A sandwich mode annulus plugging system, structure and method

Abstract

The application discloses a sandwich mode annulus plugging system, structure and method, and the sandwich mode annulus plugging system comprises an injection pipe, a traction assembly and an injection assembly, the cross-sectional shape of the injection pipe is flat; the traction assembly is arranged at one end of the injection pipe and is used for dragging the injection pipe into an annulus; the output end of the injection assembly is connected and communicated with the other end of the injection pipe and is used for injecting one or more of liquid, gas and colloid into the injection pipe. The sandwich mode annulus plugging system provided by the application can be basically unwound and uncurled and can be precisely controlled to drop to a corresponding depth in the annulus under the traction of the traction assembly and in cooperation with the flat injection pipe, so that the stability and safety of construction are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of annulus plugging, in particular to a sandwich mode annulus plugging system, structure and method. BACKGROUND

[0002] The main purpose of annulus plugging is to solve the fluid leakage problem of the annular space (referred to as "annulus") between the wellbore and the casing during drilling, completion or production. Annulus pressure causes annulus pressure to exceed the design pressure, which can easily cause gas channeling. At present, plugging structure is often used to prevent gas and liquid channeling. For example, Chinese patent 201710190571.X discloses a casing annulus plugging material, a plugging device and a plugging method. The plugging device includes a production Christmas tree device which is symmetrical along the central axis, and the production Christmas tree device is packaged in the oil well wellhead for oil production. The casing four-way of the production Christmas tree device is installed on one side of the sealing liquid discharge flange. The steel wire pipeline enters the annulus of the casing through the sealing liquid discharge flange, and the steel wire pipeline is used to pass into the plugging material.

[0003] For the above prior art, although it has a certain effect on annulus plugging, but in the process of annulus plugging construction, the injection tube is easy to produce curling and winding during the process of inserting into the annulus, which causes the injection position to deviate and the pressure to break. SUMMARY

[0004] The purpose of the present application is to overcome the above technical deficiencies, and to provide a sandwich mode annulus plugging system, structure and method to solve the technical problem that the injection tube is easy to twist and wind during the process of inserting into the annulus in the prior art.

[0005] To achieve the above technical purpose, the present application adopts the following technical scheme:

[0006] In a first aspect, the present application provides a sandwich mode annulus plugging system, comprising:

[0007] an injection tube, the cross-sectional shape of which is flat;

[0008] a traction assembly arranged at one end of the injection tube for pulling the injection tube into the annulus; and

[0009] an injection assembly, the output end of which is connected and communicated with the other end of the injection tube, for injecting one or more of liquid, gas and gel into the injection tube.

[0010] In some embodiments, both sides of the cross section of the injection tube are provided with a circular support layer, and the upper and lower inner walls in the middle of the cross section of the injection tube are provided with a semicircular support layer, and the two semicircular support layers are separable.

[0011] In some embodiments, the traction assembly comprises a visual hydraulic traction head, which is arranged at one end of the injection pipe and provided with an ultra-fine camera probe and a hydraulic jet device at the front end, respectively used for visual traction and providing traction power.

[0012] In some embodiments, the traction assembly comprises a chain-type heavy hammer, which is arranged at one end of the injection pipe and vertically dropped into the annulus by its own weight.

[0013] In some embodiments, the visual hydraulic traction head is provided with three reverse hydraulic jet holes and an electromagnetic reversing jet device, which has two horizontally opposite jet holes that can be switched on and off.

[0014] In a second aspect, the present application further provides a sandwich mode annulus plugging structure, comprising:

[0015] a production pipe;

[0016] a production casing, which is sleeved outside the production pipe and forms a first annulus therebetween;

[0017] an inner technical casing, which is sleeved outside the production casing and forms a second annulus therebetween, and the first and second annuli are respectively provided with first annulus cement and second annulus cement; and

[0018] a plugging layer group, which comprises a plugging structure glue layer and a foamed glue layer that are sequentially stacked from bottom to top on top of the first annulus cement.

[0019] In some embodiments, the plugging structure glue layer further has a nano plugging glue liquid layer inserted therein.

[0020] In some embodiments, the foamed glue layer further has a cleaning liquid layer inserted therein.

[0021] In some embodiments, the production casing is provided with a first annulus wing valve that communicates with the first annulus, and the inner technical casing is provided with a second annulus wing valve that communicates with the second annulus.

