CN116104452A

CN116104452A - Horizontal well two-stage relay type plunger lifting device and method thereof and movable ball core plunger

Info

Publication number: CN116104452A
Application number: CN202111317809.3A
Authority: CN
Inventors: 曹银平; 徐剑良; 伍翊嘉; 王勇; 蔡默仑; 钟思存; 崔健; 江松莲
Original assignee: China National Petroleum Corp; CNPC Chuanqing Drilling Engineering Co Ltd
Current assignee: China National Petroleum Corp; CNPC Chuanqing Drilling Engineering Co Ltd
Priority date: 2021-11-09
Filing date: 2021-11-09
Publication date: 2023-05-12

Abstract

The invention provides a horizontal well two-stage relay type plunger lifting device, a method thereof and a movable ball core plunger. The horizontal well two-stage relay type plunger lifting device sequentially comprises a first pressure-controlled single-flow valve, a first plunger buffer, a movable ball core plunger, a second plunger buffer, a second pressure-controlled single-flow valve, a third plunger buffer, a common plunger and a common plunger lifting wellhead device from bottom to top. The horizontal well two-stage relay type plunger lifting production method can be used for closing and opening one time to form a production cycle. The invention can realize pressure change of each part in the well by using stratum natural energy or other energy, realize reciprocating motion of the movable ball core plunger at two ends of the horizontal section oil pipe, further drive accumulated liquid near the target point of the horizontal section B to the vertical well section, and finally thoroughly discharge the liquid out of the well mouth by using a common plunger or other lifting modes.

Description

Horizontal well two-stage relay type plunger lifting device and method thereof and movable ball core plunger

Technical Field

The invention belongs to the technical field of oil and gas well drainage and production, and particularly relates to a horizontal well two-stage relay type plunger lifting device, a horizontal well two-stage relay type plunger lifting production method and a movable ball core plunger which can be used for the device and the production method.

Background

With the increasing application of horizontal wells, the development of horizontal well drainage technology is increasingly paid attention to various oil and gas fields at home and abroad. The current drainage and production technology for the horizontal well mainly comprises foam drainage and production, preferably tubular column drainage and production, gas lift drainage and production, plunger gas lift drainage and production and the like. The application of these existing drainage techniques in horizontal wells has certain effects, but also certain drawbacks.

The foam drainage technology is suitable for water-producing gas wells, and is characterized in that a certain surfactant or high molecular polymer is injected into the bottom of a well, fully contacts with accumulated liquid at the bottom of the well by stirring the well fluid, generates a large amount of low-density aqueous foam, reduces slipping loss in the well and improves the liquid lifting capacity of the well. Meanwhile, the foaming agent used in the foam drainage technology is usually put into or injected from a wellhead, and can only act near a shaft area of an A target point (corresponding to the initial position of a horizontal section oil pipe) of a horizontal well, and accumulated liquid of a longer horizontal section cannot be drained, particularly for a declining horizontal well, the foam drainage effect is more limited, and meanwhile, the foam drainage technology has the defects of short maintenance time of single operation drainage effect, lower drainage efficiency, limitation by the property of shaft liquid and the like.

The optimized tubular column drainage and production technology is that when the energy of a gas well is low and normal liquid carrying production cannot be realized, the critical liquid carrying flow is reduced and the liquid carrying production capacity of the gas well is improved by optimizing the size of a production tubular column, so that the drainage and production aim is achieved. Meanwhile, the production pipe columns with different sizes are required to be put into in different production stages in the pipe column drainage and production process, well repair operation is required, the cost is high, and the tool can not be put into the production pipe columns partially or completely along with the reduction of the diameter of the pipe columns.

The gas lift drainage and extraction technology is characterized in that high-pressure gas (natural gas or nitrogen) is injected into a shaft by using high-pressure gas energy or pressurizing equipment, and bottom accumulated liquid is returned from an oil pipe (or an oil sleeve annulus) to the ground by using the high-pressure gas energy, so that the gas lift drainage and extraction technology is limited by the backflow of lifting liquid, and the lifting efficiency of the system is poor.

The plunger gas lift drainage technology is to put a plunger in an oil pipe as a gas-liquid mechanical separation interface, fully utilize the self energy of a gas well to push the plunger to bring liquid out of a shaft, realize periodic liquid lift, effectively prevent gas channeling and liquid slipping and improve the lifting efficiency. However, in the plunger gas lift drainage process, the operation of a plunger system is severely restricted by well inclination, the maximum well inclination angle of the currently known clamp is about 70 degrees, namely, the accumulated liquid below the clamp cannot be drained, and the problem of accumulated liquid in a horizontal section is difficult to solve fundamentally.

Besides the above-mentioned several drainage technologies, the horizontal well usually uses multiple composite technologies to conduct drainage, such as a supercharging and gas lifting composite drainage technology, a plunger and foam composite drainage technology, etc., mainly makes full use of the advantages of each drainage technology, and improves the drainage efficiency of the horizontal well as much as possible.

While some studies have been made by the former regarding plungers suitable for horizontal wells:

the Chinese patent application with publication number CN107143316A,

publication number

2017, 9 and 8 discloses a novel plunger for lifting a plunger suitable for a directional well and a horizontal well, which is a cushion block type spherical plunger, but the plunger body lacks a buffer structure, is easy to damage, can only fall near an A target point, and cannot discharge liquid in a horizontal section.

The invention patent application of China with publication number of CN102817594A, which is 2012.12.12, discloses a method and a device for draining and producing gas of a horizontal well, wherein a shaft is divided into three sections, the accumulated liquid in the horizontal section is carried to a vertical well section by using the self energy of the shaft, and finally is discharged by adopting the traditional process.

