Water injection well washing system and integrated water distributor thereof

Abstract

This invention relates to the field of oil production equipment and discloses a water injection well washing system and its integrated water distributor. The integrated water distributor includes a main body (4) and a setting mechanism (5) slidably fitted onto the main body (4). A setting pressure chamber (5a) is defined between the setting mechanism (5) and the main body (4), so that when water is injected into the setting pressure chamber (5a) through the hollow channel (41) of the main body (4), the setting mechanism (5) can slide from its initial state and expand to a setting state under water pressure. The main body (4) is provided with a well washing fluid channel (3), a water injection valve (8), and a well washing water injection control mechanism (7) for controlling the on / off state of the well washing fluid channel and the opening / closing state of the water injection valve. This integrated water distributor does not require an additional cable packer to be connected through a tubing short section, which facilitates the subdivision of water injection layers with small interlayer spacing and allows for selective execution of well washing and water injection processes as needed.

Description

Technical Field

[0001] This invention relates to oil production equipment, specifically to an integrated water distributor. Furthermore, this invention also relates to a water injection and well flushing system incorporating the integrated water distributor. Background Technology

[0002] Typically, a cable packer is connected to an intelligent water distributor via a tubing short section as a single-layer water injection tool in an oilfield intelligent water injection well, suitable for layers no less than 4 meters wide. The cable packer contains a mechanical well-washing mechanism, controlled by the pressure difference between the tubing and casing: the well-washing mechanism opens when the tubing pressure is lower than the casing pressure, and closes when the tubing pressure is higher than the casing pressure. In cases requiring temporary cessation of water injection, high residual formation pressure may cause the casing pressure to exceed the tubing pressure, leading to the erroneous opening of the well-washing mechanism. Summary of the Invention

[0003] The purpose of this invention is to overcome the problem that existing single-layer water injection tools for water injection wells cannot inject water into well water injection layers with small interlayer spacing. This invention provides an integrated water distributor with a sealing function, which is suitable for injecting water into well water injection layers with small interlayer spacing, and can switch between two different working states: well washing and water injection.

[0004] To achieve the above objectives, the present invention provides an integrated water distributor, comprising a main body having a hollow channel and a setting mechanism slidably fitted onto the main body. The setting mechanism and the main body define a setting pressure chamber communicating with the hollow channel, so that when water is injected into the setting pressure chamber through the hollow channel, the setting mechanism can slide and expand to a setting state under water pressure. The main body contains a well-washing fluid channel, a water injection valve, and a well-washing water injection control mechanism for controlling the on / off state of the well-washing fluid channel and the opening / closing state of the water injection valve. When the water injection valve is open, the hollow channel communicates with the outer space of the main body. When the well-washing fluid channel is connected, the outer spaces of the main body located above and below the setting mechanism in the setting state communicate with each other.

[0005] Preferably, the well-washing fluid channel has a well-washing fluid inlet and a well-washing fluid outlet formed axially at intervals on the main body, with the well-washing fluid inlet located above the setting and sealing mechanism.

[0006] Preferably, the setting mechanism closes the well-washing fluid outlet in the initial state and opens the well-washing fluid outlet in the setting state.

[0007] Preferably, the well-washing and water-injection control mechanism includes a combined well-washing and water-injection drive shaft and a well-washing piston extending into the well-washing fluid channel and capable of being driven by the combined well-washing and water-injection drive shaft to slide relative to the main body. The water-injection valve is connected to the combined well-washing and water-injection drive shaft, and when it moves with the combined well-washing and water-injection drive shaft to an open state that connects the hollow channel to the outer space of the main body, the well-washing piston blocks the well-washing fluid channel.

[0008] Preferably, the well-washing piston is configured to have a partition block that is always located between the well-washing outlet and the water injection valve and slides in cooperation with the main body.

[0009] Preferably, the well-washing and water-injection control mechanism further includes a transmission actuator for driving the combined transmission shaft of the well-washing and water-injection system, and the main body is provided with a main control circuit that is connected to the transmission actuator.

[0010] Preferably, a cable channel is formed within the main body to allow power lines and / or signal lines to pass through the cable channel from the upper end of the main body and be electrically connected to the main control circuit and / or the drive actuator.

