Downhole target layer selection device, system and method suitable for single hydraulic control pipeline

Abstract

The present invention relates to a downhole target layer selection device, system and method suitable for a single hydraulic control pipeline, wherein the device comprises a valve body, a piston assembly, a sealing cone and a fixing pin. An oil inlet is provided at one end of the valve body and an oil outlet is provided at the other end, and a cavity is formed in the valve body. The piston assembly comprises a piston, a piston rod, a spring and a sealing ball, and the piston slides in the cavity, and a groove is formed on the outer surface of the piston. The sealing cone is fixed in the cavity, and a sealing contact is formed between the conical surface and the spherical surface of the sealing ball. An oil passage is formed on the side wall of the valve body, and the oil passage connects the first oil inlet cavity and the second oil inlet cavity, and the oil outlet is connected to the oil outlet cavity. The fixing pin is fixed on the valve body, and the fixing pin is inserted into the groove. The piston slides and rotates along the cavity under the action of the hydraulic pressure and the guidance of the fixing pin.

Description

Technical Field

[0001] The present invention relates to a downhole target layer selection device, system and method applicable to a single hydraulic control pipeline, belonging to the technical field of oil and gas drilling and completion and oil and gas production. Background Art

[0002] Smart wells are intelligent management technologies that monitor and transmit downhole pressure, temperature, and flow. Downhole flow control valves are key control devices for controlling the flow into each producing layer in smart wells. By using flow control valves, each producing layer can be independently closed, opened, or throttled, enabling real-time reservoir control and optimized production, controlling water coning and gas intrusion, accelerating production, and improving oil and gas recovery.

[0003] Existing intelligent completion technologies employ direct hydraulically driven flow control. These lack decoding capabilities, requiring independent selection of flow control valves for N downhole layers, requiring N+1 hydraulic control lines. As the number of downhole layers increases, the number of hydraulic control lines increases, making wellhead crossing difficult. Excessive downhole lines also poses operational risks. Other approaches employ electronic control to determine downhole layer positions. While simple and feasible, these methods significantly reduce the durability of electronic components in the harsh, high-temperature, high-pressure environment downhole. Summary of the Invention

[0004] In response to the above problems, the purpose of the present invention is to provide a downhole target layer selection device, system and method suitable for a single hydraulic control pipeline. The device, system and method are suitable for the target layer selection of flow control valves in different layers downhole of a single hydraulic control pipeline. The selection of target layers in different layers downhole is achieved through the different groove forms on the outer surface of the piston in each layer hydraulic control system and a variety of different pressure forms. The decoder of one layer can be opened separately to achieve flow control of the target oil and gas layer. The device has a simple structure and high reliability.

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

[0006] The present invention provides a downhole target layer selection device applicable to a single hydraulic control pipeline, which is characterized by comprising:

[0007] A valve body, one end of the valve body is provided with an oil inlet, the other end is provided with an oil outlet, a cavity is formed in the valve body, a partition is provided in the valve body, and the partition divides the valve body into a left cavity and a right cavity;

[0008] A piston assembly comprising a piston, a piston rod, a spring and a sealing ball. The piston slides in the left cavity. The piston is connected to one end of the piston rod. The other end of the piston rod passes through the partition plate and extends into the right cavity to connect with the sealing ball. The spring is sleeved on the piston rod. The two ends of the spring respectively abut against the piston and the partition plate. A first oil inlet chamber is formed on the left side of the piston. A groove is formed on the outer surface of the piston.

[0009] a sealing cone fixed in the right cavity, the sealing cone dividing the right cavity into a second oil inlet cavity and an oil outlet cavity; a conical surface formed on the sealing cone, the conical surface forming a sealing contact with the spherical surface of the sealing ball; an oil passage formed on the side wall of the valve body, the oil passage communicating with the first oil inlet cavity and the second oil inlet cavity, and the oil outlet communicating with the oil outlet cavity;

[0010] A fixing pin is fixed on the valve body and is inserted into the groove. The piston slides and rotates along the cavity under the guidance of the hydraulic pressure and the fixing pin.

[0011] Preferably, the oil inlet is provided with a hydraulic input pipeline joint, and the oil outlet is provided with a hydraulic output pipeline joint, the hydraulic input pipeline joint is connected to the hydraulic input pipeline, and the hydraulic output pipeline joint is connected to the hydraulic output pipeline.

[0012] Preferably, a sealing ring is provided on the partition plate, and the piston rod passes through the sealing ring and is in sealing and sliding connection with the partition plate.

[0013] The present invention also provides a downhole target layer selection system suitable for a single hydraulic control pipeline, comprising a long downhole hydraulic control pipeline and several downhole target layer selection devices suitable for the single hydraulic control pipeline, the long downhole hydraulic control pipeline is connected to the oil inlets of several downhole target layer selection devices, the several downhole target layer selection devices respectively correspond to different target layers, and the grooves on each valve body are different.

