CN118065817A - All-metal sealing grading well cementation tool and well cementation method - Google Patents

Abstract

The invention relates to the technical field of oil and gas well cementing equipment, in particular to an all-metal sealing grading cementing tool and a cementing method, and aims to solve the problem of insufficient reliability of the traditional grading cementing sealing tool. The invention provides an all-metal sealing grading well cementing tool which comprises a body, a closing sliding sleeve inserted in the body, a lower joint connected to the lower end of the body, and an opening sliding sleeve inserted in the closing sliding sleeve; the side wall of the body is provided with a first mud hole, the side wall of the closing sliding sleeve is provided with a second mud hole, and the first mud hole is communicated with the second mud hole; and a combined metal sealing ring is respectively arranged at the upper side and the lower side of the first mud hole between the body and the closing sliding sleeve, and is arranged on the body. The full-metal sealing grading well cementing tool can avoid the problems of unstable rubber sealing ring materials and intolerance to high temperature and corrosion by combining the contact surfaces of the metal sealing ring sealing body and the closing sliding sleeve, and ensure the underground long-term sealing effect.

Description

All-metal sealing grading well cementation tool and well cementation method

Technical Field

The invention relates to the technical field of oil and gas well cementing equipment, in particular to an all-metal sealing grading cementing tool and a cementing method.

Background

The stage cementing technology is a special well cementing process technology commonly adopted in the petroleum industry at present, is used as a key tool of the stage cementing technology, namely a stage cementing tool, also called a stage cementing device, also called a stage collar or a two-stage collar, achieves a better well cementing effect through stage cementing, and is widely applied to stage cementing tools in petroleum well cementation and well completion construction.

The prior classification cementing tool is mainly sealed in a form of an elastic O-shaped sealing ring, although the sealing performance of the tool in the early stage construction and the short term can be ensured, with the rapid development of the petroleum drilling technology, the number of deep wells and ultra-deep wells is increased year by year, the drilling frequently encounters complex underground conditions, such as single corrosion medium or two coexisting corrosion mediums of H ₂S、CO₂, and the rubber material performance caused by high temperature and high pressure at the bottom of the well is unstable, the sealing performance is poor, a series of problems of the use of the classification cementing tool, the quality of cement slurry and the like are influenced, and the sealing reliability of the classification cementing tool is insufficient.

Disclosure of Invention

The invention aims to provide an all-metal sealing grading well cementing tool and a well cementing method, which are used for solving the problem of insufficient reliability of the existing grading well cementing sealing tool.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

The full-metal sealing grading well cementing tool comprises a body, a closing sliding sleeve inserted in the body, a lower joint connected to the lower end of the body, and an opening sliding sleeve inserted in the closing sliding sleeve; the side wall of the body is provided with a first mud hole, the side wall of the closing sliding sleeve is provided with a second mud hole, and the first mud hole is communicated with the second mud hole; a combined metal sealing ring is respectively arranged on the upper side and the lower side of the first mud hole between the body and the closing sliding sleeve, and is arranged on the body; the body is sleeved on the lower joint, and a combined metal sealing ring is arranged between the body and the lower joint; in the first state, opening the sliding sleeve to seal the second mud hole; in the second state, the sliding sleeve is started to move towards the lower joint so as to open a second mud hole; in the third state, the sliding sleeve is closed to move towards the lower joint so that the first mud hole and the second mud hole are staggered.

Further, the combined metal sealing ring comprises two spring reinforced C-shaped metal sealing rings and a metal baffle ring; the spring reinforced C-shaped metal sealing ring comprises a metal ring with a C-shaped section and a spring which is arranged in the C-shaped section and extends along the circumferential direction of the metal ring; the C-shaped openings of the two spring reinforced C-shaped metal sealing rings deviate from each other, and the metal baffle ring is arranged between the two spring reinforced C-shaped metal sealing rings.

Further, the all-metal sealing grading well cementing tool also comprises a closing seat, wherein the closing seat is inserted into the closing sliding sleeve and is arranged above the opening sliding sleeve; and in the third state, the closing seat moves towards the lower joint and drives the closing sliding sleeve to move.

Further, the all-metal sealing grading well cementing tool also comprises an opening seat, and the opening seat is inserted in the closing sliding sleeve and connected with the closing sliding sleeve; the opening sliding sleeve is inserted into the opening seat and is arranged above the opening seat.

