Injection increasing wellhead protection device

Abstract

The invention provides an augmented injection well mouth protection device which comprises a liquid conveying assembly, a stroke propelling device and a plugging assembly which are sequentially connected, a liquid injection device injects liquid into the liquid conveying assembly, the liquid enters an oil well through the stroke propelling device and the plugging assembly, and the stroke propelling device is set at an oil well mouth. The plugging assembly extends into the oil well, the stroke propelling device comprises a stroke propelling component and a stroke control assembly, the stroke propelling component is connected with the liquid conveying assembly, the stroke control assembly is connected with the stroke propelling component, the plugging assembly is connected with the stroke propelling assembly, and the stroke control assembly can control the stroke propelling assembly to move. The stroke propelling assembly drives the plugging assembly to complete plugging at the preset position in the oil well in the moving process, and therefore an oil well opening can be isolated from high-pressure fluid in the oil well, the effect of protecting the oil well opening is achieved, the oil well opening can bear large pressure, and the work of energy increasing water injection can be completed.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield development, and in particular relates to an injection-enhanced wellhead protection device for plugging in an oil well. Background Art

[0002] As oilfield development enters the middle and late stages, conventional water injection to supplement energy can no longer meet the dynamic exploitation requirements of "replenishing energy and increasing oil production", especially for some high-pressure, low-porosity and low-permeability oil reservoirs that lack effective development methods. They generally face the dilemma of "high pressure, no injection, no production, low mobilization level and high production costs".

[0003] The target well group is enhanced with "ultra-high pressure and large displacement" water injection by using a fracturing vehicle group, which can replenish the old formation deficit in a short period of time, increase the reservoir pressure, and reconstruct the "flow field" of the well group to achieve the purpose of improving the recovery rate. However, the energy-enhanced throughput technology is mainly used in high-pressure, low-porosity, and low-permeability oil reservoirs with deep burial depth and high temperature, and has high construction pressure (70MPa), frequent pressure fluctuations, large displacement (1-3m3 / min), and large injection volume (1×104m3). The wellhead requires a 700-type Christmas tree. Conventional 250-type and 350-type water injection wellheads cannot meet the requirements of energy-enhanced water injection due to their limited pressure. The 700-type Christmas tree can withstand the operating pressure during the energy-enhanced water injection period, but replacing the 700-type Christmas tree during the energy-enhanced water injection period will undoubtedly increase the operating cost and construction time.

[0004] Based on the above situation, a device for protecting the wellhead is currently used, which can withstand greater pressure during energy-boosting water injection. The device lowers the delivery rod into the well through the hydraulic cylinder assembly, and the acid is delivered to the well through the delivery rod. After the packer of the wellhead protection device is set, the pressure of the squeezed acid acts on the oil pipe below the packer rubber cylinder, thereby protecting the wellhead device. The pressure of the squeezed acid does not directly act on the wellhead device, and there is no need to replace the original wellhead device. However, there are obvious weaknesses. First, the downward movement of the packer requires multiple hydraulic cylinders to move synchronously, and there is a problem of inconsistent pace; second, there is no connecting valve above the packer. When the packer enters the oil pipe, the pressure difference between the inside and the outside is easy to shear the rubber cylinder.

[0005] Based on the above, there is an urgent need to provide an enhanced injection and protection wellhead device, which can perform energy-enhanced water injection operations without replacing the 700-type oil production tree and is easy to install and disassemble. Summary of the invention

[0006] The present invention provides an injection-enhancing and protecting wellhead device, which is easy to install and disassemble, can protect the oil wellhead, enable the oil wellhead to withstand greater pressure, and can perform energy-enhancing water injection operations without using a 700-type Christmas tree.

[0007] In view of this, the present invention proposes an injection and protection wellhead device, which includes: a liquid conveying component, one end of which can be connected to a liquid injection device; a stroke propulsion device, which is sealed at the oil wellhead and connected to the other end of the liquid conveying component, and includes a stroke propulsion component and a stroke control component, the stroke propulsion component is connected to the liquid conveying component, and the stroke control component is connected to the stroke propulsion component; a plugging component, which is connected to the stroke propulsion component, and the stroke propulsion device drives the plugging component to move up and down in the oil well, so that the plugging component completes the plugging at a preset position inside the oil well.

