer cylinder is provided with a second flange, and the upper and lower ends of the upper bellows are respectively connected to the first flange and the second flange. on the orchid plate;

The lower end of the motor tail pipe is provided with a third flange, the lower end of the pull rod is provided with a fourth flange, and the upper and lower ends of the lower bellows are respectively connected to the third flange and the fourth flange.

The upper end of the inner wall of the upper bellows protective pipe is threaded to the lower end of the outer wall of the electric submersible reciprocating pump cylinder, the lower end of the upper bellows protective pipe is connected to the upper end of the motor outer cylinder by bolts, and the lower bellows protective pipe The upper end of the inner wall of the motor tail pipe is threaded to the lower end of the outer wall of the motor tail pipe, and the lower end of the outer wall of the lower bellows protective pipe is threaded to the upper end of the inner wall of the plug.

A vertical buffer spring is installed inside the plug, the upper end of the buffer spring is connected to the lower end of the pull rod, and the lower end of the buffer spring is fixed at the bottom of the plug.

The upper bellows and the lower bellows are rubber bellows.

Stainless steel springs are embedded in the upper bellows and the lower bellows.

The stainless steel spring is in a free state when the linear motor is at the lower limit, and the stainless steel spring is in the maximum energy storage state when the linear motor is at the upper limit.

The upper bellows and the lower bellows are filled with lubricating oil.

The inner walls of the upper bellows protection pipe and the lower bellows protection pipe are provided with multi-circle and equal displacement limit stops.

Beneficial effects of the utility model: the utility model adopts high-elasticity and corrosion-resistant rubber bellows, which realizes the complete isolation of the moving part of the submersible linear motor from the well fluid, and at the same time fills the bellows with lubricating oil, so that the mover shaft is always in good condition. The lubrication state ensures the trouble-free working time of the electric submersible reciprocating pump oil production system.

The utility model will be described in further detail below in conjunction with the accompanying drawings.

Description of drawings

Fig. 1 is a structural principle diagram of the utility model.

Explanation of reference signs: 1. Electric submersible reciprocating pump cylinder; 2. Oil well pump pull rod; 3. Upper bellows protection tube; 4. Upper bellows; 5. Motor outer cylinder; 6. Upper pull rod; 7. Motor tail 8, the lower bellows protective tube; 9, the lower bellows; 10, the lower rod; 11, the plug; 12, the buffer spring.

Detailed ways

At present, the problem of dynamic seal failure in the motor has become a major obstacle restricting the popularization and application of this system. Once the dynamic seal fails, the well fluid with impurities will enter the inside of the motor, causing corrosion of the mover magnetic steel, abrasion of the inner hole of the stator, and even burning of the motor, which seriously affects the service life of the oil production system. Therefore, it is necessary to redesign the dynamic sealing device of the system to meet the production needs of the oil well.

Example 1:

This embodiment provides a sealing device for an electric submersible reciprocating pump oil production system, as shown in FIG. It also includes a linear motor, the lower end of the pull rod 2 of the oil pump is connected to the upper end of the upper rod 6 of the linear motor, and the lower end of the motor outer cylinder 5 of the linear motor is connected with a plug 11;

The outer wall of the upper part of the upper tie rod 6 is covered with an upper bellows 4, and an upper bellows protection pipe 3 is arranged outside the upper bellows 4. The lower end is connected to the upper end of the motor outer cylinder 5, and the upper and lower ends of the upper bellows protection pipe 3 are respectively connected to the lower end of the electric submersible reciprocating pump cylinder 1 and the upper end of the motor outer cylinder 5;

The outer wall of the lower part of the lower rod 10 of the linear motor is covered with a lower bellows 9, and the lower bellows 9 is provided with a lower bellows protection pipe 8, the upper end of the lower bellows 9 is connected to the lower end of the motor tail pipe 7 of the linear motor, and the lower bellows 9 The lower end of the lower end is connected with the lower end of the pull rod 10, and the upper and lower ends of the lower bellows protection pipe 8 are respectively connected with the lower end of the motor tail pipe 7 and the upper end of the plug 11.

The structure in this embodiment makes the upper bellows 4 and the lower bellows 9 respectively located at the upper end and the lower end of the linear motor, so as to completely isolate the moving part of the submersible linear motor from the well fluid. As the shaft of the linear motor moves axially (represented as the axial reciprocating movement of the upper pull rod 6 and the lower pull rod 10 in the utility model), the upper bellows 4 and the lower bellows 9 are continuously stretched and Compression, to isolate the well fluid from entering the submersible motor, the upper and lower bellows protective tubes are respectively located outside the upper and lower rubber bellows, and play a guiding role in the deformation of the bellows.