[0022] In a third aspect, the present application further provides a sandwich mode annulus plugging method, comprising the following steps:

[0023] S1, the plugging injection point is located on top of the annulus cement, and an appropriate amount of foaming glue is first injected to achieve the purpose of isolation and liquid driving;

[0024] S2, a strong cleaning liquid is injected to clean the inner wall of the annulus, and an appropriate amount of inert gas is injected to bubble and clean the wall;

[0025] S3, foaming glue is injected again to isolate the strong cleaning liquid and rub and squeeze the cleaning wall.

[0026] S4, injecting cementing plugging structure glue;

[0027] S5, injecting nanoparticle non-cementing glue solution;

[0028] S6, injecting appropriate cementing plugging structure glue again.

[0029] In some embodiments, the cementing plugging structure glue has a shear strength with the annulus wall surface of the annulus of >= 30MPA, and the viscosity of the cementing plugging structure glue is <= 2000mpas at an ambient temperature of 0℃, and the shear strength between the cementing plugging structure glue and the unclean pipe wall of the annulus is >= 0.5MPA.

[0030] In some embodiments, the material particle size of the nanoparticle non-cementing glue solution is 50-800nm.

[0031] Compared with the prior art, the sandwich mode annulus plugging system provided by the application can be basically unwound and curled, and can be precisely controlled to drop to a corresponding depth in the annulus under the traction of the traction assembly and in cooperation with the flat injection pipe, thereby improving the stability and safety of construction. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a structural schematic diagram of the sandwich mode annulus plugging system provided by the embodiment of the application;

[0033] Figure 2 is a structural schematic diagram of the injection pipe of the sandwich mode annulus plugging system provided by the embodiment of the application deep into the annulus;

[0034] Figure 3 is a structural schematic diagram of the sandwich mode annulus plugging structure provided by the embodiment of the application;

[0035] Figure 4 is an injection structural schematic diagram of step one of the sandwich mode annulus plugging method provided by the embodiment of the application;

[0036] Figure 5 is an injection structural schematic diagram of step two of the sandwich mode annulus plugging method provided by the embodiment of the application;

[0037] Figure 6 is an injection structural schematic diagram of step three of the sandwich mode annulus plugging method provided by the embodiment of the application;

[0038] Figure 7 is an injection structural schematic diagram of step four of the sandwich mode annulus plugging method provided by the embodiment of the application;

[0039] Figure 8is the injection structure schematic view of step five of the sandwich mode annular leakage plugging method provided by the embodiment of the present application;

[0040] Figure 9 is the injection structure schematic view of step six of the sandwich mode annular leakage plugging method provided by the embodiment of the present application;

[0041] Figure 10 is the injection pipe cross section structure schematic view of the sandwich mode annular leakage plugging system provided by the embodiment of the present application;

[0042] Figure 11 is the visualization hydraulic traction head structure schematic view of the sandwich mode annular leakage plugging system provided by the embodiment of the present application;

[0043] Figure 12 is the cross section structure schematic view of the visualization hydraulic traction head of the sandwich mode annular leakage plugging system provided by the embodiment of the present application, in which the first direction injection hole and the second direction injection hole are both closed;

[0044] Figure 13 is the cross section structure schematic view of the visualization hydraulic traction head of the sandwich mode annular leakage plugging system provided by the embodiment of the present application, in which the first direction injection hole is opened and the second direction injection hole is closed;

[0045] Figure 14 is the cross section structure schematic view of the visualization hydraulic traction head of the sandwich mode annular leakage plugging system provided by the embodiment of the present application, in which the first direction injection hole is closed and the second direction injection hole is opened.

[0046] BRIEF DESCRIPTION OF DRAWINGS

[0047] 1, injection pipe; 101, circular support layer; 102, semicircular support layer; 2, traction assembly; 201, reverse hydraulic injection hole; 202, electromagnetic reversing injection device; 2021, electromagnetic reversing driver; 2022, spring; 2023, reversing sleeve; 2024, first through hole; 2025, second through hole; 203, first direction injection hole; 204, second direction injection hole; 205, ultra-fine camera probe; 3, injection assembly; 31, pipeline release device; 32, glue injection machine; 4, production oil pipe; 5, production casing; 501, first annular wing valve; 6, inner layer technical casing; 601, second annular wing valve; 7, first annulus; 701, first annular cement stone; 702, plugging structure glue layer; 703, foamed glue layer; 704, nano plugging glue liquid layer; 705, cleaning liquid layer; 706, gas channeling liquid channeling layer; 8, second annulus; 801, second annular cement stone; 9, formation. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0049] In order to solve the technical problem that the glue injection pipe is easy to twist and wind during insertion into the annulus, the present application provides a sandwich mode annulus plugging system, structure and method, which can realize twist-free and wind-free insertion of the glue injection pipe during insertion into the annulus.