[0008] In some optional embodiments, the liquid delivery assembly includes a first joint assembly, a liquid delivery pipeline and a second joint assembly, the first joint assembly is connected to the liquid injection device, the first joint assembly, the liquid delivery pipeline and the second joint assembly are connected in sequence, and the second joint assembly is connected to the stroke propulsion component.

[0009] In some optional embodiments, the first joint assembly includes a union joint and a first plug valve, the liquid delivery pipeline is a high-pressure hose, and the second joint assembly includes a first elbow, a second plug valve and a second elbow; the union joint is connected to the liquid injection device, the union joint, the first plug valve, the high-pressure hose, the first elbow, the second plug valve and the second elbow are connected in sequence, and the second elbow is connected to the stroke propulsion component.

[0010] In some optional embodiments, the stroke propulsion component includes a flange fixing component and a hydraulic propulsion component, and the hydraulic propulsion component is respectively connected to the flange fixing component and the blocking component; the stroke control component is connected to the hydraulic propulsion component.

[0011] In some optional embodiments, the flange fixing assembly includes a first fixing flange, a first piston rod, and a second fixing flange, the first fixing flange, the first piston rod, and the second fixing flange are connected in sequence, the first fixing flange is connected to the second joint assembly, and the second fixing flange is connected to the hydraulic propulsion component.

[0012] In some optional embodiments, the hydraulic propulsion component includes a first piston, a second piston rod, a hydraulic cylinder and a sealing flange, the two ends of the hydraulic cylinder are respectively connected to the second fixed flange and the sealing flange, the first piston is arranged inside the hydraulic cylinder, one end of the second piston rod is connected to the first piston, and the other end passes through the sealing flange and is connected to the sealing assembly.

[0013] In some optional embodiments, the sealing assembly includes a first joint, a center tube, a second piston, a rubber tube sleeve, a sealing rubber tube, a thrust rubber tube and a second joint, the first joint, the center tube, the thrust rubber tube and the second joint are connected in sequence, the rubber tube sleeve and the sealing rubber tube are sequentially sleeved on the outside of the center tube, the second piston is arranged inside the first joint, and the second piston is connected to the second piston rod.

[0014] In some optional embodiments, the stroke control assembly includes an upper stroke control assembly and a lower stroke control assembly, and the upper stroke control assembly and the lower stroke control assembly are connected to the hydraulic cylinder.

[0015] In some optional embodiments, the upstroke control assembly includes an upstroke hose, a first pressure relief valve, a first one-way valve and a first pressurizing component, the first interface end of the upstroke hose is connected to the hydraulic cylinder, the second interface end of the upstroke hose is connected to the first pressurizing component, and the pressure relief valve and the one-way valve are arranged at the second interface end.

[0016] In some optional embodiments, the downstroke control assembly includes a downstroke hose, a second pressure relief valve, a second one-way valve and a second pressurizing component, the third interface end of the downstroke hose is connected to the hydraulic cylinder, the fourth interface end of the downstroke hose is connected to the second pressurizing component, and the second pressure relief valve and the second one-way valve are arranged at the fourth interface end.

[0017] Compared with the prior art, the present invention has the following technical effects:

[0018] The present invention proposes an injection wellhead protection device, which comprises: a liquid conveying component, a stroke propulsion device and a plugging component, wherein the stroke propulsion device is respectively connected to the liquid conveying component and the plugging component, the liquid conveying component is connected to the liquid injection device, the liquid injection device injects liquid into the liquid conveying component, the liquid enters the oil well through the stroke propulsion device and the plugging component, the stroke propulsion device is sealed at the oil wellhead, the plugging component extends to the inside of the oil well, the stroke propulsion device comprises a stroke propulsion component and a stroke control component, the stroke propulsion component is connected to the liquid conveying component, the stroke control component is connected to the stroke propulsion component, the plugging component is connected to the stroke propulsion component, the stroke control component can control the movement of the stroke propulsion component, and the stroke propulsion component drives the plugging component to complete the plugging at a preset position inside the oil pipe during the movement, thereby isolating the oil wellhead from the high-pressure fluid in the oil well, playing a role in protecting the oil wellhead, enabling the oil wellhead to withstand a large pressure, and performing energy-enhanced water injection operations without using a 700-type oil production tree. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0020] Figure 1 A schematic diagram of the structure of an injection protection wellhead device provided in one embodiment of the present invention;

[0021] Figure 2 A schematic cross-sectional view of a wellhead protection device for injection enhancement provided in one embodiment of the present invention;

[0022] Figure 3 A schematic structural diagram of a blocking assembly provided in one embodiment of the present invention.

