CN110273652B

CN110273652B - Oil production well acid pickling pipe column structure and acid pickling method of oil production well

Info

Publication number: CN110273652B
Application number: CN201810209945.2A
Authority: CN
Inventors: 孙新; 南荣丽; 舒博钊
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2018-03-14
Filing date: 2018-03-14
Publication date: 2021-06-01
Anticipated expiration: 2038-03-14
Also published as: CN110273652A

Abstract

The invention provides an oil production well acid washing pipe column structure and an oil production well acid washing method, wherein the oil production well acid washing pipe column structure comprises the following components: the pipe column body comprises a liquid return channel; the separation structure is made of flexible materials and is of an annular structure, the separation structure is sleeved outside the pipe column body, and a pressure charging cavity is arranged in the separation structure; and the pressurizing channel is connected with the separation structure and communicated with the pressurizing cavity. The technical scheme of the invention solves the problem that the acid washing process is not suitable for the well-completed horizontal well screen pipe in the prior art.

Description

Oil production well acid pickling pipe column structure and acid pickling method of oil production well

Technical Field

The invention relates to the technical field of oil exploitation equipment, in particular to an oil production well acid pickling tubular column structure and an oil production well acid pickling method.

Background

The screen pipe well completion horizontal well has the advantages of simple well completion process, small pollution to a reservoir and low well completion cost, and is widely popularized and applied to oil fields. Meanwhile, in the drilling process, drilling mud is easy to form filter cakes on the well wall, and although the stability of the well bore can be ensured, the pollution of an oil layer is also caused. The existing horizontal well acid washing blockage removal process mainly adopts three modes, including a negative pressure liquid replacing mode, a coiled tubing dragging acidification process and a well completion acidification process, and has the following characteristics and problems:

the method adopts the conventional method that after a sieve tube is arranged at a designed position, a wellhead is installed, low-density liquid is adopted to replace slurry in a shaft, and negative pressure is generated in the shaft. At this time the pressure of the formation fluid is higher than the pressure of the fluid column in the wellbore so that the formation fluid passes through the filter cake and into the screen while the mud in the wellbore and the cake on the walls of the wellbore are carried to the surface. This method is to use the formation pressure to remove the wellbore contamination and create a production channel. However, due to the heterogeneity of the stratum, the stratum of the horizontal well section has the difference of permeability, the pollution of the horizontal well section at a high permeability layer is relieved due to the mode, the pollution of the horizontal well section at a low permeability layer still exists, the liquid production of the horizontal well section is uneven, water is seen too early, the anhydrous oil extraction period of the horizontal well is shortened, and the development effect is influenced.

The coiled tubing drags the acidizing process, the coiled tubing drags the acidizing process to utilize coiled tubing to connect after the flushing tool, lower into the horizontal screen pipe, carry on the fixed point to the horizontal screen pipe section from bottom to top and acidify the deblocking operation. Because the slot width of the screen is limited and the process is run inside the screen, it is not very targeted to remove mud contamination from the formation outside the screen.

The well completion acidification process is mostly applied in China at present, a well washing valve is connected to the bottom of a sieve tube to the designed depth when a well is completed, and the sieve tube section is treated in a segmented mode by an external packer. After completion, a pickling pipe column consisting of an insertion pipe, a pickling packer, a liquid discharge valve and the like is put into the sieve pipe, the pickling pipe column is matched with the external packer to divide the horizontal section into a plurality of sections, the pickling packer is set in a manner of pressing by using a sleeve, and the insertion pipe is inserted into the well washing valve on the sieve pipe at the bottom to form a well washing channel. During acidification, a reverse circulation mode is adopted, and acid liquor flows between the sieve tube and the stratum under the action of the packer, so that the purpose of pickling the open hole well wall is achieved. The scheme is suitable for a horizontal well newly completed, and for the sieve tube horizontal well completed at present, as the well washing valve of a reverse circulation channel cannot be established at the bottom of the sieve tube, the acid washing packer adopts a casing pipe to press for setting, and the setting pressure difference cannot be established for a low-pressure well, the process cannot realize the acid washing mud cake operation of the sieve tube well completed horizontal well completed conventionally completed.

