CN116988763A - Abandoned well cementing packer and cementing packing method thereof - Google Patents

Abstract

A well abandonment cementing packer and a packing method thereof, the packer comprising: releasing the tool; the releasing service mechanism comprises a lower joint, a releasing locking piece and an inner supporting sleeve, wherein the releasing locking piece is respectively connected with the lower joint and the inner supporting sleeve; the releasing component is sleeved outside the releasing locking component; the tail end of the releasing locking piece is provided with an elastic locking block; the upper end of the inner support sleeve is provided with a shearing pin, and the lower end is provided with a boss; the packer comprises a body, an upper slip, a lower slip, a rubber cylinder, a setting push cylinder, a piston and a piston cylinder, wherein the body is provided with a through hole and is connected with a releasing tool; the setting ball seat is connected with the bottom end of the piston; and the one-way injection mechanism is connected with the bottom end of the piston and surrounds the piston to form a containing space, and the setting ball seat is positioned in the containing space. The invention also provides a well abandon cement packing method.

Description

Abandoned well cementing packer and cementing packing method thereof

Technical Field

The invention relates to a petroleum drilling and production well completion technology of petroleum and natural gas, in particular to a well abandoning cementing packer and a cementing packing method thereof, which are suitable for well abandoning operation of an oil-gas well.

Background

In ocean oil and gas exploitation, well abandoning is the last link of oil and gas well operation cycle, is the crucial step of guaranteeing the marine ecological environment safety after the oil field stops producing, and well abandoning scheme is imperfect, can lead to oil gas leakage, produces serious influence to marine environment.

In the new ocean well abandoning standard, in the permanent well abandoning operation procedure of completing the exploratory well by casing or tail pipe perforation, a cement extruding packer is put into a special well within 15m above a top perforation section, cement is extruded to an oil-gas layer by adopting a trial extrusion method and an intermittent cement extruding method, and the extrusion amount is required to meet the requirement of sealing the perforation section or the highest extrusion pressure to reach the original stratum fracture pressure of the well section. After the cement extrusion is finished, a cement plug with the length not less than 50m is poured on the cement extrusion packer, and the top surface of the cement plug is detected and the pressure test is qualified.

The well abandoning mode commonly used at sea is that cement plugs are made on the oil layer section or above, then a cable or a drill string is put into a packer or a bridge plug, setting, hanging and drilling tool combination are put into, and the cement plugs are made on the packer or the bridge plug. The prior art has the defects that two times of cement plug drilling tools are required to be independently put in, one time of cable or drilling tool is fed into the setting bridge plug, the whole process takes longer, and the efficiency is lower. The cable bridge plug is used for plugging the inner sealing layer of the oil-gas well, the energy of gunpowder combustion is needed to be used as a power source for underground bridge plug setting and releasing, the technology needs to use civil explosive materials which bring inconvenience to production organizations, and meanwhile, the waste generated after the gunpowder combustion is easy to pollute the environment and is inconvenient for cleaning and maintaining tools. In particular to deep wells or ultra-deep wells, the overall operation cost is high. In addition, the process also has the risk that the packer cannot be inserted back in place after the packer is tried out of the hand, and the tool bears the high-pressure reaction of the cement squeezing operation, so that the displacement risk exists.

Disclosure of Invention

The invention aims to solve the technical problems of the prior art and provides a cement packer for abandoned wells and a cement packing method thereof.

