CN114109299A

CN114109299A - Stage cementing device and method for top cementing

Info

Publication number: CN114109299A
Application number: CN202010874342.1A
Authority: CN
Inventors: 秦金立; 阮臣良; 刘奔; 郭朝辉; 刘明; 朱玉杰; 曾艳军; 廖洪千
Original assignee: China Petroleum and Chemical Corp; Sinopec Research Institute of Petroleum Engineering
Current assignee: China Petroleum and Chemical Corp; Sinopec Research Institute of Petroleum Engineering
Priority date: 2020-08-27
Filing date: 2020-08-27
Publication date: 2022-03-01
Anticipated expiration: 2040-08-27
Also published as: CN114109299B

Abstract

The invention provides a stage cementing device for top cementing, comprising: a body; the opening assembly is arranged in the body and comprises an opening sleeve and an opening seat arranged in the opening sleeve, and in an initial state, the opening sleeve covers the circulation hole of the body and the opening seat covers the liquid inlet groove of the body; and a packer comprising a packing element having a fluid containing cavity. The opening seat can respond to one-time pressure build-up in the body to move downstream after the first-stage well cementation is finished so as to open the liquid inlet groove, and therefore liquid in the body can enter the liquid containing cavity to cause the rubber cylinder to expand. A pressure build-up is achieved by lowering an opening tool that can be engaged with an opening seat. The opening seat and the opening tool are both made of soluble material. The invention also provides a stage cementing method for top cementing.

Description

Stage cementing device and method for top cementing

Technical Field

The invention relates to a petroleum well cementing technology, in particular to a staged cementing device, and particularly relates to a packing type staged cementing device for top cementing and a staged cementing method for top cementing performed by using the device.

Background

The well cementation technology is an important technical link in the well drilling and completion process. The quality of well cementation directly affects the subsequent oil and gas exploitation operation.

The stage cementing process is a common process in well cementing technology. For horizontal well completion operations, the screen top cementing completion technique is a common technique, and the typical pipe string combination is screen + blind plate + casing outer packer + differential stage cementing device.

For the pipe column, the lowering speed of the pipe column needs to be controlled in the well entering process, and the problem that the staged cementing device is started in advance due to pressure surge is avoided. In addition, when the top cementing device finishes drilling the plug, the stage cementing device and the casing may be damaged, if serious, the casing may be windowed, and the well may be scrapped. In addition, the drilled aluminum blocks cannot be completely circulated, which causes underground falling objects and influences later operation. At the same time, improper operating parameters can also damage the graded ferrules and sleeves.

For this situation, salvage-type drill-plug-free stage grouters have been developed and used. However, this salvage type drill-plug-free stage cementing apparatus is complicated in structure and requires a fishing tool to be run in for fishing. Meanwhile, the fishing tool is easy to block during fishing and even cannot be lifted out. Once the salvaging fails, the post-treatment difficulty is large, the period is long, and the speed and efficiency increase is difficult to realize.

Disclosure of Invention

In view of the above problems, the present invention provides a packing type stage-cementing apparatus for top-cementing and a stage-cementing method for top-cementing using the same.

According to one aspect of the present invention there is provided a stage cementing apparatus for top cementing comprising: the device comprises a hollow cylindrical body with an inner cavity, wherein a through circulating hole and a liquid inlet groove which is opened towards the inner cavity are formed in the wall of the body; an opening assembly disposed within the body, the opening assembly including an opening sleeve and an opening seat disposed within the opening sleeve, wherein, in an initial state, the opening sleeve covers the circulation hole and the opening seat covers the liquid inlet tank; and the packer comprises a rubber cylinder with a liquid containing cavity and a flow passage communicated with the liquid containing cavity. Wherein the opening seat is capable of opening the liquid inlet slot in response to a downstream movement of a pressure build-up in the body, whereby liquid entering the inner cavity of the body during primary cementing is capable of entering the liquid containing cavity via the liquid inlet slot and the flow passage, thereby causing the rubber cartridge to expand. Said one hold down is achieved by lowering an opening tool engageable with said opening seat. The opening seat and the opening tool are both made of soluble material.

In a preferred embodiment, a bearing seat made of soluble material is further arranged at the lower end of the opening sleeve and used for limiting the stroke of the downstream movement of the opening seat.

In a preferred embodiment, the opening sleeve is capable of moving downstream in response to a second build-up of pressure in the body, thereby opening the circulation orifice and closing the liquid inlet tank.