Further, the all-metal sealing grading well cementing tool further comprises a fifth precise O-shaped ring, wherein the fifth precise O-shaped ring is arranged between the combined metal sealing ring and the first slurry hole, and the fifth precise O-shaped ring is arranged on the inner wall of the body.

Further, the all-metal sealed grading well cementing tool further comprises an opening sliding sleeve cutting screw which is inserted into the side walls of the opening sliding sleeve and the opening seat; in the second state, the opening sliding sleeve shearing screw is sheared, and the opening sliding sleeve moves to the lower joint to open the second mud hole.

Further, the all-metal sealed grading well cementing tool also comprises a closing sliding sleeve shearing pin which is inserted into the side walls of the closing sliding sleeve and the closing seat; in the third state, the closing sliding sleeve shearing pin is sheared, and the closing seat moves towards the lower joint and drives the closing sliding sleeve to move.

Further, the all-metal sealing grading well cementing tool also comprises a locking piece; the inner side of the body is provided with a locking block limiting groove; the locking block is inserted into the side wall of the closing sliding sleeve, one end of the locking block is abutted against the closing seat, and the other end of the locking block is inserted into the locking block limiting groove; the outer side of the closing seat is provided with a locking piece accommodating groove which is arranged above the locking piece; in the third state, the closing seat moves towards the lower joint, and the locking piece is separated from the locking piece limiting groove and enters the locking piece accommodating groove.

Further, the all-metal sealing grading well cementing tool further comprises an elastic ring, wherein the elastic ring is sleeved on the closing sliding sleeve and is abutted against the inner side of the body; an elastic ring accommodating groove is formed in the inner side of the body and is arranged below the elastic ring; in the third state, when the closing seat drives the closing sliding sleeve to move to the elastic ring accommodating groove from the lower joint, the diameter of the elastic ring is enlarged under the elastic action of the elastic ring and is clamped in the elastic ring accommodating groove.

In another aspect of the invention, a staged cementing method is provided, and the fully metal sealed staged cementing tool is used, comprising the following steps:

And (3) setting a cementing tool: a casing pipe column with an all-metal sealing grading well cementing tool is put in according to the well cementing design requirement;

Primary well cementation: cementing the casing pipe column, and injecting cement through a central through hole of the metal sealing grading cementing tool;

secondary well cementation: the first-stage rubber plug is put into the well to pressurize, the first-stage rubber plug is plugged to open the sliding sleeve, the sliding sleeve is opened to cut off the shearing screw of the opening sliding sleeve and move downwards, so that the second mud hole is opened, and cement is injected to perform well cementation;

closing the cementing tool: the closing plug is put into the well to pressurize, the closing plug plugs the closing seat, the closing seat shears the shearing pin of the closing sliding sleeve and moves downwards, and then the closing sliding sleeve is driven to move downwards, so that the second mud hole and the first mud hole are staggered;

Drilling tool: and drilling the closing seat, the opening sliding sleeve and the opening seat to recover the central through hole of the metal sealing grading cementing tool.

In summary, the technical effects achieved by the invention are as follows:

The invention provides an all-metal sealing grading well cementing tool which comprises a body, a closing sliding sleeve inserted in the body, a lower joint connected to the lower end of the body, and an opening sliding sleeve inserted in the closing sliding sleeve; the side wall of the body is provided with a first mud hole, the side wall of the closing sliding sleeve is provided with a second mud hole, and the first mud hole is communicated with the second mud hole; a combined metal sealing ring is respectively arranged on the upper side and the lower side of the first mud hole between the body and the closing sliding sleeve, and is arranged on the body; the body is sleeved on the lower joint, and a combined metal sealing ring is arranged between the body and the lower joint; in the first state, opening the sliding sleeve to seal the second mud hole; in the second state, the sliding sleeve is started to move towards the lower joint so as to open a second mud hole; in the third state, the sliding sleeve is closed to move towards the lower joint so that the first mud hole and the second mud hole are staggered.

According to the all-metal sealing grading well cementing tool provided by the invention, the contact surface of the sealing body and the closing sliding sleeve of the metal sealing ring is combined, so that the problems of unstable rubber sealing ring material, intolerance to high temperature and corrosion are avoided, the quality of cement paste injection is ensured, and the underground long-term sealing effect is ensured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a structure of an all-metal seal classification cementing tool in a first state according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a structure after drilling out an all-metal sealed graded well cementation according to an embodiment of the present invention;

FIG. 3 is a schematic view of a combined metal seal ring;

fig. 4 is a schematic structural view of a spring-reinforced C-shaped metal seal ring.

