A hydraulically controlled downhole all-metal switch valve

Abstract

The present invention relates to a hydraulically controlled downhole all-metal on-off valve, comprising a valve body and a core tube sleeved within the valve body. An annular space is formed between the valve body and the core tube, and a drive mechanism, a transmission mechanism, an inward-facing ball head assembly, and an outward-facing ball head assembly are sequentially installed in the annular space from top to bottom. The core tube is provided with a first flow groove, and the valve body is provided with a second flow groove. The inward-facing ball head assembly moves up and down to connect or block the first flow groove and the flow channel, while the outward-facing ball head assembly moves up and down to connect or block the second flow groove and the flow channel. The hydraulically controlled downhole all-metal on-off valve enables ground-based control of the opening and closing of downhole production channels in the integrated process technology for thermal recovery and injection of heavy oil in offshore oil fields, thereby promoting the development of the integrated process technology for thermal recovery and injection of heavy oil in offshore oil fields.

Description

Technical Field

[0001] The invention relates to a liquid-controlled downhole all-metal on-off valve, belonging to the field of heavy oil thermal recovery. Background Art

[0002] In heavy oil thermal recovery, steam stimulation is the primary development model, which consists of steam injection, well shut-in, blowout, and production phases. Downhole temperatures reach their highest during the heat injection process, with wellhead steam temperatures reaching 350°C and injection pressures approaching 21 MPa. These demanding downhole conditions place extremely high demands on downhole tools and contribute to relatively high production costs. To further increase production, reduce costs, and improve efficiency, offshore oilfields have developed an integrated injection-production process for heavy oil thermal recovery (using electric submersible pumps).

[0003] Implementing the integrated injection-production process for heavy oil thermal recovery (electric submersible pumps) requires surface-controlled switching of downhole tubing strings. During the initial heat injection period, the downhole production channel is closed to ensure normal injection of 350°C steam. The channel is then opened during the subsequent production period, allowing fluids in the formation to reach the pump's suction port under formation pressure. Conventional development typically uses sliding sleeves to control the opening and closing of the production channel. However, due to the high downhole temperatures in heavy oil thermal recovery wells, existing sliding sleeves cannot withstand the 350°C operating temperature requirement and are therefore unsuitable for use in production tubing systems used in heavy oil thermal recovery. This poses a significant challenge to implementing the integrated injection-production process for heavy oil thermal recovery (electric submersible pumps). Summary of the Invention

[0004] In response to the above problems, the purpose of the present invention is to provide a hydraulically controlled downhole all-metal switching valve to realize the control of the switching of the downhole production channel in the integrated process technology of thermal recovery and injection of heavy oil in offshore oil fields from the ground, thereby promoting the development of the integrated process technology of thermal recovery and injection of heavy oil in offshore oil fields.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a hydraulically controlled downhole all-metal on-off valve, comprising a valve body and a core tube sleeved in the valve body, an annular space being formed between the valve body and the core tube, and a driving mechanism, a transmission mechanism, an inward ball head assembly, and an outward ball head assembly being sequentially installed in the annular space from top to bottom;

[0007] The core tube is provided with a first flow groove, and the valve body is provided with a second flow groove;

[0008] A flow valve body is provided between the inward ball head assembly and the outward ball head assembly, and a flow channel is formed in the flow valve body, and the flow channel is used to connect the first flow groove and the second flow groove;

[0009] The bottom end of the driving mechanism is fixedly connected to the inward ball head assembly through the transmission mechanism, and pushes the inward ball head assembly to move up and down;

[0010] The inward ball head assembly moves up and down to connect or block the first flow groove and the flow channel, and the outward ball head assembly moves up and down to connect or block the second flow groove and the flow channel;

[0011] In the initial state, the first flow groove and the flow channel are connected, the fluid enters the flow channel from the core tube through the first flow groove, and pushes the outward ball head assembly downward, so that the flow channel and the second flow groove are connected, and the fluid flows out from the second flow groove.

[0012] Furthermore, the top and bottom ends of the overflow valve body are both formed with sealing surfaces, the bottom surface of the inward-facing ball head assembly is shaped to match the sealing surface of the top end of the overflow valve body, and the top surface of the outward-facing ball head assembly is shaped to match the sealing surface of the bottom end of the overflow valve body;

[0013] When the bottom surface of the inward ball head assembly abuts against the sealing surface at the top of the overflow valve body, the overflow channel is disconnected from the first overflow groove; when the bottom surface of the inward ball head assembly is separated from the sealing surface at the top of the overflow valve body, the first overflow groove and the overflow channel are connected.