[0014] Preferably, each groove on the valve body includes an initial position, several intermediate positions, an inclined sliding groove, a high-pressure extending groove and several high-pressure non-extending grooves;

[0015] When not pressed, the fixing pin is located at the initial position;

[0016] When the pressure is released, the fixing pin returns to the initial position along the inclined slot;

[0017] When the pressure is low, the fixing pin is located at the middle position;

[0018] When high pressure is applied and the piston rod pushes the sealing ball open, the fixing pin at the target layer is located at the high pressure extension groove;

[0019] When high pressure is applied and the piston rod does not push open the sealing ball, the fixing pin is located at the position where the high pressure does not extend out of the groove.

[0020] Preferably, the downhole target layer selection device includes six, and each groove on the valve body includes an initial position when the pressure is fully released, a first intermediate position, a second intermediate position, a third intermediate position, a fourth intermediate position, a fifth intermediate position, an inclined slide groove, a high-pressure extended groove, a first high-pressure non-extended groove, a second high-pressure non-extended groove, a third high-pressure non-extended groove, a fourth high-pressure non-extended groove and a fifth high-pressure non-extended groove.

[0021] The present invention also provides a method for selecting a downhole target layer applicable to a single hydraulic control pipeline. The downhole target layer selection system applicable to a single hydraulic control pipeline comprises the following steps: pressurizing the downhole long hydraulic control pipeline through a ground hydraulic station, and selecting different downhole target layers by different sequences and times of high-pressure and low-pressure pressurization.

[0022] Preferably, the high pressure and the low pressure are determined by the stiffness of the spring and the displacement of the piston; the high pressure is greater than the pressure when the hydraulic oil pushes the piston to reach the maximum displacement, and the low pressure is equal to the pressure when the piston returns to the middle position.

[0023] Preferably, the method further comprises the steps of:

[0024] Select the first layer as the target layer, and inject high pressure into the downhole hydraulic control long pipeline;

[0025] Alternatively, the second layer is selected as the target layer, and high-pressure and low-pressure cycles are applied to the downhole hydraulic control long pipeline, and then high-pressure is applied again;

[0026] Alternatively, the third layer is selected as the target layer, and high and low pressure cycles are applied twice to the downhole hydraulic control long pipeline, and then high pressure is applied once;

[0027] Alternatively, the fourth layer is selected as the target layer, and high and low pressure cycles are applied to the downhole hydraulic control long pipeline three times, followed by high pressure once;

[0028] Alternatively, the fifth layer is selected as the target layer, and high and low pressure cycles are applied to the downhole hydraulic control long pipeline four times, followed by high pressure once;

[0029] Alternatively, the sixth layer is selected as the target layer, and high and low pressure cycles are injected into the downhole hydraulic control long pipeline five times, and then high pressure is injected once.

[0030] The present invention has the following advantages due to the adoption of the above technical solution:

[0031] It is suitable for selecting target layers of flow control valves at different layers in a single hydraulic control pipeline. Through different groove forms on the outer surface of the piston in each layer's hydraulic control system and a variety of different pressure forms, the target layer selection of different layers in the well can be achieved. The decoder of one layer can be opened separately to achieve flow control of the target oil and gas layer. It has a simple structure and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those skilled in the art. The accompanying drawings are only used to illustrate the preferred embodiment and are not to be considered as limitations of the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components.

[0033] In the attached figure:

[0034] Figure 1 This is a schematic structural diagram of a downhole target layer selection device applicable to a single hydraulic control pipeline according to the present invention;

[0035] Figure 2 This is a wiring diagram of the downhole target layer selection system applicable to a single hydraulic control pipeline of the present invention.

[0036] Figure 3 This is a schematic diagram of the expansion of the groove on the piston in the first downhole target layer selection device of the present invention;

[0037] Figure 4 This is a schematic diagram of the expansion of the groove on the piston in the second downhole target layer selection device of the present invention;

[0038] Figure 5 This is a schematic diagram of the expansion of the groove on the piston in the third downhole target layer selection device of the present invention;

[0039] Figure 6 This is a schematic diagram of the expansion of the groove on the piston in the fourth downhole target layer selection device of the present invention;

[0040] Figure 7 This is a schematic diagram of the expansion of the groove on the piston in the fifth downhole target layer selection device of the present invention;

[0041] Figure 8 This is a schematic diagram of the expansion of the groove on the piston in the sixth downhole target layer selection device of the present invention; DETAILED DESCRIPTION

[0042] 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.