Icon: 100-body; 200-lower joint; 300-closing the sliding sleeve; 400-closing the seat; 500-opening the sliding sleeve; 600-opening a seat; 700-locking piece; 800-an elastic ring; 900-combining metal sealing rings; 1000-a first precision O-ring; 1100-a second precision O-ring; 1200-third precision O-ring; 1300-fourth precision O-ring; 1400-fifth precision O-ring; 1500-opening a sliding sleeve shear screw; 1600-closing the sliding sleeve shear pin; 1700-first set screw; 1800-second set screw; a-a first mud hole; b-a second mud hole; c-a lock block receiving groove; d-an elastic ring receiving groove; 310-limiting steps; 910-spring-reinforced C-metal seal ring; 920-metal baffle ring.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Some embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.

With the rapid development of petroleum drilling technology, the number of deep wells and ultra-deep wells is increased year by year, the drilling is often subjected to complex underground conditions, such as single corrosion medium or two coexisting corrosion mediums of H ₂S、CO₂, and rubber materials caused by high temperature and high pressure at the bottom of the well are unstable in performance, poor in sealing performance, and a series of problems of influencing the use of a classification cementing tool, the quality of cementing slurry and the like, so that the sealing reliability of the classification cementing tool is insufficient.

In view of this, the present invention provides an all-metal sealing classification cementing tool, which comprises a body 100, a closing sliding sleeve 300 inserted in the body 100, a lower joint 200 connected to the lower end of the body 100, and an opening sliding sleeve 500 inserted in the closing sliding sleeve 300; the side wall of the body 100 is provided with a first mud hole a, the side wall of the closing sliding sleeve 300 is provided with a second mud hole b, and the first mud hole a is communicated with the second mud hole b; a combined metal sealing ring 900 is respectively arranged on the upper side and the lower side of the first mud hole a between the body 100 and the closing sliding sleeve 300, and the combined metal sealing ring 900 is arranged on the body 100; the body 100 is sleeved on the lower joint 200, and a combined metal sealing ring 900 is arranged between the body 100 and the lower joint 200; in the first state, the sliding sleeve 500 is opened to seal the second mud hole b; in the second state, the opening slide sleeve 500 moves toward the lower joint 200 to open the second mud hole b; in the third state, the closing slide 300 moves toward the lower joint 200 so that the first mud hole a is offset from the second mud hole b.

According to the all-metal sealing grading cementing tool provided by the invention, the contact surface of the sealing body 100 and the closing sliding sleeve 300 is sealed by combining the metal sealing ring 900, so that the problems of unstable rubber sealing ring materials and intolerance to high temperature and corrosion are avoided, the quality of cement slurry injection is ensured, and the underground long-term sealing effect is ensured.

The structure and shape of the all-metal seal staged cementing tool provided in this embodiment are described in detail below with reference to fig. 1-4:

In an alternative to this embodiment, an all-metal sealed staged cementing tool comprises a body 100, a lower sub 200, a closure sleeve 300, a closure seat 400, an opening sleeve 500, and an opening seat 600. As shown in fig. 1, the lower connector 200 is connected to the lower end of the body 100, the closing slide 300 is inserted into the body 100, the closing seat 400, the opening slide 500 and the opening seat 600 are inserted into the closing slide 300, the closing seat 400 is disposed above the opening slide 500, the opening slide 500 is inserted into the opening seat 600, and the opening seat 600 is in threaded connection with the closing slide 300 and uses left-handed threads to prevent loosening during use.

Specifically, the body 100 includes upper segment, middle segment and the hypomere that connects gradually, and the both ends and the upper segment of middle segment, hypomere threaded connection respectively, upper segment and hypomere cartridge respectively in the middle segment to use the lateral wall of first holding screw 1700 screw in middle segment, two first holding screw 1700 butt respectively in the outer wall of upper segment and hypomere, in order to guarantee the connection of upper segment, middle segment and hypomere, avoid becoming flexible. The side wall of the middle section is provided with a first mud hole a, the side wall of the closing sliding sleeve 300 is provided with a second mud hole b, and the first mud hole a is communicated with the second mud hole b. The lower joint 200, the closing slide 300, the closing seat 400, the opening slide 500 and the opening seat 600 are all hollow pipes, so that the all-metal sealing classification cementing tool forms a central through hole for liquid to pass through.