[0011] Preferably, the setting mechanism includes a setting rubber tube, a setting sleeve abutting the lower end of the setting rubber tube, and a setting piston disposed between the setting sleeve and the main body and axially abutting the setting sleeve. The water pressure in the setting pressure chamber acts on the bottom surface of the setting piston so that the setting rubber tube can be expanded into a setting state by pushing the setting mechanism upward.

[0012] Preferably, a locking mechanism for locking the locking mechanism in the locking state is further provided between the locking sleeve and the main body.

[0013] A second aspect of the present invention provides a water injection well flushing system, including a casing, a tubing extending through the casing, and the aforementioned integrated water distributor connected to the bottom end of the tubing.

[0014] Through the above technical solution, the integrated water distributor of the present invention integrates a setting mechanism. Water is injected into the setting pressure chamber through the hollow channel of the main body, causing the setting mechanism to expand into a setting state. This integrates the sealing function of isolating the water injection layer and the water injection function into the water injection layer into the same tool, thus eliminating the need for an additional cable packer connected via a tubing short section. This facilitates the subdivision of water injection into downhole water injection layers with small interlayer spacing, such as a minimum of 2 meters. Simultaneously, the well-washing and water injection control mechanism controls the on / off state of the well-washing fluid channel and the opening / closing state of the water injection valve, allowing switching between well-washing and water injection states to selectively execute the well-washing and water injection processes as needed. Attached Figure Description

[0015] Figure 1This is a cross-sectional structural diagram of an integrated water distributor according to a preferred embodiment of the present invention.

[0016] Explanation of reference numerals in the attached figures

[0017] 1-Upper connector; 2-Cable channel; 3-Well washing fluid channel; 31-Well washing fluid inlet; 32-Well washing fluid outlet; 4-Main body; 41-Hollow channel; 5-Setting mechanism; 51-Setting rubber sleeve; 52-Setting sleeve; 53-Setting piston; 5a-Setting pressure chamber; 6-Setting locking mechanism; 7-Well washing water injection control mechanism; 71-Well washing piston; 711-Separator block; 72-Combined transmission shaft for well washing and water injection; 73-Transmission actuator; 8-Water injection valve; 9-Main control circuit; 10-Lower connector. Detailed Implementation

[0018] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0019] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "left," and "right" generally refer to the upper, lower, left, and right as shown in the accompanying drawings; "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0020] Reference Figure 1 As shown, one aspect of the present invention provides an integrated water distributor, including a body 4 having a hollow channel 41 and a setting mechanism 5 slidably fitted onto the body 4. The hollow channel 41 extends substantially through the axial direction of the body 4 to convey water for injection into the water injection layer. The upper and lower ends of the body 4 may be provided with an upper connector 1 and a lower connector 10, respectively. The upper connector 1 can be connected to the bottom end of a tubing via a tubing threaded connection. Since the upper connector 1 and lower connector 10 primarily function to connect the body 4 to other components, they are considered as part of the body 4 in this invention. For example, although it will be described below as a well-washing inlet 31 formed on the body 4, it also includes the form shown in the figure, formed on the upper connector 1.

[0021] A setting pressure chamber 5a is defined between the setting mechanism 5 and the main body 4. The setting pressure chamber 5a is connected to the hollow channel 41 of the main body 4 so that when water is injected into the setting pressure chamber 5a through the hollow channel 41, the setting mechanism 5 can slide from the initial state and expand to the setting state under the action of water pressure, thereby sealing the water injection layer.

[0022] To facilitate water injection and well washing operations, the main body 4 is equipped with a well washing fluid channel 3, a water injection valve 8, and a well washing water injection control mechanism 7 for controlling the on / off state of the well washing fluid channel 3 and the opening / closing state of the water injection valve 8. When the water injection valve 8 is controlled to be in the open state, the hollow channel 41 of the main body 4 connects to the outer space of the main body 4, allowing water transported in the hollow channel 41 (such as from the tubing connected to the upper connector 1) to be injected into the water injection layer. When the well washing fluid channel 3 is controlled to be in the connected state, the outer space of the main body 4 located above the setting mechanism 5 connects to the outer space below the setting mechanism 5 of the main body 4 when it is in the setting state. Thus, water injected through the casing can flow through the well washing fluid channel 3 to the annular space below the setting mechanism 5, thereby realizing the well washing operation.

