Lightweight subsea intervention equipment pressure control head and grease injection hydraulic control system therefor

Abstract

A lightweight subsea intervention equipment pressure control head and a grease injection hydraulic control system therefor, belonging to the technical field of offshore oil engineering. The pressure control head comprises a grease injection assembly (1), a grease discharge assembly (2) and a grease sealing assembly (3); the grease injection assembly is provided with a sealing grease injection port (13); the grease injection assembly injects sealing grease via the sealing grease injection port; a first-direction end of the grease injection assembly is connected to the grease discharge assembly; the grease discharge assembly is provided with a sealing grease discharge port (26); a second-direction end of the grease injection assembly is connected to the grease sealing assembly; thus, the sealing grease injected via the sealing grease injection port can be discharged via the sealing grease discharge port for recovery, and the sealing grease can also be discharged to the grease sealing assembly for sealing. The pressure control head achieves dynamic sealing of fluids or gases by means of injection of lubricating grease.

Description

Underwater light intervention equipment pressure control head and grease injection hydraulic control system thereof TECHNICAL FIELD

[0001] The application belongs to the field of offshore oil engineering, and particularly relates to an underwater light intervention equipment pressure control head and a grease injection hydraulic control system thereof. BACKGROUND

[0002] With the increasing development of oil and gas resources in China, major oilfields are facing increasingly heavy operation and maintenance pressure. The rapid development of science and technology makes it possible to greatly reduce the operation and maintenance cost of oilfields. Therefore, digitalization and intelligentization are regarded as one of the main directions of oilfield development at home and abroad. At present, domestic oilfields mainly rely on drilling ships to support underwater intervention technology and operation mode. Such underwater intervention technology uses a riser device, has high maintenance cost, lacks mobile assets, and has long operation time. Therefore, research on underwater light intervention equipment pressure control heads is less.

[0003] Therefore, it is urgent to design an underwater light intervention equipment pressure control head and a grease injection hydraulic control system thereof to solve the above problems. TECHNICAL PROBLEM

[0004] At present, domestic oilfields mainly rely on drilling ships to support underwater intervention technology and operation mode. Such underwater intervention technology uses a riser device, has high maintenance cost, lacks mobile assets, and has long operation time. Therefore, research on underwater light intervention equipment pressure control heads is less. SOLUTION

[0005] The underwater light intervention equipment pressure control head and the grease injection hydraulic control system thereof have the advantages of realizing dynamic sealing of fluid or gas and solving the problems mentioned in the background.

[0006] To achieve the above-mentioned purpose, the specific technical solutions of the underwater light intervention equipment pressure control head and the grease injection hydraulic control system thereof are as follows:

[0007] The underwater light intervention equipment pressure control head comprises a grease injection assembly, a grease discharge assembly and a grease sealing assembly. The grease injection assembly is provided with a sealing grease injection port. The grease injection assembly injects sealing grease through the sealing grease injection port. The first direction end of the grease injection assembly is connected with the grease discharge assembly. The grease discharge assembly is provided with a sealing grease discharge port. The second direction end of the grease injection assembly is connected with the grease sealing assembly. The sealing grease injected through the sealing grease injection port can be discharged and recovered through the sealing grease discharge port, and the sealing grease can also be discharged to the grease sealing assembly for sealing.

[0008] Further, the grease injection assembly comprises an injection housing, an internal filling choke pipe is connected in the injection housing, the internal filling choke pipe is communicated with a sealing grease injection port, the sealing grease injection port is arranged on the injection housing, the internal filling choke pipe is provided with a discharge passage at a first direction end, the discharge passage of the internal filling choke pipe is communicated with a grease discharge assembly, and the internal filling choke pipe is provided with a sealing passage at a second direction end, and the sealing passage of the internal filling choke pipe is communicated with a grease sealing assembly.