[0050] It should be noted that the sandwich mode annulus plugging system, structure and method described in the present application are used for but not limited to annulus plugging construction, etc. For the convenience of description, in the present application, only the sandwich mode annulus plugging system, structure and method applied to annulus plugging construction are taken as examples for description, and the principle of the sandwich mode annulus plugging system, structure and method applied to other types of annular space plugging operation is substantially the same as that applied to annulus plugging construction, which is not described here.

[0051] In the first aspect, please refer to Figure 1 and Figure 2 , Figure 1 is a structural schematic diagram of the sandwich mode annulus plugging system in an embodiment of the present application. The sandwich mode annulus plugging system includes an injection pipe 1, a traction assembly 2 and an injection assembly 3. The cross-sectional shape of the injection pipe 1 is flat, so that it has the least degree of freedom in the curling direction, reducing winding and curling. The output end of the injection assembly 3 is connected and communicated with the other end of the injection pipe 1, for injecting one or more of liquid, gas and colloid into the injection pipe 1, discharging from the end close to the visual liquid traction head 2, and injecting the plugging material into the annulus to form a corresponding plugging structure.

[0052] In one of the embodiments, in order to form the effect of basically vertically entering the annulus for the injection pipe 1, the traction assembly 2 adopts a chain type weight, which can be bent and enter the annulus space through the wing valve on the annulus, and vertically pull the injection pipe 1 downward, thereby playing the role of traction drilling.

[0053] In order to achieve controllable effect, since the chain type weight is vertically downward traction, the depth of exploration can be judged according to the unwinding length of the injection pipe 1, so as to achieve depth controllability.

[0054] In another embodiment, in order to achieve the purpose of visualized controllable drag drilling, the drag assembly 2 adopts a visualized hydraulic drag head, which is arranged at one end of the injection pipe 1, and has an ultra-fine camera probe 205 and a hydraulic jet device at the front end, and can visually and controllably guide, jet and drag the injection pipe 1 into the annulus, pass through the wing valve on the annulus into the annulus space, and jet and drag the injection pipe 1 to vertically downwardly descend, and the direction of the hydraulic jet is controllable, wherein the hydraulic jet device includes a liquid supply pump and three reverse hydraulic jet holes 201 arranged on the outer side of the visualized hydraulic drag head 2, and the liquid supply pump is connected with the visualized hydraulic drag head 2 through a pipeline for supplying liquid as a power source.

[0055] Further, referring to Figure 10 and Figure 11 , the data transmission line of the ultra-fine camera probe is connected in parallel with the injection pipe and extends to the ground and is connected with a data receiving device for visualized guidance.

[0056] Further, referring to Figure 11 , Figure 12 , Figure 13 and Figure 14 , the visualized hydraulic drag head is provided with three reverse hydraulic jet holes 201, and the inside of the visualized hydraulic drag head has a cavity connected with the liquid supply pipeline of the liquid supply pump, and liquid is supplied by the liquid supply pump, enters the cavity through the hydraulic force, and is jetted from the reverse hydraulic jet holes to form a pushing force for pushing downwardly. The visualized hydraulic drag head is provided with an electromagnetic reversing jet device 202, the electromagnetic reversing jet device 202 has two horizontally opposite jet holes which can be switched on and off, the electromagnetic reversing jet device 202 includes an electromagnetic reversing driver 2021, a spring 2022 and a reversing sleeve 2023, which are sequentially connected end to end, and the electromagnetic reversing driver 2021 is installed at the cavity end of the visualized hydraulic drag head, the electromagnetic reversing driver controls the axial movement of the reversing sleeve along the cavity of the visualized hydraulic drag head, the position is switched by the movement of the magnetically attracted reversing sleeve 2023, the first through hole 2024 is aligned with the first direction jet hole 203, or the second through hole 2025 is aligned with the second direction jet hole 204, and the visualized hydraulic drag head is guided to deviate left and right by switching the opening and closing of the first direction jet hole 203 and the second direction jet hole 204.

[0057] It can be understood that the electromagnetic reversing driver can adopt a bistable electromagnetic reversing driver, which can be switched between two stable positions, and does not need to be continuously powered to maintain these positions. Only a short time of power supply is needed each time to complete the conversion from one position to another position, which is a mature device.