Disclosure of Invention

The invention mainly aims to provide an oil production well acid washing pipe column structure and an oil production well acid washing method, and aims to solve the problem that an acid washing process is not suitable for a well-completed horizontal well screen pipe in the prior art.

In order to achieve the above object, according to one aspect of the present invention, there is provided a production well acid washing string structure comprising: the pipe column body comprises a liquid return channel; the separation structure is made of flexible materials and is of an annular structure, the separation structure is sleeved outside the pipe column body, and a pressure charging cavity is arranged in the separation structure; and the pressurizing channel is connected with the separation structure and communicated with the pressurizing cavity.

Further, the tubular column body includes first body and the second body of cover establishing outside first body, and wherein, the space in the first body forms back liquid passageway, and the space that encloses between first body and the second body forms the channel that pressurizes, and the partition structure cover establishes outside the second body.

Furthermore, a first through hole is formed in the pipe wall of the second pipe body, a second through hole is formed in the separation structure and communicated with the pressurizing cavity, and the first through hole and the second through hole are correspondingly formed.

Further, the partition structure is a plurality of, and a plurality of partition structures are arranged at intervals.

Furthermore, the oil recovery well pickling tubular column structure still includes the pipe of punching, and the union coupling of punching is provided with the discharge orifice at the one end that deviates from the well head of first body and second body on the pipe of punching, and the intraductal and liquid return channel intercommunication that punches.

Further, the oil recovery well pickling tubular column structure still includes the shutoff nipple joint, and the first end of shutoff nipple joint is connected in one of the well head that deviates from of first body and second body, and the second end of shutoff nipple joint is connected on the perforated pipe, and the clearance between the one end that deviates from the well head of the first body of shutoff nipple joint and the one end that deviates from the well head of second body to only communicate with the first body in making the perforated pipe.

Further, the oil production well pickling pipe column structure also comprises a first valve, and the first valve enables the liquid return channel and the pressurizing channel to be isolated from each other or communicated with each other.

Further, the oil production well pickling pipe column structure also comprises a second valve, and the second valve enables the liquid return channel and the oil production well to be isolated from each other or communicated with each other.

Furthermore, the oil recovery well pickling pipe column structure further comprises a first pipeline and a second pipeline which are located at a well head, the first pipeline is communicated with the liquid return channel, and the second pipeline is communicated with the pressurizing channel.

According to another aspect of the present invention, there is provided a method of acid washing a production well, wherein the production well includes a casing and a screen which are connected to each other, the method comprising: step S1: lowering the oil production well acid washing pipe column structure into the oil production well, wherein the oil production well acid washing pipe column structure is the oil production well acid washing pipe column structure, and the separation structure is positioned in the sieve tube; step S2: injecting pressure from the pressurizing channel and expanding the separating structure, wherein the separating structure is filled between the pipe column body and the sieve pipe; step S3: acid liquor is injected into the gap between the sieve tube and the tubular column body, and the acid liquor returns to the wellhead through the liquor return channel.

By applying the technical scheme of the invention, when the acid washing process is carried out on the sieve tube, the acid washing pipe column of the oil production well is put into the oil production well, and the pressure is charged into the pressure charging channel so as to expand the separation structure. The separation structure is expanded to fill the space between the pipe column body and the sieve pipe, and acid liquor flows into the gap between the sieve pipe and the stratum and cleans mud cakes. The acid liquor flows along the horizontal direction and then finally returns to the wellhead through the liquid return channel of the tubular column body, so that circulation is realized. The structure enables the well washing valve and other structures not to be arranged on the sieve tube when the acid washing operation is carried out along with the sieve tube, and further enables the acid washing process to be suitable for the well-completed horizontal well sieve tube. Therefore, the technical scheme of the invention solves the problem that the acid washing process is not suitable for the well-completed horizontal well screen pipe in the prior art.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 shows a schematic structural view of an embodiment of a production well acid washing string structure according to the present invention.