[0043] The present invention provides a downhole target layer selection device suitable for a single hydraulic control pipeline, comprising a valve body, a piston assembly, a sealing cone and a fixing pin. An oil inlet is provided at one end of the valve body and an oil outlet is provided at the other end, and a cavity is formed in the valve body. The piston assembly comprises a piston, a piston rod, a spring and a sealing ball, and the piston slides in the cavity, and a groove is formed on the outer surface of the piston. The sealing cone is fixed in the cavity, and a sealing contact is formed between the conical surface and the spherical surface of the sealing ball. An oil passage is formed on the side wall of the valve body, and the oil passage connects the first oil inlet cavity and the second oil inlet cavity, and the oil outlet is connected to the oil outlet cavity. The fixing pin is fixed to the valve body, and the fixing pin is inserted into the groove. The piston slides and rotates along the cavity under the action of the hydraulic pressure and the guidance of the fixing pin.

[0044] The device is suitable for selecting the target layer of a downhole flow control valve of a single hydraulic control pipeline. Through the different groove forms on the outer surface of the piston in each hydraulic control system and a variety of different pressure forms, the target layer selection of different layers in the downhole is realized. The decoder of one layer can be opened separately to realize the flow control of the target oil and gas layer. The device has a simple structure and high reliability.

[0045] Example 1

[0046] like Figure 1 The present invention provides a downhole target layer selection device suitable for use with a single hydraulic control pipeline. The device is connected to a flow control valve downstream and to a hydraulic station upstream via a long hydraulic control pipeline. The device comprises a valve body 1, a piston assembly, a sealing cone 16, and a fixing pin 6. The valve body 1 is provided with an oil inlet at one end and an oil outlet at the other end. A cavity is formed within the valve body 1, and a partition is provided within the valve body 1, dividing the valve body 1 into a left cavity and a right cavity.

[0047] The piston assembly includes a piston 5, a piston rod 8, a spring 9 and a sealing ball 14. The piston 5 slides in the left cavity. The piston 5 is connected to one end of the piston rod 8. The other end of the piston rod 8 passes through the partition and extends into the right cavity to be connected to the sealing ball 14. The spring 9 is sleeved on the piston rod 8. The two ends of the spring 9 are respectively in contact with the piston 5 and the partition plate. A first oil inlet chamber 3 is formed on the left side of the piston 5, and a groove is formed on the outer surface of the piston 5.

[0048] The sealing cone 16 is fixed in the right cavity, and the sealing cone 16 divides the right cavity into the second oil inlet cavity 13 on the right and the oil outlet cavity 15 on the left. A conical surface is formed on the sealing cone 16, and a sealing contact is formed between the conical surface 16 and the spherical surface of the sealing ball 14. An oil passage 7 is formed on the side wall of the valve body 1, and the oil passage 7 connects the first oil inlet cavity 3 and the second oil inlet cavity 13, and the oil outlet is connected to the oil outlet cavity 15.

[0049] The fixing pin 6 is fixed to the valve body 1 and inserted into the groove. The piston 5 slides and rotates along the cavity under the guidance of the hydraulic pressure and the fixing pin 6. The device is suitable for selecting the target layer of a downhole flow control valve in a single hydraulic control pipeline. By using different grooves on the outer surface of the piston in each hydraulic control system and various different pressure injection methods, the target layer selection of different downhole layers can be achieved. The decoder of each layer can be activated separately to achieve flow control of the target oil and gas layer. It has a simple structure and high reliability.

[0050] The oil inlet is provided with a hydraulic input pipeline joint 2, and the oil outlet is provided with a hydraulic output pipeline joint 11. The hydraulic input pipeline joint 2 is connected to the hydraulic input pipeline 1, and the hydraulic output pipeline joint 11 is connected to the hydraulic output pipeline 12.

[0051] In order to achieve sealed sliding, a sealing ring 10 is provided on the partition plate, and the piston rod 8 is sealed and slidably connected to the partition plate.

[0052] The sealing ball 14 is preferably a steel ball.

[0053] The target layer selection device suitable for a single hydraulic control pipeline allows high-pressure hydraulic oil to flow from the downhole hydraulic control long pipeline 60 and the hydraulic input pipeline 1 into the first oil inlet chamber 3, and enters the second oil inlet chamber 13 through the oil passage 7; the fixing pin 6 is inserted into the groove on the outer surface of the piston 5. When the high-pressure hydraulic oil pushes the piston 5 to move to the right, the piston 5 will move axially and rotate along the groove. When the hydraulic pressure reaches the level that pushes the sealing ball 14 open and separates the conical surface of the sealing ball 14 and the sealing cone 16, the hydraulic oil flows into the downstream flow control valve for flow control.