[0009] Further, the grease discharge assembly comprises a discharge housing, a connecting pipeline is connected in the discharge housing, a second direction end of the connecting pipeline is connected with a first direction end of the internal filling choke pipe, and a second direction end of the connecting pipeline is connected with a sealing grease discharge port, and the sealing grease discharge port is arranged on the discharge housing.

[0010] Further, the grease discharge assembly further comprises a hollow cavity arranged in the discharge housing, a sealing filling gland is fixedly connected to a first direction end of the hollow cavity, a second direction end of the hollow cavity is connected with the connecting pipeline, a side end of the hollow cavity is communicated with the sealing grease discharge port, a filling support is slidably connected in the hollow cavity, a first spring is fixedly connected to the filling support, one end of the first spring away from the filling support is fixedly connected with the sealing filling gland, and the filling support is provided with a blocking state and a communication state.

[0011] When the filling support is in the blocking state, the filling support abuts against the connecting pipeline to block the connecting pipeline, so that the connecting pipeline is not communicated with the sealing grease discharge port.

[0012] When the filling support is in the communication state, the sealing grease in the connecting pipeline overcomes the elastic force of the first spring, so that the filling support slides to the first direction end, the filling support unblocks the connecting pipeline, and the connecting pipeline is communicated with the sealing grease discharge port.

[0013] Further, the grease sealing assembly comprises an upper connecting sleeve and a lower connecting sleeve, a sleeve connector is arranged between the upper connecting sleeve and the lower connecting sleeve, the upper connecting sleeve and the lower connecting sleeve are connected through the sleeve connector, a first direction end of the upper connecting sleeve is connected with the internal filling choke pipe, and the upper connecting sleeve and the lower connecting sleeve cooperate with the internal filling choke pipe to form a gap passage for the flow sealing of high-viscosity sealing grease.

[0014] Further, the grease sealing assembly further comprises a lower sleeve head, the lower sleeve head is fixedly connected with a second direction end of the lower connecting sleeve, a bottom blocking outer shell is fixedly connected to the lower sleeve head, a bottom blocking copper sleeve and a bottom blocking pressing block are arranged in the bottom blocking outer shell, and the bottom blocking copper sleeve and the bottom blocking pressing block form a gap passage to reduce the leakage amount into the wellbore during the high sealing grease injection process.

[0015] Further, a tool capture assembly is connected with the second direction end of the grease injection sealing assembly, and the tool capture assembly is connected with the grease injection sealing assembly through an assembly connector;

[0016] The tool capture assembly comprises an upper shell and a lower shell, the upper shell and the lower shell are connected through a shell connector, and the lower shell is provided with an elastic lock claw.

[0017] Further, the upper shell is fixedly connected with a tool filling gland, the upper shell is fixedly connected with a second spring, one end of the second spring away from the upper shell is fixedly connected with an elastic lock claw hanging ring, the elastic lock claw hanging ring is fixedly connected with a hydraulic drive moving liner, the hydraulic drive moving liner is used for controlling whether the elastic lock claw is locked, and the shell connector is provided with a connecting joint, hydraulic oil can be injected into the shell connector through the connecting joint, and the elastic force of the second spring is offset through the hydraulic oil.

[0018] A grease injection hydraulic control system is used for injecting grease into a pressure control head of underwater light intervention equipment, and the hydraulic control system comprises a hydraulic pump and an overflow valve, a sealing grease storage tank is connected with the discharge end of the hydraulic pump through a hydraulic pipeline, the sealing grease storage tank is connected with the inlet end of the overflow valve through a hydraulic pipeline, an energy accumulator is connected between the sealing grease storage tank and the overflow valve through a hydraulic pipeline, a first gate valve is connected with the discharge end of the overflow valve through a hydraulic pipeline, the first gate valve is connected with a sealing grease injection inlet through a hydraulic pipeline, and a first check valve is connected on the hydraulic pipeline between the first gate valve and the sealing grease injection inlet.

