Underground electric-drive hydraulic-control miniature power device

Abstract

The invention provides an underground electric drive hydraulic control miniature power device, which belongs to the technical field of petroleum engineering, and comprises an oil path block, a front end cover and an oil tank shell, the left end of the oil path block is connected with the front end cover, the right end of the oil path block is connected with the oil tank shell, two cavities are formed among the oil path block, the front end cover and the oil tank shell, the other cavity is a micro element accommodating cavity; a circuit board, an electric pump assembly, an electromagnetic valve assembly and pressure meter assemblies are installed on the oil path block, the circuit board is electrically connected with the electromagnetic valve assembly, the two pressure meter assemblies and the electric pump assembly, and the miniature oil tank is communicated with the miniature element containing cavity through an oil injection hole in the oil path block. The liquid level of hydraulic oil in the micro-element containing cavity is higher than an inlet of the micro-pump. According to the invention, the action of the underground flow control valve can be realized through hydraulic control without a hydraulic control pipeline, the complexity of the pipeline and potential fault points can be reduced, and the reliability of the system is improved.

Description

Technical Field

[0001] This invention relates to the field of petroleum engineering technology, and in particular to a downhole electro-hydraulic control micro power device. Background Technology

[0002] Intelligent well completion technology, as an advanced reservoir production control technology, can acquire downhole monitoring data in real time, realize dynamic digitalization of reservoir development, precise stratification / section control, and improve recovery rate.

[0003] Intelligent completion systems mainly consist of a downhole flow control system, a downhole dynamic monitoring system, and an oil well production optimization system. The downhole flow control system regulates the production dynamics of each oil layer downhole through downhole flow control valves. Hydraulically driven downhole flow control valves have the advantages of high reliability and good stability, making them the preferred choice for intelligent completion technology. However, hydraulically driven downhole flow control valves require the installation of hydraulic control lines within the completion string. Surface hydraulic power controls the downhole flow control valves through these lines, achieving throttling control. Due to the large number of production layers downhole—up to six or more—a significant number of hydraulic lines need to be installed. The limited space within the wellbore restricts the number of hydraulic lines, and the fact that multiple production layers are separated by packers in the downhole string necessitates the hydraulic lines passing through these packers, creating significant challenges for on-site operations. Summary of the Invention

[0004] In view of the shortcomings of traditional electro-hydraulic composite intelligent well completion hydraulic pipelines, a downhole electro-hydraulic control micro power device is proposed, which can realize the hydraulic control pipeline and realize the action of downhole flow control valve through hydraulic control. This can reduce the complexity of the pipeline and potential failure points, and improve the reliability of the system.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: A downhole electro-hydraulic micro power device includes an oil manifold, a front end cover, and an oil tank shell. The left end of the oil manifold is connected to the front end cover, and the right end is connected to the oil tank shell. Sealing rings are installed at the connection points between the oil manifold, the front end cover, and the oil tank shell. Two cavities are formed between the oil manifold, the front end cover, and the oil tank shell, one of which is a micro oil tank and the other is a micro component receiving cavity. A circuit board, an electric pump assembly, a solenoid valve assembly, and two pressure gauge assemblies are installed on the oil manifold. The circuit board is electrically connected to the solenoid valve assembly, the two pressure gauge assemblies, and the electric pump assembly. The micro oil tank and the micro component receiving cavity are connected through an oil injection hole provided on the oil manifold. When the downhole electro-hydraulic micro power device is in operation, the hydraulic oil level in the micro component receiving cavity is higher than the inlet of the micro pump in the electric pump assembly.

[0006] Furthermore, the oil manifold has a hollow tubular structure with male oil pipe threads at both ends and a cylinder of unequal diameter in the middle. In the protruding part in the middle of the oil manifold, there are seven axial holes of unequal diameter along the circumference, namely, a solenoid valve mounting hole, an electric pump mounting hole, an oil injection hole, a second pipeline hole, a second pressure hole, a first pressure hole, and a first pipeline hole. The solenoid valve mounting hole, the electric pump mounting hole, and the oil injection hole respectively penetrate the two end faces of the protruding part in the middle of the oil manifold.

[0007] Furthermore, multiple circumferential holes are provided on different cross-sections of the raised portion in the middle of the oil passage block, which can realize the connection between different axial holes; The solenoid valve mounting hole and the electric pump mounting hole are connected sequentially through the second circumferential hole and the first circumferential hole; The three holes—the solenoid valve mounting hole, the first pressure hole, and the first pipeline hole—are connected. The solenoid valve mounting hole and the first pressure hole are connected through the fourth circumferential hole, and the first pressure hole and the first pipeline hole are connected through the third circumferential hole. The solenoid valve mounting hole, the second pressure hole, and the second pipeline hole are connected. The solenoid valve mounting hole and the second pressure hole are connected through the fifth circumferential hole, and the second pressure hole and the second pipeline hole are connected through the sixth circumferential hole.