[0023] Therefore, this integrated water distributor, by integrating the setting mechanism 5, allows water to be injected into the setting pressure chamber 5a through the hollow channel 41 of the main body 4, causing the setting mechanism 5 to expand into a setting state. This integrates the sealing function of isolating the water injection layer and the water injection function of injecting water into the water injection layer into the same tool, thus eliminating the need for an additional cable packer connected through a tubing short section. This facilitates the subdivision of water injection into downhole water injection layers with small interlayer spacing, such as a minimum of 2 meters. Simultaneously, the well-washing and water injection control mechanism 7 controls the on / off state of the well-washing fluid channel 3 and the opening / closing state of the water injection valve 8, allowing switching between well-washing and water injection states to selectively execute the well-washing and water injection processes as needed. Since the well-washing and water injection processes are not performed simultaneously, the well-washing and water injection control mechanism 7 can be configured such that: when the well-washing fluid channel 3 is in the connected state, the water injection valve 8 is in the closed state to allow for well-washing operations; when the well-washing fluid channel 3 is in the disconnected state, the water injection valve 8 is in the open state to allow for water injection operations. It should be understood that, as will be described later, the water injection valve 8 may also remain in the initial open state before being lowered into the predetermined position inside the downhole casing; before the setting mechanism 5 sets, the setting operation is achieved by utilizing the water pressure injected into the setting pressure chamber 5a through the hollow channel 41 of the main body 4, therefore, the water injection valve 8 should be kept in the closed state during the setting process.

[0024] In the preferred embodiment illustrated, the well-washing fluid channel 3 has a well-washing fluid inlet hole 31 and a well-washing fluid outlet hole 32 formed axially at intervals on the main body 4. The well-washing fluid inlet hole 31 is located above the setting mechanism 5. More specifically, the well-washing fluid inlet hole 31 is formed on the upper connector 1. Thus, water injected into the casing can enter the well-washing fluid channel 3 within the main body 4 through the well-washing fluid inlet hole 31, and flow through the well-washing fluid channel 3 to the area below the setting mechanism 5 in the setting state, thereby passing over the setting mechanism 5 and transporting the well-washing fluid to the annular space below it, thus realizing the well-washing operation.

[0025] Since well washing operations need to be performed in a set-sealed state, the well washing fluid channel 3 can remain disconnected when the set-sealing mechanism 5 is not set. Therefore, the set-sealing mechanism 5 can initially close the well washing fluid outlet 32 ​​and open it in the set-sealed state, thus making the axial distance between the well washing fluid outlet 32 ​​and the well washing fluid inlet 31 relatively small, improving structural compactness.

[0026] In a preferred embodiment of the present invention, the well-washing and water-injection control mechanism 7 can control the on / off state of the well-washing fluid channel 3 and the opening / closing state of the water injection valve 8 through the same actuator. This allows for the avoidance of accidental opening of the well-washing fluid channel due to residual formation pressure during water injection, taking advantage of the fact that the well-washing and water injection processes do not occur simultaneously. Specifically, the well-washing and water-injection control mechanism 7 may include a combined well-washing and water-injection drive shaft 72 and a well-washing piston 71 extending into the well-washing fluid channel 3 and capable of being driven to slide relative to the main body 4. For this purpose, a working channel located below the well-washing fluid outlet 32 ​​can be formed within the main body 4, and the combined well-washing and water-injection drive shaft 72 and the well-washing piston 71 extend within this working channel. The water injection valve 8 can be connected to the combined well-washing and water-injection drive shaft 72, and when it moves with the combined well-washing and water-injection drive shaft 72 to the open state, allowing the hollow channel 41 to connect to the outer space of the main body 4, the well-washing piston 71 blocks the well-washing fluid channel 3. Thus, referring to… Figure 1 As shown, when the combined well-washing and water-injection drive shaft 72 and the well-washing piston 71 are driven to their downward stop position (before well filling), the well-washing piston 71 blocks the well-washing fluid channel 3, the water injection valve 8 is in the open state, and the hollow channel 41 connects to the outer space of the main body 4; when the combined well-washing and water-injection drive shaft 72 and the well-washing piston 71 are driven to their upward stop position, the well-washing fluid channel 3 switches to the connected state, while the water injection valve 8 is in the closed state, at which time the setting and sealing operation and the well-washing operation can be performed. During the water injection process, by controlling the movement position of the combined well-washing and water-injection drive shaft 72, the opening degree of the water injection valve 8 can be adjusted, thereby controlling the water injection volume. At this time, the well-washing piston 71 can maintain the isolation of the well-washing fluid channel 3.

