Underground cement squeezing-in device capable of being backwashed

Abstract

The utility model relates to the field of underground operation tools, in particular to a special device for extruding a cement plugging agent into an underground reservoir of a scrapped well, and particularly relates to a backwashing underground cement extruding device which comprises a hollow upper connector, a hollow lower connector and a hollow insertion pipe. A hollow piston rod is fixedly connected into one end of the upper connector, the end, away from the upper connector, of the piston rod is fixedly connected with one end of the insertion pipe, the piston rod is sleeved with a sleeve, and one end of the sleeve is fixedly connected with the peripheral face of the upper connector in a sealed mode through an upper shell connected outside the sleeve in a sleeving mode. The packer is simple in structure and convenient to use, the liquid inlet channel is communicated with the inner area of the closing sliding sleeve, and the liquid inlet is communicated with the liquid outlet through the inner area of the setting sliding sleeve, the inner area of the insertion tube and the inner area of the piston rod which are communicated in sequence; and a liquid outlet channel is arranged on the upper joint and is communicated with the liquid outlet, so that backwashing of the shaft is realized.

Description

Technical Field

[0001] The utility model relates to the field of downhole working tools, in particular to a special device for squeezing cement plugging agents into downhole reservoirs of abandoned wells, and specifically relates to a downhole cement squeezing device capable of backwashing. Background Art

[0002] In the production of oil and gas, many oil and gas wells have lost their mining value due to years of exploitation and their production has declined year by year. According to environmental protection needs, cement sealing is required. Since a check valve is designed at the bottom of the commonly used cement flow-bearing product, the check valve seat is designed at the top and fixed to the outer pipe, and a spring is installed at the bottom of the valve seat. During normal operation, the spring presses against the steel ball, and the steel ball presses on the conical surface of the valve seat. The spring provides initial stress to achieve the interception seal in the lower direction. If there is liquid pressure at the bottom, the extrusion force between the steel ball and the valve seat is greater, and the seal will be tighter, forming a lower seal. Therefore, this product cannot be backwashed;

[0003] When pressure is applied to the upper part of the valve seat, after the upper force is greater than the spring force, a gap is formed between the steel ball and the valve seat, and the upper liquid can flow into the lower part.

[0004] Under normal circumstances, the steel ball is squeezed on the valve seat by the action of the spring, and the deposited foreign matter in the oil pipe cannot be discharged to the bottom. Over time, the granular foreign matter will block the internal channel of the cement flow carrier, causing the valve to be unable to seal, thereby causing construction failure. Utility Model Content

[0005] In order to solve the above problems, the utility model provides a downhole cement squeezing device capable of backwashing, which has the advantages of simple structure, convenient use, backwashing function and reliable sealing.

[0006] The utility model discloses a backwashable downhole cement squeezing device, comprising a hollow upper joint, a lower joint and a cannula, wherein a hollow piston rod is fixedly connected inside one end of the upper joint, an end of the piston rod away from the upper joint is fixedly connected to one end of the cannula, a sleeve is externally connected to the piston rod, one end of the sleeve is fixedly and sealingly connected to the outer peripheral surface of the upper joint through an upper shell body sleeved outside the sleeve, and an internal hydraulic piston sleeved on the upper piston rod is arranged in the area between the piston rod and the sleeve;

[0007] The upper shell is connected to the sleeve via a shear pin;

[0008] The insert is fixedly connected with a connecting sleeve through a working seat sleeve sleeved outside the insert, a closing sleeve is arranged inside the connecting sleeve, the closing sleeve is fixedly connected to one end of a sleeve recovery bar, the sleeve recovery bar is arranged inside the connecting sleeve, and the sleeve recovery bar is fixedly connected to the inner annular surface of the working seat sleeve;

[0009] The end of the sliding sleeve recovery fence close to the insert pipe is fixedly connected to a setting sliding sleeve for limiting the position of the steel ball through a shear pin, and the inner diameter of the setting sliding sleeve is smaller than the inner diameter of the insert pipe;

[0010] A setting assembly is also arranged outside the working setting sleeve; one end of the setting assembly away from the upper joint is sealed and fixedly connected to the lower joint, one end of the connecting sleeve is arranged in the setting assembly, and the other end of the connecting sleeve is located inside the lower joint;

[0011] The outer shell of the working seat seal is provided with a sealing rubber cylinder;

[0012] The piston rod is provided with a liquid outlet, and the closing sleeve is provided with a liquid inlet, the liquid inlet is connected to the liquid outlet through the inner area of ​​the setting sleeve, the inner area of ​​the insert pipe and the inner area of ​​the piston rod which are connected in sequence; the upper joint is provided with a liquid outlet channel, and the liquid outlet channel is connected to the liquid outlet;

[0013] The lower joint is provided with a liquid inlet channel. When the liquid inlet port is connected to the liquid inlet channel, the liquid inlet channel is connected to the inner area of ​​the closing sleeve. When the liquid inlet port is misaligned with the liquid inlet channel, the liquid inlet channel is isolated from the inner area of ​​the closing sleeve.

