Anti-overflow packing device

Abstract

The utility model discloses an anti-overflow packing device which comprises a check valve and further comprises a sealing insertion pipe, and the sealing insertion pipe is sequentially sleeved with a self-starting pressing mechanism and a packer from top to bottom. The check valve is arranged at the lower end of the drillable packer; and after the self-starting pressing mechanism is started, the packer is set and anchored. The drilling packer is arranged below a water injection layer, the drilling packer can be automatically set, high-pressure water in the water injection layer cannot overflow from a sleeve, when water injection of a water well is stopped, the pressure below the check valve is higher than the pressure above the check valve, the check valve is in a closed state, liquid on the lower layer cannot flow out reversely, and the reverse spitting situation cannot occur; the separation pin is cut off, a pipe column on the sealing insertion pipe can be used for detection and replacement operation, and overflow and blowout of a water well can be avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of oil field water injection, in particular to an anti-overflow isolation device. Background Art

[0002] When moving the pipe string in an injection well with high injection layer pressure, the water in the injection layer will spray back from the injection pipe to the ground, making it impossible to carry out the dynamic operation. If you want to move the pipe string for such an injection well, you can only release the pressure at the wellhead and let the pressure in the well drop to zero naturally. This method is called "overflow release" on site. Overflow release gradually reduces the formation pressure, and the pipe string operation can only be carried out after the pressure is released.

[0003] When overflowing, a large amount of injected water will be sprayed from the injection layer to the ground:

[0004] On the one hand, the amount of water in the injection layer is reduced, causing the formation pressure to drop, and it takes a period of time to re-inject water to restore the previous formation pressure;

[0005] On the other hand, the backflow of the injection layer will bring the formation sand out (called backflow or sand spitting in the industry) to the wellbore, making the sand-buried wellbore unable to inject water, requiring sand cleaning operations, and increasing well repair costs;

[0006] On the other hand, the water sprayed onto the ground will seriously pollute the environment, requiring investment in environmental pollution control costs;

[0007] On the other hand, it takes a long time to release the overflow, which affects the water injection of the wells and causes losses to the oil field development.

[0008] Publication (Announcement) No.: CN207568546U discloses a wellhead overflow prevention device, including a blowout prevention device. The prior art increases a sealing flow tube to gradually divide the pressure in the well on the blowout prevention device, and then controls the size of the overflow through packing. By utilizing the larger viscosity of the sealing grease and increasing the grease injection method, the gap between the cable armor and the inner wall of the choke tube is sealed by the sealing grease flow, thereby achieving the effect of reducing the overflow. However, when the wellhead pressure is too high, active overflow discharge operation is still required.

[0009] Publication (Announcement) No.: CN209990476U discloses an anti-overflow and sand-settling one-way valve, which can not only control the one-way flow of the medium, but also prevent the accumulation of sand particles, and can also adapt to the requirements of no-well operation. However, it is a separate device and is not used in combination with other downhole tools.

[0010] Publication (Announcement) No.: CN208380559U, a tubing and double-tube washable well stratified water injection system, the tubing is used for stratified water injection, the cannula, the packer, and the overflow prevention valve are set separately, and it is necessary to pressurize the oil pipe to set and anchor, and the utility model combines the cannula, the packer, and the overflow prevention valve together, and they can be set and anchored by just leaving it still.

[0011] In short, the technical solutions of the above-disclosed technologies, the technical problems to be solved and the beneficial effects produced are all different from the present utility model. Regarding more technical features, technical problems to be solved and the beneficial effects of the present utility model, there is no technical inspiration in the above-disclosed technical documents. Utility Model Content

[0012] In view of the above-mentioned defects in the prior art, the purpose of the utility model is to provide an anti-overflow isolation device, so that when the tubing is moved during well repair, there is no need to release pressure and overflow will not occur, so that the tubing can be used for well repair, overcoming the problems caused by releasing overflow and avoiding overflow during water injection well operation.

[0013] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0014] An anti-overflow isolation device comprises a check valve and a sealing insert, wherein the sealing insert is sequentially covered with a self-starting pressing mechanism and a packer from top to bottom; the check valve is arranged at the lower end of the drillable packer; and the self-starting pressing mechanism is activated to seal and anchor the packer.