In a preferred embodiment, upstream of the opening sleeve, a closing sleeve is provided, within which a closing seat is provided. Wherein the closure sleeve is configured to move downstream to close the circulation hole in response to a third hold-back pressure in the body during a second stage cementing process.

In a preferred embodiment, said third pressure build-up is achieved by lowering a closing tool engageable with said closing seat, wherein said closing seat and closing tool are both made of a soluble material.

In a preferred embodiment, the soluble material is a graphene-based soluble aluminum alloy or soluble rubber that is capable of being dissolved in a salt solution.

In a preferred embodiment, the opening seat, the receiving seat and the closing seat are coated with a protective coating insoluble in the chloride solution.

In a preferred embodiment, the salt solution is a greater than 5% KCl solution.

According to another aspect of the present invention there is provided a stage cementing method for top cementing, wherein it is carried out using the above stage cementing apparatus, the method comprising the steps of: putting the stage cementing device in place along with the pipe column; the opening tool is put into the body to be connected with the opening seat, pressure is suppressed for one time, the opening seat moves to the position of the bearing seat in a downstream mode to open the liquid inlet groove, and therefore liquid enters the liquid containing cavity through the inner cavity of the body, the liquid inlet groove and the flow channel, and the rubber cylinder is expanded; carrying out secondary pressure building to enable the opening sleeve to move downstream to open the circulation hole and cut off the communication between the liquid inlet tank and the flow channel; after the second-stage cementing operation, a closing tool is put in to be jointed with the closing seat, three times of pressure building are carried out to enable the closing sleeve to move downstream to close the circulating hole again, and meanwhile, a saline solution and a completion fluid are injected; the opening tool, opening seat, socket, closing tool and closing seat are dissolved with a salt solution.

In a preferred embodiment, the saline solution is also injected before the opening tool is run in.

In the expansion pack cementing apparatus for top-cementing according to the present invention, the pipe string is constructed to be non-enclosed. Therefore, the problem of pressure agitation does not exist in the cementing process, and the problem that the packer is expanded in advance or the grading hoop is opened in advance due to the pressure agitation caused by the improper running speed of the closed pipe column is solved.

In addition, according to the expansive packing type stage cementing device for top cementing of the present invention, the packer partially seals the annulus, thereby achieving protection of the lower reservoir, and the stage cementing portion achieves cementing work on the top of the packer.

In addition, each plug seat and each plug are made of soluble materials, and can be dissolved automatically in a saline solution environment after the well cementation is finished. There is no need to run a string of drilling tools to drill out these accessories, nor is there any need to perform fishing operations on these. Therefore, the well construction period is greatly shortened, the operation cost is reduced, and the construction efficiency is improved.

Additionally, the surfaces of the plug base (e.g., the opening base, the socket base, and the closing base) are provided with a protective coating to prevent premature dissolution of the plug base in drilling fluids containing chloride ions.

Drawings

The invention will be explained in more detail below with reference to the drawings and by means of exemplary embodiments which are schematic. In the figure:

FIG. 1 shows the overall structure of a stage-cementing installation for top-cementing according to one embodiment of the present invention, wherein the installation is in an initial state;

FIG. 2 is an enlarged partial view of the device of FIG. 1 showing the position of the opening seat and opening sleeve;

FIG. 3 shows a stage cementing apparatus for top cementing according to the present invention, wherein the glue cartridge is in an expanded state, but the circulation holes are still closed;

FIG. 4 shows a stage cementing apparatus for top cementing according to the present invention, wherein the glue cartridge is in an expanded state and the circulation holes have been opened;

FIG. 5 is a partial schematic view of a stage cementing apparatus for top cementing according to the present invention, showing the circulation holes again in a closed state;

FIG. 6 shows an opening tool according to one embodiment of the present invention; and

fig. 7 shows a closing tool according to an embodiment of the invention.

In the drawings, like parts are provided with like reference numerals. The figures are not drawn to scale.

Detailed Description

The invention will be further described with reference to the accompanying drawings. In the following, directional terms "lower," "downstream," "downward," etc. refer to a direction away from the wellhead, while "upper," "upstream," "upward," etc. refer to a direction toward the wellhead.

Fig. 1 shows a schematic construction of a stage-cementing apparatus for top-cementing according to the present invention. In this particular embodiment, the stage cementing apparatus is an expansion pack stage cementing apparatus 10.