[0023] in, Figures 1 to 3 The corresponding relationship between the reference numerals and component names in the figure is:

[0024] 1-liquid delivery assembly; 11-union joint; 12-first plug valve; 13-liquid delivery pipeline; 14-first elbow; 15-second plug valve; 16-second elbow; 2-stroke propulsion device; 21-stroke propulsion component; 211-first fixed flange; 212-first piston rod; 213-second fixed flange; 214-first piston; 215-second piston rod; 216-hydraulic cylinder; 217-sealing flange; 22- Stroke control assembly; 221-upper stroke hose; 222-first pressure relief valve; 223-first non-return valve; 224-first pressurizing component; 225-lower stroke hose; 226-second pressure relief valve; 227-second non-return valve; 228-second pressurizing component; 3-sealing assembly; 31-first joint; 32-center tube; 33-second piston; 34-rubber cylinder sheath; 35-sealing rubber cylinder; 36-thrust rubber cylinder; 37-second joint. DETAILED DESCRIPTION

[0025] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0026] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0027] As oilfield development enters the middle and late stages, conventional water injection to supplement energy can no longer meet the dynamic exploitation requirements of "replenishing energy and increasing oil production", especially for some high-pressure, low-porosity and low-permeability oil reservoirs that lack effective development methods. They generally face the dilemma of "high pressure, no injection, no production, low mobilization level and high production costs".

[0028] The target well group is enhanced with "ultra-high pressure and large displacement" water injection by using a fracturing vehicle group, which can replenish the old formation deficit in a short period of time, increase the reservoir pressure, and reconstruct the "flow field" of the well group to achieve the purpose of improving the recovery rate. However, the energy-enhanced throughput technology is mainly used in high-pressure, low-porosity, and low-permeability oil reservoirs with deep burial depth and high temperature, and has high construction pressure (70MPa), frequent pressure fluctuations, large displacement (1-3m3 / min), and large injection volume (1×104m3). The wellhead requires a 700-type Christmas tree. Conventional 250-type and 350-type water injection wellheads cannot meet the requirements of energy-enhanced water injection due to their limited pressure. The 700-type Christmas tree can withstand the operating pressure during the energy-enhanced water injection period, but replacing the 700-type Christmas tree during the energy-enhanced water injection period will undoubtedly increase the operating cost and construction time.

[0029] Based on the above situation, a device for protecting the wellhead is currently used, which can withstand greater pressure during energy-boosting water injection. The device lowers the delivery rod into the well through the hydraulic cylinder assembly, and the acid is delivered to the well through the delivery rod. After the packer of the wellhead protection device is set, the pressure of the squeezed acid acts on the oil pipe below the packer rubber cylinder, thereby protecting the wellhead device. The pressure of the squeezed acid does not directly act on the wellhead device, and there is no need to replace the original wellhead device. However, there are obvious weaknesses. First, the downward movement of the packer requires multiple hydraulic cylinders to move synchronously, and there is a problem of inconsistent pace; second, there is no connecting valve above the packer. When the packer enters the oil pipe, the pressure difference between the inside and the outside is easy to shear the rubber cylinder.

[0030] The present invention provides an injection-enhancing and protective wellhead device, which is easy to install and disassemble, can protect the wellhead device, enable the oil wellhead to withstand greater pressure, and can perform energy-enhancing water injection operations without using a 700-type Christmas tree.