[0054] Example 2

[0055] like Figure 2As described above, Example 2 of the present invention provides a downhole target layer selection system applicable to a single hydraulic control pipeline, comprising a long downhole hydraulic control pipeline 60 and several downhole target layer selection devices applicable to a single hydraulic control pipeline as described in Example 1, wherein the long downhole hydraulic control pipeline 60 is connected to the oil inlets of the several downhole target layer selection devices, and the several downhole target layer selection devices correspond to different target layers, and the grooves on each of the valve bodies 1 are different. Through a ground hydraulic station, the long downhole hydraulic control pipeline 60 is pressurized, and the selection of different downhole target layers is achieved by different sequences and times of high-pressure and low-pressure pressurization.

[0056] Specifically, taking the case where the downhole target layer selection device applicable to a single hydraulic control pipeline includes six as an example, the number of target layers is six, and the downhole target layer selection system applicable to a single hydraulic control pipeline is used to select six target layers.

[0057] The pistons 5 at different target layers are the first layer piston, the second layer piston, the third layer piston, the fourth layer piston, the fifth layer piston and the sixth layer piston. The groove forms of the six layers of pistons 5 in the well are different, such as Figures 2 to 7 shown.

[0058] like Figure 3 As shown, the grooves on the outer surface of the first layer of piston include an initial position 17, a first intermediate position 18, a second intermediate position 19, a third intermediate position 20, a fourth intermediate position 21, a fifth intermediate position 22, an inclined groove 23, a first layer of high-pressure protruding groove 24, a first layer of first high-pressure non-protruding groove 25, a first layer of second high-pressure non-protruding groove 26, a first layer of third high-pressure non-protruding groove 27, a first layer of fourth high-pressure non-protruding groove 28, and a first layer of fifth high-pressure non-protruding groove 29.

[0059] like Figure 4 As shown, the grooves on the outer surface of the second layer of piston include an initial position 17, a first intermediate position 18, a second intermediate position 19, a third intermediate position 20, a fourth intermediate position 21, a fifth intermediate position 22, an inclined groove 23, a second layer of high-pressure extending groove 31, a second layer of first high-pressure non-extending groove 30, a second layer of second high-pressure non-extending groove 32, a second layer of third high-pressure non-extending groove 33, a second layer of fourth high-pressure non-extending groove 34, and a second layer of fifth high-pressure non-extending groove 35;

[0060] like Figure 5As shown, the grooves on the outer surface of the third layer of the piston include an initial position 17, a first intermediate position 18, a second intermediate position 19, a third intermediate position 20, a fourth intermediate position 21, a fifth intermediate position 22, an inclined groove 23, a third layer of high-pressure extending groove 38, a third layer of first high-pressure non-extending groove 36, a third layer of second high-pressure non-extending groove 37, a third layer of third high-pressure non-extending groove 39, a third layer of fourth high-pressure non-extending groove 40, and a third layer of fifth high-pressure non-extending groove 41;

[0061] like Figure 6 As shown, the grooves on the outer surface of the piston of the fourth layer include an initial position 17, a first intermediate position 18, a second intermediate position 19, a third intermediate position 20, a fourth intermediate position 21, a fifth intermediate position 22, an inclined groove 23, a high-pressure extending groove 45 of the fourth layer, a first high-pressure non-extending groove 42 of the fourth layer, a second high-pressure non-extending groove 43 of the fourth layer, a third high-pressure non-extending groove 44 of the fourth layer, a fourth high-pressure non-extending groove 46 of the fourth layer, and a fifth high-pressure non-extending groove 47 of the fourth layer;

[0062] like Figure 7 As shown, the outer surface grooves of the fifth layer of piston include an initial position 17, a first intermediate position 18, a second intermediate position 19, a third intermediate position 20, a fourth intermediate position 21, a fifth intermediate position 22, an inclined slide groove 23, a fifth layer of high-pressure extending groove 52, a fifth layer of first high-pressure non-extending groove 48, a fifth layer of second high-pressure non-extending groove 49, a fifth layer of third high-pressure non-extending groove 50, a fifth layer of fourth high-pressure non-extending groove 51, and a fifth layer of fifth high-pressure non-extending groove 53;

[0063] like Figure 8 As shown, the grooves on the outer surface of the piston of the sixth layer include an initial position 17, a first intermediate position 18, a second intermediate position 19, a third intermediate position 20, a fourth intermediate position 21, a fifth intermediate position 22, an inclined groove 23, a high-pressure extending groove 59 of the sixth layer, a first high-pressure non-extending groove 54 of the sixth layer, a second high-pressure non-extending groove 55 of the sixth layer, a third high-pressure non-extending groove 56 of the sixth layer, a fourth high-pressure non-extending groove 57 of the sixth layer, and a fifth high-pressure non-extending groove 58 of the sixth layer;

[0064] The downhole hydraulic control long pipeline 60 and the downhole hydraulic input pipelines 1 are connected in the following manner: Figure 2 Connect as shown.