The opening sliding sleeve 500 is inserted into the opening seat 600, an annular boss is arranged on the outer circle of the upper end of the opening sliding sleeve 500, and after the opening sliding sleeve 500 moves downwards, the annular boss of the opening sliding sleeve 500 can be abutted against the upper end of the opening seat 600 so as to drive the opening seat 600 to move downwards. Further, the annular boss of the opening sliding sleeve 500 is located above the second mud hole b, the opening seat 600 is located below the second mud hole b, and when the opening sliding sleeve 500 moves down to the annular boss to abut against the opening seat 600, the opening sliding sleeve 500 is located below the second mud hole b.

In an alternative scheme of this embodiment, the inner wall of the closing slide 300 is provided with a limiting step 310, the limiting step 310 is located below the closing seat 400 and above the opening slide 500, and when the closing seat 400 moves downward, the closing seat 400 abuts against the limiting step 310.

In an alternative scheme of the embodiment, the all-metal sealing grading cementing tool further comprises an opening sliding sleeve shear screw 1500, wherein the opening sliding sleeve shear screw 1500 is inserted into the side walls of the opening sliding sleeve 500 and the opening seat 600; in the second state, the opening slide shear screw 1500 is sheared, and the opening slide 500 is moved toward the lower joint 200 to open the second mud hole b.

In an alternative scheme of the embodiment, the metal sealing grading cementing tool further comprises a closing sliding sleeve shear pin 1600, wherein the closing sliding sleeve shear pin 1600 is inserted into the side walls of the closing sliding sleeve 300 and the closing seat 400; in the third state, the closure slide shear pin 1600 is sheared and the closure seat 400 is moved toward the lower joint 200.

In an alternative to this embodiment, the all-metal seal staged cementing tool further comprises a locking block 700; the inner side of the body 100 is provided with a locking block limiting groove; the locking piece 700 is inserted into the side wall of the closing sliding sleeve 300, one end of the locking piece is abutted against the closing seat 400, and the other end of the locking piece is inserted into the locking piece limiting groove, so that the closing sliding sleeve 300 and the body 100 are prevented from being displaced relatively in the axial direction. The outer side of the closing seat 400 is provided with a locking piece accommodating groove c which is arranged above the locking piece 700; in the third state, the closing seat 400 moves toward the lower joint 200, the locking piece 700 is separated from the locking piece limiting groove and enters the locking piece accommodating groove c, at this time, the locking piece 700 is inserted into the side wall of the closing sliding sleeve 300, one end of the locking piece 700 is inserted into the locking piece accommodating groove c, and the other end of the locking piece 700 abuts against the inner side of the body 100, so that the closing seat 400 can drive the closing sliding sleeve 300 to move downward.

In order to ensure that the locking piece 700 can be separated from the locking piece limiting groove, the lower end surface of the locking piece limiting groove is an inclined surface, so that after the closing seat 400 moves downwards and abuts against the limiting step 310, the closing seat 400 drives the closing sliding sleeve 300 to move downwards, and under the guidance of the inclined surface at the lower end of the locking piece limiting groove, the locking piece 700 is separated from the locking piece limiting groove and enters the locking piece accommodating groove c, so that the closing sliding sleeve 300 is separated from the body 100, and the closing sliding sleeve can move.

In an alternative scheme of the embodiment, the all-metal sealing grading cementing tool further comprises an elastic ring 800, wherein the elastic ring 800 is sleeved on the closing sliding sleeve 300 and is abutted against the inner side of the body 100; an elastic ring accommodation groove d is formed in the inner side of the body 100, and the elastic ring accommodation groove d is arranged below the elastic ring 800; in the third state, when the closing seat 400 drives the closing sliding sleeve 300 to move to the elastic ring accommodating groove d toward the lower joint 200, the elastic ring 800 has a larger diameter under the elastic action of the elastic ring 800 and is clamped in the elastic ring accommodating groove d to limit the closing sliding sleeve 300, at this time, the lower end of the closing sliding sleeve 300 abuts against the lower joint 200 and the elastic ring 800 is simultaneously embedded into the closing sliding sleeve 300 and the elastic ring accommodating groove d.