[0014] Furthermore, the main body includes a buckle, an upper joint, an upper cylinder, the flow valve body, a lower cylinder, a connector and a lower joint, which are connected in sequence from top to bottom;

[0015] The driving mechanism and the inward ball head assembly are arranged in the annular space formed by the upper cylinder and the core tube;

[0016] The top and bottom ends of the outer diameter of the overflow valve body are fixedly connected to the upper cylinder and the lower cylinder respectively, and the inner diameter of the overflow valve body is in sealing contact with the core tube;

[0017] A hydraulic channel is provided in the upper joint, which is in communication with the drive mechanism. A control pressure is input into the drive mechanism through the hydraulic channel. Under the action of the control pressure, the drive mechanism drives the transmission mechanism and the inward ball head assembly to move up and down.

[0018] The second flow groove is arranged on the lower cylinder, and the outward ball head assembly is arranged in the annular space formed by the lower cylinder and the core tube.

[0019] Furthermore, the driving mechanism includes a hydraulic component, an upper pressure ring and a lower pressure ring, and the top and bottom ends of the hydraulic component are fixedly installed between the upper cylinder and the core tube through the upper pressure ring and the lower pressure ring respectively.

[0020] Furthermore, the hydraulic assembly includes a sealing joint, a pressure-bearing cylinder, a core shaft, a welding head and an elastic component. A control pipeline interface is provided at the top of the sealing joint. The control pipeline interface is connected to the hydraulic channel inside the upper joint through a control pipeline. The bottom end of the control pipeline interface is sealed and fixedly connected to the pressure-bearing cylinder. The bottom end of the pressure-bearing cylinder is sealed and fixedly connected to the welding head. The core shaft passes through the sealing joint, the pressure-bearing cylinder and the welding head in sequence. The bottom end of the core shaft extends from the welding head. The elastic component is sleeved on the outside of the core shaft. Under the action of the control pressure, the core shaft compresses the elastic component downward.

[0021] Furthermore, the transmission mechanism includes a transmission push ring and a transmission core tube, the transmission push ring is fixedly connected to the bottom end of the core shaft, the top end of the transmission core tube is fixedly connected to the transmission push ring, the first flow groove is arranged on the transmission core tube, the core tube includes a fixed core tube and the transmission core tube, the driving mechanism is located in the annular space formed between the fixed core tube and the upper cylinder, and the transmission mechanism, the inward ball head assembly and the outward ball head assembly are located in the annular space between the transmission core tube and the valve body.

[0022] Furthermore, the inward ball head assembly is sleeved on the top of the transmission core tube, and the inward ball head assembly includes an inward spring seat, an inward guide screw, an inward pre-tightening spring and an inward ball head. The inward spring seat is annular, and the inward guide screw includes a plurality of them. The plurality of inward guide screws are arranged in an array along the circumferential direction on the inward spring seat, and each of the inward guide screws is fixedly sleeved with an inward pre-tightening spring. A guide groove is provided on the inward ball head at a position opposite to the inward guide screw. The inward guide screw is inserted in the corresponding guide groove and slides along the guide groove under the action of external force. When the inward ball head assembly moves downward and abuts against the top surface of the excess flow valve body, the first excess flow groove and the excess flow channel are disconnected. When the inward ball head assembly moves upward and separates from the top surface of the excess flow valve body, the first excess flow groove and the excess flow channel are connected.

[0023] Furthermore, the outward-pointing ball head assembly is arranged in the annular space formed by the lower cylinder and the connector, and the outward-pointing ball head assembly includes an outward-pointing ball head, an outward-pointing guide screw, an outward-pointing pre-tightening spring and an outward-pointing spring seat. The top surface of the outward-pointing ball head is formed with an inward-concave arc surface that cooperates with the bottom sealing surface of the excess flow valve body. The outward-pointing guide screw is fixed on the outward-pointing spring seat, and the outward-pointing pre-tightening spring is sleeved on the outward-pointing guide screw. The bottom and top ends of the outward-pointing pre-tightening spring are respectively fixed on the outward-pointing spring seat and the outward-pointing ball head. The bottom of the outward-pointing ball head is provided with a guide groove that cooperates with the outward-pointing guide screw. In the initial state, the outward-pointing pre-tightening spring is in a compressed state, the outward-pointing ball head abuts against the bottom end of the excess flow channel, and the second excess flow groove and the excess flow channel are disconnected.