As shown in fig. 1, the expansion packing stage cementing apparatus 10 comprises a hollow cylindrical body 100. The body 100 includes an inner cavity 110 formed therein, a circulation hole 120 penetrating through a wall of the body, and an inlet tank 130 (see fig. 2) communicating with the inner cavity 110 but not penetrating through the wall of the body. An upper fitting 140 is attached to the upstream end of the body 100 for connection to other components of the bushing. The liquid inlet tank 130 is disposed downstream of the circulation hole 120. The circulation hole 120 is a circulation hole for secondary cementing, the function of which is well known in the art and will not be described in detail herein. The function of the inlet tank 130 will be described in detail below.

In accordance with the present invention, an opening assembly 300 is provided within the cylindrical body 100 of the expansion pack cementing apparatus 10, which includes an opening sleeve 310 disposed within the body 100, and an opening seat 320 disposed within the opening sleeve 310. According to the present invention, the opening seat 320 is made of a soluble material. Wherein the opening sleeve 310 is coupled with the body 100 by the first shear pin 180 and covers the circulation hole 120 in an initial state as shown in fig. 1. As shown in fig. 2, the opening seat 320 is connected to the opening housing 310 by the second shear pin 182 and covers the inlet tank 130. In the embodiment shown in fig. 1 and 2, the first shear pin 180 is disposed downstream of the circulation hole 120, but upstream of the second shear pin 182. Wherein the shear stress of the first shear pin 180 is set to be greater than the shear stress of the second shear pin 182, i.e. the second shear pin 182 will shear before the first shear pin 180.

In this document, the term "initial state" is also referred to as "first state", i.e., the state before the circulation hole 120 is opened. Figures 1 to 3 all show the stage cementing apparatus 10 in an initial state. The term "soluble material" refers to a material that is soluble in the environment of a salt solution, such as graphene-based soluble aluminum alloys or soluble rubbers, and the like. The term "salt solution" refers to a salt solution containing chloride ions, such as a KCl solution, preferably a KCl solution greater than 5%.

Additionally, according to an embodiment of the present invention, the opening assembly 300 may further include a socket 330. As shown more clearly in fig. 2, the socket 330 is secured, such as by threads, within the opening sleeve 310, preferably at the downstream end of the opening sleeve 310. The receptacle 330 is for receiving the opening seat 320 moved downward, i.e., defining a stroke of the downward movement of the opening seat 320. This downward movement of the opening seat 320 will be described in detail below. According to the present invention, the socket 330 is made of a soluble material.

As shown in fig. 1, the inflatable packer stage cementing apparatus 100 further comprises a packer 200 disposed downstream of the cylindrical body 100 in accordance with the present invention. The packer 200 includes a packing valve body 210 that is fixedly coupled to the downstream end of the body 100, such as by threaded engagement. The isolation valve body 210 is, for example, a cylindrical structure, and a step 215 is provided on an inner wall thereof. Packer 200 further includes a base pipe 250, for example, fixedly connected to the downstream end of packing valve body 210, and a packing element 220 disposed outside base pipe 250. In the illustrated embodiment, the upstream end of the base pipe 250 extends into the interior cavity of the isolation valve body 210 and is threadably connected to the downstream end of the isolation valve body 210. A lower joint 270 is provided at the downstream end of the cartridge 220. The lower sub 270, together with a short sleeve 272 secured thereto, is used to connect subsequent tools.

As shown in fig. 2, the packing valve body 210 includes a flow passage 230 extending axially therein, which communicates with the liquid inlet slot 130 in the body 100 (specific communication details are not shown in the cross-section of fig. 2). The flow passage 230 extends axially through the isolation valve body 210. In addition, as shown in fig. 1, the cartridge 220 includes a liquid containing chamber 240 communicating with the flow passage 230. The liquid-containing chamber 240 may also be formed to extend axially within the glue cartridge 230. In an alternative embodiment, fluid chamber 240 may be formed by a gap between base pipe 250 and gel cartridge 230. In addition, two support sleeves 260 spaced apart from each other are provided outside the rubber cylinder 230. Wherein the upstream first support sleeve 260 is connected to the packing valve body 210 and the downstream second support sleeve 260 is connected to the lower coupling 270. The two support sleeves 260 may serve to limit the axial position at which the rubber cartridge 220 expands. That is, the portion of the rubber sleeve 220 between the two support sleeves 260 can be expanded outward.

Further, as shown in fig. 1, a closing sleeve 450 is further provided in the body 100 at an upstream of the opening sleeve 310. In the initial state, the closing sleeve 450 directly abuts the opening sleeve 310 and is connected to the body 100 by the third shear pin 184. A closing seat 460 is provided at the upper end of the closing sleeve 450. According to the invention, the closure seat 460 is made of a soluble material. In a preferred embodiment, as shown in fig. 5, a snap spring 462 is provided on an outer wall of the closing sleeve 450, and a snap spring groove 118 capable of being engaged with the snap spring 462 is provided on an inner wall of the body 100. The specific function of the closure sleeve 450 and closure seat 460, as well as the circlip 462 and the circlip slot 118, will be described below.