In summary, the inventors have analyzed and studied to show that: the existing known horizontal well drainage and production technology is basically only effective for accumulated liquid near and on a target point of a shaft A, but is difficult to 'reach' the accumulated liquid in a horizontal section, and the biggest problem restricting the capacity of the horizontal well to be exerted is the accumulated liquid in the horizontal section, so that the problem that the accumulated liquid in the horizontal section is to be solved urgently for improving the recovery ratio of the horizontal well is solved.

Disclosure of Invention

The present invention aims to address at least one of the above-mentioned deficiencies of the prior art. For example, one of the purposes of the invention is to solve the problem of difficult drainage and production of liquid in the horizontal section caused by the fact that the conventional lifting process device cannot reach the vicinity of the tail end of the oil pipe.

In order to achieve the above purpose, according to one aspect of the present invention, a two-stage relay type plunger lifting device for a horizontal well is provided, which comprises a first pressure-controlled single-flow valve, a first plunger buffer, a movable ball plunger, a second plunger buffer, a second pressure-controlled single-flow valve, a third plunger buffer, a common plunger and a common plunger lifting wellhead device, wherein the first pressure-controlled single-flow valve is located in a horizontal section oil pipe and is arranged near a B target point, and can be closed when the pressure in the horizontal section oil pipe is greater than a first pressure value, and can be opened when the pressure in the horizontal section oil pipe is less than the first pressure value, so that the horizontal section oil pipe is correspondingly isolated from and communicated with a well bottom fluid; the movable ball core plunger is arranged in the horizontal section oil pipe in a mode that the right buffer table is closer to the tail end of the oil pipe; the second pressure-controlled single-flow valve is positioned in the oil pipe and near the A target point, and can be closed when the pressure in the horizontal section oil pipe is larger than a second pressure value and opened when the pressure in the horizontal section oil pipe is smaller than the second pressure value, so that the horizontal section oil pipe is correspondingly isolated and communicated with the sleeve; the third pressure-controlled check valve is arranged at the bottom of the straight well section oil pipe and can be closed when the pressure in the straight well section oil pipe is larger than a third pressure value and opened when the pressure in the straight well section oil pipe is smaller than the third pressure value, so that the straight well section oil pipe is isolated and communicated with the horizontal section oil pipe correspondingly.

In an exemplary embodiment of the horizontal well two-stage relay type plunger lifting device, the first plunger buffer may be disposed close to the first pressure-controlled single-flow valve, the second plunger buffer may be disposed close to the second pressure-controlled single-flow valve so as to buffer the movable ball plunger abutted during movement, and the third plunger buffer may be disposed close to the third pressure-controlled single-flow valve so as to buffer the common plunger abutted during movement.

In one exemplary embodiment of the horizontal well two-stage relay type plunger lifting device of the present invention, one or more of the first pressure-controlled check valve, the second pressure-controlled check valve, and the third pressure-controlled check valve may have a check valve structure that may include: a columnar valve body having an outer diameter equal to the inner diameter of the oil pipe; the fluid channel is arranged in the length direction of the columnar valve body in a penetrating manner; the pressure cavity is arranged in the columnar valve body; a pressure-sensitive bladder that is accommodated in a portion of the pressure chamber and has one end fixed to the pressure chamber and the other end; the pressure guide channel is arranged in the columnar valve body and can communicate the pressure to be measured with the other part of the pressure cavity, so that the pressure sensing air bag correspondingly expands or contracts when the pressure to be measured is reduced or increased; the limiting mechanism is arranged in the columnar valve body; the valve groove is arranged in the columnar valve body and is used for communicating the other part of the pressure cavity with the limiting mechanism; the valve rod is arranged in the valve groove and is provided with a rod body provided with a valve hole, one end fixedly connected with the other end of the pressure sensing air bag and the other end positioned in the limiting mechanism, and the valve hole can correspondingly disconnect or connect the fluid channel when the valve rod is driven by the expansion or contraction of the pressure sensing air bag. Wherein, the fluid channel can be S-shaped, the pressure guide channel can be J-shaped. In addition, the limit mechanism may further include a limit table and a limit groove, the limit groove may be capable of accommodating the other end of the moving valve rod, and the limit table may be capable of preventing the other end of the valve rod from being separated from the limit groove.

In an exemplary embodiment of the horizontal well two-stage relay type plunger lifting device, the movable ball core plunger comprises a movable ball core, a left buffer table, a right buffer table, an outer cylinder and an inner cylinder, wherein the outer cylinder and the inner cylinder are sleeved with each other, an annular flow channel surrounding a central axis of the inner cylinder is formed between the outer cylinder and the inner cylinder, a central flow channel along the central axis is formed in the inner cylinder, and one or more communication holes for communicating the annular flow channel and the central flow channel are formed in the wall of the inner cylinder; the right end of the left buffer table is fixedly connected with the left end of the outer cylinder and the left end of the inner cylinder, and a central flow passage through hole capable of communicating the central flow passage with the outside is formed at the axial center position of the left buffer table; the left end of the right buffer table is fixedly connected with the right end of the inner cylinder and is fixedly connected with the right end of the outer cylinder through an end plate provided with an annular flow passage through hole, and the annular flow passage through hole can communicate the annular flow passage with the outside; the movable ball core is arranged in the central flow passage and can freely move in the central flow passage.

In addition, the movable ball core plunger can further comprise a spiral diversion trench arranged on the outer wall of the outer cylinder. In addition, the movable ball core plunger can further comprise a left ball core clamping groove arranged at the joint of the central runner and the central runner through hole and a right ball core clamping groove arranged at the joint of the left end of the right buffer table and the right end of the inner barrel.