[0024] Furthermore, the interior of the lower joint is hollow, and the hydraulically controlled downhole all-metal switch valve also includes a power buffer assembly, which is fixedly installed in the lower joint. The top of the power buffer assembly is connected to the transmission core tube to buffer the force of the downward movement of the inward ball head assembly.

[0025] Furthermore, the power buffer assembly includes a power spring core tube, a power spring bracket, a first power spring push ring, a second power spring push ring, a first power spring, a second power spring, a power spring seat, a plurality of power spring guide rods, a first open retaining ring and a second open retaining ring. The power spring core tube, the transmission core tube and the fixed core tube are configured to form the core tube together. The bottom ends of the plurality of power spring guide rods are fixed on the power spring seat in an array along the circumferential direction. The top nuts of the power spring guide rods are fixed. The power spring bracket is sleeved outside the plurality of power spring guide rods. The first power spring is fixedly sleeved on the power spring guide rod and is located in the power spring bracket. The bottom end of the first power spring abuts against the bottom end of the power spring bracket. The top end of the power spring is connected to the first power spring push ring, the second power spring is fixedly sleeved on the power spring guide rod and is located outside the power spring bracket, the bottom end of the second power spring is abutted against the top end of the power spring bracket, the top end of the second power spring is connected to the second power spring push ring, the power spring core tube is fixedly sleeved in the power spring bracket, the first open retaining ring and the second open retaining ring are installed on the power spring core tube at intervals, the first power spring push ring and the second power spring push ring are respectively provided with grooves abutting against the first open retaining ring and the second open retaining ring, when the power spring core tube moves downward, the first open retaining ring and the second open retaining ring are driven downward to compress the first power spring and the second power spring.

[0026] Furthermore, the sealing surface is an arc surface.

[0027] Furthermore, the elastic component is a bellows.

[0028] Furthermore, the bellows include a plurality of bellows, and the plurality of bellows are sealed and connected in sequence through spacer rings.

[0029] The present invention has the following advantages due to the adoption of the above technical solution:

[0030] The hydraulically controlled downhole all-metal on-off valve of the present invention has all its components made of metal materials, which solves the problem that the sealing components in the prior art cannot meet the requirements of heavy oil thermal recovery technology due to insufficient temperature resistance.

[0031] The normally open design not only meets the required functions of the string, but also takes into account the technical considerations for the emergency response plan of the tool in case of loss of control.

[0032] It is possible to control the opening and closing of the downhole production channel in the integrated process technology of thermal recovery and injection of heavy oil in offshore oil fields from the ground, and promote the development of the integrated process technology of thermal recovery and injection of heavy oil in offshore oil fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. Throughout the drawings, the same reference numerals are used to denote the same components. In the drawings:

[0034] Figure 1 This is a schematic diagram of the overall structure of the hydraulically controlled downhole all-metal switch valve of the present invention in an open state;

[0035] Figure 2 This is a schematic diagram of the overall structure of the hydraulically controlled downhole all-metal switch valve of the present invention in a closed state;

[0036] Figure 3 Schematic diagram of the structure of the upper joint of the present invention;

[0037] Figure 4 This is a schematic diagram of the hydraulic assembly structure of the present invention;

[0038] Figure 5 Schematic diagram of the inward ball head assembly structure;

[0039] Figure 6 for Figure 5 sectional view of;

[0040] Figure 7 Schematic diagram of the outward ball head assembly structure;

[0041] Figure 8 for Figure 7 sectional view of;

[0042] Figure 9 Schematic diagram of the power spring assembly structure;

[0043] Figure 10 for Figure 9 sectional view of . DETAILED DESCRIPTION

[0044] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0045] An embodiment of the present invention provides a hydraulically controlled downhole all-metal on-off valve, comprising a valve body and a core tube sleeved in the valve body, an annular space being formed between the valve body and the core tube, and a driving mechanism, a transmission mechanism, an inward ball head assembly and an outward ball head assembly being sequentially installed in the annular space from top to bottom; a first flow groove is provided on the core tube, and a second flow groove is provided on the valve body; a flow valve body is provided between the inward ball head assembly and the outward ball head assembly, and a flow channel is formed in the flow valve body, and the flow channel is used to connect the first flow groove and the second flow groove; the driving mechanism The bottom end is fixedly connected to the inward ball head assembly through the transmission mechanism, and pushes the inward ball head assembly to move up and down; the inward ball head assembly moves up and down to connect or block the first flow groove and the flow channel, and the outward ball head assembly moves up and down to connect or block the second flow groove and the flow channel; in the initial state, the first flow groove and the flow channel are connected, and the fluid enters the flow channel from the core tube through the first flow groove, and pushes the outward ball head assembly downward to connect the flow channel and the second flow groove, and the fluid flows out from the second flow groove.