[0065] On the other hand, the present invention also provides a downhole target layer selection suitable for a single hydraulic control pipeline, which is selected using the above-mentioned intelligent well downhole target layer selection hydraulic control system, including the following steps: pressurizing the downhole hydraulic control long pipeline 60 through the ground hydraulic station, and inputting hydraulic power signals to the hydraulic control systems of each layer through the hydraulic input pipeline 1; selecting six target layers in the downhole by different sequences and times of high and low pressure, and completely releasing the pressure after each layer selection, and fixing the pin 6 at the initial position 17.

[0066] In a specific embodiment, a smart well is selected to select a target layer for a downhole flow control valve using the present invention, including the following steps:

[0067] (1) Apply high pressure to the downhole hydraulic control long pipeline 60 through the ground hydraulic station.

[0068] The pressure values of the high pressure and the low pressure are determined by the stiffness of the spring 9 and the displacement of the piston 5; in this embodiment, the selected high pressure is 10MPa (greater than the pressure of 8MPa when the hydraulic oil pushes the piston 5 to reach the maximum displacement), and the low pressure is 5MPa (equal to the pressure of 5MPa when the piston 5 returns to the middle position).

[0069] In this embodiment, the flow conditions of the hydraulic control system for each layer selection are as follows:

[0070] 1) Flow situation of the hydraulic control system for selecting the first layer: high-pressure hydraulic oil flows from the downhole hydraulic control long pipeline 60 and the hydraulic input pipeline 1 into the first oil inlet chamber 3, and enters the second oil inlet chamber 13 through the oil passage 7; the fixing pin 6 is inserted into the groove on the outer surface of the piston 5. When the high-pressure hydraulic oil pushes the piston 5 to move to the right, the piston 5 will move axially and rotate along the direction of the groove; when there is no pressure, the fixing pin 6 is at the initial position 17. After high pressure is applied, the fixing pin 6 is located at the high-pressure extension groove 24 of the first layer; the piston 5 moves to the right by the maximum displacement, thereby pushing the piston rod 8 to push open the steel ball 14, and the high-pressure hydraulic oil flows into the oil outlet chamber 15, and flows into the lower opening hydraulic control system through the hydraulic output pipeline 12, and the first target layer is selected; after complete pressure relief, the piston 5 retreats to the left under the push of the spring 9, and the fixing pin 6 returns to the initial position 17 along the groove on the outer surface of the piston 5 and passes through the first intermediate position 18 and the inclined slide groove 23.

[0071] 2) Liquid flow situation of the hydraulic control system for selecting the second layer: high-pressure hydraulic oil flows into the first oil inlet chamber 3 and the second oil inlet chamber 13; when not pressurized, the fixed pin 6 is located at the initial position 17. After high pressure is applied, the high-pressure hydraulic oil pushes the piston 5 to move to the right, and the fixed pin 6 is located at the first high-pressure non-extended groove 30 of the second layer; the rightward movement of the piston 5 is less than the maximum displacement, the piston rod 8 does not push open the steel ball 14, the second oil inlet chamber 13 is not connected to the oil outlet chamber 15, and the second target layer is not selected; after complete pressure relief, the fixed pin 6 returns to the initial position 17.

[0072] 3) Liquid flow situation of the hydraulic control system for selecting the third layer: high-pressure hydraulic oil flows into the first oil inlet chamber 3 and the second oil inlet chamber 13; when not pressurized, the fixed pin 6 is located at the initial position 17. After high pressure is applied, the high-pressure hydraulic oil pushes the piston 5 to move to the right, and the fixed pin 6 is located at the first high-pressure non-extended groove 36 of the third layer; the rightward movement of the piston 5 is less than the maximum displacement, the piston rod 8 does not push open the steel ball 14, the second oil inlet chamber 13 is not connected to the oil outlet chamber 15, and the third target layer is not selected; after complete pressure relief, the fixed pin 6 returns to the initial position 17.

[0073] 4) Liquid flow situation of the hydraulic control system for selecting the fourth layer: high-pressure hydraulic oil flows into the first oil inlet chamber 3 and the second oil inlet chamber 13; when not pressurized, the fixed pin 6 is located at the initial position 17. After high pressure is applied, the high-pressure hydraulic oil pushes the piston 5 to move to the right, and the fixed pin 6 is located at the first high-pressure non-extended groove 42 of the fourth layer; the rightward movement of the piston 5 is less than the maximum displacement, the piston rod 8 does not push open the steel ball 14, the second oil inlet chamber 13 is not connected to the oil outlet chamber 15, and the fourth target layer is not selected; after complete pressure relief, the fixed pin 6 returns to the initial position 17.