[0031] The present invention provides an injection and protection wellhead device, comprising: a liquid conveying component 1, connected to a liquid injection device; a stroke propulsion device 2, which is sealed at the oil wellhead and connected to the other end of the liquid conveying component 1, and comprises a stroke propulsion component 21 and a stroke control component 22, the stroke propulsion component 21 is connected to the liquid conveying component 1, and the stroke control component 22 is connected to the stroke propulsion component 21, driving the stroke propulsion component 21 to move in the depth direction of the oil well; a plugging component 3, which extends to the inside of the oil well and is connected to the stroke propulsion component 21, and the stroke propulsion device 2 drives the plugging component 3 to move up and down in the oil well, so that the plugging component 3 completes the plugging at a preset position inside the oil well.

[0032] Specifically, the stroke propulsion device 2 is respectively connected to the liquid conveying component 1 and the plugging component 3, the liquid conveying component 1 is connected to the liquid injection device, the liquid injection device injects liquid into the liquid conveying component 1, the liquid passes through the stroke propulsion device 2 and the plugging component 3 into the oil well, the stroke propulsion device 2 is sealed at the oil wellhead, the plugging component 3 extends to the inside of the oil well, the stroke propulsion device 2 includes a stroke propulsion component 21 and a stroke control component 22, the stroke propulsion component 21 is connected to the liquid conveying component 1, the stroke control component 22 is connected to the stroke propulsion component 21, the plugging component 3 is connected to the stroke propulsion component 21, the stroke control component 22 can control the stroke propulsion component 21 to move up and down in the depth direction of the oil well, the stroke propulsion component 21 brings the plugging component 3 to the preset position inside the oil well, and the plugging component 3 completes the plugging at the preset position inside the oil well, thereby isolating the oil wellhead from the high-pressure fluid in the oil well, playing a role in protecting the oil wellhead, so that the oil wellhead can withstand a large pressure, and can perform energy-enhanced water injection operations without using a 700-type oil production tree.

[0033] Furthermore, the liquid injection device may be a fracturing truck, which delivers 1 to 3 m3 / min of liquid into the oil well through the "injection protection wellhead device" provided by the present invention to perform energy-enhanced water injection on the oil well. The liquid delivery component 1 includes a liquid delivery pipeline 13, which is used to connect the fracturing truck and the stroke propulsion component 21, the stroke control component 22 is connected to the stroke propulsion component 21, and the plugging component 3 is connected to the stroke propulsion component 21. The stroke control component 22 can control the stroke propulsion component 21 to move up and down in the depth direction of the oil well. The stroke propulsion component 21 brings the plugging component 3 to a preset position inside the oil well. The plugging component 3 completes the plugging at the preset position inside the oil well, thereby isolating the oil wellhead from the high-pressure fluid in the oil well, playing a role in protecting the oil wellhead, so that the oil wellhead can withstand a large pressure, and energy-enhanced water injection operations can be performed without using a 700-type oil production tree.

[0034] In some optional embodiments, the liquid delivery assembly 1 includes a first joint assembly, a liquid delivery pipeline 13 and a second joint assembly, the first joint assembly is connected to the liquid injection device, the first joint assembly, the liquid delivery pipeline 13 and the second joint assembly are connected in sequence, and the second joint assembly is connected to the stroke propulsion component 21.

[0035] Specifically, the first joint assembly includes a union joint 11 and a first plug valve 12, the liquid delivery pipeline 13 is a high-pressure hose, and the second joint assembly includes a first elbow 14, a second plug valve 15 and a second elbow 16; the union joint 11 is connected to the liquid injection device, and the union joint 11, the first plug valve 12, the high-pressure hose, the first elbow 14, the second plug valve 15 and the second elbow 16 are connected in sequence, and the second elbow 16 is connected to the stroke propulsion component 21.

[0036] In some optional embodiments, the stroke propulsion component 21 includes a flange fixing component and a hydraulic propulsion component, and the hydraulic propulsion component is respectively connected to the flange fixing component and the blocking component 3; the stroke control component 22 is connected to the hydraulic propulsion component.