In an alternative to this embodiment, to ensure long-term sealing performance downhole, the composite metal seal 900 includes two spring-reinforced C-shaped metal seal rings 910 and a metal retainer ring 920; the spring reinforced C-shaped metal sealing ring 910 comprises a metal ring with a C-shaped cross section and a spring which is arranged in the C-shaped cross section and extends along the circumferential direction of the metal ring as shown in fig. 4; the C-shaped openings of the two spring-reinforced C-shaped metal sealing rings 910 are away from each other, and a metal retainer ring 920 is disposed between the two spring-reinforced C-shaped metal sealing rings 910 to provide stable support for the spring-reinforced C-shaped metal sealing rings 910, avoiding arc-shaped upper line contact 910 of the two spring-reinforced C-shaped metal sealing rings, as shown in fig. 3. Long-term sealing under the action of bidirectional pressure is ensured by combining the metal sealing rings 900, and the influence of high temperature and corrosion is avoided by the all-metal material.

Specifically, the combined metal sealing rings 900 are respectively arranged on the upper side and the lower side of the first mud hole a, and the combined metal sealing rings 900 are arranged at the joint of the body 100 and the lower joint 200 so as to ensure the sealing between the closing sliding sleeve 300 and the lower joint 200 and the body 100, so that two groups of sealing are formed by three combined metal sealing rings 900, one group of sealing is arranged on the upper side and the lower side of the first mud hole a, the other group of sealing is arranged at the joint of the body 100 and the lower joint 200 so as to ensure the sealing between the body 100 and the closing sliding sleeve 300 and the lower joint 200, and the sealing effect is prevented from being influenced at the joint of the first mud hole a and the body 100 and the lower joint 200.

To facilitate the installation of the composite metal seal 900, an upper mounting groove is formed between the upper and middle sections of the body 100, and a lower mounting groove is formed between the middle and lower sections. That is, steps are arranged at two ends of the middle section, a gap is kept between the lower end of the upper section and the steps at the upper end to form a lower mounting groove, and a gap is kept between the upper end of the lower section and the steps at the lower end to form a lower mounting groove, so that the combined metal sealing ring 900 can be inserted into the middle section firstly, then the upper section and the lower section are respectively connected with the middle section, and the seal at the position is a dynamic sealing structure.

Similarly, a mounting groove is formed between the body 100 and the lower joint 200 by combining to mount the combined metal seal ring 900, specifically, as shown in fig. 1, the body 100 is sleeved on the lower joint 200, a step is provided on the inner side of the body 100, a step is provided on the outer side of the lower joint 200, and the seal is a static seal structure. A second fastening screw 1800 is inserted on the lower section of the body 100, and the second fastening screw 1800 abuts against the outer wall of the lower joint to prevent loosening.

In an alternative of this embodiment, the all-metal sealing classification cementing tool further includes a fifth precise O-ring 1400, the fifth precise O-ring 1400 is disposed between the combined metal sealing ring 900 and the first mud hole a, and the fifth precise O-ring 1400 is mounted on the body 100, so as to prevent the mud particles from damaging the metal sealing surface when the closing sliding sleeve 300 moves downward.

In this embodiment, two annular grooves are disposed on the outer side of the opening sliding sleeve 500, one of the annular grooves is disposed on an annular boss at the upper end of the opening sliding sleeve 500 and is used for installing a third precise O-ring 1200 to ensure sealing between the opening sliding sleeve 500 and the closing sliding sleeve 300, and the other annular groove is used for installing a first precise O-ring 1000 to ensure sealing between the opening sliding sleeve 500 and the opening seat 600; an annular groove is formed at the outer side of the opening seat 600 for installing a second precise O-ring 1100 to ensure sealing between the opening seat 600 and the closing sliding sleeve 300; an annular groove is provided on the outer side of the closure seat 400 for mounting a fourth precision O-ring 1300 to ensure sealing between the closure seat 400 and the closure sliding sleeve 300. The sealing performance is ensured through the O-shaped ring, so that the well cementation process is ensured to be carried out smoothly.