[0014] Preferably, the setting seal assembly comprises a conical rising cone and a conical lower rising cone sleeved on the working setting seal sleeve, the rising cone and the lower rising cone are arranged opposite to each other, and a fixed slip is sleeved on the working setting seal sleeve between the rising cone and the lower rising cone, both ends of the fixed slip are flared, and one end of the fixed slip matches and is slidably connected to the rising cone, and the other end of the fixed slip matches and is slidably connected to the lower rising cone, and teeth for fixing and connecting to the inner wall of the wellbore are uniformly distributed on the outer circumferential surface of the fixed slip, and the lower rising cone is fixedly and sealingly connected to the lower joint;

[0015] When the rising cone and the lower rising cone approach each other, the fixed slip expands radially along the insertion tube.

[0016] Preferably, one end of the rising cone away from the lower rising cone is abutted against the rubber tube retaining ring through a sealing rubber tube, a self-locking ring is fixedly arranged outside the insert, the self-locking ring is arranged in the working seat sealing sleeve, the inner wall of the working seat sealing sleeve is provided with a self-locking thread, the self-locking ring is an expanding sleeve provided with a circumferential opening, and the outer circumferential surface of the self-locking ring is provided with self-locking teeth;

[0017] When the working seat sleeve moves along the axial direction of the insert tube and the self-locking thread contacts the self-locking teeth, the self-locking ring limits the movement of the working seat sleeve.

[0018] The utility model has a simple structure and is easy to use. A liquid inlet channel is connected to the internal area of ​​the closing sleeve, and the liquid inlet is connected to the liquid outlet through the internal area of ​​the setting sleeve, the internal area of ​​the insert pipe and the internal area of ​​the piston rod which are connected in sequence. A liquid outlet channel is provided on the upper joint, and the liquid outlet channel is connected to the liquid outlet to realize backwashing of the wellbore.

[0019] The utility model utilizes the rising cone and the lower rising cone to approach each other, and the fixed slips expand radially along the insert pipe to achieve effective sealing of the utility model; the outer peripheral surface of the fixed slips is evenly distributed with teeth for fixing and connecting to the inner wall of the wellbore to further ensure the reliability of the sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of the utility model.

[0021] Figure 2 It is a schematic diagram of the structure of the utility model after the steel ball is put into it.

[0022] Figure 3 Open the structural diagram for the cement channel.

[0023] Figure 4 This is a schematic diagram of the installation position of the self-locking ring.

[0024] Figure 5 Schematic diagram of the self-locking ring structure.

[0025] Figure 6 Schematic diagram of closing the sliding sleeve.

[0026] Figure markings: 1-upper joint, 2-lower joint, 3-internal hydraulic piston, 4-insertion tube, 5-sealing rubber cylinder, 6-fixed slip, 9-rising cone, 10-lower rising cone, 11-closing sleeve, 12-setting sleeve, 13-liquid outlet, 14-steel ball, 15-connecting sleeve, 16-liquid inlet, 17-rubber cylinder retaining ring, 18-self-locking thread, 19-self-locking ring. DETAILED DESCRIPTION

[0027] The utility model discloses a backwashable downhole cement squeezing device, comprising a hollow upper joint 1, a lower joint 2 and a cannula 4, wherein a hollow piston rod is fixedly connected to the interior of one end of the upper joint 1, and an end of the piston rod away from the upper joint 1 is fixedly connected to one end of the cannula 4, a sleeve is connected to the outer surface of the piston rod, and one end of the sleeve is fixedly and sealingly connected to the outer peripheral surface of the upper joint 1 through an upper shell sleeved outside the sleeve, and an internal hydraulic piston 3 sleeved on the upper piston rod is arranged in the area between the piston rod and the sleeve;

[0028] The upper shell is connected to the sleeve via a shear pin;