[0019] The hydraulic control system comprises a sealing grease recovery tank, the sealing grease recovery tank is connected with the sealing grease storage tank through a hydraulic pipeline, a second check valve is arranged on the hydraulic pipeline between the sealing grease recovery tank and the sealing grease storage tank, a second gate valve is connected with the sealing grease recovery tank through a hydraulic pipeline, the second gate valve is connected with a sealing grease discharge outlet through a hydraulic pipeline, and a third check valve is connected on the hydraulic pipeline between the second gate valve and the sealing grease discharge outlet. Advantages

[0020] The present application has the following advantages:

[0021] 1. Dynamic lubrication sealing: by injecting lubricating grease, dynamic sealing of fluid or gas is realized. The lubricating grease injection stop valve is used for controlling the injection and sealing of the lubricating grease, and ensures the sealing performance and operation reliability of the system.

[0022] 2. Tool string capture: the tool capture device can automatically lock the downhole tool string, and ensure the safe fixation. The tool capture device adopts a normally closed design, is opened through a hydraulic mode, and is combined with the packing seal box design, so that the space is saved.

[0023] 3. Double-seal case provides redundant sealing: The double-seal case provides redundant sealing for the seal case to increase the reliability of the system. Each rubber element is equipped with a grease injection point to ensure sealing effect and lubrication performance.

[0024] 4. Precise control of grease injection: Pressure and temperature sensors and flow sensors are used to monitor the pressure, temperature and flow changes of the grease in the system. It provides real-time working parameter feedback to ensure the safe operation of the system. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a structural schematic diagram of the pressure control head and hydraulic control system of the present application;

[0026] Figure 2 is a structural schematic diagram of the pressure control head of the present application;

[0027] Figure 3 is a structural schematic diagram of the grease injection assembly, grease discharge assembly and grease sealing assembly of the present application;

[0028] Figure 4 is a structural schematic diagram of the tool capture assembly of the present application;

[0029] Figure 5 is a structural schematic diagram of the grease hydraulic control system of the present application;

[0030] Marked in the figure: 1, grease injection assembly; 11, injection housing; 12, internal filling choke tube; 13, sealing grease injection port; 2, grease discharge assembly; 21, discharge housing; 22, filling support; 23, sealing filling gland; 24, first spring; 25, hollow cavity; 26, sealing grease discharge port; 27, connecting pipeline; 3, grease sealing assembly; 31, upper connecting sleeve; 32, sleeve connector; 33, lower connecting sleeve; 34, lower sleeve head; 35, bottom plug outer shell; 36, bottom plug copper sleeve; 37, bottom plug pressing block; 4, assembly connector; 5, tool capture assembly; 51, upper housing; 52, housing connector; 53, lower housing; 54, tool filling gland; 55, second spring; 56, elastic lock jaw hanging ring; 57, hydraulic drive moving liner; 58, elastic lock jaw; 6, hydraulic pump; 61, third one-way valve; 62, second gate valve; 63, sealing grease recovery tank; 64, second one-way valve; 65, sealing grease storage tank; 66, accumulator; 67, overflow valve; 68, first gate valve; 69, first one-way valve. Embodiment of the present application

[0031] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of the present application.

[0032] Those skilled in the art can understand that the combination of features of different embodiments means to be within the scope of the present application and form different embodiments, although some embodiments herein include certain features instead of other features included in other embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0033] One underwater light intervention equipment pressure control head and a grease injection hydraulic control system thereof are described below with reference to FIGS. 1 to 5.

[0034] The underwater light intervention equipment pressure control head comprises a grease injection assembly 1, a grease discharge assembly 2 and a grease sealing assembly 3. The grease injection assembly 1 is provided with a grease injection inlet 13. The grease injection assembly 1 injects sealing grease through the grease injection inlet 13. The first direction end A of the grease injection assembly 1 is connected with the grease discharge assembly 2. The grease discharge assembly 2 is provided with a grease discharge outlet 26. The second direction end B of the grease injection assembly 1 is connected with the grease sealing assembly 3. The sealing grease injected through the grease injection inlet 13 can be discharged and recovered through the grease discharge outlet 26. The sealing grease can also be discharged to the grease sealing assembly 3 for sealing.