The invention further provides a horizontal well two-stage relay type plunger lifting production method, which is realized by adopting the horizontal well two-stage relay type plunger lifting device.

In one exemplary embodiment of the horizontal well two-stage relay plunger lift production method of the present invention, the production method may comprise one or more production cycles consisting of a single shut-in and a single open-in, the production cycle may comprise the steps of:

s1, after the well is closed, the pressure in the straight well section oil pipe is increased, so that a third pressure-controlled single-flow valve is closed, fluid in the straight well section oil pipe cannot enter the horizontal section oil pipe, a common plunger is separated from a common plunger lifting wellhead device and falls down along the straight well section oil pipe under the action of gravity, and finally the straight well section oil pipe is located on a third plunger buffer; during the production period, the fluid in the horizontal section oil pipe is discharged into the vertical section oil pipe at the well opening stage of the previous production period, and the pressure in the horizontal section oil pipe is reduced, so that the second pressure-controlled single-flow valve is opened, and the fluid in the annular space of the sleeve can flow into the horizontal section oil pipe through the second pressure-controlled single-flow valve; the fluid flowing into the horizontal section oil pipe flows into the central flow passage of the movable ball core plunger through the central flow passage through hole and pushes the movable ball core to move rightwards, finally, the movable ball core plunger stops at the right end of the central flow passage, and therefore the movable ball core plunger is forced to move towards the tail end of the oil pipe; along with the inflow of fluid and the movement of the movable ball core plunger to the tail end of the oil pipe, the pressure in the horizontal section of the oil pipe is increased, so that the first pressure-controlled check valve is closed, and the movable ball core plunger finally stops in front of the first plunger buffer; when the pressure in the horizontal section oil pipe is increased to a certain set critical value, the second pressure-controlled check valve is closed;

s2, after the well is opened, the pressure of the well mouth is reduced, the common plunger pushes the upper liquid of the common plunger to move upwards along the oil pipe of the straight well section, the pressure of the upper part of the third pressure-controlled single-flow valve is reduced, the third pressure-controlled single-flow valve is opened, the fluid in the oil pipe of the horizontal section flows into the straight well section under the action of the bottom hole pressure, the common plunger is further pushed to move upwards to the well mouth, and the liquid flowing into the oil pipe of the straight well section from the oil pipe of the horizontal section in the well opening stage of the last production period is discharged out of the well mouth; during the period, the movable ball core plunger pushes the liquid in the horizontal section oil pipe to move to the initial position of the horizontal section oil pipe, the pressure in the oil pipe near the first pressure-controlled check valve is reduced, the first pressure-controlled check valve is opened, the fluid at the bottom of the well enters the horizontal section oil pipe from the first pressure-controlled check valve, and the movable ball core plunger is further pushed to move to the initial position of the horizontal section oil pipe; when the movable ball plunger touches the second plunger buffer, the liquid discharging process from the horizontal section oil pipe to the vertical well section oil pipe is finished; after the well is closed, the next production period is started, and the process is repeated in a circulating way, so that the drainage and the extraction of the accumulated liquid in the horizontal section are realized.

In another exemplary embodiment of the horizontal well two-stage relay type plunger lifting production method, in the step S1, during the moving process of the movable ball core plunger, fluid in the right horizontal section oil pipe of the movable ball core plunger can flow into the annular flow passage through hole and flow into the central flow passage through the communication hole, and the fluid is converged with fluid pushing the movable ball core, so that the moving resistance of the movable ball core plunger to the tail end of the oil pipe is reduced. In addition, in the step S2, in the process that the movable ball core plunger moves to the initial position of the horizontal section oil pipe, fluid at the tail end of the oil pipe can enter the annular flow passage of the movable ball core plunger under the pressure action through the annular flow passage through hole, and enter the central flow passage through the inner and outer flow passage communication hole, so that the movable ball core is pushed to move leftwards, finally, the movable ball core plunger is stopped at the left end of the central flow passage, the movable ball core plunger is completely sealed, and the discharge efficiency of the liquid in the horizontal section oil pipe is improved.

Compared with the prior art, the invention has the beneficial effects that at least one of the following contents is included: 1) The energy of a shaft is fully utilized, so that the drainage efficiency is improved; 2) The problem of difficult drainage and extraction of liquid accumulation in the horizontal section caused by the fact that a conventional lifting process device cannot reach the vicinity of the target point B is solved, and the recovery ratio of liquid in the horizontal section is effectively improved.

Drawings

The foregoing and/or other objects and features of the invention will become more apparent from the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 illustrates a schematic view of an exemplary embodiment of a horizontal well two-stage relay type plunger lifting device of the present invention;

FIG. 2 shows a schematic diagram of the external structure of one of the pressure-controlled check valves of FIG. 1;

FIG. 3 shows a cross-sectional view of the pressure controlled check valve of FIG. 2 in an open state;

FIG. 4 shows a cross-sectional view of the pressure controlled check valve of FIG. 2 in a closed state;

FIG. 5 shows a schematic view of the external structure of the movable core plunger of FIG. 1;

FIG. 6 shows a front cross-sectional view of the movable core plunger of FIG. 5;

fig. 7 shows a right side cross-sectional view of the movable core plunger of fig. 5.