Wherein the figures include the following reference numerals:

10. a tubular column body; 11. a first pipe body; 12. a second tube body; 20. a liquid return channel; 30. a partition structure; 40. a pressurizing channel; 50. perforating a pipe; 51. an overflowing hole; 60. plugging short sections; 70. a first valve; 80. a second valve; 90. a first pipeline; 100. a second pipeline; 200. a sleeve; 300. a screen pipe; 400. and (4) acid liquor.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the application, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

As shown in fig. 1, the oil recovery well pickling line structure of the present embodiment includes a line body 10, a partition structure 30, and a pressurizing passage 40. Wherein, the column body 10 includes a liquid return passage 20. The separation structure 30 is made of flexible material and is in an annular structure, the separation structure 30 is sleeved outside the tubular column body 10, and a pressure charging cavity is arranged in the separation structure 30. The pressurizing passage 40 is connected to the partition structure 30 and communicates with the pressurizing chamber.

By applying the technical scheme of the embodiment, when the screen pipe is subjected to the acid washing process, the acid washing pipe column of the oil production well is lowered into the oil production well, and the pressurizing channel 40 is pressurized to expand the separation structure 30. The separation structure 30 is expanded to fill the space between the pipe column body 10 and the sieve pipe, and acid liquid flows into the gap between the sieve pipe and the stratum and cleans mud cakes. The acid liquor flows along the horizontal direction and finally returns to the wellhead through the liquid return channel 20 of the pipe column body 10, so that circulation is realized. The structure enables the well washing valve and other structures not to be arranged on the sieve tube when the acid washing operation is carried out along with the sieve tube, and further enables the acid washing process to be suitable for the well-completed horizontal well sieve tube. Therefore, the technical scheme of the embodiment solves the problem that the acid washing process is not suitable for the completed horizontal well screen pipe in the prior art.

As shown in fig. 1, in the present embodiment, the column body 10 includes a first tube 11 and a second tube 12 sleeved outside the first tube 11. The space in the first tube 11 forms a liquid return channel 20, the space enclosed between the first tube 11 and the second tube 12 forms a pressurizing channel 40, and the partition structure 30 is sleeved outside the second tube 12. Specifically, first body 11 and second body 12 are hollow tube structure, and the diameter of second body 12 is greater than the diameter of first body 11, and then makes second body 12 can overlap and establish outside first body 11. Preferably, the first tube 11 and the second tube 12 are concentrically arranged. The space within the first body 11 forms a return passage 20 from which acid can be returned to the wellhead. The first body 11 and the second body 12 define an annular space therebetween that forms a plenum 40. The partition structure 30 may be expanded by applying pneumatic or hydraulic pressure to the annular space between the first tube 11 and the second tube 12. Further, the partition structure 30 is sleeved outside the second tube 12, and the pressure-filled cavity in the partition structure 30 is communicated with the annular space between the first tube 11 and the second tube 12.

Preferably, in the technical solution of this embodiment, a first through hole is provided on the tube wall of the second tube 12, a second through hole is provided on the partition structure 30, the second through hole is communicated with the pressurizing cavity, and the first through hole and the second through hole are correspondingly provided. Specifically, the partition structure 30 in the present embodiment may be an annular sleeve structure made of rubber, and the partition structure 30 has an annular punching cavity. When the annular space between the first and second

tubular bodies

11 and 12 is charged with hydraulic pressure, the fluid is introduced into the pressurizing chamber through the first and second through-holes and expands the partition structure 30, thereby filling the gap between the screen and the support of the pipe string body 10.

As shown in fig. 1, in the solution of the present embodiment, there are a plurality of partition structures 30, and the plurality of partition structures 30 are arranged at intervals. Specifically, a plurality of partition structures 30 are provided at intervals in the axial direction.