Example 2:

The connection relationship in the above-mentioned embodiment 1 may be the case in this embodiment: a first flange is provided at the connection between the pull rod 2 of the oil well pump and the upper rod 6, and a second flange is provided at the upper end of the motor outer cylinder 5. The upper and lower ends of the upper bellows 4 are respectively connected to the first flange and the second flange; the lower end of the motor tail pipe 7 is provided with a third flange, and the lower end of the lower rod 10 is provided with a fourth flange. The upper and lower ends of the lower bellows 9 are respectively connected to the third flange and the fourth flange.

The flanges are respectively connected to the upper and lower rods of the submersible linear motor, and the flanges connected to the bellows are also used as the support of the corrugated protective tube to prevent the corrugated tube from directly contacting the corrugated protective tube and damaging the outside of the corrugated tube.

Several flanges in this embodiment are connected to the upper bellows 4 and the lower bellows 9 in a very sealed manner, so that the well fluid will not enter the moving part of the linear motor from here. Such a structure can make the movement of the linear motor The part is sealed and surrounded by the flange, the upper bellows 4 and the lower bellows 9, and no well fluid can penetrate during the movement, which ensures the complete sealed operation inside the motor.

Example 3:

The peripheral protection pipe column in the above-mentioned embodiment 1 has the following structure in this embodiment. The upper end of the inner wall of the upper bellows protection pipe 3 is threaded to the lower end of the outer wall of the electric submersible reciprocating pump cylinder 1. The upper bellows The lower end of the protective pipe 3 is connected to the upper end of the motor outer cylinder 5 by bolts, the upper end of the inner wall of the lower bellows protective pipe 8 is threaded to the lower end of the outer wall of the motor tail pipe 7, and the lower end of the outer wall of the lower bellows protective pipe 8 is threaded to the plug 11 the upper end of the inner wall.

This structure guarantees the working environment of the upper bellows 4 and the lower bellows 9, making them less susceptible to interference from the external well fluid environment, more able to ensure long-term operation of the equipment, and prolonging its service life to a certain extent.

Example 4:

On the basis of the above-mentioned embodiments 1, 2, and 3, a vertical buffer spring 12 is installed inside the plug 11 in this embodiment. It is fixed at the bottom of the plug 11.

Because the running state of the linear motor is to reciprocate along the axial direction, this structure can make the pull rod of the linear motor have a certain buffer during operation, and will not mechanically collide with the plug to damage the linear motor.

Example 5:

In this embodiment, the upper bellows 4 and the lower bellows 9 are specifically rubber bellows, and the rubber bellows are relatively flexible, and can stretch and shrink repeatedly under the premise of meeting the sealing requirement. Compared with other materials The corrugated pipe is more suitable for the structure type of the utility model. Moreover, the corrugated structure can be designed so that the two sides of the corrugated are vertical, so that the stretching and compression of the corrugated pipe will be smoother and the stress will be smaller.

Further, the upper bellows 4 and the lower bellows 9 are embedded with stainless steel springs, which can not only increase their elasticity, but also prevent the bellows from being stretched or compressed excessively. The stainless steel spring is in a free state when the linear motor is at the lower limit, and the stainless steel spring is in the maximum energy storage state when the linear motor is at the upper limit. When the linear motor moves downward to the limit position, it drags the oil pump to discharge the well fluid, and the spring releases the stored energy, which reduces the working current of the submersible linear motor and reduces the energy consumption of the system.

In this embodiment, the upper bellows 4 and the lower bellows 9 are filled with lubricating oil, so that the moving parts of the linear motor are always in a good lubricating state, while maintaining the pressure balance between the inner cavity and the well fluid.

Embodiment 6:

On the basis of the above-mentioned embodiments 1 to 5, in this embodiment, the inner walls of the upper bellows protection pipe 3 and the lower bellows protection pipe 8 are provided with multi-circle and equal displacement limit stops. Since the upper bellows 4 and the lower bellows 9 may have uneven stretching in some positions during the reciprocating movement, and in severe cases, they may overlap and affect the service life of the bellows. The setting of these limit stops is quite Because the bellows are divided into multiple small units, each limit stopper is equivalent to a wiper, which can correct a small section of bellows to ensure that the bellows of each unit stretch evenly.