Reference numerals illustrate:

1-a first pressure-controlled check valve, 101-a fluid channel, 102-a pressure guide channel, 103-a pressure cavity, 104-a pressure sensing air bag, 105-a valve rod, 106-a limit groove, 107-a limit table, 108-a valve hole and 109-a valve groove;

2-movable ball core plunger, 21-left buffer table, 22-right buffer table, 23-outer cylinder, 24-spiral diversion trench, 25-annular runner through hole, 26-annular runner, 27-inner cylinder, 28-communication hole, 29-central runner, 210-movable ball core, 211-central runner through hole, 212-right ball core clamping slot and 213-left ball core clamping slot;

3-second pressure-controlled single flow valve, 4-third pressure-controlled single flow valve, 5-ordinary plunger lifting wellhead device, 6-sleeve pipe, 7-oil pipe, 8-ordinary plunger, 9-third plunger buffer, 10-second plunger buffer, 11-first plunger buffer.

Detailed Description

Hereinafter, a horizontal well two-stage relay type plunger lifting device, a method thereof and a movable ball core plunger of the present invention will be described in detail with reference to exemplary embodiments.

It should be noted that the terms "upper," "lower," "left," "right," "inner," "outer," and the like are merely used for convenience of description and to construct a relative orientation or positional relationship, and are not intended to indicate or imply that the components in question must have that particular orientation or position.

FIG. 1 illustrates a schematic view of an exemplary embodiment of a horizontal well two-stage relay type plunger lifting device of the present invention.

As shown in fig. 1, in an exemplary embodiment of the present invention, the horizontal well two-stage relay type plunger lifting device includes a first pressure-controlled single flow valve 1, a first plunger damper 11, a movable ball plunger 2, a second plunger damper 10, a second pressure-controlled single flow valve 3, a third pressure-controlled single flow valve 4, a third plunger damper 9, a common plunger 8, and a common plunger lifting wellhead 5 sequentially disposed in a tubing 7 in a direction from a distal end of the tubing to a wellhead. Here, the end of the oil pipe corresponds to the B target point, and may approximately correspond to the position of the first pressure-controlled check valve 1 in fig. 1. The common plunger lifting wellhead may also be a common plunger gas lifting wellhead.

As shown in fig. 1, the first pressure-controlled single-flow valve 1 is located in the horizontal section oil pipe, is arranged at the tail end of the oil pipe, and can be closed when the pressure in the horizontal section oil pipe is greater than a first pressure value, so that the horizontal section oil pipe is isolated from the well bottom fluid; and can also open when the pressure in the horizontal leg tubing is less than the first pressure value, thereby placing the horizontal leg tubing in fluid communication with the well bottom. Here, in the present invention, the horizontal section of the oil pipe may not be completely horizontal, for example, may be slightly inclined, or may even have a fluctuation in the inclination direction in terms of a longer scale.

The second pressure-controlled check valve 3 is positioned in the oil pipe 7, is arranged near the initial position of the horizontal section oil pipe, and can be closed when the pressure in the horizontal section oil pipe is larger than a second pressure value, so that the horizontal section oil pipe is isolated from the sleeve 6; it is also possible to open when the pressure in the horizontal section of tubing is less than the second pressure value, thereby placing the horizontal section of tubing in communication with the casing 6. Here, the horizontal section tubing start position corresponds to the a target point, and may correspond approximately to the position of the horizontal section tubing start in fig. 1.

The third pressure-controlled check valve 4 is arranged at the bottom of the straight well section oil pipe and can be closed when the pressure in the straight well section oil pipe is larger than a third pressure value, so that the straight well section oil pipe is isolated from the horizontal section oil pipe; and the vertical well section oil pipe can be opened when the pressure in the vertical well section oil pipe is smaller than a third pressure value, so that the vertical well section oil pipe is communicated with the horizontal well section oil pipe.

FIG. 2 shows a schematic diagram of the external structure of one of the pressure-controlled check valves of FIG. 1; FIG. 3 shows a cross-sectional view of the pressure controlled check valve of FIG. 2 in an open state; fig. 4 shows a cross-sectional view of the pressure-controlled check valve of fig. 2 in a closed state.

One or more of the first pressure-controlled check valve 1, the second pressure-controlled check valve 3, and the third pressure-controlled check valve 4 may have a check valve structure as shown in fig. 2 to 4.

As shown in fig. 2 to 4, the single flow valve structure may include: the valve comprises a columnar valve body as a body, a fluid passage 101, a pressure guide passage 102, a pressure chamber 103, a pressure sensing bladder 104, a valve rod 105, a limit mechanism composed of a limit groove 106 and a limit table 107, a valve hole 108, and a valve groove 109.

Specifically, the columnar valve body has an outer diameter equal to the inner diameter of the oil pipe 7.

The fluid channel 101 penetrates the columnar valve body in the longitudinal direction (corresponding to the vertical direction in fig. 3), and can realize the unidirectional conduction function by allowing the fluid at the upper end of the columnar valve body to flow to the lower end of the columnar valve body in the conduction state. For example, the fluid passage 101 may be S-like in shape to better mate with the valve bore 108 of the valve stem 105. However, the present invention is not limited thereto, and for example, the fluid passage may also take a spiral form or other forms.

The pressure chamber 103 is provided in the cylindrical valve body, and may be, for example, a cylindrical cavity as shown in fig. 3. The pressure-sensitive bladder 104 is accommodated in a portion (e.g., upper portion) of the pressure chamber 103, and has one end (e.g., upper end or top end) fixed to the pressure chamber 103, and the other end (e.g., lower end or bottom end). The pressure sensing bladder 104 is inflated to a predetermined pressure. The pressure guide channel 102 is arranged in the columnar valve body, and can communicate the pressure to be measured of the fluid at the upper end of the columnar valve body with the other part (for example, the lower part) of the pressure cavity 103, so that the pressure sensing air bag 104 correspondingly expands when the pressure to be measured is reduced; and causes the pressure sensing bladder 104 to correspondingly contract as the pressure to be measured increases. For example, the pressure-conducting channel 102 may be J-shaped to facilitate better communication with the pressure chamber 103. However, the present invention is not limited thereto, and for example, the pressure guide passage may also take a spiral form or other forms.