[0008] Furthermore, the end of the solenoid valve mounting hole near the micro-component receiving cavity is connected to the solenoid valve assembly, and the end of the electric pump mounting hole near the micro-component receiving cavity is connected to the electric pump assembly. A first output line of the solenoid valve is installed on the first pipeline hole, and the end of the first output line of the solenoid valve extends to the left end face of the front cover and is located outside the front cover. A second output line of the solenoid valve is installed on the second pipeline hole, and the end of the second output line of the solenoid valve extends to the left end face of the front cover and is located outside the front cover. A pressure gauge assembly is installed on the first pressure hole and the second pressure hole respectively. The pressure gauge assembly installed on the first pressure hole is used to measure the pressure of the hydraulic oil in the first output line of the solenoid valve. The pressure gauge assembly installed on the second pressure hole is used to measure the pressure of the hydraulic oil in the second output line of the solenoid valve.

[0009] Furthermore, the electric pump assembly includes a micro motor, a micro pump, and a micro pump mounting end. The output shaft of the micro motor is coaxially threaded to the input shaft of the micro pump. The outer side of the left end of the micro pump mounting end is threaded to the micro pump, and the output port of the micro pump communicates with the central hole of the micro pump mounting end. The right end of the micro pump mounting end is mounted on the electric pump mounting hole, and the central hole of the micro pump mounting end communicates with the electric pump mounting hole. The inner side of the left end of the micro pump mounting end is sealed to the micro pump through an O-ring.

[0010] Furthermore, the downhole electro-hydraulic micro power unit also includes a check valve, an overflow valve, and a hydraulic control line sleeve. The check valve is installed in the electric pump mounting hole, and the end face of the check valve and the micro pump fixing end are in contact connection, and the inner cavity of the check valve is connected to the central hole of the micro pump fixing end; the overflow valve is installed at the end of the electric pump mounting hole near the micro oil tank, and a hydraulic control line sleeve is installed at the end of the overflow valve near the micro oil tank. A cavity is provided between the relief valve and the check valve. This cavity is connected to the inlet end of the relief valve and is also connected to the first circumferential hole. When the pressure at the output port of the check valve is greater than the maximum pressure set by the relief valve, the relief valve is opened, and the excess hydraulic oil flows back to the miniature oil tank through the relief valve.

[0011] Furthermore, the end of the micro motor furthest from the micro pump is connected to the motor end face fixing block, which is mounted on the oil passage block.

[0012] Furthermore, the solenoid valve assembly includes a solenoid valve and sealing rings. The end of the solenoid valve disposed in the solenoid valve mounting hole is provided with a solenoid valve T port, a solenoid valve A port, a solenoid valve P port, and a solenoid valve B port. A first solenoid valve sealing ring is provided between the solenoid valve T port and the solenoid valve A port, a second solenoid valve sealing ring is provided between the solenoid valve A port and the solenoid valve P port, a third solenoid valve sealing ring is provided between the solenoid valve P port, and a fourth solenoid valve sealing ring is provided at the end of the solenoid valve B port away from the solenoid valve P port.

[0013] Furthermore, the pressure gauge assembly includes a transition joint, a protective cylinder, a pressure gauge, a plug, and a core sealing plug. One end of the protective cylinder is threaded to the transition joint, and the other end is threaded to the plug, so that the protective cylinder forms a relatively sealed space to accommodate the pressure gauge. The pressure gauge is placed inside the protective cylinder and is mounted on the transition joint. The end of the plug away from the protective cylinder is equipped with a core sealing plug. A first pressure gauge sealing ring is installed at the connection between the core sealing plug and the plug. A second pressure gauge sealing ring is installed at the contact area between the plug and the protective cylinder. A third pressure gauge sealing ring is installed at the contact area between the transition joint and the pressure gauge. A fourth pressure gauge sealing ring is installed at the contact area between the transition joint and the protective cylinder.

[0014] Furthermore, a first O-ring is installed at the connection point between the left end of the front cover and the oil manifold, a second O-ring is installed at the connection point between the right end of the front cover and the oil manifold, a third O-ring is installed at the connection point between the left end of the oil tank shell and the oil manifold, and a fourth O-ring is installed at the connection point between the right end of the oil tank shell and the oil manifold.

[0015] Compared with existing technologies, the downhole electro-hydraulic micro power unit described in this invention has the following advantages: the entire downhole electro-hydraulic micro power unit can be made into a short section and connected to the downhole flow control valve without hydraulic control pipeline, avoiding the problem of long hydraulic pipelines passing through packers, reducing the manufacturing difficulty of packers, reducing the difficulty of downhole construction operations, and facilitating the realization of multi-layer intelligent well completion in downhole.