As shown in fig. 1, in the technical solution of this embodiment, the oil recovery well pickling column structure further includes a perforated pipe 50, the perforated pipe 50 is connected to the ends of the first pipe 11 and the second pipe 12 that are away from the wellhead, the perforated pipe 50 is provided with an overflowing hole 51, and the inside of the perforated pipe 50 is communicated with the liquid return channel 20. Specifically, the perforated pipe 50 has a hollow pipe structure, and the pipe wall of the perforated pipe 50 is provided with an overflowing hole 51. The acid liquid can flow into the perforated pipe 50 through the overflowing hole 51, enter the straight first pipeline 90 and finally flow back to the wellhead.

As shown in fig. 1, in the technical scheme of this embodiment, the structure of the acid washing pipe column for the oil production well further includes a plugging nipple 60, a first end of the plugging nipple 60 is connected to one end of the first pipe body 11 and the second pipe body 12, which deviates from the wellhead, and a second end of the plugging nipple 60 is connected to the perforated pipe 50. The plugging nipple 60 plugs a gap between one end of the first pipe body 11 deviating from the wellhead and one end of the second pipe body 12 deviating from the wellhead, so that the interior of the perforated pipe 50 is only communicated with the interior of the first pipe body 11. Specifically, the plugging nipple 60 is connected between the pipe column body 10 and the perforated pipe 50, and the plugging nipple 60 is of a sleeve structure and seals an opening between the first pipe body 11 and the second pipe body 12. The perforated pipe 50 is connected with the plugging nipple 60 and then is communicated with the interior of the first pipe body 11, namely the liquid return channel 20.

As shown in fig. 1, in the solution of this embodiment, the structure of the production well pickling line further includes a first valve 70, and the first valve 70 isolates or communicates the fluid return passage 20 and the pressurizing passage 40 from each other. When the first valve 70 is opened, the fluid return passage 20 and the pressurizing passage 40 are communicated with each other, and when the first valve 70 is closed, the fluid return passage 20 and the pressurizing passage 40 are isolated from each other. Further, when the pipe string body 10 is put into the production well, the first valve 70 needs to be in an open state. When the pickling operation is performed, the first valve 70 needs to be in a closed state.

As shown in fig. 1, in the solution of this embodiment, the structure of the production well pickling line further includes a second valve 80, and the second valve 80 isolates or communicates the fluid return channel 20 from or with the production well. When the second valve 80 is opened, the fluid return passage 20 is in communication with the production well. When the second valve 80 is closed, the fluid return passage 20 is isolated from the well. When putting the tubular column body 10 into the oil production well and carrying out the pickling operation, the second valve 80 keeps the closed state, and when the tubular column body 10 needs to be lifted up after the pickling operation is finished, the first valve 70 and the second valve 80 are both in the open state, so that the liquid in the first tubular body 11 and between the first tubular body 11 and the second tubular body 12 flows out, and the tubular column body 10 is convenient to take out.

As shown in fig. 1, in the solution of this embodiment, the structure of the production well pickling line further includes a first pipeline 90 and a second pipeline 100 at the wellhead, the first pipeline 90 is communicated with the fluid return channel 20, and the second pipeline 100 is communicated with the pressurizing channel 40. Specifically, the first line 90 may be connected to a device for storing acid and the second line 100 may be connected to a pressurizing device, such as a pump truck.

The present application also provides a method for acid washing a production well, wherein the production well includes a casing 200 and a screen 300 which are connected to each other, the method for acid washing a production well according to the present application including:

step S1: lowering the oil production well acid washing pipe column structure into the oil production well, wherein the oil production well acid washing pipe column structure is the oil production well acid washing pipe column structure, and the separation structure 30 is positioned in the sieve tube 300;

step S2: injecting pressure from the pressurizing passage 40 and expanding the partition structure 30, the partition structure 30 being filled between the pipe string body 10 and the screen 300;

step S3: acid fluid 400 is injected from the gap between the screen 300 and the tubular body 10, and the acid fluid 400 is returned to the wellhead through the fluid return passage 20.