[0046] The hydraulically controlled downhole all-metal on-off valve, whose components are all made of metal materials, solves the problem that the original technology cannot meet the technical requirements of heavy oil thermal recovery due to the insufficient temperature resistance of the seals. The normally open design not only meets the required functions of the tubing string, but also takes technical considerations in advance for the emergency response plan for the tool's loss of control. It realizes the control of the opening and closing of the downhole production channel in the integrated process technology of heavy oil thermal recovery and injection production in offshore oil fields from the ground, promoting the development of the integrated process technology of heavy oil thermal recovery and injection production in offshore oil fields.

[0047] Example 1

[0048] like Figure 1 and Figure 2As shown, the hydraulically controlled downhole all-metal switch valve comprises a valve body and a core tube sleeved in the valve body, an annular space is formed between the valve body and the core tube, and a driving mechanism, a transmission mechanism, an inward ball head assembly and an outward ball head assembly are sequentially installed in the annular space from top to bottom; a first flow groove is provided on the core tube, and a second flow groove is provided on the valve body; a flow valve body 1-4 is provided between the inward ball head assembly and the outward ball head assembly, and a flow channel is formed in the flow valve body 1-4, and the flow channel is used to connect the first flow groove and the second flow groove; the driving mechanism The bottom end is fixedly connected to the inward ball head assembly through the transmission mechanism, and pushes the inward ball head assembly to move up and down; the inward ball head assembly moves up and down to connect or block the first flow groove and the flow channel, and the outward ball head assembly moves up and down to connect or block the second flow groove and the flow channel; in the initial state, the first flow groove and the flow channel are connected, and the fluid enters the flow channel from the core tube through the first flow groove, and pushes the outward ball head assembly downward to connect the flow channel and the second flow groove, and the fluid flows out from the second flow groove.

[0049] During a pressure loss event, the inward valve ball assembly separates from the overflow valve body, while the outward valve ball assembly seals with the overflow valve body. Fluid can now flow upward from the system, sequentially through the first overflow groove on the core tube and the overflow channel on the overflow valve body, pushing the outward ball assembly downward and then flowing outward through the second overflow groove in the valve body. In this state, the production channel is open, allowing for lifting operations.

[0050] During pressure injection, control pressure is input through the hydraulic control line connected to the upper connector, causing the drive mechanism to push the transmission mechanism downward. This mechanism then drives the inward-facing ball assembly downward until it seals with the flow-through valve body. This closes the inward-to-outward flow channel. In this state, the fluid production channel is closed, allowing heat injection operations to proceed.

[0051] The hydraulically controlled downhole all-metal on-off valve, whose components are all made of metal materials, solves the problem that the original technology cannot meet the technical requirements of heavy oil thermal recovery due to the insufficient temperature resistance of the seals. The inward ball head assembly adopts a normally open design. While meeting the required functions of the tubing string, it also takes technical considerations in advance for the emergency response plan for the tool's loss of control. It realizes the control of the opening and closing of the downhole production channel in the integrated process technology of heavy oil thermal recovery and injection in offshore oil fields from the ground, promoting the development of the integrated process technology of heavy oil thermal recovery and injection in offshore oil fields.

[0052] The top and bottom ends of the overflow valve body 1-4 are both formed with sealing surfaces. The bottom surface of the inward-facing ball head assembly is shaped to match the sealing surface at the top of the overflow valve body 1-4, and the top surface of the outward-facing ball head assembly is shaped to match the sealing surface at the bottom of the overflow valve body 1-4. When the bottom surface of the inward-facing ball head assembly abuts the sealing surface at the top of the overflow valve body 1-4, the overflow channel is disconnected from the first overflow groove. When the bottom surface of the inward-facing ball head assembly is separated from the sealing surface at the top of the overflow valve body 1-4, the first overflow groove and the overflow channel are connected. The sealing surfaces are arc-shaped surfaces.