[0016] (1) The present invention adopts a structure without hydraulic pipelines. The connection of each micro hydraulic component inside the device is achieved by machining hydraulic holes in the mechanical structure, thereby simplifying the system structure and reducing potential failure points; (2) By using the downhole electro-hydraulic micro power device described in this invention, the downhole flow control valve can be seamlessly connected with the micro motor and micro pump, making the transmission of hydraulic power more efficient and improving the overall response speed of the intelligent well completion control system. (3) The present invention integrates all components of the electro-hydraulic micro power unit and mechanical structure into a short section, which effectively reduces the number of parts. The short section can be threadedly connected to downhole tools such as tubing or flow control valve, which effectively improves the compactness and reliability of the overall structure. (4) The present invention directly eliminates the hydraulic pipelines required in the traditional hydraulic control system. This not only eliminates the complexity and potential failure points caused by pipeline layout and sealing, but more importantly, it significantly reduces the radial dimension of the device (greatly reduces the maximum outer diameter), thus providing key support for the compact and modular integration of the multi-layer intelligent well completion system. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 An external view of a downhole electro-hydraulic micro power unit; Figure 2 yes Figure 1 The sectional diagram; Figure 3 This is a schematic diagram of the structure of a downhole electro-hydraulic micro power unit (left front view, which also hides the front end cover and the outer shell of the oil tank). Figure 4 This is a schematic diagram of the structure of a downhole electro-hydraulic micro power unit (left rear view, which also hides the front cover and the outer shell of the oil tank). Figure 5 This is a schematic diagram of the oil passage block structure; Figure 6 for Figure 5 AA section view diagram; Figure 7 for Figure 6 BB cross-sectional diagram in the middle; Figure 8 for Figure 6 CC section view diagram; Figure 9 for Figure 6 DD sectional view diagram; Figure 10 This is a schematic diagram of the electric pump assembly. Figure 11 This is a schematic diagram of the structure of a solenoid valve; Figure 12 This is a schematic diagram of the pressure gauge assembly; Figure 13 This is a schematic diagram of an electro-hydraulic control system.

[0018] Explanation of reference numerals in the attached figures: 1. Manifold block; 2. Front end cover; 3. First O-ring seal assembly; 4. Circuit board; 5. Motor end face fixing block; 6. Electric pump assembly; 7. Second O-ring seal assembly; 8. Check valve; 9. Overflow valve; 10. Third O-ring seal assembly; 11. Hydraulic control line ferrule; 12. Oil tank shell; 13. Fourth O-ring seal assembly; 14. Solenoid valve assembly; 15. Pressure gauge assembly; 16. First circumferential hole; 17. Second circumferential hole; 18. Third circumferential hole; 19. Fourth circumferential hole; 20. Fifth circumferential hole; 21. Sixth circumferential hole; 22. Downhole flow control valve; 1a. Solenoid valve mounting hole; 1b. Electric pump mounting hole; 1c. Oil filling hole; 1d. Second pipeline hole; 1e. Second pressure hole; 1f. First pressure hole; 1g. First pipeline hole; 61. Miniature motor; 62. Miniature pump; 63. O-ring seal; 64. Miniature pump mounting end; 121. Miniature fuel tank; 141. Solenoid valve T port; 142. First solenoid valve sealing ring; 143. Solenoid valve A port; 144. Second solenoid valve sealing ring; 145. Solenoid valve P port; 146. Third solenoid valve sealing ring; 147. Solenoid valve B port; 148. Fourth solenoid valve sealing ring; 149. Solenoid valve first output line; 150. Solenoid valve second output line; 151. Transition joint; 152. Protective cylinder; 153. Pressure gauge; 154. Plug; 155. Core sealing plug; 156. First pressure gauge sealing ring; 157. Second pressure gauge sealing ring; 158. Third pressure gauge sealing ring; 159. Fourth pressure gauge sealing ring. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] like Figures 1-13 As shown, this invention discloses a downhole electro-hydraulic control micro power device, which can provide hydraulic power and hydraulic reversing function for the electro-hydraulic composite intelligent well completion downhole flow control valve 22. It eliminates the need for hydraulic control pipelines and surface hydraulic control cabinets, reducing the manufacturing difficulty of packers and the complexity of running the completion string. Specifically, it includes a manifold block 1, a front end cover 2, and a tank shell 12. The left end of the manifold block 1 is connected to the front end cover 2, and the right end is connected to the tank shell 12. Sealing rings are installed at the connections between the manifold block 1 and the front end cover 2 and the tank shell 12. Specifically, a first O-ring seal is installed at the connection between the left end of the front end cover 2 and the manifold block 1, a second O-ring seal group 7 is installed at the connection between the right end of the front end cover 2 and the manifold block 1, a third O-ring seal is installed at the connection between the left end of the tank shell 12 and the manifold block 1, and a fourth O-ring seal is installed at the connection between the right end of the tank shell 12 and the manifold block 1. Two cavities are formed between the oil manifold 1, the front cover 2, and the outer shell of the oil tank 12. One cavity is a micro oil tank 121, and the other is a micro component receiving cavity. The oil manifold 1 is equipped with a circuit board 4, an electric pump assembly 6, a solenoid valve assembly 14, and two pressure gauge assemblies 15. The circuit board 4 is electrically connected to the solenoid valve assembly 14, the two pressure gauge assemblies 15, and the electric pump assembly 6. The circuit board 4 can control the start and stop of the micro motor 61, as well as the reversing action of the solenoid valve assembly 14 and supply power to the two pressure gauge assemblies 15. The micro oil tank 121 and the micro component receiving cavity are connected through an oil injection hole 1c on the oil manifold 1. When the downhole electro-hydraulic control micro power unit is in operation, the hydraulic oil level in the micro component receiving cavity is higher than the inlet of the micro pump 62 in the electric pump assembly 6, ensuring that the micro pump 62 is completely submerged in the hydraulic oil, effectively preventing the micro pump 62 from sucking dry.