[0037] Specifically, the liquid delivery component 1 includes a first joint component, a liquid delivery pipeline 13 and a second joint component, the first joint component includes a union joint 11 and a first plug valve 12, the liquid delivery pipeline 13 is a high-pressure hose, and the second joint component includes a first elbow 14, a second plug valve 15 and a second elbow 16; the union joint 11 is connected to the liquid injection device, and the union joint 11, the first plug valve 12, the high-pressure hose, the first elbow 14, the second plug valve 15 and the second elbow 16 are connected in sequence, the second elbow 16 is connected to the flange fixing component, and the flange fixing component, the hydraulic propulsion component and the blocking component 3 are connected in sequence.

[0038] In some optional embodiments, the flange fixing assembly includes a first fixing flange 211, a first piston rod 212, and a second fixing flange 213. The first fixing flange 211, the first piston rod 212, and the second fixing flange 213 are connected in sequence. The first fixing flange 211 is connected to the second joint assembly, and the second fixing flange 213 is connected to the hydraulic propulsion component.

[0039] Specifically, the first fixed flange 211 includes a flange plate and a fixed sleeve, the flange plate and the fixed sleeve are integrally formed, or the flange plate and the fixed sleeve are welded, the fixed sleeve of the first fixed flange 211 is sleeved on the outside of the second elbow 16, the second fixed flange 213 includes a flange plate and a fixed sleeve, or the flange plate and the fixed sleeve are welded, the fixed sleeve of the second fixed flange 213 is sleeved on the hydraulic propulsion component, the first piston rod 212 is respectively connected to the first fixed flange 211 and the second fixed flange 213, optionally, the first piston rod 212 is respectively threadedly connected to the first fixed flange 211 and the second fixed flange 213.

[0040] In some optional embodiments, the hydraulic propulsion component includes a first piston 214, a second piston rod 215, a hydraulic cylinder 216 and a sealing flange 217, the two ends of the hydraulic cylinder 216 are respectively connected to the second fixed flange 213 and the sealing flange 217, the first piston 214 is arranged inside the hydraulic cylinder 216, one end of the second piston rod 215 is connected to the first piston 214, and the other end passes through the sealing flange 217 and is connected to the blocking assembly 3.

[0041] Specifically, the fixing sleeve of the second fixing flange 213 is sleeved on the end of the hydraulic cylinder 216, the first piston 214 is arranged inside the hydraulic cylinder 216, the first piston 214 is respectively connected to the second fixing flange 213 and one end of the second piston rod 215, and the other end of the second piston rod 215 is connected to the plugging assembly 3. The stroke control assembly 22 is connected to the hydraulic cylinder 216, and the stroke control assembly 22 injects hydraulic oil into the hydraulic cylinder 216, which can push the first piston 214 to move inside the hydraulic cylinder 216. The first piston 214 drives the flange fixing assembly and the second piston rod 215 to move during the movement, and the second piston rod 215 drives the plugging assembly 3 to move to a preset position inside the oil well, for example, 0.5 meters into the oil well. The stroke propulsion component 21 is sealed at the oil well head through the sealing flange 217, the plugging assembly 3 can extend to the inside of the oil well, and the liquid conveying assembly 1 is arranged above the ground.

[0042] In some optional embodiments, the sealing assembly 3 includes a first joint 31, a center tube 32, a second piston 33, a rubber tube sleeve 34, a sealing rubber tube 35, a thrust rubber tube 36 and a second joint 37. The first joint 31, the center tube 32, the thrust rubber tube 36 and the second joint 37 are connected in sequence, the rubber tube sleeve 34 and the sealing rubber tube 35 are sequentially sleeved on the outside of the center tube 32, the second piston 33 is arranged inside the first joint 31, and the second piston 33 is connected to the second piston rod 215.