[0035] The grease discharge outlet 26 is provided to realize dynamic circulation of the sealing grease.

[0036] The grease injection assembly 1 comprises an injection housing 11. An internal filling choke pipe 12 is connected in the injection housing 11. The internal filling choke pipe 12 is in communication with the grease injection inlet 13. The grease injection inlet 13 is arranged on the injection housing 11. The internal filling choke pipe 12 is provided with a discharge passage at the first direction end A. The discharge passage of the internal filling choke pipe 12 is in communication with the grease discharge assembly 2. The internal filling choke pipe 12 is provided with a sealing passage at the second direction end B. The sealing passage of the internal filling choke pipe 12 is in communication with the grease sealing assembly 3.

[0037] The grease discharge assembly 2 comprises a discharge housing 21. A connecting pipeline 27 is connected in the discharge housing 21. The second direction end B of the connecting pipeline 27 is connected with the first direction end A of the internal filling choke pipe 12. The second direction end B of the connecting pipeline 27 is connected with the grease discharge outlet 26. The grease discharge outlet 26 is arranged on the discharge housing 21.

[0038] The grease discharging assembly 2 further comprises a hollow cavity 25 formed in the discharging shell 21, a first direction end A of the hollow cavity 25 is fixedly connected with a sealing filling gland 23, a second direction end B of the hollow cavity 25 is connected with the connecting pipeline 27, a side end of the hollow cavity 25 is communicated with the sealing grease discharging outlet 26, and a filling support 22 is slidably connected in the hollow cavity 25, the filling support 22 is fixedly connected with a first spring 24, one end of the first spring 24 away from the filling support 22 is fixedly connected with the sealing filling gland 23, and the filling support 22 is provided with a blocking state and a communicating state.

[0039] When the filling support 22 is in the blocking state, the filling support 22 abuts against the connecting pipeline 27 to block the connecting pipeline 27, so that the connecting pipeline 27 is not communicated with the sealing grease discharging outlet 26.

[0040] When the filling support 22 is in the communicating state, the sealing grease in the connecting pipeline 27 overcomes the elastic force of the first spring 24, so that the filling support 22 slides to the first direction end A, the filling support 22 unblocks the connecting pipeline 27, and the connecting pipeline 27 is communicated with the sealing grease discharging outlet 26.

[0041] The fixed connection mode of the hollow cavity 25 and the sealing filling gland 23 is preferably fixed by locking screws, and in other embodiments of the application, other fixed modes can also be selected as long as the hollow cavity 25 and the sealing filling gland 23 can be fixed.

[0042] The first spring 24 is arranged to realize pressure holding and isolation of the external environment, and the filling support 22 is arranged to control the pressure of the discharged sealing grease.

[0043] Preferably, the first spring 24 is a pressure-resistant spring, and in other embodiments of the application, other types of springs can also be selected.

[0044] Preferably, the filling support 22 is a rubber element filling support 22, and in other embodiments of the application, other types of filling supports 22 can also be selected.

[0045] An asperity surface type steel pipe flange asbestos rubber gasket is arranged at the connection between the hollow cavity 25 and the sealing filling gland 23 to prevent leakage.

[0046] An asperity surface type steel pipe flange asbestos rubber gasket is arranged at the connection between the hollow cavity 25 and the connecting pipeline 27 to prevent leakage.

[0047] An asperity surface type steel pipe flange asbestos rubber gasket is arranged at the connection between the connecting pipeline 27 and the injection shell 11 to prevent leakage.

[0048] The discharging shell 21 and the connecting pipeline 27 are fixedly connected by a hydraulic locking joint.

[0049] The injection housing 11 is fixedly connected with the upper connecting sleeve 31 through a hydraulic locking joint.