[0022] The electric pump assembly 6 includes a micro motor 61, a micro pump 62, and a micro pump mounting end 64. The output shaft of the micro motor 61 is coaxially threaded to the input shaft of the micro pump 62. The outer left end of the micro pump mounting end 64 is threaded to the micro pump 62, and the output port of the micro pump 62 communicates with the center hole of the micro pump mounting end 64. The right end of the micro pump mounting end 64 is threaded to the electric pump mounting hole 1b, and the center hole of the micro pump mounting end 64 communicates with the electric pump mounting hole 1b. The inner left end of the micro pump mounting end 64 is sealed to the micro pump 62 by an O-ring seal 63. Preferably, the end of the micro motor 61 furthest from the micro pump 62 is connected to the motor end face fixing block 5, which is mounted on the oil passage block 1. The inner side of the motor end face fixing block 5 is consistent with the outer diameter of the central tube of the oil circuit block 1. The motor end face fixing block 5 is welded to the central tube of the oil circuit block 1. The motor end face fixing block 5 is provided with a threaded hole, which can be threaded to the end face of the micro motor 61. The motor end face fixing block 5 can effectively improve the installation stability of the electric pump assembly 6, thereby improving the reliability of the electric pump assembly 6. In the description of the present invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention. In addition, the terms "first", "second", etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, features defined with "first", "second", etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0023] The solenoid valve assembly 14 includes a hydraulic directional solenoid valve and a sealing ring. The solenoid valve is a miniature three-position four-way solenoid valve, which can switch the output high-pressure pipeline of the solenoid valve according to the preset signal. When the solenoid valve is not energized, it has a neutral unloading function. At this time, the two output hydraulic pipelines of the solenoid valve are short-circuited with the return oil port. When the coil of the miniature three-position four-way solenoid directional valve is energized, the flow control valve can be activated. When de-energized, the flow control valve can be stopped.

[0024] The solenoid valve, located within the solenoid valve mounting hole 1a, has a solenoid valve port T 141, a solenoid valve port A 143, a solenoid valve port P 145, and a solenoid valve port B 147 at one end. A first solenoid valve sealing ring 142 is positioned between solenoid valve port T 141 and solenoid valve port A 143; a second solenoid valve sealing ring 144 is positioned between solenoid valve port A 143 and solenoid valve port P 145; a third solenoid valve sealing ring 146 is positioned between solenoid valve port P 145 and solenoid valve port B 147; and a fourth solenoid valve sealing ring 148 is positioned at the end of solenoid valve port B 147 furthest from solenoid valve port P 145. These four sealing rings effectively seal and isolate solenoid valve ports A 143, P 145, and B 147.

[0025] The downhole electro-hydraulic micro power unit also includes a one-way valve 8, an overflow valve 9, and a hydraulic control line clamp 11. The one-way valve 8 is installed in the electric pump mounting hole 1b, and the one-way valve 8 is in contact with the end face of the micro pump fixing end 64. The inner cavity of the one-way valve 8 is connected to the center hole of the micro pump fixing end 64. The overflow valve 9 is installed at the end of the electric pump mounting hole 1b near the micro oil tank 121, and the hydraulic control line clamp 11 is installed at the end of the overflow valve 9 near the micro oil tank 121. The presence of the hydraulic control line clamp 11 can prevent the overflow valve 9 from sliding out of the mounting hole under high hydraulic pressure.