[0015] Furthermore, the self-starting pressing mechanism includes a retaining ring, a starting pin, a hydraulic cylinder, and a fixed piston;

[0016] Specifically, the retaining ring is fixedly arranged on the upper end of the sealing insert, and the sealing insert is fixedly arranged with a fixed piston below the retaining ring;

[0017] Specifically, a movable piston is arranged on the inner wall of the hydraulic cylinder, the hydraulic cylinder is sleeved outside the retaining ring, the sealing insert and the fixed piston, and the movable piston is between the fixed piston and the retaining ring;

[0018] Specifically, the hydraulic cylinder is provided with a connecting hole, the connecting hole connects the upper end surface of the movable piston with the outside, and a self-melting pin is arranged in the connecting hole;

[0019] Specifically, the starting pin passes through the upper end of the hydraulic cylinder and is inserted into the retaining ring;

[0020] Specifically, sealing devices are provided between the hydraulic cylinder and the retaining ring, the sealing insert and the fixed piston.

[0021] Furthermore, an upper joint is provided at the upper end of the retaining ring, and the inner wall of the lower end of the retaining ring is threadedly connected to the outer wall of the upper end of the sealing insert, and the connection is kept sealed.

[0022] Furthermore, the sealing cannula and the fixed piston are a combined component.

[0023] Furthermore, the retaining ring and the inner wall of the upper end of the hydraulic cylinder are provided with an upper sealing ring, and the upper sealing ring is between the connecting hole and the starting pin;

[0024] Specifically, a sliding sealing ring is provided on the inner wall of the movable piston;

[0025] Specifically, a lower sealing ring is provided on the outer wall of the fixed piston.

[0026] Further, the packer is a drillable packer;

[0027] Specifically, the drillable packer comprises a central pipe, and the central pipe is covered with an upper pressure ring, an upper anchoring mechanism, a setting mechanism, a lower anchoring mechanism, and a lower pressure ring in sequence from top to bottom;

[0028] Specifically, the central tube is sleeved on the sealing insert, a sealing mechanism is provided between the sealing insert and the central tube, a separation pin is provided between the central tube and the sealing insert, the separation pin passes through the central tube and is inserted into the sealing insert;

[0029] Specifically, the upper end surface of the central tube is below the fixed piston, and the lower end surface of the hydraulic cylinder contacts the upper end surface of the upper pressure ring.

[0030] Furthermore, a communication groove is formed on the hydraulic cylinder, and the communication groove is located below the fixed piston.

[0031] Furthermore, the upper anchoring mechanism comprises an upper slip and an upper cone which are arranged in sequence, the sealing mechanism comprises a rubber cylinder, and the lower anchoring mechanism comprises a lower cone and a lower slip which are arranged in sequence.

[0032] Furthermore, the sealing mechanism is at least one cannula sealing ring, and the sealing mechanism prevents the liquid flow from passing through the gap between the sealed cannula and the central tube.

[0033] Furthermore, the check valve is fixedly connected to the lower pressure ring.

[0034] Compared with the prior art, the utility model has the following beneficial effects:

[0035] The utility model is placed above the water injection layer, and the drillable packer can be automatically sealed, so that the high-pressure water in the water injection layer will not overflow from the casing. When the water well stops injection, the pressure below the check valve is higher than the pressure above, and the check valve is in a closed state. The lower layer liquid will not flow out in the reverse direction and will not spit out. When the water injection pipe column is lifted up for inspection and replacement, the separation pin is sheared off, and the pipe column above the sealing plug can be lifted up for inspection and replacement, and the water well will not overflow or blowout. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The utility model is a structural schematic diagram of an anti-overflow sealing device.

[0037] In the figure: 1. upper joint; 2. starting pin; 3. upper sealing ring; 4. self-melting pin; 5. sliding sealing ring; 6. hydraulic cylinder; 6-1. connecting hole; 6-2. closed cavity; 6-3. connecting groove; 7. sealing insert; 8. lower sealing ring; 9. fixed piston; 10. separation pin; 11. insert sealing ring; 12. drillable packer; 13. check valve. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0039] Embodiment 1:

[0040] See also Figure 1 The utility model provides an anti-overflow isolation device, including a sealing insert 7, which is sequentially covered with a self-starting pressing mechanism and a drillable packer 12 from top to bottom. A check valve 13 is provided at the lower end of the drillable packer 12. After the self-starting pressing mechanism is started, the drillable packer 12 is sealed and anchored.

[0041] The self-starting pressing mechanism includes a baffle ring, a starting pin 2, a hydraulic cylinder 6, and a fixed piston 9. The baffle ring is fixedly arranged at the upper end of the sealing insert 7. The sealing insert 7 is fixedly provided with a fixed piston 9 below the baffle ring. A movable piston is arranged on the inner wall of the hydraulic cylinder 6. The hydraulic cylinder 6 is sleeved outside the baffle ring, the sealing insert 7, and the fixed piston 9. The movable piston is between the fixed piston 9 and the baffle ring. The hydraulic cylinder 6 is provided with a connecting hole 6-1. The connecting hole 6-1 connects the upper end surface of the movable piston with the outside world. A self-melting pin 4 is arranged in the connecting hole 6-1. The starting pin 2 passes through the upper end of the hydraulic cylinder 6 and is inserted into the baffle ring; a sealing device is arranged between the hydraulic cylinder 6 and the baffle ring, the sealing insert 7, and the fixed piston 9.