In order to achieve the above object, the present invention provides a well abandonment cementing packer, comprising:

releasing the tool;

the releasing service mechanism comprises a lower joint, a releasing locking piece and an inner supporting sleeve, wherein the lower joint is used for connecting an upper drill string, and the releasing locking piece is respectively connected with the lower joint and the inner supporting sleeve and is used for realizing the connection between the lower joint and a releasing tool; the releasing tool is sleeved outside the releasing locking piece; the tail end of the releasing locking piece is provided with an elastic locking block for locking and separating from the releasing tool; the upper end of the inner support sleeve is provided with a shearing pin, the lower end of the inner support sleeve is provided with a boss for supporting the elastic locking block to keep a locking state, when the inner support sleeve is pressed down or thrown into a ball, the shearing pin is sheared, the inner support sleeve moves down, the locking function is released, and the drill string is separated from the releasing tool;

the packer comprises a packer body, an upper slip, a lower slip, a rubber cylinder, a setting push cylinder, a piston and a piston cylinder, wherein the packer body is provided with a through hole and is connected with the releasing tool, the upper slip, the rubber cylinder and the lower slip are sequentially sleeved outside the packer body, the piston is installed at the lower end of the packer body, the piston cylinder is sleeved on the piston, and the setting push cylinder is sleeved outside the packer body and is connected with the piston cylinder;

the setting ball seat is connected with the bottom end of the piston and is used for sealing the interior of the upper pipe column after ball injection in the drill string; and

the one-way injection mechanism is connected with the bottom end of the piston and forms a containing space together with the bottom end surface of the piston, the setting ball seat is positioned in the containing space, and the one-way injection mechanism is used for controlling cement to flow into the lower end of the packer in a one-way and preventing cement from flowing upwards after the packer is cemented.

The abandoned well cementing packer is characterized in that the one-way injection mechanism is a two-stage one-way floating valve, the two-stage one-way floating valve comprises a first one-way floating valve and a second one-way floating valve, the first one-way floating valve is connected with the tail end of the piston, the second one-way floating valve is connected with the first one-way floating valve, and the first one-way floating valve and the second one-way floating valve are coaxially arranged with the packer body.

In order to better achieve the purpose, the invention also provides a well abandoning cement packing method, wherein the well abandoning cement packer is adopted for well abandoning packing, and the method comprises the following steps:

s100, a drill string carries the waste well cementing packer to enter a well;

s200, setting balls are thrown, so that the well abandoning cementing packer is set and hung;

s300, injecting cement into the lower end of the waste well cementing packer;

s400, releasing the abandoned well cementing packer, and cementing the upper end of the abandoned well cementing packer; and

s500, providing a service tool of the well abandoning cementing packer, and completing well abandoning operation.

The well abandon cement packing method, wherein step S100 further comprises:

s101, checking whether the abandoned well cementing packer and accessories meet the operation requirements or not on an operation platform;

s102, connecting the abandoned well cementing packer with a drill string, and lowering the abandoned well cementing packer to a preset depth of a target well along with the drill string;

s103, after the abandoned well cementing packer is lowered in place, the unidirectional injection mechanism is opened in a positive circulation mode to carry out a circulation test; and

and S104, after the normal forward circulation test, performing a reverse circulation pressure holding test to verify whether the reverse closing of the one-way injection mechanism is normal.

The well abandoning cement packing method, wherein step S200 further includes:

s201, putting a setting ball into the drill string and conveying the setting ball to a shearing ball seat of the abandoned well cementing packer;

s202, after the setting ball is in place, forming a sealing space in the drill string, pressing the abandoned well cementing packer, lifting and pressing the drill string down, and verifying that the slip setting of the abandoned well cementing packer is qualified;

s203, annular pressurizing is carried out on the abandoned well cementing packer, and annular sealing of the abandoned well cementing packer is verified to be qualified; and

and S204, continuously pressing to the setting ball seat of the abandoned well cementing packer for shearing.

In the above well abandoning cement packing method, in step S204, hydraulic pressure is pumped into the drill string to a setting pressure, setting pins of pistons of the well abandoning cement packer are sheared, the pistons push a setting push cylinder of the well abandoning cement packer to ascend, the position of an upper slip of the well abandoning cement packer is kept unchanged, the setting push cylinder pushes a lower slip and an extrusion rubber cylinder of the well abandoning cement packer, and the lower slip and the upper slip stretch out and bite a casing to complete the setting and hanging of the packer; and the rubber cylinder is extruded and expanded to the casing pipe to finish the setting, hanging and setting of the waste well cementing packer.