[0058] In one embodiment, referring to Figure 10 In order to ensure the lowest flow area and structural strength when the injection pipe 1 is wound around, the two side walls of the cross section of the injection pipe 1 are provided with a circular support layer 101 to provide structural strength on both sides and further weaken the bendability towards both sides, thereby reducing the probability of winding and curling. The upper and lower inner walls in the middle of the cross section of the injection pipe 1 are provided with a semicircular support layer 102 to provide support for the middle part and avoid excessive compression of the wound part on the release winding machine, which can cause pressure flow interruption. The two semicircular support layers 102 can be separated.

[0059] In one embodiment, referring to Figure 3 The injection assembly 3 includes a pipeline release device 31 and a glue injection machine 32. The output end of the glue injection machine 32 is connected to the end of the injection pipe 1. The injection pipe 1 is wound around the pipeline release device 31. The pipeline release device 31 is used for releasing or winding the injection pipe 1. The pipeline release device 31 lifts and winds the injection pipe 1 and releases the wound pipe. At the same time, the glue injection machine 32 discharges the plugging material through the injection pipe 1 and injects it into the annular space to plug.

[0060] It can be understood that the pipeline release device 31 can use an existing mature electric or hydraulic winding machine to achieve winding and releasing of the injection pipe 1, which is not limited here. The glue injection machine 32 can use an existing mature high-pressure grouting machine, a high-pressure piston pump, or a high-pressure gear pump double-component controllable proportion glue injection pump to achieve the purpose of high-pressure injection of the plugging material into the annular space, which is not limited here.

[0061] Secondly, referring to Figure 2 and Figure 3The present invention also provides a sandwich-mode annular plugging structure, including a production tubing 4, a production casing 5, an inner technical casing 6, and a plugging layer group. The production tubing 4 is mainly used to extract crude oil or natural gas from underground reservoirs to surface facilities; the production casing 5 is sleeved on the outside of the production tubing 4, mainly used to protect the wellbore structure, isolate different geological layers, and provide a fluid transmission channel, forming a first annulus 7 between the production casing 5 and the production tubing 4; the inner technical casing 6 is sleeved on the outside of the production casing 5, and the inner technical casing 6 is usually placed after the production casing 5 has been installed, forming a second annulus 8 between the inner technical casing 6 and the production casing 5. A first annulus cement stone 701 and a second annulus cement stone 8 are respectively disposed in the first annulus 7 and the second annulus 8. 01. Both the first annular cement stone 701 and the second annular cement stone 801 are annular cement stones. The annular cement stone is a solid cement layer formed by injecting cement slurry into the annulus between the casing and the well wall inside the wellbore and allowing it to harden, providing basic well wall support. The plugging layer group includes a plugging structural adhesive layer 702 and a foamed colloid layer 703 stacked sequentially from bottom to top on the first annular cement stone 701 in the first annulus 7. During the plugging operation, the foamed colloid layer 703 injected first has the purpose of isolating and displacing liquid, reducing the obstruction of stagnant liquid in the annulus. On this basis, the plugging structural adhesive layer 702 is injected to obtain a better plugging effect.

[0062] In one embodiment, please refer to Figure 3 The leak-sealing structural adhesive layer 702 is further interposed with a nano-leaking adhesive liquid layer 704. The process involves injecting a portion of the leak-sealing structural adhesive, then injecting the nano-leaking adhesive liquid, and then injecting the leak-sealing structural adhesive again. This achieves the purpose of interposing the nano-leaking adhesive liquid layer 704 within the leak-sealing structural adhesive layer 702. When the adhesive layer 702 develops cracks over time, under the action of pressure difference, the nanoparticle material and the highly viscous, non-consolidating adhesive liquid are squeezed into the cracks, thus sealing the leak.

[0063] It is understandable that nano-sealing adhesives contain nanoparticles and are not solidified adhesives.

[0064] In one embodiment, please refer to Figure 3 In order to clean the inner wall of the annulus and avoid the impact of residual liquid and gas / liquid leakage on the cleaning process, as well as to reduce the impact of the cleaning part on the plugging structure, a cleaning liquid layer 705 is also inserted inside the foamed colloid layer 703. Injecting a portion of the foamed colloid achieves the purpose of isolating and repelling liquid, and then injecting a strong cleaning liquid can achieve a better cleaning effect. Injecting foamed colloid again achieves the purpose of isolating the strong cleaning liquid and rubbing and squeezing to clean the wall surface, thus forming a structure in which a cleaning liquid layer 705 is inserted inside the foamed colloid layer 703.

[0065] In one embodiment, please refer to Figure 2 In order to control the opening and closing of the internal injection of the first annulus 7 and the second annulus respectively, the production sleeve 5 is provided with a first annulus wing valve 501 communicating with the first annulus 7, and the inner layer technical sleeve 6 is provided with a second annulus wing valve 601 communicating with the second annulus 8.