[0027] To avoid interference between the water injection and well washing processes, in addition to rationally setting the relative positions of the combined well washing and water injection drive shaft 72, the well washing piston 71, the well washing fluid channel 3, and the water injection valve 8, a partition block 711 that slides in conjunction with the main body 4 (working channel) can be installed on the part of the well washing piston 71 located between the well washing fluid outlet 32 ​​and the water injection valve 8. This partition block 711 can prevent leakage to the well washing fluid channel 3 during water injection or leakage of well washing fluid to the water injection valve 8 during well washing. Furthermore, the partition block 711 can also guide the well washing piston 71 to move stably.

[0028] The combined well-washing and water-injection drive shaft 72 and the well-washing piston 71 can be driven axially by a suitable actuator, such as a relay. In the preferred embodiment illustrated, the well-washing and water-injection control mechanism 7 further includes a transmission actuator 73 for driving the combined well-washing and water-injection drive shaft 72, and a main control circuit 9 connected to the transmission actuator 73 is provided within the main body 4. A cable channel 2 may also be formed within the main body 4 to allow power lines and / or signal lines to pass through the cable channel 2 from the upper end of the main body 4 and be electrically connected to the main control circuit 9 and / or the transmission actuator 73. In the preferred embodiment illustrated, the cable channel 2 extends from the upper connector 1 to the lower connector 10 so that the control cable passes through its extension. In an alternative embodiment, control components, such as the main control circuit 9, can be located outside the main body 4, as long as they can drive the combined well-washing and water-injection drive shaft 72 and the well-washing piston 71 via the transmission actuator 73.

[0029] Continue to refer to Figure 1 As shown, the setting mechanism 5 may include a setting rubber tube 51, a setting sleeve 52 abutting against the lower end of the setting rubber tube 51, and a setting piston 53 disposed between the setting sleeve 52 and the main body 4 and axially abutting against the setting sleeve 52. The setting rubber tube 51 may be limited by the aforementioned connector 1. The water pressure in the setting pressure chamber 5a acts on the bottom surface of the setting piston 53, so that the setting rubber tube 51 can be expanded into a setting state by pushing the setting mechanism 5 upward. A setting locking mechanism 6 may also be provided between the setting sleeve 52 and the main body 4 to lock the setting mechanism 5 in the setting state.

[0030] Based on this, another aspect of the present invention provides a water injection well flushing system, which includes a casing, a tubing extending through the casing, and an integrated water distributor connected to the bottom end of the tubing, wherein the integrated water distributor is the integrated water distributor provided in the above aspect of the present invention.

[0031] To facilitate a better understanding of the technical solution and advantages of the present invention, the operation process is described in general below with reference to the preferred embodiments shown in the accompanying drawings:

[0032] Before being lowered into the well, the setting mechanism 5 is in an unset state. The well washing piston 71, the water injection valve 8, and the combined well washing and water injection drive shaft 72 are all located at the lower end. At this time, the well washing outlet 32 ​​is in the closed state, and the water injection valve 8 is in the open state.

[0033] After the tubing is connected to the top of the main body 4, it is lowered into the downhole casing to the predetermined position. The main control circuit 9 controls the transmission actuator 73, causing the well-washing piston 71, water injection valve 8, and the combined well-washing and water injection drive shaft 72 to move upwards to the upper end. At this time, the well-washing outlet 32 ​​is open, and the water injection valve 8 is closed. During setting, water is injected into the hollow channel 41 of the main body 4 through the tubing. The water pressure in the setting pressure chamber 5a pushes the setting piston 53, causing the setting sleeve 52 to move upwards, squeezing the setting rubber cylinder 51, causing it to expand outwards, thus completing the setting. The setting locking mechanism 6 has a backstop function, which locks the setting sleeve 52 in a position that keeps the setting rubber cylinder 51 in an expanded state.

[0034] During water injection, water is injected into the oil pipe via a water injection pump. The main control circuit 9 controls the transmission actuator 73 to move the combined well-washing and water injection transmission shaft 72 up and down, thereby changing the position of the water injection valve 8 to control the water injection volume. At this time, the well-washing piston 71 is always in the state of isolating the well-washing fluid passage 3.