The well abandon cement packing method described above, wherein in step S300, further includes:

s301, continuously driving hydraulic pressure in a drill string until a pin of a shearing ball seat of the waste well cementing packer is sheared, wherein the shearing ball seat is separated from a sealing position;

s302, continuing to press to enable the unidirectional injection mechanism to be kept in an open state under the hydraulic action, and squeezing cement to a production zone section below the cement injection packer of the abandoned well according to requirements;

s303, after the set cement amount is reached, the extrusion and the cementing are finished, and the unidirectional injection mechanism is automatically closed to prevent the cement paste from flowing back;

s304, if the cement paste flows back, the pressure is suppressed and waiting for coagulation; and

and S305, if no cement paste flows back, directly pressing down the preset tonnage, and removing the setting tool.

The above method for sealing cement from abandoned well, in step S400, further comprises:

s401, lifting the tool to a preset position after the well abandoning cementing packer is released from the setting tool; and

s402, performing cementing operation according to requirements, injecting cement in the drill string to a target position through a lower joint of the waste well cementing packer, and completing cementing extrusion operation.

The above method for sealing cement from abandoned well, in step S500, further comprises:

s501, after the cementing plug is finished, slowly pressing down a drill string, transmitting acting force to a lower joint of the abandoned well cementing packer, cutting off a pin of the lower joint, descending, pushing an inner supporting sleeve of the abandoned well cementing packer, cutting off the pin of the inner supporting sleeve, pushing the pin to the lower end, and losing locking of a releasing locking piece of the abandoned well cementing packer; and

s502, lifting the drill string, wherein the lower connector drives the releasing locking piece and the inner supporting sleeve to be lifted together, and well abandoning operation is completed.

The invention has the technical effects that:

the invention is suitable for well abandoning operation of oil and gas wells, can realize setting and hanging of the packer by one pipe column, squeeze cement at the lower part, then take off the packer, and perform cementing operation above the packer. Can meet the standards of the offshore cement squeezing and plugging reservoir, in particular to the cement squeezing operation of a high-pressure gas well. The packer has the advantages that the whole structure is simple, the setting tool is used for finishing setting, hanging and squeezing cement, and the packer can be reused after cement plugs are plugged, so that the operation time is saved, and the economic benefit is high.

The invention will now be described in more detail with reference to the drawings and specific examples, which are not intended to limit the invention thereto.

Drawings

FIG. 1 is a schematic diagram of an embodiment of the present invention;

FIGS. 2A-2E are process diagrams of a method according to an embodiment of the invention.

Wherein reference numerals are used to refer to

1 lower connector

2 releasing locking piece

3 inner support sleeve

4 releasing tool

5 packer body

6 upper slips

7 rubber cylinder

8 lower slips

9 setting push cylinder

10 piston

11 piston cylinder

12-seat ball seat

13 first one-way float valve

14 second one-way float valve

15 drill string

16 sleeve

17 cement

Detailed Description

The structural and operational principles of the present invention are described in detail below with reference to the accompanying drawings:

referring to fig. 1, fig. 1 is a schematic structural diagram of an embodiment of the present invention. The invention relates to a cement injection packer for a abandoned well, which comprises the following components: releasing the tool 4, and finally leaving the tool downhole; the releasing service mechanism comprises a lower joint 1, a releasing locking piece 2 and an inner supporting sleeve 3, wherein the lower joint 1 is used for connecting an upper drill string 15, the releasing locking piece 2 is respectively connected with the lower joint 1 and the inner supporting sleeve 3, and is used for realizing the connection between the lower joint 1 and a releasing tool 4; the releasing tool 4 is sleeved outside the releasing locking piece 2; the tail end of the releasing locking piece 2 is provided with an elastic locking block for locking and separating from the releasing tool 4; the upper end of the inner support sleeve 3 is provided with a shearing pin, the lower end of the inner support sleeve 3 is provided with a boss for supporting the elastic locking block to keep a locking state, when the inner support sleeve 3 is pressed down or thrown into a ball, the shearing pin is sheared off, the inner support sleeve 3 moves down, the locking function is released, and the drill string 15 is separated from the releasing tool 4; the packer comprises a packer body 5, an upper slip 6, a lower slip 8, a rubber cylinder 7, a setting push cylinder 9, a piston 10 and a piston cylinder 11, wherein the packer body 5 is provided with a through hole and is connected with a releasing tool 4, the upper slip 6, the rubber cylinder 7 and the lower slip 8 are sequentially sleeved outside the packer body 5, the piston 10 is mounted at the lower end of the packer body 5, the piston cylinder 11 is sleeved on the piston 10, and the setting push cylinder 9 is sleeved outside the packer body 5 and is connected with the piston cylinder 11; the setting ball seat 12 is connected with the bottom end of the piston 10 and is used for sealing the interior of the upper pipe column after ball injection in the drill column 15, and after ball injection in the drill column 15, the ball can be located on the setting ball seat 12 and has a sealing function, so that the interior of the upper pipe column is in a sealing state, a setting and hanging packer can be pressed, the ball seat can be broken after setting is finished, or a soluble ball is injected, and the ball is directly dissolved, so that the well cementation operation is not influenced; and the unidirectional injection mechanism is connected with the bottom end of the piston 10 and encloses a containing space together with the bottom end surface of the piston 10, the setting ball seat 12 is positioned in the containing space, and the unidirectional injection mechanism is used for controlling the cement 17 to flow into the lower end of the packer in one direction and preventing the cement 17 from returning upwards after the cement 17 is injected into the packer.

The lower joint 1, the releasing locking piece 2 and the inner supporting sleeve 3 of the embodiment are service tools, and the lower joint 1 and the releasing locking piece 2 are connected with a track through keys and can slide relatively, so that mechanical pressing action is realized. The releasing locking piece 2 is connected with the inner supporting sleeve 3 through a shearing pin, and the inner supporting sleeve 3 moves downwards after the pin is sheared, so that the lower end elastic locking piece of the releasing locking piece 2 loses locking effect. The lower end of the releasing tool 4 is connected with a packer, and the releasing tool and the packer are left in the well bore after releasing. After the inner support sleeve 3 is assembled with the releasing locking piece 2, the locking block at the tail end of the releasing locking piece 2 is locked by the tail end of the inner support sleeve 3, and the shape is kept fixed. When the pin is sheared by mechanical or hydraulic action of the inner supporting sleeve 3, the inner supporting sleeve 3 moves downwards, the locking block at the tail end of the releasing locking piece 2 is elastic, and the elastic locking block is deformed by lifting the service tool, so that the function of locking the releasing tool 4 is lost, and releasing separation is realized. The one-way injection mechanism is preferably a two-stage one-way float valve, the two-stage one-way float valve comprises a first one-way float valve 13 and a second one-way float valve 14, the first one-way float valve 13 is connected with the tail end of the piston 10, the second one-way float valve 14 is connected with the first one-way float valve 13, and the first one-way float valve 13 and the second one-way float valve 14 are coaxially arranged with the packer body 5.

The unidirectional injection mechanism may further comprise a sliding sleeve and a switch, the sliding sleeve is connected with the tail end of the piston 10, the switch is installed on the sliding sleeve, and the sliding sleeve and the packer body 5 are coaxially arranged.