A limit groove 106 and a limit table 107 of the limit mechanism are provided in the columnar valve body. The limit groove 106 can accommodate the lower end of the moving valve stem 105. The limit table 107 can prevent the lower end of the valve rod 105 from being separated from the limit groove 106. However, it should be noted that the structure of the limiting mechanism used in the present invention is not limited thereto, and it is possible for those skilled in the art to implement other structures for accommodating the movement of the lower end of the valve stem and preventing the removal thereof.

A valve spool 109 is provided in the columnar valve body and communicates the lower portion of the pressure chamber 103 with a stopper mechanism. The valve stem 105 is provided in the valve groove 109, and has a stem provided with a valve hole 108, one end fixedly connected to the lower end (e.g., upper end) of the pressure-sensitive bladder 104, and the other end (e.g., lower end) located in the stopper mechanism.

As shown in fig. 4, the valve hole 108 can be driven by the valve rod 105 when the pressure sensing air bag 104 is inflated, so that the fluid channel 101 is correspondingly disconnected; the valve rod 105 can be driven by the contraction of the pressure sensing bladder 104 to correspondingly conduct the fluid channel 101, as shown in fig. 3.

However, it should be noted that the structure of the pressure-controlled check valve used in the present invention is not limited thereto, and it is possible for one skilled in the art to use other check valves capable of realizing pressure-controlled unidirectional conduction as the first pressure-controlled check valve 1, the second pressure-controlled check valve 3, and/or the third pressure-controlled check valve 4 in the present exemplary embodiment.

The movable core plunger 2 is disposed in the horizontal section of tubing in the form of a right bumper (e.g., right end in fig. 1, 5, 6) closer to the end of the tubing.

FIG. 5 shows a schematic view of the external structure of the movable core plunger of FIG. 1; FIG. 6 shows a front cross-sectional view of the movable core plunger of FIG. 5; fig. 7 shows a right side cross-sectional view of the movable core plunger of fig. 5.

As shown in fig. 5 to 7, the movable core plunger includes a movable core 210, left and right buffer tables 21 and 22, an outer cylinder 23, an inner cylinder 27 fitted in the outer cylinder 23, and a spiral guide groove 24, a left core catching groove 213, and a right core catching groove 212.

An annular flow passage 26 is formed between the outer tube 23 and the inner tube 27 around a central axis of the inner tube 27 (right and left direction in fig. 6). The inner barrel 27 has a central flow passage 29 formed therein along the central axis. The inner tube 27 has a wall provided with one or more communication holes 28 for communicating the annular flow passage 26 with the center flow passage 29.

The right end of the left buffer 21 is fixedly connected to the left end of the outer tube 23 and the left end of the inner tube 27, and a center flow passage through hole 211 is formed in the center of the left buffer 21 to allow the center flow passage 29 to communicate with the outside. In addition, the outer cylinder can be integrally formed with the left buffer table.

The left end of the right buffer table 22 is fixedly connected with the right end of the inner cylinder 27, and is fixedly connected with the right end of the outer cylinder 23 through an end plate provided with an annular flow passage through hole 25, and the annular flow passage through hole 25 can communicate the annular flow passage 26 with the outside. In addition, the inner tube can be integrated with the right buffer table.

The movable core 210 is disposed in the central flow passage 29 and is free to move in the central flow passage 29.

The spiral diversion trench 24 is arranged on the outer wall of the outer cylinder, thereby being more beneficial to the smooth movement of the movable ball core plunger in the horizontal section oil pipe along the left-right direction of fig. 1 and 6. However, the movable core plunger of the present invention is not limited thereto, and may not contain a spiral guide groove, but may be replaced by other means such as an outer wall of an outer cylinder having a lower friction coefficient, or adjusting lubrication in an oil pipe.

The left ball core clamping groove 213 may be disposed at the connection between the central flow channel 29 and the central flow channel through hole 211, so as to be more beneficial to accommodating and left limiting the movable ball core 210. The right ball core clamping groove 212 can be arranged at the connection position of the left end of the right buffer table 22 and the right end of the inner barrel 27, thereby being more beneficial to the accommodation and right limit of the movable ball core 210. However, the movable ball core plunger is not limited to the above, and does not contain a left ball core clamping groove and a right ball core clamping groove, but the limit of the movable ball core is realized directly through the shrinkage of the connecting parts at the left side and the right side of the central flow passage.

As shown in fig. 1, the first plunger buffer 11 is disposed near the left side of the first pressure-controlled check valve 1, and the second plunger buffer 10 is disposed near the right side of the second pressure-controlled check valve 3, so as to buffer the movable ball plunger 2 that approaches during movement, so as to protect the first pressure-controlled check valve 1 and the second pressure-controlled check valve 3. The third plunger damper 9 is disposed near the upper side of the third pressure-controlled check valve 4, so as to play a role in damping the common plunger 8 approaching during movement, so as to protect the third pressure-controlled check valve 4.

Additionally, while the above exemplary embodiments illustrate the use of a third plunger buffer and the cooperation of a conventional plunger with a conventional plunger lifting wellhead to effect fluid lifting of a vertical wellbore section; however, the horizontal well two-stage relay type plunger lifting device of the invention is not limited to this, for example, a third plunger buffer and a common plunger are not arranged, and the common plunger lifting wellhead device is replaced by a lifting wellhead device, so that lifting modes such as natural liquid discharge, foam extraction, gas lift extraction and the like can be directly adopted to replace common plunger lifting fluid.