[0053] The main body includes a variable buckle 1-1, an upper joint 1-2, an upper cylinder 1-3, the overflow valve body 1-4, a lower cylinder 1-5, a connecting body 1-6 and a lower joint 1-7 which are connected in sequence from top to bottom; the driving mechanism and the inward ball head assembly are arranged in the annular space formed by the upper cylinder 1-3 and the core tube; the top and bottom ends of the outer diameter of the overflow valve body 1-4 are fixedly connected to the upper cylinder 1-3 and the lower cylinder 1-5 respectively, and the inner diameter of the overflow valve body 1-4 is in sealing contact with the core tube; a hydraulic channel connected to the driving mechanism is provided in the upper joint 1-2, and a control pressure is input into the driving mechanism through the hydraulic channel. Under the action of the control pressure, the driving mechanism drives the transmission mechanism and the inward ball head assembly to move up and down; the second overflow groove is arranged on the lower cylinder 1-5, and the outward ball head assembly is arranged in the annular space formed by the lower cylinder 1-5 and the core tube.

[0054] The driving mechanism includes a hydraulic component 2-3, an upper pressure ring 2-2 and a lower pressure ring 2-4. The top and bottom ends of the hydraulic component 2-3 are fixedly installed between the upper cylinder 1-3 and the core tube through the upper pressure ring 2-2 and the lower pressure ring 2-4 respectively. The hydraulic assembly 2-3 includes a sealing joint 2-3-1, a pressure-bearing cylinder 2-3-2, a core shaft 2-3-5, a welding head 2-3-6 and an elastic component 2-3-3. A control pipeline interface is provided at the top of the sealing joint 2-3-1. The control pipeline interface is connected to the internal hydraulic channel of the upper joint 1-2 through a control pipeline. The bottom end of the control pipeline interface is sealed and fixedly connected to the pressure-bearing cylinder 2-3-2. The bottom end of the pressure-bearing cylinder 2-3-2 is sealed and fixedly connected to the welding head 2-3-6. The core shaft passes through the sealing joint 2-3-1, the pressure-bearing cylinder 2-3-2 and the welding head 2-3-6 in sequence. The bottom end of the core shaft extends from the welding head 2-3-6. The elastic component is sleeved on the outside of the core shaft 2-3-5. Under the action of the control pressure, the core shaft 2-3-5 compresses the elastic component 2-3-3 downward.

[0055] The elastic component 2-3-3 is a bellows, which includes multiple bellows, which are sequentially connected by spacer ring seals 2-3-4.

[0056] The transmission mechanism includes a transmission push ring 3-1 and a transmission core tube 3-2, the transmission push ring 3-1 is fixedly connected to the bottom end of the core shaft 2-3-5, the top of the transmission core tube 3-2 is fixedly connected to the transmission push ring 3-1, the first flow groove is arranged on the transmission core tube 3-2, the core tube includes a fixed core tube and the transmission core tube 3-2, the driving mechanism is located in the annular space formed between the fixed core tube and the upper cylinder 1-3, the transmission mechanism, the inward ball head assembly and the outward ball head assembly are located in the annular space between the transmission core tube 3-2 and the valve body.

[0057] The inward ball head assembly is sleeved on the top of the transmission core tube 3-2, and the inward ball head assembly includes an inward spring seat 4-1, an inward guide screw 4-2, an inward preload spring 4-3 and an inward ball head 4-4. The inward spring seat 4-1 is annular, and the inward guide screw 4-2 includes multiple inward guide screws 4-2. Multiple inward guide screws 4-2 are installed on the inward spring seat 4-1 in an array along the circumferential direction, and each inward guide screw 4-2 is fixedly sleeved with an inward preload spring 4-3, a guide groove is provided on the inward ball head 4-4 at a position opposite to the inward guide screw 4-2, and the inward guide screw 4-2 is inserted in the corresponding guide groove and slides along the guide groove under the action of external force. When the inward ball head assembly moves downward and abuts against the top surface of the excess flow valve body 1-4, the first excess flow groove and the excess flow channel are disconnected, and when the inward ball head assembly moves upward and separates from the top surface of the excess flow valve body 1-4, the first excess flow groove and the excess flow channel are connected.

[0058] The outward ball head assembly is arranged in the annular space formed by the lower cylinder 1-5 and the connector 1-6, and the outward ball head assembly includes an outward ball head 5-1, an outward guide screw 5-2, an outward preload spring 5-3 and an outward spring seat 5-4. The top surface of the outward ball head 5-1 is formed with an inward concave arc surface that matches the bottom sealing surface of the overflow valve body 1-4. The outward guide screw 5-2 is fixed on the outward spring seat 5-4. The outward preload spring The spring 5-3 is sleeved on the outward guide screw 5-2, and the bottom end and top end of the outward pre-tightening spring 5-3 are respectively fixed on the outward spring seat 5-4 and the outward ball head 5-1. The bottom of the outward ball head 5-1 is provided with a guide groove that cooperates with the outward guide screw 5-2. In the initial state, the outward pre-tightening spring 5-3 is in a compressed state, the outward ball head 5-1 is in contact with the bottom end of the flow channel, and the second flow groove and the flow channel are disconnected.