[0043] Specifically, one end of the first joint 31 is connected to the second piston rod 215, and the other end of the first joint 31 is provided with a groove, which is recessed from the outer surface of the first joint 31 to the inner surface. The center tube 32 is provided with a groove whose outer surface is recessed from the inner surface. One end of the center tube 32 is connected to the inner surface of the first joint 31, the rubber sleeve 34 is sleeved on the outer surfaces of the first joint 31 and the center tube 32, the sealing rubber sleeve 35 is sleeved on the outer surface of the center tube 32, the rubber sleeve 34 and the sealing rubber sleeve 35 are arranged inside the grooves of the first joint 31 and the center tube 32, the inner surface of the rubber sleeve 34 is threadedly connected to the first joint 31, the thrust rubber sleeve 36 is connected to the inner surface of the center tube 32, and the second joint 37 is connected to the inner surface of the thrust rubber sleeve 36. The fracturing truck injects liquid into the well through the liquid delivery component 1, the stroke propulsion device 2 and the plugging component 3. The liquid flows at a speed of 1 to 3 m / min. The thrust rubber cylinder 36 of the plugging component 3 generates a load force to compress the sealing rubber cylinder 35 under the action of the internal and external pressure difference, and further compresses the sealing rubber cylinder 35, so that the high-pressure fluid in the oil wellhead is isolated, thereby protecting the wellhead device.

[0044] In some optional embodiments, the stroke control assembly 22 includes an upper stroke control assembly and a lower stroke control assembly, and the upper stroke control assembly and the lower stroke control assembly are connected to the hydraulic cylinder 216 .

[0045] Specifically, the position where the hydraulic cylinder 216 is connected to the lower stroke control assembly is higher than the position where the hydraulic cylinder 216 is connected to the upper stroke control assembly. The upper stroke control assembly injects hydraulic oil into the hydraulic cylinder 216, which can push the first piston 214 to move upward inside the hydraulic cylinder 216. During the upward movement of the first piston 214, the flange fixing assembly and the second piston rod 215 are driven to move, and the second piston rod 215 drives the plugging assembly 3 to move to a preset position inside the oil well. The lower stroke control assembly can push the first piston 214 to move downward inside the hydraulic cylinder 216. During the downward movement of the first piston 214, the flange fixing assembly and the second piston rod 215 are driven to move downward, and the second piston rod 215 drives the plugging assembly 3 to move to a preset position inside the oil well.

[0046] In some optional embodiments, the upstroke control assembly includes an upstroke hose 221, a first pressure relief valve 222, a first check valve 223 and a first pressurizing component 224, the first interface end of the upstroke hose 221 is connected to the hydraulic cylinder 216, the second interface end of the upstroke hose 221 is connected to the first pressurizing component 224, and the first pressure relief valve 222 and the first check valve 223 are arranged at the second interface end.

[0047] Specifically, the first pressurizing component 224 is a hydraulic pump. When the plugging assembly 3 needs to be moved toward the oil well head, the upstroke control assembly starts to work, and the hydraulic pump injects hydraulic oil into the hydraulic cylinder 216 through the upstroke hose 221, which can push the first piston 214 to move upward inside the hydraulic cylinder 216. During the upward movement of the first piston 214, the flange fixing assembly and the second piston rod 215 are driven to move, and the second piston rod 215 drives the plugging assembly 3 to move to a preset position inside the oil well.

[0048] In some optional embodiments, the downstroke control assembly includes a downstroke hose 225, a second pressure relief valve 226, a second one-way valve 227 and a second pressurizing component 228, the third interface end of the downstroke hose 225 is connected to the hydraulic cylinder 216, the fourth interface end of the downstroke hose 225 is connected to the second pressurizing component 228, and the second pressure relief valve 226 and the second one-way valve 227 are arranged at the fourth interface end.

[0049] Specifically, the second pressurizing component 228 is a hydraulic pump. When the plugging assembly 3 needs to move in the direction away from the oil well head, the downstroke control assembly starts to work, and the downstroke control assembly can push the first piston 214 to move downward inside the hydraulic cylinder 216. During the downward movement of the first piston 214, the flange fixing assembly and the second piston rod 215 are driven to move downward, and the second piston rod 215 drives the plugging assembly 3 to move to a preset position inside the oil well.

[0050] The specific use steps of the "injection protection wellhead device" provided by the present invention are as follows: Step 1: Installation preparation work. Step 2: Install the liquid delivery component 1. Step 3: Adjust the position of the plugging component 3 in the oil well. Step 4: Perform energy-enhanced water injection in the oil well. Step 5: Adjust the position of the plugging component 3 in the oil well again. Step 6: Restore the original wellhead.

[0051] Specifically, installation preparation work includes: preparing a special platform, ground anchors, ropes, lifting lugs, cranes, etc.