The working process of the all-metal sealing grading cementing tool provided by the embodiment is as follows:

In the field implementation process, a sleeve pipe column with an all-metal sealing grading well cementing tool is put in according to the well cementing design requirement, after a primary cement injection well cementing process is completed through a central through hole of the all-metal sealing grading well cementing tool, a primary rubber plug is put in, a sliding sleeve 500 is opened after a well mouth is pressurized, a sliding sleeve is opened under the action of hydraulic pressure to cut off a sliding sleeve cutting screw 1500 and then starts to move downwards, a second mud hole b is discharged and injected, and the central through hole, the second mud hole b and a first mud hole a of the all-metal sealing grading well cementing tool are communicated, so that a secondary cement injection well cementing operation is implemented; after the secondary cementing operation is completed, closing the closure plug into the closure seat 400 after the wellhead is pressurized, shearing off the closure sliding sleeve shearing pin 1600, descending the closure seat 400, pushing the lock block 700 to move towards the closure seat 400 under the pushing of the inclined plane of the lock block limiting groove, and falling into the lock block accommodating groove c; under the continuous hydraulic force pushing, the closing seat 400, the locking block 700 and the closing sliding sleeve 300 descend together until the closing sliding sleeve 300 is abutted against the lower joint 200, and at the moment, the first mud hole a and the second mud hole b are staggered, so that the mud holes are permanently closed, and the staged cementing operation is completed.

After the staged cementing operation is completed, the closing seat 400, the opening sliding sleeve 500 and the opening seat 600 are drilled out, as shown in fig. 2, which is a schematic structural diagram of the fully-metal sealed staged cementing tool after the staged cementing operation is completed and drilled out.

The all-metal sealing grading cementing tool provided by the embodiment adopts the spring reinforced C-shaped metal sealing ring 910, meets the requirements of axial dynamic sealing and long-term static sealing under the conditions of high temperature, high pressure and high mineralization, ensures the sealing reliability of the grading cementing tool under the conditions of corrosion and high temperature and high pressure, solves the problem of lasting sealing of a sealing piece, and improves the reliability of the grading cementing sealing tool.

Based on the all-metal sealed graded well cementing tool provided by the embodiment, a graded well cementing method is provided, and the all-metal sealed graded well cementing tool is used and comprises the following steps:

S100, setting a cementing tool: and (5) setting a casing pipe column with an all-metal sealing grading well cementing tool according to well cementing design requirements.

S200-primary well cementation: cementing is carried out in the casing pipe column, and cement is injected through the central through hole of the metal sealing grading cementing tool.

S300-secondary well cementation: and the first-stage rubber plug is put into the well to pressurize, the first-stage rubber plug is plugged to open the sliding sleeve 500, the opening sliding sleeve 500 cuts off the opening sliding sleeve cutting screw 1500 and moves downwards, so that the second mud hole b is opened, and cement is injected to perform well cementation.

S400, closing the cementing tool: the closing plug is put down, the wellhead is pressurized, the closing plug seals the closing seat 400, the closing seat 400 shears the closing sliding sleeve shearing pin 1600 and moves downwards, and then the closing sliding sleeve 300 is driven to move downwards, so that the second mud hole b and the first mud hole a are staggered.

S500-drilling tool: the closing seat 400, the opening slide sleeve 500 and the opening seat 600 are drilled out to restore the central through hole of the metal seal classification cementing tool.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims (10)

1. The all-metal sealing grading well cementing tool is characterized by comprising a body (100), a closing sliding sleeve (300) inserted into the body (100), a lower joint (200) connected to the lower end of the body (100), and an opening sliding sleeve (500) inserted into the closing sliding sleeve (300);

A first mud hole (a) is formed in the side wall of the body (100), a second mud hole (b) is formed in the side wall of the closing sliding sleeve (300), and the first mud hole (a) is communicated with the second mud hole (b);

A combined metal sealing ring (900) is respectively arranged between the body (100) and the closing sliding sleeve (300) at the upper side and the lower side of the first slurry hole (a), and the combined metal sealing ring (900) is installed on the body (100);

The body (100) is sleeved on the lower joint (200), and the combined metal sealing ring (900) is arranged between the body (100) and the lower joint (200);

In the first state, the opening sliding sleeve (500) seals the second mud hole (b);

In a second state, the opening slide sleeve (500) moves towards the lower joint (200) to open the second mud hole (b);

In a third state, the closing slide sleeve (300) moves towards the lower joint (200) so that the first mud hole (a) and the second mud hole (b) are staggered.