[0026] A cavity is provided between the relief valve 9 and the check valve 8. This cavity is connected to the inlet end of the relief valve 9 and also communicates with the first circumferential hole 16. When the pressure at the output port of the check valve 8 exceeds the maximum pressure set by the relief valve 9, the relief valve 9 is opened, and excess hydraulic oil flows back to the miniature oil tank 121 through the relief valve 9, thus achieving the safety protection function of the entire main hydraulic pipeline. By installing a miniature relief valve 9 as a bypass at the outlet of the micro pump 62, the safety of the miniature hydraulic system is effectively achieved.

[0027] A micro motor 61 drives a micro pump 62 to provide downhole hydraulic power and control the fluid. A three-position four-way solenoid valve enables hydraulic reversing and unloading functions. The opening of the downhole flow control valve 22 can be adjusted via the three-position four-way solenoid valve, which is a prior art technology. A micro oil tank 121 provides the hydraulic oil source and is connected to the inlet and return oil lines. In actual operation, the micro motor 61 drives the micro pump 62 to pump hydraulic oil from the micro oil tank 121. The hydraulic oil enters the check valve 8 through the output port of the micro pump 62, and then is delivered by the check valve 8 to the solenoid valve assembly 14. Finally, the solenoid valve assembly 14 delivers the hydraulic oil to the downhole flow control valve 22 through the reversing function of the solenoid valve, so as to drive the downhole flow control valve 22 to work. When the pressure at the output port of the check valve 8 is greater than the maximum pressure set by the relief valve 9, the excess hydraulic oil flows back to the micro oil tank 121 through the relief valve 9.

[0028] The oil passage block 1 is a hollow tubular structure with male oil pipe threads at both ends and a cylinder of unequal diameter in the middle. In the middle protruding part of the oil passage block 1, there are seven axial holes of unequal diameter along the circumference, namely, solenoid valve mounting hole 1a, electric pump mounting hole 1b, oil injection hole 1c, second pipeline hole 1d, second pressure hole 1e, first pressure hole 1f, and first pipeline hole 1g. Among them, the solenoid valve mounting hole 1a, electric pump mounting hole 1b, and oil injection hole 1c respectively penetrate the two end faces of the middle protruding part of the oil passage block 1.

[0029] Multiple circumferential holes are provided on different cross-sections of the raised portion in the middle of the oil passage block 1, enabling communication between holes in different axial directions. Specifically, the solenoid valve mounting hole 1a and the electric pump mounting hole 1b are connected sequentially through the second circumferential hole 17 and the first circumferential hole 16. The solenoid valve mounting hole 1a, the first pressure hole 1f, and the first pipeline hole 1g are connected, with the solenoid valve mounting hole 1a and the first pressure hole 1f connected through the fourth circumferential hole 19, and the first pressure hole 1f and the first pipeline hole 1g connected through the third circumferential hole 18. The solenoid valve mounting hole 1a, the second pressure hole 1e, and the second pipeline hole 1d are connected, with the solenoid valve mounting hole 1a and the second pressure hole 1e connected through the fifth circumferential hole 20, and the second pressure hole 1e and the second pipeline hole 1d connected through the sixth circumferential hole 21.

[0030] The end of the solenoid valve mounting hole 1a near the micro-component receiving cavity is connected to the solenoid valve assembly 14. Preferably, the solenoid valve assembly 14 is threadedly connected to the solenoid valve mounting hole 1a. The end of the electric pump mounting hole 1b near the micro-component receiving cavity is connected to the electric pump assembly 6. A first output line 149 of the solenoid valve is installed on the first pipeline hole 1g. The end of the first output line 149 of the solenoid valve extends to the left end face of the front end cover 2 and is located outside the front end cover 2. A second output line 150 of the solenoid valve is installed on the second pipeline hole 1d. The end of the second output line 150 of the solenoid valve extends to the left end face of the front end cover 2 and is located outside the front end cover 2. A pressure gauge assembly 15 is installed on the first pressure hole 1f and the second pressure hole 1e respectively. Preferably, the two pressure gauge assemblies 15 are respectively connected to the first pressure hole 1f and the second pressure hole 1e. A pressure port 1f and a second pressure port 1e are threaded together. The pressure gauge assembly 15 is used to monitor the pressure of the output pipeline of the miniature three-position four-way solenoid valve in real time and feeds back the measured data to the control unit. The control unit is existing technology. The control unit is electrically connected to the pressure gauge 153, the three-position four-way solenoid valve, and the electric pump assembly 6. Through the control unit, the monitoring data fed back by the pressure gauge can be read, data processing and analysis can be performed, and the operation of the downhole miniature three-position four-way solenoid valve and the micro pump 62 can be automatically controlled to ensure the safety and stability of the system during operation. Specifically, the pressure gauge assembly 15 installed on the first pressure port 1f is used to measure the pressure of the hydraulic oil in the first output pipeline 149 of the solenoid valve; the pressure gauge assembly 15 installed on the second pressure port 1e is used to measure the pressure of the hydraulic oil in the second output pipeline 150 of the solenoid valve.