In addition, in the case where the principle of the above-described exemplary embodiment is not changed, the partial structure of the movable core plunger may be changed, for example, the shape, arrangement, pitch, aperture, and other parameters of the communication holes that communicate the inner and outer flow passages may be changed.

In another exemplary embodiment of the invention, the horizontal well two-stage relay type plunger lifting production method is realized by adopting the horizontal well two-stage relay type plunger lifting device.

When the invention is applied, the inner diameter of the oil pipe 7 of the same plunger running well section is required to be consistent, and all devices including each pressure-controlled check valve and the movable ball core plunger 2 can be preset in the oil pipe 7 and put into a shaft together with the oil pipe 7. If the fishing is needed, the movable ball plunger 2 can be operated to the second plunger buffer 10 by using a switching well system, and the fishing is finished by using a conventional fishing tool.

As shown in fig. 1, with one shut-in and one open-in as one production cycle, a specific implementation of an exemplary embodiment of the horizontal well two-stage relay type plunger lifting production method of the present invention may include the following steps:

s1, after the well is shut in, the pressure in the straight well section oil pipe 7 is increased, so that the third pressure-controlled single flow valve 4 is closed, the upper fluid and the lower fluid of the third pressure-controlled single flow valve 4 are blocked, meanwhile, the common plunger 8 is separated from the common plunger lifting wellhead device 5 and falls down along the straight well section oil pipe 7 under the action of gravity, and finally, the straight well section oil pipe is located on the third plunger buffer 9.

Further, as shown in fig. 3, the third pressure-controlled single-flow valve 4 is installed in the oil pipe 7, and the fluid channel 101 is the only channel for fluid passing through the third pressure-controlled single-flow valve. When the pressure in the straight well section oil pipe is reduced, the pressure is transmitted into the pressure cavity 103 through the pressure guide channel 102, so that the internal pressure of the pressure sensing air bag 104 is larger than the external pressure, and the pressure sensing air bag 104 expands to drive the valve rod 105 to move downwards. When the valve bore 108 communicates with the fluid passage 101, the pressure-controlled check valve is opened. The limiting table 107 moves in the limiting groove 106 to prevent the valve rod 105 from being displaced too much to cause the pressure-controlled check valve to close again. Similarly, as shown in fig. 4, when the external pressure increases, the pressure sensing air bag 104 will shrink to drive the valve rod 105 to move upwards, so that the valve hole 108 is disconnected from the fluid channel 101, the pressure-controlled check valve is closed, and the limit table 107 will prevent the valve rod 105 from moving upwards too much to be separated from the valve groove 109.

During this time, since the fluid in the horizontal section tubing 7 is discharged into the vertical section during the open phase of the previous production cycle, the pressure in the horizontal section tubing 7 is reduced, i.e. the pressure in the horizontal section casing 6 is greater than the pressure in the corresponding horizontal section tubing 7, causing the second pressure-controlled check valve 3 to open into the tubing, at which time the horizontal section casing 6 communicates with the tubing 7, and the fluid in the oil collar air flows into the horizontal section tubing 7 via said second pressure-controlled check valve 3.

Further, as shown in fig. 6, the fluid flowing into the horizontal section oil pipe 7 flows into the central flow passage 29 of the movable ball core plunger 2 through the central flow passage through hole 211, and pushes the movable ball core to move rightward, and finally stops in the right ball core clamping groove 212, so that the movable ball core plunger 2 moves toward the target point B under force.

Further, in the moving process of the movable ball plunger 2, the fluid at the side close to the tail end of the oil pipe 7 flows into the annular flow passage 26 through the annular flow passage through hole 25 and flows into the central flow passage 29 through the communication hole 28, so that the fluid is converged with the fluid pushing the movable ball plunger, and the moving resistance of the movable ball plunger 2 to the target point B is reduced.

Further, the outer surface of the outer cylinder 23 of the movable ball plunger 2 is carved with a spiral guiding groove 24, and in the moving process, fluid can rotate the movable ball plunger 2 through the spiral guiding groove 24, so that friction between the movable ball plunger 2 and the oil pipe 7 is reduced.

Further, as the fluid flows in and the movable ball plunger 2 moves toward the target B, the pressure in the horizontal section oil pipe 7 increases, i.e. the pressure in the horizontal section oil pipe 7 is greater than the pressure in the outer sleeve 6 at the end of the horizontal section oil pipe, so that the first pressure-controlled check valve 1 is closed, i.e. the oil pipe 7 is disconnected from the sleeve 6 at the first pressure-controlled check valve, and at this time, the movable ball plunger 2 finally stops before the first plunger buffer 11.

When the pressure in the horizontal section oil pipe 7 is increased to a certain set critical value, namely the pressure of the horizontal well section sleeve 6 is larger than the pressure in the corresponding horizontal well section oil pipe 7, the second pressure-controlled check valve 3 is closed, and at the moment, the horizontal section sleeve 6 is disconnected from the oil pipe 7.

S2, after the well is opened, wellhead pressure is reduced, namely, wellhead pressure is larger than wellhead pressure, so that the common plunger 8 pushes liquid on the upper portion of the common plunger to move upwards along the straight well section oil pipe 7, meanwhile, pressure on the upper portion of the third pressure-controlled check valve 4 is reduced, namely, pressure on the lower portion of the third pressure-controlled check valve 4 is larger than pressure on the upper portion of the third pressure-controlled check valve, and then the third pressure-controlled check valve 4 is opened towards the direction of the diameter section oil pipe 7, and at the moment, the diameter section oil pipe 7 is communicated with the horizontal section oil pipe 7. The fluid in the horizontal section oil pipe 7 flows into the vertical well section under the action of the bottom hole pressure, further pushes the common plunger 8 to move upwards to the well mouth, and the liquid flowing into the vertical well section oil pipe from the horizontal section oil pipe in the well opening stage of the previous production cycle is discharged out of the well mouth.