[0074] 5) Liquid flow situation of the hydraulic control system for selecting the fifth layer: high-pressure hydraulic oil flows into the first oil inlet chamber 3 and the second oil inlet chamber 13; when not pressurized, the fixed pin 6 is located at the initial position 17. After high pressure is applied, the high-pressure hydraulic oil pushes the piston 5 to move to the right, and the fixed pin 6 is located at the first high-pressure non-extended groove 48 of the fifth layer; the rightward movement of the piston 5 is less than the maximum displacement, the piston rod 8 does not push open the steel ball 14, the second oil inlet chamber 13 is not connected to the oil outlet chamber 15, and the fifth target layer is not selected; after complete pressure relief, the fixed pin 6 returns to the initial position 17.

[0075] 6) Liquid flow situation of the hydraulic control system for selecting the sixth layer: high-pressure hydraulic oil flows into the first oil inlet chamber 3 and the second oil inlet chamber 13; when not pressurized, the fixed pin 6 is located at the initial position 17. After high pressure is applied, the high-pressure hydraulic oil pushes the piston 5 to move to the right, and the fixed pin 6 is located at the first high-pressure non-extended groove 54 of the sixth layer; the rightward movement of the piston 5 is less than the maximum displacement, the piston rod 8 does not push open the steel ball 14, the second oil inlet chamber 13 is not connected to the oil outlet chamber 15, and the sixth target layer is not selected; after complete pressure relief, the fixed pin 6 returns to the initial position 17.

[0076] (2) Through the ground hydraulic station, the downhole hydraulic control long pipeline 60 is subjected to a high-low pressure cycle (one high pressure, one low pressure), and then a high pressure cycle.

[0077] In this embodiment, the flow conditions of the hydraulic control system for each layer selection are as follows:

[0078] 1) First layer selection hydraulic control system fluid flow situation: high-pressure hydraulic oil flows into the first oil inlet chamber 3 and the second oil inlet chamber 13; when not pressurized, the fixed pin 6 is at the initial position 17. After the first high pressure, the piston 5 moves to the right, and the fixed pin 6 is located at the high-pressure extended groove 24 of the first layer. After the second low pressure, due to the pressure reduction, the piston 5 retreats downward to the left, and the fixed pin 6 retreats to the first intermediate position 18. After the third high pressure, the piston 5 moves to the right, and the fixed pin 6 is located at the first high-pressure non-extended groove 25 of the first layer; the rightward movement of the piston 5 is less than the maximum displacement, the piston rod 8 does not push open the steel ball 14, the second oil inlet chamber 13 is not connected to the oil outlet chamber 15, and the first target layer is not selected; the pressure is completely released, the piston 5 retreats to the left under the push of the spring 9, and the fixed pin 6 returns to the initial position 17 along the groove on the outer surface of the piston 5 and passes through the first intermediate position 18 and the inclined slide groove 23.

[0079] 2) Liquid flow situation of the hydraulic control system for selecting the second layer: high-pressure hydraulic oil flows into the first oil inlet chamber 3 and the second oil inlet chamber 13; when not pressurized, the fixed pin 6 is located at the initial position 17. After the first high pressure is applied, the piston 5 moves to the right, and the fixed pin 6 is located at the first high-pressure non-extended groove 30 of the second layer. After the second low pressure is applied, due to the pressure reduction, the piston 5 retreats downward to the left, and the fixed pin 6 retreats to the first middle position 18. After the third high pressure is applied, the piston 5 moves to the right, and the fixed pin 6 is located at the high-pressure extended groove 31 of the second layer; the piston 5 moves to the right by the maximum displacement, thereby pushing the piston rod 8 to push open the steel ball 14, and the high-pressure hydraulic oil flows into the oil outlet chamber 15, and flows into the lower opening hydraulic control system through the hydraulic output pipeline 12, and the second target layer is selected; after complete pressure relief, the fixed pin 6 returns to the initial position 17.

[0080] 3) Liquid flow situation of the hydraulic control system for selecting the third layer: high-pressure hydraulic oil flows into the first oil inlet chamber 3 and the second oil inlet chamber 13; when not pressurized, the fixed pin 6 is located at the initial position 17. After the first high pressure is applied, the piston 5 moves to the right, and the fixed pin 6 is located at the first high-pressure non-extended groove 36 of the third layer. After the second low pressure is applied, due to the pressure reduction, the piston 5 retreats downward to the left, and the fixed pin 6 retreats to the first middle position 18. After the third high pressure is applied, the piston 5 moves to the right, and the fixed pin 6 is located at the second high-pressure non-extended groove 37 of the third layer; the rightward movement of the piston 5 is less than the maximum displacement, the piston rod 8 does not push open the steel ball 14, the second oil inlet chamber 13 is not connected to the oil outlet chamber 15, and the third target layer is not selected; after complete pressure relief, the fixed pin 6 returns to the initial position 17.