[0031] The pressure gauge assembly 15 includes a transition joint 151, a protective cylinder 152, a pressure gauge 153, a plug 154, and a core sealing plug 155. One end of the protective cylinder 152 is threadedly connected to the transition joint 151, and the other end is threadedly connected to the plug 154, forming a relatively sealed space within the protective cylinder 152 to house the pressure gauge 153. The threaded connection facilitates installation and disassembly while ensuring a tight connection. The pressure gauge 153 is housed inside the protective cylinder 152 and mounted on the transition joint 151. The protective cylinder 152 provides protection for the pressure gauge 153, shielding it from the harsh downhole environment. The position of the pressure gauge 153 within the protective cylinder 152 is determined by its structural characteristics through a specific structural design to ensure stable operation. The core sealing plug 155 is installed at the end of the plug 154 furthest from the protective cylinder 152. The core sealing plug 155, based on its structural characteristics, is designed to fit tightly with the plug 154.

[0032] A first pressure gauge sealing ring 156 is installed at the connection between the core sealing plug 155 and the plug 154, which can effectively prevent liquid from leaking from this part; a second pressure gauge sealing ring 157 is installed at the contact part between the plug 154 and the protective cylinder 152, which can ensure the seal between the plug 154 and the protective cylinder 152 and ensure the sealing of the entire pressure gauge assembly 15 and the external hydraulic system. A third pressure gauge sealing ring 158 is installed at the contact point between the transition joint 151 and the pressure gauge 153 to ensure the sealing between the pressure gauge 153 and the transition joint 151. The contact area between the transition joint 151 and the protective cylinder 152 is equipped with a fourth pressure gauge sealing ring 159, which can ensure the seal between the transition joint 151 and the protective cylinder 152 and guarantee the sealing of the entire pressure gauge assembly 15 connected to the external hydraulic system.

[0033] In practical applications, to reduce the difficulty of downhole installation, all components and mechanical structures of the electro-hydraulic micro-power unit are integrated into a single downhole sub. This effectively reduces the number of parts, and the sub can be threaded into downhole tools such as tubing or flow control valves, improving the overall compactness and reliability. The mechanical structure can withstand high temperatures and pressures, providing safety protection for the micro-hydraulic components.

[0034] The micro-pump 62, micro-motor 61, micro three-position four-way electromagnetic reversing valve, and pressure gauge 153 selected in this invention are capable of withstanding high temperatures in the downhole producing formation and are compact in size, being micro hydraulic components that are easy to integrate with mechanical structures. The entire downhole micro electro-hydraulic control device is designed as a mechanical short section, which connects to the downhole flow control valve 22 without a hydraulic control pipeline, avoiding the problem of long hydraulic pipelines passing through the packer, reducing the manufacturing difficulty of the packer, lowering the difficulty of downhole construction operations, and facilitating the realization of multi-layer intelligent well completion in the downhole.