[0052] The steps of installing the liquid delivery assembly 1 include: installing a special platform around the KZ65-35 type water injection wellhead. Remove the threaded flange at the top of the KZ65-35 type water injection wellhead, open the union 11 to the maximum, close the first plug valve 12, install four lifting ears on the first fixed flange 211, use a crane to vertically lift the "injection protection wellhead device", insert the plugging assembly 3 into the interior of the KZ65-35 type water injection oil well, and fix the sealing flange 217 to the main valve with bolts; install four lifting ears on the second fixed flange 213, and connect and fix it with the ground anchor with steel wire. If the original wellhead is KZ65-21 type, a conversion flange needs to be installed.

[0053] Adjust the position of the plugging assembly 3 in the oil well, specifically including, after the "injection protection wellhead device" is fixedly connected to the wellhead, the second plug valve 15 is closed, the second pressure relief valve 226 of the downstroke hose 225 is closed, and the first piston 214 is ensured to be at the top dead center. Perform an overall pressure test, and the pressure test value is based on the rated working pressure of the oil production tree. After the pressure test is qualified, open the first plug valve 12 to the maximum, connect the downstroke hose 225 to the second pressurizing component 228, and inject hydraulic oil into the second pressurizing component 228 to push the first piston 214 to drive the first fixed flange 211, the first piston rod 212, and the second piston rod 215 to move downward, ensuring that the plugging assembly 3 enters 0.5 meters into the oil well, and the second pressurizing component 228 stops pressurizing, and the first fixed flange 211 and the second fixed flange 213 are fixed with a long screw.

[0054] The specific steps of performing energy-enhanced water injection in an oil well include: installing a safety valve on the casing valve and the oil pipe gate of the KZ65-35 type water injection wellhead, the set pressure of the safety valve is set at 35MPa, and the safety valve is connected to the blowdown line to protect the pressure of the KZ65-35 type water injection wellhead from not exceeding 35MPa. The union 11 is connected to the fracturing vehicle group, and 1-3m3 / min of liquid is injected into the well. The thrust rubber cylinder 36 of the plugging assembly 3 generates a load force to compress the sealing rubber cylinder 35 under the action of the internal and external pressure difference, compressing the sealing rubber cylinder 35, isolating the oil wellhead from the high-pressure fluid in the oil well, playing a role in protecting the wellhead, and starting the energy-enhanced water injection operation.

[0055] Re-adjusting the position of the plugging component 3 in the oil well specifically includes, after completing the energy-boosting water injection operation, closing the first plug valve 12, closing the second pressure relief valve 226 of the downstroke hose 225, removing the long screw between the first fixed flange 211 and the second fixed flange 213, slowly opening the second pressure relief valve 226 of the downstroke hose 225 to release the hydraulic oil, and controlling the upward speed of the first piston 214. If the first piston 214 cannot move upward on its own, the first pressurizing component 224 injects hydraulic oil into the hydraulic cylinder 216 to push the first piston 224 to drive the first fixed flange 211, the first piston rod 212, and the second piston rod 215 to move upward. After the plugging component 3 passes through the first plug valve 12, the first plug valve 12 at the oil wellhead is closed, the valve in the oil well slowly releases the pressure to zero, and the "injection protection wellhead device" is removed from the wellhead to complete the energy-boosting water injection operation.

[0056] The specific steps of restoring the original wellhead include installing the threaded flange at the top of the KZ65-35 water injection wellhead, closing the union 11, removing the special ladder installed around the KZ65-35 water injection wellhead; and removing the safety valve and the blowdown pipe line.

[0057] In the present invention, the term "plurality" means at least two or more than two, unless otherwise clearly defined. The terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0058] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0059] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A wellhead device for injection protection, characterized in that: include: A liquid delivery assembly (1), connected to the liquid injection device; A stroke propulsion device (2) is set at the oil well head and connected to the other end of the liquid delivery assembly (1), comprising a stroke propulsion component (21) and a stroke control component (22), wherein the stroke propulsion component (21) is connected to the liquid delivery assembly (1), and the stroke control component (22) is connected to the stroke propulsion component (21), so as to drive the stroke propulsion component (21) to move in the depth direction of the oil well; The plugging component (3) extends into the oil well and is connected to the stroke propulsion component (21). The stroke propulsion device (2) drives the plugging component (3) to move up and down in the oil well, so that the plugging component (3) completes the plugging at a preset position in the oil well.