[0029] The insert pipe 4 is fixedly connected to a connecting sleeve 15 through a working seat sleeve sleeved outside the insert pipe 4, a closing sleeve 11 is arranged inside the connecting sleeve 15, the closing sleeve 11 is fixedly connected to one end of a sleeve recovery bar, the sleeve recovery bar is arranged inside the connecting sleeve 15, and the sleeve recovery bar is fixedly connected to the inner annular surface of the working seat sleeve;

[0030] The end of the sliding sleeve recovery fence close to the cannula 4 is fixedly connected to a setting sliding sleeve 12 for limiting the position of the steel ball 14 through a shear pin, and the inner diameter of the setting sliding sleeve 12 is smaller than the inner diameter of the cannula 4;

[0031] A sealing assembly is also provided outside the working sealing sleeve; one end of the sealing assembly away from the upper joint 1 is sealed and fixedly connected to the lower joint 2, one end of the connecting sleeve 15 is provided inside the sealing assembly, and the other end of the connecting sleeve 15 is located inside the lower joint 2;

[0032] The outer shell of the working seat seal is provided with a sealing rubber cylinder 5;

[0033] The piston rod is provided with a liquid outlet 8, and the closing sleeve 11 is provided with a liquid inlet 16, and the liquid inlet 16 is connected to the liquid outlet 8 through the inner area of ​​the setting sleeve 12, the inner area of ​​the cannula 4 and the inner area of ​​the piston rod which are connected in sequence; the upper joint 1 is provided with a liquid outlet channel, and the liquid outlet channel is connected to the liquid outlet 8;

[0034] The lower joint 2 is provided with a liquid inlet channel. When the liquid inlet port 16 is connected to the liquid inlet channel, the liquid inlet channel is connected to the inner area of ​​the closing sleeve 11. When the liquid inlet port 16 is misaligned with the liquid inlet channel, the liquid inlet channel is isolated from the inner area of ​​the closing sleeve 11.

[0035] The sealing assembly comprises a conical rising cone 9 and a conical lower rising cone 10 sleeved on the working sealing sleeve, the rising cone 9 and the lower rising cone 10 are arranged opposite to each other, and a fixed slip 6 is also sleeved on the working sealing sleeve between the rising cone 9 and the lower rising cone 10, both ends of the fixed slip 6 are flared, and one end of the fixed slip 6 matches and is slidably connected to the rising cone 9, and the other end of the fixed slip 6 matches and is slidably connected to the lower rising cone 10, and the outer peripheral surface of the fixed slip 6 is evenly distributed with teeth for fixing and connecting to the inner wall of the wellbore, and the lower rising cone 10 is fixedly and sealingly connected to the lower joint 2;

[0036] When the rising cone 9 and the lower rising cone 10 approach each other, the fixed slips 6 expand radially along the insertion tube 4 .

[0037] One end of the rising cone 9 away from the lower rising cone 10 is butted against the rubber tube retaining ring 17 through the sealing rubber tube 5. A self-locking ring 19 is fixedly arranged outside the insert tube 4. The self-locking ring 19 is arranged in the working seat sealing sleeve. The inner wall of the working seat sealing sleeve is provided with a self-locking thread 18. The self-locking ring 19 is an expansion sleeve with a circumferential opening, and the outer peripheral surface of the self-locking ring 19 is provided with self-locking teeth.

[0038] When the working seat sleeve moves axially along the insert 4 and the self-locking thread 18 contacts the self-locking teeth, the self-locking ring 19 limits the movement of the working seat sleeve.

[0039] When in use, for the scrapped oil and gas wells that need to be sealed, the utility model is lowered to the upper part of the reservoir using an oil pipe string. After it is lowered to the position, the wellhead is installed and connected to the cement truck. First, the well is backwashed. The liquid enters the inside of the insert pipe 4 through the liquid inlet 16 from the liquid inlet channel on the lower joint 2, and flows out from the inside of the insert pipe 4 through the liquid outlet 8 and the liquid outlet channel. The wellbore replacement and well washing operation is carried out to clean out all the debris in the oil pipe and complete the backwashing operation.