2. An all-metal seal classified cementing tool as claimed in claim 1, wherein,

The combined metal sealing ring (900) comprises two spring reinforced C-shaped metal sealing rings (910) and a metal baffle ring (920);

The spring reinforced C-shaped metal sealing ring (910) comprises a metal ring with a C-shaped cross section and a spring which is arranged in the C-shaped cross section and extends along the circumferential direction of the metal ring;

the C-shaped openings of the two spring reinforced C-shaped metal sealing rings (910) are away from each other, and the metal baffle ring (920) is arranged between the two spring reinforced C-shaped metal sealing rings (910).

3. The all-metal seal classified cementing tool according to claim 1, further comprising a closing seat (400), said closing seat (400) being inserted in said closing sliding sleeve (300) and arranged above said opening sliding sleeve (500);

In a third state, the closing seat (400) moves towards the lower joint (200) and drives the closing sliding sleeve (300) to move.

4. An all-metal sealed stage cementing tool according to claim 3, further comprising an opening seat (600), said opening seat (600) being inserted in said closing slide (300) and connected to said closing slide (300);

the opening sliding sleeve (500) is inserted into the opening seat (600) and is arranged above the opening seat (600).

5. The all-metal seal stage cementing tool according to claim 4, further comprising a fifth precision O-ring (1400), said fifth precision O-ring (1400) disposed between said composite metal seal ring (900) and said first mud hole (a), said fifth precision O-ring (1400) mounted to an inner wall of said body (100).

6. The all-metal seal classification cementing tool according to claim 5, further comprising an opening sleeve shear screw (1500), the opening sleeve shear screw (1500) being inserted into sidewalls of the opening sleeve (500) and the opening seat (600);

In a second state, the opening slide shear screw (1500) is sheared, and the opening slide (500) moves toward the lower joint (200) to open the second mud hole (b).

7. The all-metal seal classification cementing tool according to claim 6, further comprising a closing sleeve shear pin (1600), the closing sleeve shear pin (1600) being inserted into sidewalls of the closing sleeve (300) and the closing seat (400);

in a third state, the closing slide shearing pin (1600) is sheared, and the closing seat (400) moves towards the lower joint (200) and drives the closing slide (300) to move.

8. The all-metal seal classified cementing tool of claim 7, further comprising a locking block (700);

A locking block limiting groove is formed in the inner side of the body (100);

The locking block (700) is inserted into the side wall of the closing sliding sleeve (300), one end of the locking block is abutted against the closing seat (400), and the other end of the locking block is inserted into the locking block limiting groove;

A locking block accommodating groove (c) is formed in the outer side of the closing seat (400), and the locking block accommodating groove (c) is arranged above the locking block (700);

in a third state, the closing seat (400) moves towards the lower joint (200), and the locking block (700) is separated from the locking block limiting groove and enters the locking block accommodating groove (c).

9. The all-metal seal classified cementing tool according to claim 8, further comprising an elastic ring (800), wherein the elastic ring (800) is sleeved on the closing sliding sleeve (300) and abuts against the inner side of the body (100);

an elastic ring accommodating groove (d) is formed in the inner side of the body (100), and the elastic ring accommodating groove (d) is arranged below the elastic ring (800);

In the third state, the closing seat (400) drives the closing sliding sleeve (300) to move towards the lower joint (200) to the elastic ring accommodating groove (d), and the elastic ring (800) is larger in diameter and is clamped in the elastic ring accommodating groove (d) under the self elastic action.

10. A staged cementing method characterized by using the all-metal sealed staged cementing tool of claim 9 comprising the steps of:

and (3) setting a cementing tool: a casing pipe column with the all-metal sealing grading well cementing tool is put in according to the well cementing design requirement;

Primary well cementation: cementing the casing pipe column, and injecting cement through a central through hole of the metal sealing grading cementing tool;

Secondary well cementation: a first-stage rubber plug is put in, the wellhead is pressurized, the first-stage rubber plug seals the opening sliding sleeve (500), the opening sliding sleeve (500) shears off the opening sliding sleeve shearing screw (1500) and moves downwards, so that a second mud hole (b) is opened, and cement is injected for cementing;

Closing the cementing tool: a closing plug is put into the well to pressurize, the closing plug seals the closing seat (400), the closing seat (400) shears the closing sliding sleeve shearing pin (1600) and moves downwards, and then the closing sliding sleeve (300) is driven to move downwards, so that the second mud hole (b) and the first mud hole (a) are staggered;

Drilling tool: and drilling out the closing seat (400), the opening sliding sleeve (500) and the opening seat (600) to recover the central through hole of the metal sealing grading cementing tool.