[0035] During well washing, the main control circuit 9 controls the transmission actuator 73 to drive the combined well washing and water injection drive shaft 72 upward, first completely closing the water injection valve 8. The combined well washing and water injection drive shaft 72 continues to move upward until the well washing piston 71 is in the state of opening the well washing fluid channel 3. At this time, water is injected through the casing, and the water in the casing will enter from the well washing fluid inlet 31, pass over the setting mechanism 5, and reach the well washing fluid outlet 32, thus completing the well washing function.

[0036] The integrated water distributor provided by this invention seals the water injection layer through a set-sealing mechanism, thereby combining the functions of sealing and water injection into a single tool. This allows for the subdivision of downhole water injection layers with a minimum spacing of 2 meters. Considering that well washing and water injection processes are not performed simultaneously, an electrically controlled well washing piston and a shared transmission shaft for well washing and water injection are provided. Switching between the two working states can be completed through a single transmission actuator.

[0037] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An integrated water distributor, characterized in that, The system includes a main body (4) having a hollow channel (41) and a setting mechanism (5) slidably fitted onto the main body (4). The setting mechanism (5) and the main body (4) define a setting pressure chamber (5a) that communicates with the hollow channel (41). When water is injected into the setting pressure chamber (5a) through the hollow channel (41), the setting mechanism (5) can slide from its initial state and expand to a setting state under water pressure. The main body (4) is provided with a well-washing fluid channel (3), a water injection valve (8), and a well-washing water injection control mechanism (7) for controlling the on / off state of the well-washing fluid channel (3) and the opening / closing state of the water injection valve (8). When the water injection valve (8) is open, the hollow channel (41) communicates with the main body (4). The outer space of the body (4) is connected in the connected state, so that the outer spaces above and below the setting mechanism (5) in the set-sealing state of the body (4) are connected to each other. The well-washing water injection control mechanism (7) includes a well-washing water injection combined drive shaft (72) and a well-washing piston (71) that extends into the well-washing fluid channel (3) and can be driven to slide relative to the body (4) by the well-washing water injection combined drive shaft (72). The water injection valve (8) is connected to the well-washing water injection combined drive shaft (72), and when it moves with the well-washing water injection combined drive shaft (72) to the open state so that the hollow channel (41) is connected to the outer space of the body (4), the well-washing piston (71) blocks the well-washing fluid channel (3).

2. The integrated water distributor according to claim 1, characterized in that, The well-washing fluid channel (3) has a well-washing fluid inlet hole (31) and a well-washing fluid outlet hole (32) formed axially at intervals on the main body (4), and the well-washing fluid inlet hole (31) is located above the setting and sealing mechanism (5).

3. The integrated water distributor according to claim 2, characterized in that, The setting and sealing mechanism (5) closes the well washing outlet (32) in the initial state and opens the well washing outlet (32) in the setting and sealing state.

4. The integrated water distributor according to claim 2, characterized in that, The well-washing piston (71) is configured to have a partition block (711) that is always located between the well-washing outlet (32) and the water injection valve (8) and slides in cooperation with the body (4).

5. The integrated water distributor according to claim 1, characterized in that, The well-washing and water-injection control mechanism (7) also includes a transmission actuator (73) for driving the combined transmission shaft (72) of the well-washing and water-injection, and the main body (4) is provided with a main control circuit (9) that is connected to the transmission actuator (73).

6. The integrated water distributor according to claim 5, characterized in that, A cable channel (2) is formed within the main body (4) to allow power lines and / or signal lines to pass through the cable channel (2) from the upper end of the main body (4) and be electrically connected to the main control circuit (9) and / or the drive actuator (73).

7. The integrated water distributor according to claim 1, characterized in that, The setting mechanism (5) includes a setting rubber tube (51), a setting sleeve (52) abutting the lower end of the setting rubber tube (51), and a setting piston (53) disposed between the setting sleeve (52) and the main body (4) and axially abutting the setting sleeve (52). The water pressure in the setting pressure chamber (5a) acts on the bottom surface of the setting piston (53) so that the setting rubber tube (51) can be expanded into a setting state by pushing the setting mechanism (5) upward.

8. The integrated water distributor according to claim 7, characterized in that, A locking mechanism (6) for locking the locking mechanism (5) in the locking state is also provided between the locking sleeve (52) and the main body (4).

9. A water injection well flushing system, characterized in that, It includes a casing, a tubing extending through the casing, and an integrated water distributor according to any one of claims 1 to 8 connected to the bottom end of the tubing.

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