[0050] The grease injection sealing assembly 3 comprises the upper connecting sleeve 31 and the lower connecting sleeve 33, and the sleeve connector 32 is arranged between the upper connecting sleeve 31 and the lower connecting sleeve 33. The upper connecting sleeve 31 is connected with the lower connecting sleeve 33 through the sleeve connector 32. The first direction end A of the upper connecting sleeve 31 is connected with the internal filling choke pipe 12. The upper connecting sleeve 31 and the lower connecting sleeve 33 cooperate with the internal filling choke pipe 12 to form a gap channel for the flow sealing of high-viscosity sealing grease.

[0051] The grease injection sealing assembly 3 further comprises a lower sleeve head 34 fixedly connected with the second direction end B of the lower connecting sleeve 33. The bottom plug housing 35 is fixedly connected to the lower sleeve head. The bottom plug copper sleeve 36 and the bottom plug pressing block 37 are arranged in the bottom plug housing. The gap channel is formed between the bottom plug copper sleeve 36 and the bottom plug pressing block 37 to reduce the leakage amount into the wellbore during the high sealing grease injection process.

[0052] The control head further comprises a tool capturing assembly 5 connected with the second direction end B of the grease injection sealing assembly 3. The tool capturing assembly 5 is connected with the grease injection sealing assembly 3 through the assembly connector 4.

[0053] The tool capturing assembly 5 comprises an upper housing 51 and a lower housing 53. The upper housing 51 is connected with the lower housing 53 through a housing connector 52. The lower housing 53 is provided with an elastic locking claw 58 which can lock the tool string through elastic deformation.

[0054] Further, the tool filling pressing cover 54 is fixedly connected to the upper housing 51. The second spring 55 is fixedly connected to the upper housing 51. The elastic locking claw hanging ring 57 is fixedly connected to the end of the second spring 55 away from the upper housing 51. The hydraulic drive moving liner 57 is fixedly connected to the elastic locking claw hanging ring 57. The hydraulic drive moving liner 57 is used to control whether the elastic locking claw 58 is locked. The connecting joint is arranged on the housing connector 52. Hydraulic oil can be injected into the housing connector 52 through the connecting joint to offset the elastic force of the second spring 55.

[0055] The tool capturing assembly 5 can automatically lock the tool string into the well to ensure its safe fixation. The tool capturing assembly 5 adopts a normally closed design and is opened through a hydraulic mode. The tool capturing assembly 5 is combined with the packing seal box design to save space.

[0056] The grease injection hydraulic control system injects grease to the pressure control head of the underwater light intervention equipment, and the hydraulic control system comprises a hydraulic pump 6 and an overflow valve 67, the discharge end of the hydraulic pump 6 is connected with a sealing grease storage tank 65 through a hydraulic pipeline, the sealing grease storage tank 65 is connected with the inlet end of the overflow valve 67 through a hydraulic pipeline, an energy accumulator 66 is connected between the sealing grease storage tank 65 and the overflow valve 67 through a hydraulic pipeline, the discharge end of the overflow valve 67 is connected with a first gate valve 68 through a hydraulic pipeline, the first gate valve 68 is connected with a sealing grease injection inlet 13 through a hydraulic pipeline, and a first check valve 69 is connected on the hydraulic pipeline between the first gate valve 68 and the sealing grease injection inlet 13.

[0057] The hydraulic control system comprises a sealing grease recovery tank 63, the sealing grease recovery tank 63 is connected with the sealing grease storage tank 65 through a hydraulic pipeline, a second check valve 64 is arranged on the hydraulic pipeline between the sealing grease recovery tank 63 and the sealing grease storage tank 65, a second gate valve 62 is connected on the sealing grease recovery tank 63 through a hydraulic pipeline, the second gate valve 62 is connected with a sealing grease discharge outlet 26 through a hydraulic pipeline, and a third check valve 61 is connected on the hydraulic pipeline between the second gate valve 62 and the sealing grease discharge outlet 26.