As shown in fig. 1 and 2, in an initial state, the opening sleeve 310 of the opening assembly 300 is connected to the body 100 by the first shear pin 180 and covers the circulation hole 120. Meanwhile, the opening seat 320 of the opening assembly 300 is connected to the opening housing 310 by the second shear pin 182 and covers the fluid inlet tank 130. At this time, the inner cavity 110 of the body 100 is not communicated with the flow passage 230 in the packing valve body 210 of the packer 200. Thus, the displacement fluid entering the inner cavity 110 of the body 100 during the first stage cementing process cannot enter the flow passage 230 in the packing valve body 210 of the packer 200.

In the stage cementing method for top cementing according to the present invention, an expansion pack type stage cementing apparatus 10 is run in with the string. And circulating for one week after the pipe column is lowered to a preset position. At this stage, saline solution may preferably be injected to ensure that the plug seat and the lower portion of the opening tool 400 that is then lowered are also in saline solution, ensuring and accelerating the dissolution of the lower portion.

Thereafter, as shown in fig. 3, when an opening tool 400 as shown in fig. 6 is put into the expansive packing type stage cementing device 10 according to the present invention, the opening tool 400 is engaged with the opening seat 320 during the downward movement, thereby blocking the inner cavity 110 of the body 100. By performing a hold down (which is referred to herein as a "primary hold down") in the body 100, the second shear pin 182 shears off. In this case, the opening tool 400 moves downward together with the opening seat 320 until the opening seat 320 abuts on the socket 330. At this time, the fluid inlet tank 130 is no longer stopped by the opening seat 320 due to the downward movement of the opening seat 320, thereby communicating with the inner cavity 110. Thus, the displacement fluid in the inner cavity 110 can enter the fluid containing cavity 240 in the rubber cylinder 220 through the fluid inlet slot 130 and the fluid passage 230 in the packing valve body 210. Thus, the rubber sleeve 220 expands to be attached to the well wall, and the annular space is isolated into an upper part and a lower part, so that the condition that the upper cement sinks to pollute the reservoir is avoided.

Thereafter, the hold-down (which is referred to herein as "secondary hold-down") continues in the body 100, causing the first shear pin 180 to shear. In this case, the opening sleeve 310 can move downward relative to the body 100 until it abuts on the step 215 of the packing valve body 210, as shown in fig. 4. At this time, the circulation hole 120 is exposed, and the fluid inlet tank 130 is stopped again by the opening sleeve 310 moved downward, thereby cutting off its communication with the inner chamber 110. In this case, a secondary cementing operation may be performed.

In the secondary circulation and cementing process, after cementing is complete, a shut-off tool 410 as shown in FIG. 7 may be run in and replaced. The displacement fluid includes a brine solution and a completion fluid. As shown in fig. 5, when the closing tool 410 is dropped onto the closing seat 460 and forms a seal, the upper portion of the closing seat 460 forms a closed cavity. At this point, a hold pressure (referred to herein as "three hold pressures") is performed in the body 100, causing the third shear pin 184 to shear. In this way, the closure sleeve 450 descends relative to the body 110 and closes the circulation hole 120 again. In this position, the snap spring 462 provided on the outer wall of the closing sleeve 450 enters the snap spring groove 118 provided on the inner wall of the body 100. The reverse movement of the closing sleeve 450 can be prevented by the engagement of the circlip 462 and the circlip groove 118, thereby achieving permanent closing of the circulation hole 120.

According to the present invention, the opening tool 400 is preferably a flexible opening plug, and the closing tool 410 is preferably a closing plug. Meanwhile, the closing tool 410 and the opening tool 400 are made of soluble materials.

According to a preferred embodiment of the invention, all the plug seats, i.e. the opening seat 320, the socket 330 and the closing seat 460, are coated with a protective coating insoluble in the chloride solution. Thus, in the case of drilling fluids containing chloride ions, the plug seats (i.e., the open seat 320, the receptacle 330, and the closed seat 460) that come into contact with the drilling fluid do not dissolve prematurely due to the presence of the protective coating. Upon contact of the plug base with the plug or other base, the protective coating may rupture under the contact pressure, thereby exposing the soluble material therein. In this case, the soluble material of the plug base (e.g., graphene-based material) may come into contact with the injected salt solution, and dissolution may occur. This makes it possible to control the dissolution rate so that dissolution occurs at a desired timing.