[0081] 4) Liquid flow situation of the hydraulic control system for selecting the fourth layer: high-pressure hydraulic oil flows into the first oil inlet chamber 3 and the second oil inlet chamber 13; when not pressurized, the fixed pin 6 is located at the initial position 17. After the first high pressure is applied, the piston 5 moves to the right, and the fixed pin 6 is located at the first high-pressure non-extended groove 42 of the fourth layer. After the second low pressure is applied, due to the pressure reduction, the piston 5 retreats downward to the left, and the fixed pin 6 retreats to the first middle position 18. After the third high pressure is applied, the piston 5 moves to the right, and the fixed pin 6 is located at the second high-pressure non-extended groove 43 of the third layer; the rightward movement of the piston 5 is less than the maximum displacement, the piston rod 8 does not push open the steel ball 14, the second oil inlet chamber 13 is not connected to the oil outlet chamber 15, and the fourth target layer is not selected; after complete pressure relief, the fixed pin 6 returns to the initial position 17.

[0082] 5) Liquid flow situation of the hydraulic control system for selecting the fifth layer: high-pressure hydraulic oil flows into the first oil inlet chamber 3 and the second oil inlet chamber 13; when not pressurized, the fixed pin 6 is located at the initial position 17. After the first high pressure is applied, the piston 5 moves to the right, and the fixed pin 6 is located at the first high-pressure non-extended groove 48 of the fifth layer. After the second low pressure is applied, due to the pressure reduction, the piston 5 retreats downward to the left, and the fixed pin 6 retreats to the first middle position 18. After the third high pressure is applied, the piston 5 moves to the right, and the fixed pin 6 is located at the second high-pressure non-extended groove 49 of the fifth layer; the rightward movement of the piston 5 is less than the maximum displacement, the piston rod 8 does not push open the steel ball 14, the second oil inlet chamber 13 is not connected to the oil outlet chamber 15, and the fifth target layer is not selected; after complete pressure relief, the fixed pin 6 returns to the initial position 17.

[0083] 6) Flow situation of the hydraulic control system for selecting the sixth layer: high-pressure hydraulic oil flows into the first oil inlet chamber 3 and the second oil inlet chamber 13; when not pressurized, the fixed pin 6 is located at the initial position 17. After the first high pressure is applied, the piston 5 moves to the right, and the fixed pin 6 is located at the first high-pressure non-extended groove 54 of the sixth layer. After the second low pressure is applied, due to the pressure reduction, the piston 5 retreats downward to the left, and the fixed pin 6 retreats to the first middle position 18. After the third high pressure is applied, the piston 5 moves to the right, and the fixed pin 6 is located at the second high-pressure non-extended groove 55 of the sixth layer; the rightward movement of the piston 5 is less than the maximum displacement, the piston rod 8 does not push open the steel ball 14, the second oil inlet chamber 13 is not connected to the oil outlet chamber 15, and the sixth target layer is not selected; after complete pressure relief, the fixed pin 6 returns to the initial position 17.

[0084] (3) Similarly, through the surface hydraulic station, the downhole hydraulic control long pipeline 60 is subjected to a second high-low pressure cycle, and then a high pressure cycle is applied, and the third target layer is selected; after the pressure is completely released, the fixed pin 6 returns to the initial position 17;

[0085] Through the surface hydraulic station, the downhole hydraulic control long pipeline 60 is cycled three times with high and low pressure, and then high pressure is applied once, and the fourth target layer is selected; after the pressure is completely released, the fixed pin 6 returns to the initial position 17;

[0086] Through the surface hydraulic station, the downhole hydraulic control long pipeline 60 is cycled through high and low pressure four times, and then high pressure is applied once, and the fifth target layer is selected; after the pressure is completely released, the fixed pin 6 returns to the initial position 17;

[0087] Through the surface hydraulic station, the downhole hydraulic control long pipeline 60 is cycled five times with high and low pressure, and then high pressure is applied once, and the sixth target layer is selected; after the pressure is completely released, the fixed pin 6 returns to the initial position 17;

[0088] In summary, the present invention adopts different outer surface groove forms of each layer of pistons, and uses different high and low pressure pressure sequences and combinations of times of a single hydraulic pipeline to achieve the selection of six target layers underground. It has the advantages of simple scheme, minimum number of hydraulic control pipelines, relatively low device processing accuracy requirements, stable system, and long service life. Compared with the existing technology, it has significant progress.