[0035] In practical work, to better illustrate the function and implementation of the downhole electro-hydraulic micro-power unit, a schematic diagram of its hydraulic principle is shown below. Figure 13As shown, the entire device includes a miniature oil tank 121, a miniature motor 61, a miniature pump 62, a check valve 8, a relief valve 9, a three-position four-way solenoid valve, and a pressure gauge 153. The miniature motor 61 drives the miniature pump 62 to pump hydraulic oil from the miniature oil tank 121. The relief valve 9 serves as a pressure limiting protection in the main pipeline. The three-position four-way solenoid valve has its P port 145 as the oil inlet and its T port 141 as the oil return port. The T port 141 of the solenoid valve is connected to the miniature oil tank 121, and the A port 143 and B port 147 of the solenoid valve are the output ports. The hydraulic oil in the main pipeline is connected to the solenoid valve P port 145 of the three-position four-way solenoid valve after passing through the one-way valve 8. The solenoid valve A port 143 is connected to the second output line 150 of the solenoid valve, and the solenoid valve B port 147 is connected to the first output line 149 of the solenoid valve. Then, the first output line 149 and the second output line 150 of the solenoid valve are respectively connected to the two hydraulic control ends of the downhole flow control valve 22. The downhole flow control valve 22 is equivalent to a hydraulic cylinder, and the valve of the downhole flow control valve 22 is equivalent to the piston of the hydraulic cylinder. The three-position four-way solenoid valve has three positions: left (left coil energized), middle (left and right coils de-energized), and right (right coil energized). When both coils are de-energized, the three-position four-way solenoid valve is in the middle position, with solenoid valve A port 143, solenoid valve B port 147, and solenoid valve T port 141 fully conductive. This is equivalent to a hydraulic short circuit at both ends of the downhole flow control valve 22 and pressure relief to the miniature oil tank 121, so the downhole flow control valve 22 remains stationary. When the left coil of the three-position four-way solenoid valve is energized, solenoid valve P port 145 and solenoid valve A port 143 are conductive and connected to the left end of the downhole flow control valve 22, while solenoid valve B port 147 is de-energized. 47. When solenoid valve T port 141 is turned on and connected to the right end of downhole flow control valve 22, the piston of downhole flow control valve 22 moves to the right because solenoid valve A port 143 is high pressure and solenoid valve B port 147 is low pressure. When the coil at the right end of the three-position four-way solenoid valve is energized, solenoid valve P port 145 and solenoid valve B port 147 are turned on and connected to the right end of downhole flow control valve 22, while solenoid valve A port 143 and solenoid valve T port 141 are turned on and connected to the left end of downhole flow control valve 22. Because solenoid valve B port 147 is high pressure and solenoid valve A port 143 is low pressure, the piston of downhole flow control valve 22 moves to the left.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A downhole electro-hydraulic micro power unit, characterized in that: The system includes an oil manifold (1), a front cover (2), and an oil tank shell (12). The left end of the oil manifold (1) is connected to the front cover (2), and the right end is connected to the oil tank shell (12). Sealing rings are installed at the connection points between the oil manifold (1), the front cover (2), and the oil tank shell (12). Two cavities are formed between the oil manifold (1), the front cover (2), and the oil tank shell (12), one of which is a miniature oil tank (121), and the other is a miniature component receiving cavity. A circuit board (4) is mounted on the oil manifold (1). The system includes an electric pump assembly (6), a solenoid valve assembly (14), and two pressure gauge assemblies (15). The circuit board (4) is electrically connected to the solenoid valve assembly (14), the two pressure gauge assemblies (15), and the electric pump assembly (6). The micro oil tank (121) is connected to the micro component receiving cavity through the oil injection hole (1c) provided on the oil circuit block (1). When the downhole electric hydraulic control micro power device is in working condition, the hydraulic oil level in the micro component receiving cavity is higher than the inlet of the micro pump (62) in the electric pump assembly (6).

2. The downhole electro-hydraulic micro power unit according to claim 1, characterized in that: The oil passage block (1) is a hollow tubular structure with oil pipe male threads at both ends and a cylinder of unequal diameter in the middle. In the middle protruding part of the oil passage block (1), there are seven axial holes of unequal diameter along the circumference, namely, solenoid valve mounting hole (1a), electric pump mounting hole (1b), oil injection hole (1c), second pipeline hole (1d), second pressure hole (1e), first pressure hole (1f), and first pipeline hole (1g). Among them, the solenoid valve mounting hole (1a), electric pump mounting hole (1b) and oil injection hole (1c) respectively penetrate the two end faces of the middle protruding part of the oil passage block (1).

3. The downhole electro-hydraulic micro power unit according to claim 2, characterized in that: Multiple circumferential holes are provided on different cross sections of the protruding part in the middle of the oil passage block (1), which can realize the connection between different axial holes; The solenoid valve mounting hole (1a) and the electric pump mounting hole (1b) are connected sequentially through the second circumferential hole (17) and the first circumferential hole (16); The three holes, namely the solenoid valve mounting hole (1a), the first pressure hole (1f), and the first pipeline hole (1g), are connected. The solenoid valve mounting hole (1a) and the first pressure hole (1f) are connected through the fourth circumferential hole (19), and the first pressure hole (1f) and the first pipeline hole (1g) are connected through the third circumferential hole (18). The three holes, namely the solenoid valve mounting hole (1a), the second pressure hole (1e), and the second pipeline hole (1d), are connected. The solenoid valve mounting hole (1a) and the second pressure hole (1e) are connected through the fifth circumferential hole (20), and the second pressure hole (1e) and the second pipeline hole (1d) are connected through the sixth circumferential hole (21).

4. A downhole electro-hydraulic micro power unit according to claim 3, characterized in that: The end of the solenoid valve mounting hole (1a) near the micro-component receiving cavity is connected to the solenoid valve assembly (14), and the end of the electric pump mounting hole (1b) near the micro-component receiving cavity is connected to the electric pump assembly (6). The first output line (149) of the solenoid valve is installed on the first pipeline hole (1g). The end of the first output line (149) of the solenoid valve extends to the left end face of the front end cover (2) and is located outside the front end cover (2). The second output line (150) of the solenoid valve is installed on the second pipeline hole (1d). The end of the second output line (150) away from the second line hole (1d) extends to the left end face of the front cover (2) and is located outside the front cover (2). A pressure gauge assembly (15) is installed on the first pressure hole (1f) and the second pressure hole (1e). The pressure gauge assembly (15) installed on the first pressure hole (1f) is used to measure the pressure of the hydraulic oil in the first output line (149) of the solenoid valve. The pressure gauge assembly (15) installed on the second pressure hole (1e) is used to measure the pressure of the hydraulic oil in the second output line (150) of the solenoid valve.