[0042] An upper joint 1 is provided at the upper end of the retaining ring, and the inner wall of the lower end of the retaining ring is threadedly connected to the outer wall of the upper end of the sealing insert 7, and the connection is kept sealed.

[0043] The sealing insert 7 and the fixed piston 9 can be designed as a combination to reduce processing costs, and the combination is also within the protection scope of the present utility model.

[0044] The start pin 2 prevents the hydraulic cylinder 6 from axially moving with the drillable packer 12 during the process of going down into the well.

[0045] Preferably, the retaining ring and the upper inner wall of the hydraulic cylinder 6 are provided with an upper sealing ring 3, and the upper sealing ring 3 is between the connecting hole 6-1 and the starting pin 2. The upper sealing ring 3 seals the gap between the retaining ring and the upper inner wall of the hydraulic cylinder 6, so that the hydraulic pressure cannot be transmitted to the connecting hole 6-1 and the upper end surface of the movable piston under the upper sealing ring 3. The space between the movable piston, the retaining ring and the hydraulic cylinder is a hydraulic chamber.

[0046] Preferably, the inner wall of the movable piston is provided with a sliding sealing ring 5, and the sliding sealing ring 5 seals the gap between the inner wall of the movable piston and the outer wall of the sealing insert 7. The sliding sealing ring 5, the upper sealing ring 3, and the self-melting pin 4 seal the hydraulic chamber together.

[0047] Preferably, the outer wall of the fixed piston 9 is provided with a lower sealing ring 8, and the lower sealing ring 8 seals the gap between the inner wall of the hydraulic cylinder 6 and the fixed piston 9, so that the hydraulic cylinder 6, the sealing insert 7, and the fixed piston 9 form a closed cavity 6-2, and the closed cavity 6-2 is filled with air. The sliding sealing ring 5 and the lower sealing ring 8 jointly seal the closed cavity 6-2.

[0048] Specifically, the drillable packer 12 includes a central pipe, and the central pipe is covered with an upper pressure ring, an upper anchoring mechanism, a setting mechanism, a lower anchoring mechanism, and a lower pressure ring in sequence from top to bottom;

[0049] The center tube is sleeved on the sealing insert 7, a sealing mechanism is arranged between the sealing insert 7 and the center tube, a separation pin 10 is arranged between the center tube and the sealing insert 7, the separation pin 10 passes through the center tube and is inserted into the sealing insert 7, the upper end surface of the center tube is below the fixed piston 9, the lower end surface of the hydraulic cylinder 6 contacts the upper end surface of the upper pressure ring, and when the hydraulic cylinder moves downward, the drillable packer 12 completes the setting and anchoring.

[0050] The hydraulic cylinder 6 is provided with a connecting groove 6 - 3 , which is located below the fixed piston 9 , to ensure pressure balance between the upper and lower ends of the drillable packer 12 and prevent the packer from setting during the downhole process.

[0051] Preferably, the upper anchoring mechanism comprises an upper slip and an upper cone which are arranged in sequence, the sealing mechanism is a rubber cylinder, and the lower anchoring mechanism comprises a lower cone and a lower slip.

[0052] Preferably, the sealing mechanism is at least one cannula sealing ring 11, and the sealing mechanism prevents the liquid flow from passing through the gap between the sealing cannula 7 and the central tube.

[0053] The one-flow valve 13 is fixedly connected to the lower pressure ring. When the pressure at the bottom of the one-flow valve 13 is higher than or equal to the pressure at the top, the one-flow valve 13 is in a closed state. When the pressure at the top of the one-flow valve 13 is higher than the pressure at the bottom, the one-flow valve 13 is in an open state, so that the liquid can only flow from top to bottom through the one-flow valve 13, but cannot flow from bottom to top through the one-flow valve 13.