According to the invention, after cementing, the accessories (including the parts such as the opening tool 400, the closing tool 410, the opening seat 320, the bearing seat 330 and the closing seat 460) made of soluble materials are dissolved in the environment of the injected saline solution, so that the full path is realized. At the same time, there is no need to run a string of drilling tools to drill out these accessories, nor to salvage them. Therefore, the well construction period is greatly shortened, the operation cost is reduced, and the construction efficiency is improved.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the features mentioned in the embodiments can be combined in any way, without structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. Stage cementing installation (10) for top cementing comprising:

a hollow cylindrical body (100) having an inner cavity (110), a through circulation hole (120) provided on the wall of the body, and an inlet tank (130) open to the inner cavity;

an opening assembly (300) disposed within the body, the opening assembly including an opening sleeve (310) and an opening seat (320) disposed within the opening sleeve (310), wherein, in an initial state, the opening sleeve (310) covers the circulation hole (120) and the opening seat (320) covers the liquid inlet tank (130); and

a packer (200) comprising a packing element (220) having a fluid chamber (240), and a flow passage (230) in communication with the fluid chamber (240),

wherein the opening seat (320) is capable of opening the liquid inlet slot (130) in response to a set pressure downstream movement in the body (100), whereby liquid entering the inner cavity (110) of the body (100) during primary cementing is capable of entering the liquid holding cavity (240) via the liquid inlet slot (130) and the flow channel (230) resulting in expansion of the cement cartridge (220),

said pressure build-up being effected by the lowering of an opening tool (400) engageable with said opening seat (320), and

the opening seat (320) and the opening tool (400) are both made of a soluble material.

2. Stage cementing device according to claim 1, characterized in that at the lower end of the opening sleeve (310) there is also provided a socket (330) made of soluble material for limiting the stroke of the downstream movement of the opening seat (320).

3. Stage cementing installation according to claim 1 or 2, characterized in that the opening sleeve (310) is movable downstream in response to a secondary pressure hold-back in the body (100) so as to open the circulation holes (120) and close the liquid intake slots (130).

4. Stage cementing device according to any one of the claims 1 to 3, characterized in that a closing sleeve (450) is provided upstream of the opening sleeve (310), a closing seat (460) being provided within the closing sleeve (450), wherein the closing sleeve (450) is configured to be movable downstream in response to three pressure holds in the body (100) during a second stage cementing process, thereby closing the circulation hole (120).

5. Stage cementing device according to claim 4, characterized in that the three times of pressure building is achieved by lowering a closing tool (410) engageable with the closing seat (460), wherein both the closing seat (460) and the closing tool (410) are made of a soluble material.

6. The staged cementing apparatus according to any one of claims 1 to 5, wherein the soluble material is a graphene-based soluble aluminum alloy or a soluble rubber that is soluble in a salt solution.

7. Cementing device according to claim 6, characterized in that the opening seat (320), the receptacle seat (330) and the closing seat (460) are coated with a protective coating insoluble in saline solution.

8. The stage cementing apparatus according to claim 6 or 7, characterized in that the salt solution is a KCl solution of more than 5%.

9. A stage cementing method for top cementing, wherein it is performed with a stage cementing apparatus according to any one of the claims 1 to 8, said method comprising the steps of:

putting the stage cementing device (10) in place along with the pipe column;

the opening tool (400) is put into engagement with the opening seat (320), and once pressure building is carried out to enable the opening seat (320) to move downstream to the bearing seat (330) to open the liquid inlet groove (130), so that liquid enters the liquid containing cavity (240) through the inner cavity (110), the liquid inlet groove (130) and the flow channel (230) of the body (100), and the rubber cylinder (220) is expanded;

secondary pressure building is carried out to enable the opening sleeve (310) to move downstream to open the circulation hole (120), and meanwhile, the communication between the liquid inlet groove (130) and the flow channel (230) is cut off;

after the secondary cementing operation, a closing tool (410) is put into engagement with the closing seat (460), three times of pressure building are carried out to move the closing sleeve (450) downstream to close the circulation hole (120) again, and simultaneously, a saline solution and a completion fluid are injected;

dissolving the opening tool (400), the opening seat (320), the socket (330), the closing tool (410) and the closing seat (460) with a saline solution.

10. Stage cementing method according to claim 9, characterized in, that a salt solution is injected before running in the opening tool (400).