[0058] The hydraulic pump 6 is arranged to provide initial pressure for high-viscosity sealing grease, the overflow valve 67 is arranged to protect the hydraulic pump 6, the energy accumulator 66 is arranged to serve as a temporary functional element and provide pressure for the sealing grease, the first gate valve 68 and the second gate valve 62 are arranged to cooperate with the control end to realize the closing of the sealing grease injection circuit, and the first check valve 69, the second check valve 64 and the third check valve 61 are arranged to control the flow direction of the sealing grease.

[0059] The grease injection hydraulic control system is arranged to realize the dynamic circulation of high-viscosity sealing grease.

[0060] The present application has the following advantages:

[0061] 1. Dynamic lubrication sealing: The injection of lubricating grease realizes the dynamic sealing of fluid or gas. The lubricating grease injection stop valve is used to control the injection and sealing of lubricating grease, and ensures the sealing performance and the reliability of the system.

[0062] 2. Tool string capture: The tool capture device can automatically lock the tool string into the well, and ensure the safe fixation. The tool capture device adopts a normally closed design and is opened through a hydraulic mode, and is combined with the packing seal box design, so that the space is saved.

[0063] 3. Double seal box provides redundant sealing: The double seal box provides redundant sealing for the seal box, so as to increase the reliability of the system. One lubricating grease injection point is arranged between each rubber element, so as to ensure the sealing effect and lubrication performance.

[0064] 4. Precise control of grease injection: pressure temperature sensor and flow sensor are used to monitor the pressure, temperature and flow changes of the grease in the system. It provides real-time working parameter feedback to ensure the safe operation of the system.

[0065] Obviously, the above embodiments of the present application are only examples for the purpose of clarity, and are not intended to limit the embodiments of the present application. For those skilled in the art, other different forms of changes or variations can be made on the basis of the above description. Here, it is not necessary and impossible to exhaust all the embodiments. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application. Industrial applicability

[0066] The underwater light intervention equipment pressure control head and its grease injection hydraulic control system can provide real-time working parameter feedback to ensure the safe operation of the system, save space and have the advantage of realizing dynamic sealing of fluid or gas.

Claims

1. A pressure control head for a lightweight underwater intervention device, characterized in that, It includes a grease injection assembly, a grease discharge assembly, and a grease sealing assembly. The grease injection assembly is provided with a grease injection port, through which grease is injected. The grease injection assembly is connected to the grease discharge assembly in a first direction. The grease discharge assembly is provided with a grease discharge port. The grease injection assembly is connected to the grease sealing assembly in a second direction, so that the grease injected through the grease injection port can be discharged and recycled through the grease discharge port, or the grease can be discharged to the grease sealing assembly for sealing.

2. The pressure control head for underwater lightweight intervention equipment according to claim 1, characterized in that, The grease injection assembly includes an injection housing, an internal filling obstruction tube connected inside the injection housing, the internal filling obstruction tube communicating with the grease injection port, the grease injection port being located on the injection housing, the internal filling obstruction tube having a discharge channel in a first direction communicating with the grease discharge assembly, and the internal filling obstruction tube having a sealing channel at a second direction end communicating with the grease sealing assembly.

3. The pressure control head for underwater lightweight intervention equipment according to claim 2, characterized in that, The grease discharge assembly includes a discharge housing, a connecting pipe connected inside the discharge housing, a second-direction end of the connecting pipe connected to a first-direction end of the internal filling baffle tube, and a sealing grease discharge outlet located on the discharge housing.