To sum up, the sealing device used in the electric submersible reciprocating pump oil production system of the present utility model completely isolates the moving part of the submersible linear motor from the well fluid, so as to obtain a longer trouble-free working time.

The above examples are only illustrations of the present utility model, and do not constitute a limitation to the protection scope of the present utility model. All designs identical or similar to the present utility model belong to the protection scope of the present invention.

Claims (9)

1. the seal arrangement for electric submersible oil reciprocation pump oil production system, comprise the oil well pump pull bar (2) of electric submersible oil reciprocation pump pump barrel (1), electric submersible oil reciprocation pump pump barrel (1) inside, also comprise linear electric motor, it is characterized in that: oil well pump pull bar (2) lower end connects upper connecting rod (6) upper end of linear electric motor, and the lower end of the motor urceolus (5) of linear electric motor is connected with plug (11);

Upper connecting rod (6) external wall of upper portion cover has upper bellows (4), upper bellows (4) is outside equipped with bellows protecting tube (3), the upper end of upper bellows (4) is connected to oil well pump pull bar (2) and upper connecting rod (6) joint, the lower end of upper bellows (4) is connected to the upper end of motor urceolus (5), and the upper and lower end of upper bellows protecting tube (3) connects the lower end of electric submersible oil reciprocation pump pump barrel (1) and the upper end of motor urceolus (5) respectively;

Lower link (10) the bottom outer wall cover of linear electric motor has lower bellows (9), lower bellows (9) is outside equipped with lower bellows protecting tube (8), the upper end of lower bellows (9) connects the lower end of the motor tail pipe (7) of linear electric motor, the lower end of lower bellows (9) connects lower link (10) lower end, and the upper and lower end of lower bellows protecting tube (8) connects the lower end of motor tail pipe (7) and the upper end of plug (11) respectively.

2. as claimed in claim 1 for the seal arrangement of electric submersible oil reciprocation pump oil production system, it is characterized in that: described oil well pump pull bar (2) and upper connecting rod (6) joint are provided with the first flange plate, the upper end of motor urceolus (5) is provided with the second flange plate, and the upper and lower end of upper bellows (4) is connected on the first flange plate and the second flange plate;

The lower end of described motor tail pipe (7) is provided with three-flange dish, and lower link (10) lower end is provided with the 4th flange plate, and the upper and lower end of lower bellows (9) is connected on three-flange dish and the 4th flange plate.

3. as claimed in claim 1 or 2 for the seal arrangement of electric submersible oil reciprocation pump oil production system, it is characterized in that: the inwall upper end of described upper bellows protecting tube (3) is threaded connection in the outer wall lower end of electric submersible oil reciprocation pump pump barrel (1), the lower end of described upper bellows protecting tube (3) is bolted the upper end of motor urceolus (5), the inwall upper end of lower bellows protecting tube (8) is threaded connection the outer wall lower end of motor tail pipe (7), and the outer wall lower end of lower bellows protecting tube (8) is threaded connection the inwall upper end of plug (11).

4. as claimed in claim 3 for the seal arrangement of electric submersible oil reciprocation pump oil production system, it is characterized in that: described plug (11) inside is provided with the damping spring (12) of vertical direction, the upper end of described damping spring (12) is connected to lower link (10) underpart, and the lower end of damping spring (12) is fixed on plug (11) bottom.

5. the seal arrangement for electric submersible oil reciprocation pump oil production system as described in claim 1 or 2 or 4, is characterized in that: described upper bellows (4) and lower bellows (9) are rubber corrugated pipe.

6., as claimed in claim 5 for the seal arrangement of electric submersible oil reciprocation pump oil production system, it is characterized in that: described upper bellows (4) and lower bellows (9) are embedded with stainless steel spring.

7. as claimed in claim 6 for the seal arrangement of electric submersible oil reciprocation pump oil production system, it is characterized in that: described stainless steel spring is in free state when linear electric motor are in lower limit, described stainless steel spring is in maximum energy storage state when linear electric motor are in upper limit.

8. the seal arrangement for electric submersible oil reciprocation pump oil production system as claimed in claims 6 or 7, is characterized in that: be full of lubricant oil in described upper bellows (4) and lower bellows (9).

9. the seal arrangement for electric submersible oil reciprocation pump oil production system as described in claim 1 or 2 or 4 or 6 or 7, is characterized in that: the positive stop described upper bellows protecting tube (3) and lower bellows protecting tube (8) inwall being provided with the displacements such as multi-turn.