[0059] The lower end of the flow channel is provided with a spherical surface that seals with the outward-facing ball head 5-1, and the lower end of its inner diameter is provided with a sealing surface that seals with the upper end of the inner diameter of the connector 1-6. The lower section cylinder 1-5 is hollow inside and has a second flow channel in the middle. The connector is hollow inside, with the upper and lower ends of its outer diameter fixedly and sealedly connected to the flow valve body 1-4, the cylinder 1-5, and the lower joint 1-7, respectively. The upper portion of its inner diameter extends upward and seals with the lower end of the inner diameter of the flow valve body 1-4. The outward-facing ball head assembly is located in the annular space formed by the lower section cylinder 1-5 and the connector 1-6.

[0060] The lower joint 1-7 is hollow inside, and the hydraulically controlled downhole all-metal switch valve also includes a power buffer assembly, which is fixedly installed in the lower joint 1-7. The top of the power buffer assembly is connected to the transmission core tube 3-2 to buffer the force of the downward movement of the inward ball head assembly.

[0061] The power buffer assembly includes a power spring seat 6-1, a power spring core tube 6-4, a power spring bracket 6-2, a first power spring push ring 6-6, a second power spring push ring 6-7, a first power spring 6-5, a second power spring 6-10, a plurality of power spring guide rods 6-9, a first open baffle ring 6-8 and a second open baffle ring 6-3. The power spring core tube 6-4, the transmission core tube 3-2 and the fixed core tube are configured to form the core tube together. The bottom ends of the plurality of power spring guide rods 6-9 are fixed on the power spring seat 6-1 in an array along the circumferential direction. The top nut of the power spring guide rod 6-9 is fixed. The power spring bracket 6-2 is sleeved on the outside of the plurality of power spring guide rods 6-9. The first power spring 6-5 is fixedly sleeved on the power spring guide rod 6-9 and is located in the power spring bracket 6-2. The bottom end of the first power spring 6-5 abuts against the bottom end of the power spring bracket 6-2. The top of 6-5 is connected with the first power spring push ring 6-6, the second power spring 6-10 is fixedly sleeved on the power spring guide rod 6-9 and is located outside the power spring bracket 6-2, the bottom end of the second power spring 6-5 is abutted with the top of the power spring bracket 6-2, the top of the second power spring 6-5 is connected with the second power spring push ring 6-7, the power spring core tube 6-4 is fixedly sleeved in the power spring bracket 6-2, the first open baffle ring 6-8 and the second open baffle ring 6-3 are installed on the power spring core tube 6-4 at intervals, the first power spring push ring 6-6 and the second power spring push ring 6-7 are respectively provided with grooves abutting with the first open baffle ring 6-8 and the second open baffle ring 6-3, when the power spring core tube 6-4 moves downward, it drives the first open baffle ring 6-8 and the second open baffle ring 6-3 to compress the first power spring 6-5 and the second power spring 6-10 downward.

[0062] The specific actions of the hydraulically controlled downhole all-metal switch valve when in use are as follows:

[0063] During a decompression event, all components within the system are in their default positions under the action of the power spring assembly. The hydraulic assembly is in a contracted state, the inward valve ball assembly is separated from the overflow valve body in a normally open state, the outward valve ball assembly is in a sealed engagement with the overflow valve body 1-4, and the power spring assembly is in a pre-compressed state. At this point, fluid can flow upward from the system, sequentially through the first flow groove of the transmission core tube 3-2 and the flow passage of the overflow valve body 1-4, pushing downward on the ball head of the outward ball head assembly, and then flowing outward through the second flow groove of the lower cylinder. In this state, the liquid production channel is open, allowing lifting operations.