5. A downhole electro-hydraulic micro power unit according to claim 1, characterized in that: The electric pump assembly (6) includes a micro motor (61), a micro pump (62), and a micro pump mounting end (64). The output shaft of the micro motor (61) is coaxially threaded with the input shaft of the micro pump (62). The outer side of the left end of the micro pump mounting end (64) is threaded with the micro pump (62), and the output port of the micro pump (62) is connected to the center hole of the micro pump mounting end (64). The right end of the micro pump mounting end (64) is installed on the electric pump mounting hole (1b), and the center hole of the micro pump mounting end (64) is connected to the electric pump mounting hole (1b). The inner side of the left end of the micro pump mounting end (64) is sealed with the micro pump (62) through an O-ring seal (63).

6. A downhole electro-hydraulic micro power unit according to claim 5, characterized in that: The downhole electro-hydraulic micro power unit also includes a check valve (8), an overflow valve (9), and a hydraulic control line sleeve (11). The check valve (8) is installed in the electric pump mounting hole (1b), and the end face of the check valve (8) and the micro pump fixed end (64) are in contact connection, and the inner cavity of the check valve (8) is connected to the center hole of the micro pump fixed end (64). The overflow valve (9) is installed at the end of the electric pump mounting hole (1b) near the micro oil tank (121), and the hydraulic control line sleeve (11) is installed at the end of the overflow valve (9) near the micro oil tank (121). A cavity is provided between the relief valve (9) and the check valve (8). The cavity is connected to the inlet end of the relief valve (9) and is also connected to the first circumferential hole (16). When the pressure at the output port of the check valve (8) is greater than the maximum pressure set by the relief valve (9), the relief valve (9) is turned on, and the excess hydraulic oil flows back to the miniature oil tank (121) through the relief valve (9).

7. A downhole electro-hydraulic micro power unit according to claim 5, characterized in that: The end of the micro motor (61) away from the micro pump (62) is connected to the motor end face fixing block (5), and the motor end face fixing block (5) is installed on the oil passage block (1).

8. A downhole electro-hydraulic micro power unit according to claim 1, characterized in that: The solenoid valve assembly (14) includes a solenoid valve and a sealing ring. The solenoid valve is provided with a solenoid valve T port (141), a solenoid valve A port (143), a solenoid valve P port (145), and a solenoid valve B port (147) at one end of the solenoid valve mounting hole (1a). A first solenoid valve sealing ring (142) is provided between the solenoid valve T port (141) and the solenoid valve A port (143). A second solenoid valve sealing ring (144) is provided between the solenoid valve A port (143) and the solenoid valve P port (145). A third solenoid valve sealing ring (146) is provided between the solenoid valve P port (145) and the solenoid valve B port (147). A fourth solenoid valve sealing ring (148) is provided at the end of the solenoid valve B port (147) away from the solenoid valve P port (145).

9. A downhole electro-hydraulic micro power unit according to claim 1, characterized in that: The pressure gauge assembly (15) includes a transition joint (151), a protective sleeve (152), a pressure gauge (153), a plug (154), and a core sealing plug (155). One end of the protective sleeve (152) is threadedly connected to the transition joint (151), and the other end is threadedly connected to the plug (154), so that the protective sleeve (152) forms a relatively sealed space to accommodate the pressure gauge (153). The pressure gauge (153) is placed inside the protective sleeve (152), and the pressure gauge (153) is mounted on the transition joint (151). The plug (154) 154) A core sealing plug (155) is installed at the end away from the protective cylinder (152); a first pressure gauge sealing ring (156) is installed at the connection between the core sealing plug (155) and the plug (154); a second pressure gauge sealing ring (157) is installed at the contact part between the plug (154) and the protective cylinder (152); a third pressure gauge sealing ring (158) is installed at the contact part between the transition joint (151) and the pressure gauge; and a fourth pressure gauge sealing ring (159) is installed at the contact part between the transition joint (151) and the protective cylinder (152).

10. A downhole electro-hydraulic micro power unit according to claim 1, characterized in that: A first O-ring is installed at the connection point between the left end of the front cover (2) and the oil circuit block (1), a second O-ring assembly (7) is installed at the connection point between the right end of the front cover (2) and the oil circuit block (1), a third O-ring is installed at the connection point between the left end of the oil tank shell (12) and the oil circuit block (1), and a fourth O-ring is installed at the connection point between the right end of the oil tank shell (12) and the oil circuit block (1).

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