Meanwhile, the fluid flow in the oil pipe 7 drives the movable ball core plunger 2 to move towards the A target point, the pressure in the oil pipe 7 near the first pressure-controlled check valve 1 is reduced, namely the pressure in the oil pipe 7 at the first pressure-controlled check valve 1 is smaller than the pressure in the sleeve 6, so that the first pressure-controlled check valve 1 is opened towards the diameter section oil pipe 7, namely the corresponding oil pipe 7 at the first pressure-controlled check valve 1 is communicated with the sleeve 6, and the fluid in the sleeve 6 flows into the horizontal section oil pipe 7 through the first pressure-controlled check valve 1, so that the movable ball core plunger 2 is further pushed to move towards the A target point.

Further, as shown in fig. 6, in the process of moving the movable ball plunger 2 to the target point a, the fluid at the end of the oil pipe enters the annular flow passage 26 of the movable ball plunger 2 through the annular flow passage through hole 25 under the action of pressure, flows into the central flow passage 29 through the internal and external flow communication holes, pushes the movable ball to move leftwards, and finally sits in the left ball core clamping groove 213, so that the movable ball plunger 2 is completely sealed, and the discharge efficiency of the liquid in the horizontal section oil pipe 7 is improved.

Further, when the movable ball plunger 2 touches the second plunger buffer 10, the liquid discharging process of the horizontal section oil pipe 7 to the vertical well section oil pipe 7 is finished, and the next production period is entered after well closing, so that the process is circularly reciprocated, and the problem of difficult liquid accumulation and extraction in the horizontal section is solved.

Although the present invention has been described above with reference to the exemplary embodiments and the accompanying drawings, it should be apparent to those of ordinary skill in the art that various modifications can be made to the above-described embodiments without departing from the spirit and scope of the claims.

Claims

1. A movable ball core plunger is characterized in that the movable ball core plunger comprises a movable ball core, a left buffer table, a right buffer table, an outer cylinder and an inner cylinder which are sleeved with each other,

an annular flow passage surrounding the central axis of the inner cylinder is formed between the outer cylinder and the inner cylinder, a central flow passage along the central axis is formed in the inner cylinder, and one or more communication holes for communicating the annular flow passage and the central flow passage are formed in the wall of the inner cylinder;

the right end of the left buffer table is fixedly connected with the left end of the outer cylinder and the left end of the inner cylinder, and a central flow passage through hole capable of communicating the central flow passage with the outside is formed at the axial center position of the left buffer table;

the left end of the right buffer table is fixedly connected with the right end of the inner cylinder and is fixedly connected with the right end of the outer cylinder through an end plate provided with an annular flow passage through hole, and the annular flow passage through hole can communicate the annular flow passage with the outside;

the movable ball core is arranged in the central flow passage and can freely move in the central flow passage.

2. The movable core plunger of claim 1, further comprising a spiral guide groove disposed on an outer wall of the outer barrel.

3. The movable core plunger of claim 1, further comprising a left core detent disposed at a junction of the central flow passage and the central flow passage through hole, and a right core detent disposed at a junction of the left end of the right bumper deck and the right end of the inner barrel.

4. A horizontal well two-stage relay type plunger lifting device, which is characterized by comprising a first pressure-controlled single-flow valve, a first plunger buffer, a movable ball core plunger, a second plunger buffer, a second pressure-controlled single-flow valve, a third pressure-controlled single-flow valve and a lifting wellhead device which are sequentially arranged in an oil pipe along the direction from the tail end of the oil pipe to the wellhead, wherein,

the first pressure-controlled single-flow valve is positioned in the horizontal section oil pipe and arranged at the tail end of the oil pipe, and can be closed when the pressure in the horizontal section oil pipe is larger than a first pressure value and opened when the pressure in the horizontal section oil pipe is smaller than the first pressure value, so that the horizontal section oil pipe is correspondingly isolated and communicated with well bottom fluid;

the movable ball core plunger is arranged in the horizontal section oil pipe in a mode that the right buffer table is closer to the tail end of the oil pipe;

the second pressure-controlled single-flow valve is positioned in the oil pipe and is arranged near the initial position of the horizontal section oil pipe, and can be closed when the pressure in the horizontal section oil pipe is larger than a second pressure value and opened when the pressure in the horizontal section oil pipe is smaller than the second pressure value, so that the horizontal section oil pipe is correspondingly isolated and communicated with the sleeve;

the third pressure-controlled check valve is arranged at the bottom of the straight well section oil pipe and can be closed when the pressure in the straight well section oil pipe is larger than a third pressure value and opened when the pressure in the straight well section oil pipe is smaller than the third pressure value, so that the straight well section oil pipe is isolated and communicated with the horizontal section oil pipe correspondingly.

5. The horizontal well two-stage relay type plunger lifting device according to claim 4, wherein the first plunger buffer is arranged close to the first pressure-controlled check valve, and the second plunger buffer is arranged close to the second pressure-controlled check valve so as to buffer the movable ball plunger which is abutted in the movement process.

6. The horizontal well two-stage relay type plunger lifting device according to claim 4, further comprising a third plunger damper and a common plunger sequentially arranged between the third pressure-controlled check valve and the lifting wellhead device along the direction from the tail end of the oil pipe to the wellhead.

7. The horizontal well two-stage relay type plunger lifting device according to claim 6, wherein the third plunger buffer is arranged close to the third pressure-controlled check valve so as to buffer the common plunger which is abutted in the movement process.