2. The injection protection wellhead device according to claim 1, characterized in that: The liquid delivery assembly (1) comprises a first joint assembly, a liquid delivery pipeline (13) and a second joint assembly, wherein the first joint assembly is connected to the liquid injection device, the first joint assembly, the liquid delivery pipeline (13) and the second joint assembly are connected in sequence, and the second joint assembly is connected to the stroke propulsion component (21).

3. The injection protection wellhead device according to claim 2, characterized in that: The first joint assembly comprises a union joint (11) and a first plug valve (12); the liquid delivery pipeline (13) is a high-pressure hose; and the second joint assembly comprises a first elbow (14), a second plug valve (15) and a second elbow (16); The union (11) is connected to the liquid injection device, the union (11), the first stopcock (12), the high-pressure hose, the first elbow (14), the second stopcock (15) and the second elbow (16) are connected in sequence, and the second elbow (16) is connected to the stroke propulsion component (21).

4. The injection protection wellhead device according to claim 3, characterized in that: The stroke propulsion component (21) comprises a flange fixing component and a hydraulic propulsion component, wherein the hydraulic propulsion component is respectively connected to the flange fixing component and the blocking component (3); the stroke control component (22) is connected to the hydraulic propulsion component.

5. The injection protection wellhead device according to claim 4, characterized in that: The flange fixing assembly comprises a first fixing flange (211), a first piston rod (212), and a second fixing flange (213); the first fixing flange (211), the first piston rod (212), and the second fixing flange (213) are connected in sequence; the first fixing flange (211) is connected to the second joint assembly; and the second fixing flange (213) is connected to the hydraulic propulsion component.

6. The injection protection wellhead device according to claim 5, characterized in that: The hydraulic propulsion component comprises a first piston (214), a second piston rod (215), a hydraulic cylinder (216) and a sealing flange (217); the two ends of the hydraulic cylinder (216) are respectively connected to the second fixing flange (211) and the sealing flange (217); the first piston (214) is arranged inside the hydraulic cylinder (216); one end of the second piston rod (215) is connected to the first piston (214), and the other end passes through the sealing flange (217) and is connected to the blocking assembly (3).

7. The injection protection wellhead device according to claim 6, characterized in that: The plugging assembly (3) comprises a first joint (31), a central tube (32), a second piston (33), a rubber sleeve (34), a sealing rubber sleeve (35), a thrust rubber sleeve (36) and a second joint (37); the first joint (31), the central tube (32), the thrust rubber sleeve (36) and the second joint (37) are connected in sequence; the rubber sleeve (34) and the sealing rubber sleeve (35) are sleeved on the outside of the central tube (32) in sequence; the second piston (33) is arranged inside the first joint (31); and the second piston (33) is connected to the second piston rod (215).

8. The injection protection wellhead device according to claim 7, characterized in that: The stroke control assembly (22) comprises an upper stroke control assembly and a lower stroke control assembly, and the upper stroke control assembly and the lower stroke control assembly are in communication with the hydraulic cylinder (216).

9. The injection protection wellhead device according to claim 8, characterized in that: The upstroke control assembly comprises an upstroke hose (221), a first pressure relief valve (222), a first non-return valve (223) and a first pressurizing component (224); the first interface end of the upstroke hose (221) is connected to the hydraulic cylinder (216); the second interface end of the upstroke hose is connected to the first pressurizing component (224); the first pressure relief valve (222) and the first non-return valve (223) are arranged at the second interface end.

10. The injection protection wellhead device according to claim 8, characterized in that: The downstroke control assembly comprises a downstroke hose (225), a second pressure relief valve (226), a second non-return valve (227) and a second pressurizing component (228); the third interface end of the downstroke hose (225) is connected to the hydraulic cylinder (216); the fourth interface end of the downstroke hose (225) is connected to the second pressurizing component (228); the second pressure relief valve (226) and the second non-return valve (227) are arranged at the fourth interface end.

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