[0064] During pressure injection, control pressure is input through the hydraulic control line connected to the upper connector 1-2. This pressure is transmitted to the hydraulic assembly via the tee structure within the upper connector 1-2. Under this pressure, the hydraulic assembly extends the core shaft downward. Simultaneously, the core shaft 2-3-5 pushes the transmission push ring 3-1 and the transmission core tube 3-2 downward. The transmission core tube 3-2 drives the inward-facing ball head assembly downward and compresses the power spring assembly until the inward-facing ball head seals with the overflow valve body 1-4. At this point, the fluid flow path from inside to outside is closed. In this state, the liquid production channel is closed, allowing heat injection operations to proceed.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A hydraulically controlled downhole all-metal switch valve, characterized in that: It comprises a valve body and a core tube sleeved in the valve body, an annular space is formed between the valve body and the core tube, and a driving mechanism, a transmission mechanism, an inward ball head assembly and an outward ball head assembly are sequentially installed in the annular space from top to bottom; The core tube is provided with a first flow groove, and the valve body is provided with a second flow groove; A flow valve body is provided between the inward ball head assembly and the outward ball head assembly, and a flow channel is formed in the flow valve body, and the flow channel is used to connect the first flow groove and the second flow groove; The bottom end of the driving mechanism is fixedly connected to the inward ball head assembly through the transmission mechanism, and pushes the inward ball head assembly to move up and down; The inward ball head assembly moves up and down to connect or block the first flow groove and the flow channel, and the outward ball head assembly moves up and down to connect or block the second flow groove and the flow channel; In an initial state, the first flow groove and the flow channel are connected, and the fluid enters the flow channel from the core tube through the first flow groove and pushes the outward ball head assembly downward, so that the flow channel is connected to the second flow groove, and the fluid flows out from the second flow groove; The transmission mechanism includes a transmission push ring and a transmission core tube, the inward ball head assembly is sleeved on the top of the transmission core tube, the inward ball head assembly includes an inward spring seat, an inward guide screw, an inward pre-tightening spring and an inward ball head, the inward spring seat is annular, the inward guide screw includes a plurality of, and the plurality of inward guide screws are arranged in an array along the circumferential direction on the inward spring seat, each of the inward guide screws is fixedly sleeved with an inward pre-tightening spring, a guide groove is provided on the inward ball head at a position opposite to the inward guide screw, the inward guide screw is inserted in the corresponding guide groove and slides along the guide groove under the action of external force, when the inward ball head assembly moves downward and abuts against the top surface of the excess flow valve body, the first excess flow groove and the excess flow channel are disconnected, when the inward ball head assembly moves upward and separates from the top surface of the excess flow valve body, the first excess flow groove and the excess flow channel are connected.

2. The hydraulically controlled downhole all-metal switch valve according to claim 1, characterized in that: The top and bottom ends of the overflow valve body are both formed with sealing surfaces, the bottom surface of the inward-facing ball head assembly is matched with the sealing surface of the top end of the overflow valve body, and the top surface of the outward-facing ball head assembly is matched with the sealing surface of the bottom end of the overflow valve body; When the bottom surface of the inward ball head assembly abuts against the sealing surface at the top of the overflow valve body, the overflow channel is disconnected from the first overflow groove; when the bottom surface of the inward ball head assembly is separated from the sealing surface at the top of the overflow valve body, the first overflow groove and the overflow channel are connected.

3. The hydraulically controlled downhole all-metal switch valve according to claim 1, characterized in that: The valve body includes a buckle, an upper joint, an upper cylinder, the overflow valve body, a lower cylinder, a connector and a lower joint, which are connected in sequence from top to bottom; The driving mechanism and the inward ball head assembly are arranged in the annular space formed by the upper cylinder and the core tube; The top and bottom ends of the outer diameter of the overflow valve body are fixedly connected to the upper cylinder and the lower cylinder respectively, and the inner diameter of the overflow valve body is in sealing contact with the core tube; A hydraulic channel is provided in the upper joint, which is in communication with the drive mechanism. A control pressure is input into the drive mechanism through the hydraulic channel. Under the action of the control pressure, the drive mechanism drives the transmission mechanism and the inward ball head assembly to move up and down. The second flow groove is arranged on the lower cylinder, and the outward ball head assembly is arranged in the annular space formed by the lower cylinder and the core tube.

4. The hydraulically controlled downhole all-metal switch valve according to claim 3, characterized in that: The driving mechanism includes a hydraulic assembly, an upper pressure ring and a lower pressure ring. The top end and the bottom end of the hydraulic assembly are fixedly installed between the upper cylinder and the core tube through the upper pressure ring and the lower pressure ring respectively.