8. The horizontal well two-stage relay plunger lift device of claim 4, wherein one or more of the first, second, and third pressure-controlled check valves have a check valve structure comprising:

a columnar valve body having an outer diameter equal to the inner diameter of the oil pipe;

the fluid channel is arranged in the length direction of the columnar valve body in a penetrating manner;

the pressure cavity is arranged in the columnar valve body;

a pressure-sensitive bladder that is accommodated in a portion of the pressure chamber and has one end fixed to the pressure chamber and the other end;

the pressure guide channel is arranged in the columnar valve body and can communicate the pressure to be measured with the other part of the pressure cavity, so that the pressure sensing air bag correspondingly expands or contracts when the pressure to be measured is reduced or increased;

the limiting mechanism is arranged in the columnar valve body;

the valve groove is arranged in the columnar valve body and is used for communicating the other part of the pressure cavity with the limiting mechanism;

the valve rod is arranged in the valve groove and is provided with a rod body provided with a valve hole, one end fixedly connected with the other end of the pressure sensing air bag and the other end positioned in the limiting mechanism, and the valve hole can correspondingly disconnect or connect the fluid channel when the valve rod is driven by the expansion or contraction of the pressure sensing air bag.

9. The horizontal well two-stage relay plunger lifting device of claim 8, wherein the fluid channel is S-shaped and the pressure guide channel is J-shaped.

10. The horizontal well two-stage relay type plunger lifting device according to claim 8, wherein the limiting mechanism comprises a limiting table and a limiting groove, the limiting groove can accommodate the other end of the moving valve rod, and the limiting table can prevent the other end of the valve rod from being separated from the limiting groove.

11. A method for producing a horizontal well by two-stage relay type plunger lifting, which is characterized in that the method is realized by adopting the device as claimed in any one of claims 4 to 10.

12. The horizontal well two-stage relay plunger lift production method of claim 11, wherein the production method comprises one or more production cycles consisting of one shut-in and one open-in, the production cycles comprising the steps of:

s1, after the well is closed, the pressure in the straight well section oil pipe is increased, so that a third pressure-controlled single-flow valve is closed, fluid in the straight well section oil pipe cannot enter the horizontal section oil pipe, a common plunger is separated from a common plunger lifting wellhead device and falls down along the straight well section oil pipe under the action of gravity, and finally the straight well section oil pipe is located on a third plunger buffer;

during the production period, the fluid in the horizontal section oil pipe is discharged into the vertical section oil pipe at the well opening stage of the previous production period, and the pressure in the horizontal section oil pipe is reduced, so that the second pressure-controlled single-flow valve is opened, and the fluid in the annular space of the sleeve can flow into the horizontal section oil pipe through the second pressure-controlled single-flow valve;

the fluid flowing into the horizontal section oil pipe flows into the central flow passage of the movable ball core plunger through the central flow passage through hole and pushes the movable ball core to move rightwards, finally, the movable ball core plunger stops at the right end of the central flow passage, and therefore the movable ball core plunger is forced to move towards the tail end of the oil pipe;

along with the inflow of fluid and the movement of the movable ball core plunger to the tail end of the oil pipe, the pressure in the horizontal section of the oil pipe is increased, so that the first pressure-controlled check valve is closed, and the movable ball core plunger finally stops in front of the first plunger buffer;

when the pressure in the horizontal section oil pipe is increased to a certain set critical value, the second pressure-controlled check valve is closed;

s2, after the well is opened, the pressure of the well mouth is reduced, the common plunger pushes the upper liquid of the common plunger to move upwards along the oil pipe of the straight well section, the pressure of the upper part of the third pressure-controlled single-flow valve is reduced, the third pressure-controlled single-flow valve is opened, the fluid in the oil pipe of the horizontal section flows into the straight well section under the action of the bottom hole pressure, the common plunger is further pushed to move upwards to the well mouth, and the liquid flowing into the oil pipe of the straight well section from the oil pipe of the horizontal section in the well opening stage of the last production period is discharged out of the well mouth;

during the period, the movable ball core plunger pushes the liquid in the horizontal section oil pipe to move to the initial position of the horizontal section oil pipe, the pressure in the oil pipe near the first pressure-controlled check valve is reduced, the first pressure-controlled check valve is opened, the fluid at the bottom of the well enters the horizontal section oil pipe from the first pressure-controlled check valve, and the movable ball core plunger is further pushed to move to the initial position of the horizontal section oil pipe;

when the movable ball plunger touches the second plunger buffer, the liquid discharging process from the horizontal section oil pipe to the vertical well section oil pipe is finished;

after the well is closed, the next production period is started, and the process is repeated in a circulating way, so that the drainage and the extraction of the accumulated liquid in the horizontal section are realized.

13. The method for lifting and producing horizontal well two-stage relay type plungers according to claim 11, wherein in the step S1, the fluid in the right horizontal section oil pipe of the movable ball plunger flows into the annular flow passage through hole and flows into the central flow passage through the communication hole in the moving process of the movable ball plunger, and the fluid is converged with the fluid pushing the movable ball plunger, so that the resistance of the movable ball plunger moving towards the tail end of the oil pipe is reduced.

14. The method for lifting and producing horizontal well two-stage relay type plungers according to claim 11, wherein in the step S2, in the process that the movable ball plunger moves to the initial position of the horizontal section oil pipe, fluid at the tail end of the oil pipe enters the annular runner of the movable ball plunger under the action of pressure through the annular runner through holes, and enters the central runner through the internal and external flowing holes, so that the movable ball plunger is pushed to move leftwards and finally stops at the left end of the central runner, the movable ball plunger is completely sealed, and the liquid discharge efficiency in the horizontal section oil pipe is improved.