When the tool works, the tool is lowered to a preset depth, setting balls are thrown into the drill string 15, the setting balls are set to the setting ball seat 12, a sealing space is formed in the drill string 15, hydraulic pressure is applied to the setting pressure in the drill string 15, setting pins of the piston 10 are sheared, the piston 10 pushes the setting push cylinder 9 to ascend, the position of the upper slips 6 is kept motionless, the setting push cylinder 9 pushes the lower slips 8 and the extrusion rubber cylinder 7, the lower slips 8 and the upper slips 6 are led to extend out and bite the casing 16, the permanent packer is set and hung, the rubber cylinder 7 is extruded, the rubber cylinder 7 is expanded and sealed to the casing 16, and the permanent packer is set and hung.

After ball throwing is performed, hydraulic pressure is transmitted to the piston 10 through the through hole, the piston 10 pushes the setting pushing cylinder 9, the setting pushing cylinder 9 pushes the upper slip 6 and the lower slip 8 and extrudes the rubber cylinder 7, so that the upper slip 6 and the lower slip 8 extend out, slip teeth bite into the sleeve 16 to anchor the whole packer, and the rubber cylinder 7 extrudes and seals the upper cavity and the lower cavity. The packer can be formed to pack an upper annulus and a lower annulus, and the pressure influence is avoided; by the meshing action of the slips and the casing 16, the tool position is fixed, and the risk that mechanical force and fluid pressure may cause the packer to slide can be eliminated; when the lower end is cemented 17, the pressure is higher, the excluder ring is empty, and the cement 17 cannot return from the annulus.

The pin in the drill string 15, which is continuously driven to the shearing ball seat by hydraulic pressure, is sheared, the ball seat is separated from the sealing position, the first one-way floating valve 13 and the second one-way floating valve 14 are continuously driven to be kept in an open state under the action of the hydraulic pressure, and cement 17 can be extruded downwards to the stratum. After the designed cement 17 is extruded, the pump is stopped, the extrusion of cement 17 is finished, and at the moment, the first one-way floating valve 13 and the second one-way floating valve 14 are automatically closed, so that the backflow of cement paste can be prevented.

The drill string 15 is slowly pressed down, acting force is transmitted to the lower joint 1, the pin of the lower joint 1 is cut off and then descends, the inner supporting sleeve 3 is pushed to the lower end, the pin of the inner supporting sleeve 3 is cut off and then pushed to the lower end, the locking function of the elastic claw of the releasing locking piece 2 is lost, after the locking of the releasing locking piece 2 by the inner supporting sleeve 3 is not carried out, the drill string 15 is lifted up, the lower joint 1 drives the releasing locking piece 2 and the inner supporting sleeve 3 to be separated from the cement squeezing packer system, and releasing work is completed. Lifting the drill string 15 to a preset position, squeezing cement according to the design, injecting cement 17 in the drill string 15 to a target position through the lower joint 1, and lifting the whole pipe string and service tools after squeezing cement.

Referring to fig. 2A-2E, fig. 2A-2E are process diagrams of a method according to an embodiment of the invention, respectively. Wherein fig. 2A shows a drill string 15 carrying a cementing 17 packer into a well; FIG. 2B is a set ball setting, set cement 17 packer; FIG. 2C shows the lower end of the packer cement 17; FIG. 2D shows a packer release tool 4 with a cementing 17 at the upper end of the packer; FIG. 2E shows the completion of the well abandonment operation with the service tool. The well abandoning cement 17 packing method can adopt the well abandoning cement packer to carry out well abandoning packing, and comprises the following steps:

step S100, connecting a drill string 15 with a waste well cementing packer, and enabling the drill string 15 to carry the waste well cementing packer into a well and to be put into a preset position in the well;

step S200, setting balls are thrown, after the balls are thrown on the ground and sent to a ball seat through a drill string 15, hydraulic setting and hanging abandoned well cementing packers are arranged in the drill string 15, and the abandoned well cementing packers are made to finish setting and hanging;

step S300, pumping cement slurry through a drill string 15, and injecting cement 17 into the lower end of the waste well cementing packer;

step S400, the abandoned well cementing packer releasing tool 4 is used for cementing 17 to the upper end of the abandoned well cementing packer; and

and S500, performing actions such as mechanical pressing and the like on the releasing service mechanism through the drill string 15, unlocking the locking function of the inner supporting sleeve 3 and the releasing tool 4, separating the releasing service mechanism from the packer, and providing the service tool for the well abandoning cementing packer, so that well abandoning operation is completed.