5. The hydraulically controlled downhole all-metal switch valve according to claim 4, characterized in that: The hydraulic assembly includes a sealing joint, a pressure-bearing cylinder, a core shaft, a welding head and an elastic component. A control pipeline interface is provided at the top of the sealing joint. The control pipeline interface is connected to the hydraulic channel inside the upper joint through a control pipeline. The bottom end of the control pipeline interface is sealed and fixedly connected to the pressure-bearing cylinder. The bottom end of the pressure-bearing cylinder is sealed and fixedly connected to the welding head. The core shaft passes through the sealing joint, the pressure-bearing cylinder and the welding head in sequence. The bottom end of the core shaft extends from the welding head. The elastic component is sleeved on the outside of the core shaft. Under the action of the control pressure, the core shaft compresses the elastic component downward.

6. The hydraulically controlled downhole all-metal switch valve according to claim 5, characterized in that: The transmission push ring is fixedly connected to the bottom end of the core shaft, the top end of the transmission core tube is fixedly connected to the transmission push ring, the first flow groove is arranged on the transmission core tube, the core tube includes a fixed core tube and the transmission core tube, the driving mechanism is located in the annular space formed between the fixed core tube and the upper cylinder, and the transmission mechanism, the inward ball head assembly and the outward ball head assembly are located in the annular space between the transmission core tube and the valve body.

7. The hydraulically controlled downhole all-metal switch valve according to claim 6, characterized in that: The outward-pointing ball head assembly is arranged in the annular space formed by the lower cylinder and the connecting body, and the outward-pointing ball head assembly includes an outward-pointing ball head, an outward-pointing guide screw, an outward-pointing pre-tightening spring and an outward-pointing spring seat. The top surface of the outward-pointing ball head is formed with an inward-concave arc surface that matches the bottom sealing surface of the excess flow valve body. The outward-pointing guide screw is fixed on the outward-pointing spring seat, and the outward-pointing pre-tightening spring is sleeved on the outward-pointing guide screw. The bottom and top ends of the outward-pointing pre-tightening spring are respectively fixed on the outward-pointing spring seat and the outward-pointing ball head. The bottom of the outward-pointing ball head is provided with a guide groove that matches the outward-pointing guide screw. In the initial state, the outward-pointing pre-tightening spring is in a compressed state, the outward-pointing ball head abuts against the bottom end of the excess flow channel, and the second excess flow groove and the excess flow channel are disconnected.

8. The hydraulically controlled downhole all-metal switch valve according to claim 6, characterized in that: The lower joint is hollow inside, and the hydraulically controlled downhole all-metal switch valve also includes a power buffer assembly, which is fixedly installed in the lower joint. The top of the power buffer assembly is connected to the transmission core tube to buffer the force of the downward movement of the inward ball head assembly.

9. The hydraulically controlled downhole all-metal switch valve according to claim 8, characterized in that: The power buffer assembly includes a power spring core tube, a power spring bracket, a first power spring push ring, a second power spring push ring, a first power spring, a second power spring, a power spring seat, a plurality of power spring guide rods, a first open retaining ring and a second open retaining ring. The power spring core tube, the transmission core tube and the fixed core tube are configured to form the core tube together. The bottom ends of the plurality of power spring guide rods are fixed on the power spring seat in an array along the circumferential direction. The top nut of the power spring guide rod is fixed. The power spring bracket is sleeved outside the plurality of power spring guide rods. The first power spring is fixedly sleeved on the power spring guide rod and is located in the power spring bracket. The bottom end of the first power spring abuts against the bottom end of the power spring bracket. The first power The top end of the spring is connected to the first power spring push ring, the second power spring is fixedly sleeved on the power spring guide rod and is located outside the power spring bracket, the bottom end of the second power spring is abutted against the top end of the power spring bracket, the top end of the second power spring is connected to the second power spring push ring, the power spring core tube is fixedly sleeved in the power spring bracket, the first open baffle ring and the second open baffle ring are installed on the power spring core tube at intervals, the first power spring push ring and the second power spring push ring are respectively provided with grooves abutting against the first open baffle ring and the second open baffle ring, when the power spring core tube moves downward, the first open baffle ring and the second open baffle ring are driven downward to compress the first power spring and the second power spring.

10. The hydraulically controlled downhole all-metal switch valve according to claim 2, characterized in that: The sealing surface is an arc surface.

11. The hydraulically controlled downhole all-metal switch valve according to claim 5, characterized in that: The elastic component is a bellows.

12. The hydraulically controlled downhole all-metal switch valve according to claim 11, characterized in that: The bellows include a plurality of bellows, which are sealed and connected in sequence via spacer rings.

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