4. The pressure control head for underwater lightweight intervention equipment according to claim 3, characterized in that, The grease discharge assembly also includes a hollow cavity formed in the discharge housing. A sealing filling cap is fixedly connected to the first direction end of the hollow cavity, the second direction end of the hollow cavity is connected to the connecting pipeline, the side end of the hollow cavity is connected to the sealing grease discharge outlet, a filling bracket is slidably connected in the hollow cavity, a first spring is fixedly connected to the filling bracket, the end of the first spring away from the filling bracket is fixedly connected to the sealing filling cap, and the filling bracket has a blocking state and a connecting state. When the filler bracket is in the blocked state, the filler bracket abuts against the connecting pipe, blocking the connecting pipe and preventing the connecting pipe from being connected to the sealing grease outlet; When the filling support is in the connected state, the sealing grease in the connecting pipe overcomes the elastic force of the first spring, causing the filling support to slide towards the first direction end, so that the filling support can unblock the connecting pipe, and the connecting pipe is connected to the sealing grease outlet.

5. The pressure control head for underwater lightweight intervention equipment according to claim 2, characterized in that, The grease-filling sealing assembly includes an upper connecting sleeve and a lower connecting sleeve. A sleeve connector is provided between the upper and lower connecting sleeves, and the upper and lower connecting sleeves are connected through the sleeve connector. The first direction end of the upper connecting sleeve is connected to the internal filling flow-blocking tube. The upper and lower connecting sleeves and the internal filling flow-blocking tube cooperate to form a gap channel for high-viscosity sealing grease to flow and seal.

6. The pressure control head for underwater lightweight intervention equipment according to claim 5, characterized in that, The grease-sealing assembly also includes a lower casing head, which is fixedly connected to the second direction end of the lower connecting casing. A bottom plug shell is fixedly connected to the lower casing head, and a bottom plug copper sleeve and a bottom plug pressure block are provided inside the bottom plug shell. A gap channel is formed between the bottom plug copper sleeve and the bottom plug pressure block to reduce the amount of leakage into the wellbore during the injection of high-sealing grease.

7. The pressure control head for underwater lightweight intervention equipment according to claim 1, characterized in that, It also includes a tool capture assembly, which is connected to the second direction end of the grease injection sealing assembly, and the tool capture assembly and the grease injection sealing assembly are connected via an assembly connector; The tool capture assembly includes an upper housing and a lower housing, which are connected by a housing connector. The lower housing is equipped with an elastic locking claw, which can lock the tool string through elastic deformation.

8. The pressure control head for underwater lightweight intervention equipment according to claim 7, characterized in that, A tool filling cap is fixedly connected to the upper housing, and a second spring is fixedly connected to the upper housing. An elastic locking claw ring is fixedly connected to the end of the second spring away from the upper housing. A hydraulically driven moving liner is fixedly connected to the elastic locking claw ring. The hydraulically driven moving liner is used to control whether the elastic locking claw is locked. A connection joint is provided on the housing connector, and hydraulic oil can be injected into the housing connector through the connection joint. The hydraulic oil cancels out the elastic force of the second spring.

9. A grease injection hydraulic control system, characterized in that, Grease is injected into the pressure control head of the underwater lightweight intervention equipment according to any one of claims 1-8. The hydraulic control system includes a hydraulic pump and an overflow valve. The outlet end of the hydraulic pump is connected to a grease storage tank via a hydraulic pipeline. The grease storage tank is connected to the inlet end of the overflow valve via a hydraulic pipeline. An accumulator is connected to the hydraulic pipeline between the grease storage tank and the overflow valve. The outlet end of the overflow valve is connected to a first gate valve via a hydraulic pipeline. The first gate valve is connected to the grease injection port via a hydraulic pipeline. A first check valve is connected to the hydraulic pipeline between the first gate valve and the grease injection port.

10. The grease injection hydraulic control system according to claim 9, characterized in that, The hydraulic control system includes a grease recovery tank, which is connected to a grease storage tank via a hydraulic line. A second check valve is installed on the hydraulic line between the grease recovery tank and the grease storage tank. A second gate valve is connected to the grease recovery tank via a hydraulic line. The second gate valve is connected to the grease discharge outlet via a hydraulic line. A third check valve is connected to the hydraulic line between the second gate valve and the grease discharge outlet.

Images