[0040] At the wellhead, a steel ball 14 is put into the tubing string, and the steel ball 14 is waited for 20 minutes until it is seated on the sealing sleeve 12. The tubing string is pressurized, and the liquid in the tubing flows out from the liquid outlet 8 of the piston rod and enters the internal area of ​​the upper joint 1, the external shell, and the sealing sleeve 12. Since the piston rod and the upper joint 1 are fixed with threads, when the internal pressure is increased, the hydraulic pressure will push the internal hydraulic piston 3 forward. When the pressure exceeds the shear pin shear force between the external shell and the sleeve, the shear pin will be cut off, and the sealing piston will be pushed to drive the sealing assembly downward. The rising cone 9 and the lower rising cone 10 will push out the fixed slip 6 and press it on the inner wall of the wellbore. When the self-locking thread 18 contacts the self-locking teeth, self-locking is achieved, thereby achieving the fixation of the utility model in the wellbore, and at the same time, the rubber cylinder expands to achieve product sealing;

[0041] Continue to increase the pressure inside the oil pipe to cut off the shear pin between the sleeve recovery fence and the setting sleeve 12, and the setting sleeve 12 falls into the lower sleeve recovery fence. The liquid inlet 16 is connected with the liquid inlet channel, and cement enters the injection layer through the liquid inlet channel, so as to squeeze cement into the lower reservoir.

Claims

1. A backwashable downhole cement squeezing device, comprising a hollow upper joint, a lower joint and a cannula, characterized in that: A hollow piston rod is fixedly connected inside one end of the upper joint, and an end of the piston rod away from the upper joint is fixedly connected to one end of the insert tube, and a sleeve is connected to the piston rod, and one end of the sleeve is fixed and sealed to the outer peripheral surface of the upper joint through an upper shell sleeved outside the sleeve, and an internal hydraulic piston sleeved on the upper piston rod is arranged in the area between the piston rod and the sleeve; The upper shell is connected to the sleeve via a shear pin; The insert is fixedly connected with a connecting sleeve through a working seat sleeve sleeved outside the insert, a closing sleeve is arranged inside the connecting sleeve, the closing sleeve is fixedly connected to one end of a sleeve recovery bar, the sleeve recovery bar is arranged inside the connecting sleeve, and the sleeve recovery bar is fixedly connected to the inner annular surface of the working seat sleeve; The end of the sliding sleeve recovery fence close to the insert pipe is fixedly connected to a setting sliding sleeve for limiting the position of the steel ball through a shear pin, and the inner diameter of the setting sliding sleeve is smaller than the inner diameter of the insert pipe; A setting assembly is also arranged outside the working setting sleeve; one end of the setting assembly away from the upper joint is sealed and fixedly connected to the lower joint, one end of the connecting sleeve is arranged in the setting assembly, and the other end of the connecting sleeve is located inside the lower joint; The outer shell of the working seat seal is provided with a sealing rubber cylinder; The piston rod is provided with a liquid outlet, and the closing sleeve is provided with a liquid inlet, the liquid inlet is connected to the liquid outlet through the inner area of ​​the setting sleeve, the inner area of ​​the insert pipe and the inner area of ​​the piston rod which are connected in sequence; the upper joint is provided with a liquid outlet channel, and the liquid outlet channel is connected to the liquid outlet; The lower joint is provided with a liquid inlet channel. When the liquid inlet port is connected to the liquid inlet channel, the liquid inlet channel is connected to the inner area of ​​the closing sleeve. When the liquid inlet port is misaligned with the liquid inlet channel, the liquid inlet channel is isolated from the inner area of ​​the closing sleeve.

2. A backwashable downhole cement squeezing device as claimed in claim 1, characterized in that: The sealing assembly comprises a conical rising cone and a conical lower rising cone sleeved on the working sealing sleeve, the rising cone and the lower rising cone are arranged opposite to each other, and a fixed slip is sleeved on the working sealing sleeve between the rising cone and the lower rising cone, both ends of the fixed slip are flared, and one end of the fixed slip matches and is slidably connected to the rising cone, and the other end of the fixed slip matches and is slidably connected to the lower rising cone, and teeth for fixing and connecting to the inner wall of the wellbore are evenly distributed on the outer circumferential surface of the fixed slip, and the lower rising cone is fixedly and sealingly connected to the lower joint; When the rising cone and the lower rising cone approach each other, the fixed slip expands radially along the insertion tube.

3. A backwashable downhole cement squeezing device as claimed in claim 2, characterized in that: One end of the rising cone away from the lower rising cone is abutted against the rubber sleeve baffle ring through a sealing rubber sleeve, a self-locking ring is fixedly arranged outside the insert, the self-locking ring is arranged in the working seat sealing sleeve, the inner wall of the working seat sealing sleeve is provided with a self-locking thread, the self-locking ring is an expansion sleeve provided with a circumferential opening, and the outer circumferential surface of the self-locking ring is provided with self-locking teeth; When the working seat sleeve moves along the axial direction of the insert tube and the self-locking thread contacts the self-locking teeth, the self-locking ring limits the movement of the working seat sleeve.

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