According to the structure, the oil production well acid pickling pipe column structure and the oil production well acid pickling method have the following characteristics:

the invention relates to a pipe column process method for a horizontal well completed by a conventional sieve pipe, which aims at solving the problems that the prior sieve pipe completed horizontal well in an oil field has no packing outside a sieve pipe, the production is reduced because the acid washing blockage removal operation is not carried out or the production is carried out for a long time during the production, and the acidification blockage removal is needed.

The application range is as follows: the utility model relates to a production acidizing removes stifled technical field, it has solved the problem that the near wellbore area reservoir bed is polluted and is blockked up in the production process, has realized removing stifled and the pickling of near wellbore stratum to the screen pipe, has simple structure, and the operation risk is little, and one trip tubular column alright thoroughly wash the characteristics of screen pipe annulus and near wellbore area reservoir bed.

The application relates to a tubular column process method which comprises a concentric outer tube inlet, a concentric inner tube inlet, a concentric tube steering valve, a self-sealing well sealing device, a sleeve, a concentric tube, an oil layer, a sieve tube, a plurality of concentric tube acid washing packers, a liquid discharge valve, a circulating valve, a concentric tube sealing short section, a perforated tube, a guide head and a sleeve gate from top to bottom. The technical scheme of the application can meet the operation requirement of acidizing and plugging removal of the sieve tube horizontal well in the conventional well completion mode, thoroughly clean mud cake pollution between the sieve tube and the stratum and achieve the aim of acidizing and production increase; the defects of weak pertinence of acidizing the tubular column and removing mud pollution of the continuous oil pipe are overcome, and meanwhile, additional tools are not required to be added during well completion; has higher operability and economic benefit.

In the application, concentric double pipes are adopted in the pipe column structure, and the technical scheme can be realized by adopting parallel double pipes, but the operation difficulty of the concentric double pipes is lower.

The acid washing method can realize the blockage removal of the horizontal section sieve tube of the horizontal well and the reservoir pollution removal of the near-wellbore area, and the main construction process comprises the following steps:

(1) putting the oil production well pickling pipe column structure into the well, and enabling liquid to enter the first pipe body 11 and the second pipe body 12 from the perforated pipe 50 and the first valve 70;

(2) after the pipe column is put in place, a self-sealing blowout preventer is installed at the well mouth, a ball is thrown into the first pipe body 11, and the top of the first pipe body 11 is connected with a concentric pipe steering valve;

(3) the first valve 70 is closed after the first pipe 11 is pressurized, and the ball seat fall into the perforated pipe 50 after being pressurized, so that the first pipe 11 and the second pipe 12 are sealed. Connecting a first pipeline 90 of the concentric tube steering valve with a return-drain liquid tank, and connecting a second pipeline 100 with a pump truck;

(4) the annulus of the first pipe body 11 and the second pipe body 12 is suppressed and kept under pressure at the wellhead through a concentric pipe diverter, a separation structure 30 is set, and the horizontal well screen section is sealed and separated into a plurality of sections by the separation structure 30;

(5) according to the design, the screen section of the horizontal well is pickled in a reverse circulation mode, after acid liquor enters the horizontal section, the separation structure 30 in the screen pipe is sealed to occupy a liquid flow channel, the acid liquor can only enter an annular space between the screen pipe and the well wall through the screen pipe and flow to the well bottom, then enters the first pipe body 11 through the perforated pipe 50 and is returned to a ground liquid tank through an inner pipe of a concentric pipe steering valve, and therefore the effect of removing mud cake pollution in the area close to the well is achieved;

(6) when the tubular column needs to be lifted after the pickling is finished, firstly, a ball is thrown from the wellhead, the inner pipe is pressed, the second valve 80 is opened, the ball and the ball seat are pressed and taken off into the perforated pipe 50 by the pressure increase, the first tubular body 11 and the second tubular body 12 are communicated, the tubular column is lifted, and the pickling process is completed.

The relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

In the description of the present application, it is to be understood that the orientation or positional relationship indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the orientation or positional relationship shown in the drawings, and are used for convenience of description and simplicity of description only, and in the case of not making a reverse description, these directional terms do not indicate and imply that the device or element being referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the scope of the present application; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

Spatially relative terms, such as "above … …," "above … …," "above … …," "above," and the like, may be used herein for ease of description to describe one device or feature's spatial relationship to another device or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term "above … …" can include both an orientation of "above … …" and "below … …". The device may be otherwise variously oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

It should be noted that the terms "first", "second", and the like are used to define the components, and are only used for convenience of distinguishing the corresponding components, and the terms have no special meanings unless otherwise stated, and therefore, the scope of protection of the present application is not to be construed as being limited.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An oil recovery well pickling tubular column structure, comprising:

a column body (10), the column body (10) comprising a liquid return channel (20);

the separation structure (30) is made of flexible materials and is of an annular structure, the separation structure (30) is sleeved outside the pipe column body (10), and a pressurizing cavity is formed in the separation structure (30);

a charging channel (40) connected to said partition structure (30) and communicating with said charging chamber;

the pipe column body (10) comprises a first pipe body (11) and a second pipe body (12) sleeved outside the first pipe body (11), wherein a space in the first pipe body (11) forms the liquid return channel (20), a space enclosed between the first pipe body (11) and the second pipe body (12) forms the pressurizing channel (40), and the separation structure (30) is sleeved outside the second pipe body (12); a first through hole is formed in the pipe wall of the second pipe body (12), a second through hole is formed in the separation structure (30), the second through hole is communicated with the pressurizing cavity, and the first through hole and the second through hole are correspondingly arranged;

the punching pipe (50) is connected to one ends, away from the wellhead, of the first pipe body (11) and the second pipe body (12), the punching pipe (50) is provided with a overflowing hole (51), and the punching pipe (50) is communicated with the liquid return channel (20);

the first end of shutoff nipple joint (60) is connected first body (11) with deviating from of second body (12) one of well head is served, the second end of shutoff nipple joint (60) is connected on perforating pipe (50), shutoff nipple joint (60) shutoff deviating from of first body (11) the one end of well head with deviating from of second body (12) clearance between the one end of well head, so that only in perforating pipe (50) with communicate in first body (11).

2. A production well pickling line structure according to claim 1, wherein said partition structure (30) is provided in plurality, and a plurality of said partition structures (30) are provided at intervals.

3. The production well pickling line structure according to claim 1, further comprising a first valve (70), wherein the first valve (70) isolates or communicates the fluid return passage (20) and the pressurizing passage (40) from each other.

4. The production well pickling line structure of claim 1, further comprising a second valve (80), wherein the second valve (80) isolates or communicates the fluid return passage (20) from or with a production well.

5. The production well pickling line structure according to claim 1, further comprising a first pipeline (90) and a second pipeline (100) at a wellhead, wherein the first pipeline (90) is communicated with the fluid return passage (20), and the second pipeline (100) is communicated with the pressurizing passage (40).

6. A method for pickling a production well, wherein the production well comprises a casing (200) and a screen (300) connected to each other, the method comprising:

step S1: lowering the production well sour string structure into a production well, the production well sour string structure being the production well sour string structure of any one of claims 1 to 5, the partition structure (30) being located within the screen (300);

step S2: injecting pressure from within the plenum (40) and expanding the spacer structure (30), the spacer structure (30) being packed between the tubular string body (10) and the screen (300);

step S3: injecting acid liquor (400) from a gap between the screen pipe (300) and the pipe column body (10), wherein the acid liquor (400) returns to a wellhead through the liquid return channel (20).