Wherein, step S100 further comprises:

step S101, checking whether the abandoned well cementing packer and accessories meet the operation requirement or not on an operation platform;

step S102, connecting the abandoned well cementing packer with a drill string 15, and lowering the abandoned well cementing packer to a preset depth of a target well along with the drill string 15;

step S103, after the abandoned well cementing packer is lowered in place, a one-way injection mechanism is opened in a positive circulation mode to carry out a circulation test; and

and step S104, after the normal forward circulation test, performing a reverse circulation pressure holding test to verify whether the reverse closing of the one-way injection mechanism is normal.

Wherein, step S200 further comprises:

step S201, putting a setting ball into the drill string 15 and sending the setting ball to a shear ball seat of the well abandonment cement injection packer;

step S202, after the setting ball is in place, forming a sealing space in the drill string 15, pressing the abandoned well cementing packer, lifting and pressing the drill string 15 down, and verifying that the slip setting of the abandoned well cementing packer is qualified;

step S203, annulus pressing is carried out on the abandoned well cementing packer, and annulus sealing of the abandoned well cementing packer is verified to be qualified; and

and S204, continuously pressing the setting ball seat 12 of the well abandoning cement injection packer to shear.

In step S204, hydraulic pressure is applied to setting pressure in the drill string 15, a setting pin of a piston 10 of the well-abandoning cement packer is sheared, the piston 10 pushes a setting push cylinder 9 of the well-abandoning cement packer to ascend, the position of an upper slip 6 of the well-abandoning cement packer is kept still, the setting push cylinder 9 pushes a lower slip 8 and an extrusion glue cylinder 7 of the well-abandoning cement packer, and the lower slip 8 and the upper slip 6 extend out and bite a casing 16 to complete packer setting; the rubber cylinder 7 is extruded and expanded to the sleeve 16, so that the setting, hanging and setting of the well-abandoning cementing packer is completed.

In step S300, further includes:

step S301, continuously pumping hydraulic pressure in the drill string 15 until the pin of the shear ball seat of the abandoned well cementing packer is sheared, wherein the shear ball seat is separated from a sealing position;

step S302, continuing to press to enable the unidirectional injection mechanism to be kept in an open state under the hydraulic action, and squeezing cement 17 to a production zone section below the cement injection packer of the abandoned well according to requirements;

step S303, after the set cement 17 amount is reached, the squeezing cement 17 is ended, and the one-way injection mechanism is automatically closed to prevent the cement paste from flowing back;

step S304, if the cement paste flows back, the pressure is suppressed and waiting for coagulation; and

and step S305, if no cement paste flows back, directly pressing down the preset tonnage, and removing the setting tool.

In step S400, further includes:

step S401, lifting the tool to a preset position after the tool is released from the setting tool of the well abandoning cementing packer; and

and step S402, performing cementing 17 plugging operation according to requirements, injecting the cement 17 in the drill string 15 to a target position through the lower joint 1 of the waste well cementing packer, and completing cementing 17 extrusion operation.

In step S500, further includes:

step S501, after the cement 17 is pumped, slowly pressing down the drill string 15, transmitting acting force to the lower joint 1 of the waste well cement packer, and descending after shearing a pin of the lower joint 1 to push the inner support sleeve 3 of the waste well cement packer, wherein the pin of the inner support sleeve 3 is pushed to the lower end after shearing, so that the locking of the release locking piece 2 of the waste well cement packer is lost; and

step S502, lifting the drill string 15, wherein the lower joint 1 drives the release locking piece 2 and the inner supporting sleeve 3 to be lifted together, and well abandoning operation is completed.