[0054] Embodiment 2:

[0055] This embodiment provides a method for using an overflow prevention isolation device, which specifically includes the following steps:

[0056] S1. Connect an overflow prevention isolation device to the bottom of the water injection string;

[0057] S2, after being lowered into the well, an overflow prevention and isolation device is lowered with the water injection string to the designed position, and then waits for 24 hours, the self-melting pin 4 dissolves, and the well pressure is transmitted to the hydraulic cavity under the upper sealing ring 3 through the connecting hole 6-1. The well pressure and the air in the closed cavity 6-2 form a pressure difference, and the pressure difference pushes the hydraulic cylinder 6 downward to apply pressure through the movable piston, and after the pin 2 is cut off, it moves downward to apply pressure to the drillable packer 12, so that it is anchored and sealed. After the drillable packer 12 is anchored and sealed, water injection can be carried out normally;

[0058] S3, when the water well is stopped, the pressure below the check valve 13 is higher than the pressure above, the check valve 13 is in a closed state, the well fluid will not overflow, and no backflow will occur;

[0059] S4. When the water injection pipe string is lifted up for inspection and replacement, the separation pin 10 is cut off, and the sealing insert 7 and the pipe string above can be lifted up for inspection and replacement, and the water well will not overflow (no backflow);

[0060] When the water injection string is lowered again after inspection and replacement, the tail of the water injection string is connected to the sealing cannula 7, and the sealing cannula 7 is then inserted into the drillable packer 12. The surface is pressurized with 2-3t of the string weight, and water injection can be carried out again.

[0061] S5. When it is necessary to drill out the drillable packer 12, a milling tool is lowered to drill out the drillable packer 12 to make the wellbore unblocked.

[0062] All components and connection methods of components not discussed in this application belong to the known technologies in this technical field and can be directly applied without further explanation.

[0063] In the present invention, the term "plurality" means two or more than two, unless otherwise clearly defined. The terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0064] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "front" and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation on the present invention.

[0065] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0066] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. An anti-overflow isolation device, comprising a check valve, characterized in that: It also includes a sealing cannula, which is covered with a self-starting pressing mechanism and a packer in sequence from top to bottom; The check valve is arranged at the lower end of the drillable packer; The self-starting pressing mechanism is started to seal and anchor the packer.

2. The overflow prevention isolation device according to claim 1, characterized in that: The self-starting pressing mechanism includes a retaining ring, a starting pin, a hydraulic cylinder, and a fixed piston; The retaining ring is fixedly arranged on the upper end of the sealing insert, and the sealing insert is fixedly arranged with a fixed piston below the retaining ring; The inner wall of the hydraulic cylinder is provided with a movable piston, the hydraulic cylinder is sleeved outside the retaining ring, the sealing insert and the fixed piston, and the movable piston is between the fixed piston and the retaining ring; The hydraulic cylinder is provided with a connecting hole, the connecting hole connects the upper end surface of the movable piston with the outside, and a self-melting pin is arranged in the connecting hole; The starting pin passes through the upper end of the hydraulic cylinder and is inserted into the retaining ring; Sealing devices are arranged between the hydraulic cylinder and the retaining ring, the sealing insert and the fixed piston.

3. The overflow prevention isolation device according to claim 2, characterized in that: An upper joint is arranged at the upper end of the retaining ring, and the inner wall of the lower end of the retaining ring is threadedly connected with the outer wall of the upper end of the sealing insert, and the connection is kept sealed.

4. The overflow prevention isolation device according to claim 2, characterized in that: The sealing cannula and the fixed piston are a combined part.

5. The overflow prevention isolation device according to claim 2, characterized in that: The inner wall of the upper end of the retaining ring and the hydraulic cylinder is provided with an upper sealing ring, and the upper sealing ring is between the connecting hole and the starting pin; The inner wall of the movable piston is provided with a sliding sealing ring; The outer wall of the fixed piston is provided with a lower sealing ring.

6. An overflow prevention isolation device according to any one of claims 2 to 5, characterized in that: The packer is a drillable packer; The drillable packer comprises a central tube, and the central tube is covered with an upper pressure ring, an upper anchoring mechanism, a setting mechanism, a lower anchoring mechanism, and a lower pressure ring in sequence from top to bottom; The central tube is sleeved on the sealing insert, a sealing mechanism is provided between the sealing insert and the central tube, a separation pin is provided between the central tube and the sealing insert, the separation pin passes through the central tube and is inserted into the sealing insert; The upper end surface of the central tube is below the fixed piston, and the lower end surface of the hydraulic cylinder is in contact with the upper end surface of the upper pressure ring.

7. The overflow prevention isolation device according to claim 6, characterized in that: A communication groove is provided on the hydraulic cylinder, and the communication groove is located below the fixed piston.

8. The overflow prevention isolation device according to claim 6, characterized in that: The upper anchoring mechanism comprises an upper slip and an upper cone which are arranged in sequence, the setting mechanism comprises a rubber cylinder, and the lower anchoring mechanism comprises a lower cone and a lower slip which are arranged in sequence.

9. The overflow prevention isolation device according to claim 6, characterized in that: The sealing mechanism is at least one cannula sealing ring, and the sealing mechanism prevents liquid flow from passing through the gap between the sealed cannula and the central tube.

10. The overflow prevention isolation device according to claim 6, characterized in that: The check valve is fixedly connected to the lower pressure ring.

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