[0089] 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 downhole target layer selection device suitable for a single hydraulic control pipeline, characterized in that: include: A valve body, one end of the valve body is provided with an oil inlet, the other end is provided with an oil outlet, a cavity is formed in the valve body, a partition is provided in the valve body, and the partition divides the valve body into a left cavity and a right cavity; A piston assembly comprising a piston, a piston rod, a spring and a sealing ball. The piston slides in the left cavity. The piston is connected to one end of the piston rod. The other end of the piston rod passes through the partition plate and extends into the right cavity to connect with the sealing ball. The spring is sleeved on the piston rod. The two ends of the spring respectively abut against the piston and the partition plate. A first oil inlet chamber is formed on the left side of the piston. A groove is formed on the outer surface of the piston. a sealing cone fixed in the right cavity, the sealing cone dividing the right cavity into a second oil inlet cavity and an oil outlet cavity; a conical surface formed on the sealing cone, the conical surface forming a sealing contact with the spherical surface of the sealing ball; an oil passage formed on the side wall of the valve body, the oil passage communicating with the first oil inlet cavity and the second oil inlet cavity, and the oil outlet communicating with the oil outlet cavity; A fixing pin is fixed on the valve body and is inserted into the groove. The piston slides and rotates along the cavity under the guidance of the hydraulic pressure and the fixing pin.

2. The downhole target layer selection device applicable to a single hydraulic control pipeline according to claim 1, characterized in that: The oil inlet is provided with a hydraulic input pipeline joint, the oil outlet is provided with a hydraulic output pipeline joint, the hydraulic input pipeline joint is connected to the hydraulic input pipeline, and the hydraulic output pipeline joint is connected to the hydraulic output pipeline.

3. The downhole target layer selection device applicable to a single hydraulic control pipeline according to claim 1, characterized in that: A sealing ring is provided on the partition plate, and the piston rod passes through the sealing ring and is in sealing and sliding connection with the partition plate.

4. A downhole target layer selection system applicable to a single hydraulic control pipeline, characterized in that: It comprises a long downhole hydraulic control pipeline and several downhole target layer selection devices applicable to a single hydraulic control pipeline as described in any one of claims 1 to 3, wherein the long downhole hydraulic control pipeline is connected to the oil inlets of the several downhole target layer selection devices, the several downhole target layer selection devices respectively correspond to different target layers, and the grooves on each valve body are different.

5. The downhole target layer selection system applicable to a single hydraulic control pipeline according to claim 4, characterized in that: Each groove on the valve body includes an initial position, a plurality of intermediate positions, an inclined sliding groove, a high-pressure extending groove and a plurality of high-pressure non-extending grooves; When not pressed, the fixing pin is located at the initial position; When the pressure is released, the fixing pin returns to the initial position along the inclined slot; When the pressure is low, the fixing pin is located in the middle position; When high pressure is applied and the piston rod pushes the sealing ball open, the fixing pin at the target layer is located at the high pressure extension groove; When high pressure is applied and the piston rod does not push open the sealing ball, the fixing pin is located at the position where the high pressure does not extend out of the groove.

6. The downhole target layer selection system applicable to a single hydraulic control pipeline according to claim 4, characterized in that: The downhole target layer selection device includes six, and the grooves on each valve body include an initial position when the pressure is fully released, a first intermediate position, a second intermediate position, a third intermediate position, a fourth intermediate position, a fifth intermediate position, an inclined slide groove, a high-pressure extended groove, a first high-pressure non-extended groove, a second high-pressure non-extended groove, a third high-pressure non-extended groove, a fourth high-pressure non-extended groove and a fifth high-pressure non-extended groove.

7. A method for selecting a downhole target layer applicable to a single hydraulic control pipeline, characterized in that: The downhole target layer selection system applicable to a single hydraulic control pipeline according to any one of claims 4 to 6 comprises the steps of: pressurizing the downhole long hydraulic control pipeline through a ground hydraulic station, and selecting different downhole target layers by different sequences and times of high-pressure and low-pressure pressurization.

8. The method for selecting a downhole target layer applicable to a single hydraulic control pipeline according to claim 7, characterized in that: The high pressure and the low pressure are determined by the stiffness of the spring and the displacement of the piston; the high pressure is greater than the pressure when the hydraulic oil pushes the piston to reach the maximum displacement, and the low pressure is equal to the pressure when the piston returns to the middle position.

9. The method for selecting a downhole target layer applicable to a single hydraulic control pipeline according to claim 7, characterized in that: Including steps: Select the first layer as the target layer, and inject high pressure into the downhole hydraulic control long pipeline; Alternatively, the second layer is selected as the target layer, and high-pressure and low-pressure cycles are applied to the downhole hydraulic control long pipeline, and then high-pressure is applied again; Alternatively, the third layer is selected as the target layer, and high and low pressure cycles are applied twice to the downhole hydraulic control long pipeline, and then high pressure is applied once; Alternatively, the fourth layer is selected as the target layer, and high and low pressure cycles are applied to the downhole hydraulic control long pipeline three times, followed by high pressure once; Alternatively, the fifth layer is selected as the target layer, and high and low pressure cycles are applied to the downhole hydraulic control long pipeline four times, followed by high pressure once; Alternatively, the sixth layer is selected as the target layer, and high and low pressure cycles are injected into the downhole hydraulic control long pipeline five times, and then high pressure is injected once.

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