The invention is suitable for the well abandoning operation of oil and gas wells, and the tool mainly comprises a releasing service mechanism, a permanent packer, a setting ball seat, a one-way float valve and the like, wherein the one-way float valve can also be replaced by a sliding sleeve and a matched switching tool. The tool has simple structure and reliable performance, can meet the requirement that a drill string can realize the setting, sitting and hanging of a bridge plug, can squeeze cement in a production interval, can take off the packer in a mechanical or hydraulic mode, and can directly strike the cement plug above the packer after the tool is taken off. The tool overcomes the defects of the conventional cementing well abandoning tool, and achieves the aims of reducing risks, improving the well abandoning operation quality, enhancing the efficiency and reducing the cost. The packer can be set and hung by one pipe column, cement extrusion in the production interval can be carried out, then the packer can be removed by mechanical or hydraulic pressure, and a cement plug is arranged above the packer. Can meet the new standards of the offshore cement squeezing and plugging reservoir, in particular to the cement squeezing operation of a high-pressure gas well. The whole structure is relatively simple, the service tool can be repeatedly used after setting, hanging, squeezing cement and beating cement plugs, the operation time is saved, and the economic benefit is high. Overcomes the defects of the cementing well abandoning tool in the prior art, reduces the risk, improves the well abandoning operation quality, and realizes the functions of synergy and cost reduction.

Of course, the present invention is capable of other various embodiments and its several details are capable of modification and variation in light of the present invention, as will be apparent to those skilled in the art, without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (9)

1. A well abandonment cementing packer, comprising:

releasing the tool;

the releasing service mechanism comprises a lower joint, a releasing locking piece and an inner supporting sleeve, wherein the lower joint is used for connecting an upper drill string, and the releasing locking piece is respectively connected with the lower joint and the inner supporting sleeve and is used for realizing the connection between the lower joint and a releasing tool; the releasing tool is sleeved outside the releasing locking piece; the tail end of the releasing locking piece is provided with an elastic locking block for locking and separating from the releasing tool; the upper end of the inner support sleeve is provided with a shearing pin, the lower end of the inner support sleeve is provided with a boss for supporting the elastic locking block to keep a locking state, when the inner support sleeve is pressed down or thrown into a ball, the shearing pin is sheared, the inner support sleeve moves down, the locking function is released, and the drill string is separated from the releasing tool;

the packer comprises a packer body, an upper slip, a lower slip, a rubber cylinder, a setting push cylinder, a piston and a piston cylinder, wherein the packer body is provided with a through hole and is connected with the releasing tool, the upper slip, the rubber cylinder and the lower slip are sequentially sleeved outside the packer body, the piston is installed at the lower end of the packer body, the piston cylinder is sleeved on the piston, and the setting push cylinder is sleeved outside the packer body and is connected with the piston cylinder;

the setting ball seat is connected with the bottom end of the piston and is used for sealing the interior of the upper pipe column after ball injection in the drill string; and

the one-way injection mechanism is connected with the bottom end of the piston and forms a containing space together with the bottom end surface of the piston, the setting ball seat is positioned in the containing space, and the one-way injection mechanism is used for controlling cement to flow into the lower end of the packer in a one-way and preventing cement from flowing upwards after the packer is cemented.

2. The well abandonment cementing packer of claim 1, wherein the one-way injection mechanism is a two-stage one-way float valve comprising a first one-way float valve connected to the end of the piston and a second one-way float valve connected to the first one-way float valve, the first one-way float valve and the second one-way float valve being coaxially disposed with the packer body.

3. A well abandonment cement packing method, which is characterized in that the well abandonment cement packer as set forth in claim 1 or 2 is adopted for well abandonment packing, and comprises the following steps:

s100, a drill string carries the waste well cementing packer to enter a well;

s200, setting balls are thrown, so that the well abandoning cementing packer is set and hung;

s300, injecting cement into the lower end of the waste well cementing packer;

s400, releasing the abandoned well cementing packer, and cementing the upper end of the abandoned well cementing packer; and

s500, providing a service tool of the well abandoning cementing packer, and completing well abandoning operation.

4. The well-abandoned cement packing method of claim 3, wherein step S100 further comprises:

s101, checking whether the abandoned well cementing packer and accessories meet the operation requirements or not on an operation platform;

s102, connecting the abandoned well cementing packer with a drill string, and lowering the abandoned well cementing packer to a preset depth of a target well along with the drill string;

s103, after the abandoned well cementing packer is lowered in place, the unidirectional injection mechanism is opened in a positive circulation mode to carry out a circulation test; and

and S104, after the normal forward circulation test, performing a reverse circulation pressure holding test to verify whether the reverse closing of the one-way injection mechanism is normal.

5. The well-abandoned cement packing method of claim 3 or 4, wherein step S200 further comprises:

s201, putting a setting ball into the drill string and conveying the setting ball to a shearing ball seat of the abandoned well cementing packer;

s202, after the setting ball is in place, forming a sealing space in the drill string, pressing the abandoned well cementing packer, lifting and pressing the drill string down, and verifying that the slip setting of the abandoned well cementing packer is qualified;

s203, annular pressurizing is carried out on the abandoned well cementing packer, and annular sealing of the abandoned well cementing packer is verified to be qualified; and

and S204, continuously pressing to the setting ball seat of the abandoned well cementing packer for shearing.

6. The well abandonment cement packing method of claim 5, wherein in step S204, hydraulic pressure is applied to the drill string to set pressure, set pins of pistons of the well abandonment cement packer shear, the pistons push a set push cylinder of the well abandonment cement packer to move upwards, the position of an upper slip of the well abandonment cement packer is kept still, the set push cylinder pushes a lower slip and an extrusion rubber cylinder of the well abandonment cement packer, and the lower slip and the upper slip extend and bite a casing to complete the set hanging of the packer; and the rubber cylinder is extruded and expanded to the casing pipe to finish the setting, hanging and setting of the waste well cementing packer.

7. The well-abandoned cement packing method according to claim 3 or 4, wherein in step S300, further comprising:

s301, continuously driving hydraulic pressure in a drill string until a pin of a shearing ball seat of the waste well cementing packer is sheared, wherein the shearing ball seat is separated from a sealing position;

s302, continuing to press to enable the unidirectional injection mechanism to be kept in an open state under the hydraulic action, and squeezing cement to a production zone section below the cement injection packer of the abandoned well according to requirements;

s303, after the set cement amount is reached, the extrusion and the cementing are finished, and the unidirectional injection mechanism is automatically closed to prevent the cement paste from flowing back;

s304, if the cement paste flows back, the pressure is suppressed and waiting for coagulation; and

and S305, if no cement paste flows back, directly pressing down the preset tonnage, and removing the setting tool.

8. The well-abandoned cement packing method according to claim 3 or 4, wherein in step S400, further comprising:

s401, lifting the tool to a preset position after the well abandoning cementing packer is released from the setting tool; and

s402, performing cementing operation according to requirements, injecting cement in the drill string to a target position through a lower joint of the waste well cementing packer, and completing cementing extrusion operation.

9. The well-abandoned cement packing method according to claim 3 or 4, wherein in step S500, further comprising:

s501, after the cementing plug is finished, slowly pressing down a drill string, transmitting acting force to a lower joint of the abandoned well cementing packer, cutting off a pin of the lower joint, descending, pushing an inner supporting sleeve of the abandoned well cementing packer, cutting off the pin of the inner supporting sleeve, pushing the pin to the lower end, and losing locking of a releasing locking piece of the abandoned well cementing packer; and

s502, lifting the drill string, wherein the lower connector drives the releasing locking piece and the inner supporting sleeve to be lifted together, and well abandoning operation is completed.