[0066] Thirdly, the present invention also provides a sandwich-mode annular leak sealing method, comprising the following steps:

[0067] S1. The leak-stopping injection point is located at the top of the annular cement stone. First, an appropriate amount of foaming colloid is injected to achieve the purpose of isolation and liquid dispersal. The foaming colloid is the main component of the foaming colloid layer 703.

[0068] S2. Inject a powerful cleaning solution to clean the inner wall of the annulus and inject an appropriate amount of inert gas to bubble and clean the wall. The powerful cleaning solution is the main component of the cleaning solution layer.

[0069] S3. Inject foaming colloid again to isolate the powerful cleaning liquid and rub and scrub the wall surface to form a foaming colloid layer 703 with a cleaning liquid layer 705 inserted in it.

[0070] S4. Inject adhesive for sealing and plugging the leak. The adhesive for sealing and plugging the leak is the main component of the 702 sealing and plugging adhesive layer.

[0071] S5. Inject nanoparticle-containing non-consolidated adhesive. The nanoparticle-containing non-consolidated adhesive is the main component of the nano-plugging adhesive layer 704. After a long time, the adhesive-bonded plugging structure adhesive develops cracks. Under the action of pressure difference, the nanoparticle material and the high-viscosity non-consolidated adhesive are squeezed into the cracks to plug the leak.

[0072] S6. Inject an appropriate amount of adhesive to seal the leak again, thereby preventing gas and liquid leakage from occurring in the adhesive gaps over time and providing a pressure differential for sealing the leak.

[0073] Understandably, when using a pump for dispensing adhesive, a pump can also be used to inject a cleaning solution mixed with nitrogen.

[0074] The shear strength of the adhesive bonding the leak-stopping structural adhesive to the clean annular wall is ≥30MPa, and the viscosity of the adhesive bonding the leak-stopping structural adhesive is ≤2000MPa at an ambient temperature of 0℃. The shear strength between the adhesive bonding the leak-stopping structural adhesive and the unclean annular wall is ≥0.5MPa.

[0075] Furthermore, the particle size of the non-consolidated nanoparticle adhesive is 50-800 nm.

[0076] Understandably, foaming resin colloids can be used for foaming properties. The required resin height can be calculated based on the maximum pressure ≤ 1 MPa of the annulus, the inner and outer diameters of the annulus, and the safety factor. The type of cleaning fluid can be selected based on the cleanliness of the annulus's inner surface, whether there is liquid accumulation on the top of the annulus cement stone, and whether the liquid is water-based or oil-based; there is no single limitation here. The required over-injection margin for resin can be calculated based on the distance of the cement stone sealing the annulus from the ground surface. In addition, the amount of catalyst to be added to the injected colloid can be calculated based on the actual situation, the formation temperature range of the annulus construction section, and the expected curing time, as well as the appropriate type of sealing adhesive; there is no single limitation here, and an appropriate amount of diluent can be added to improve fluidity if necessary.

[0077] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A sandwich-mode annular sealing method, characterized in that, Applicable to sandwich-mode annular leak sealing systems and sandwich-mode annular leak sealing structures, including the following steps: S1. The leak-stopping injection point is located at the top of the annular cement stone. First, inject an appropriate amount of foaming colloid to achieve the purpose of isolation and liquid dispersal. S2. Inject a powerful cleaning solution to clean the inner wall of the annulus and inject an appropriate amount of inert gas to bubble and clean the wall. S3. Inject foaming colloid again to isolate the powerful cleaning liquid and rub and scrub the wall surface. S4. Inject structural adhesive for bonding and sealing; S5. Inject non-consolidating adhesive containing nanoparticles; S6. Inject an appropriate amount of structural adhesive for sealing and plugging leaks again; The sandwich-mode annular leak sealing system includes: The injection tube has a flat cross-sectional shape; A traction assembly, disposed at one end of the injection tube, is used to traction the injection tube vertically into the annulus; and An injection assembly, the output of which is connected and communicates with the other end of the injection tube, for injecting one or more of liquid, gas and colloid into the injection tube; The sandwich-mode annular plugging structure includes: Production of oil pipes; A production casing is fitted over the outside of the production oil pipe, forming a first annulus between them; An inner technical sleeve is fitted over the outer side of the production sleeve, forming a second annulus between them. A first annulus cement stone and a second annulus cement stone are respectively disposed within the first and second annulus. The leak-stopping layer assembly comprises a leak-stopping structural adhesive layer and a foamed colloid layer, which are stacked sequentially from bottom to top on the top of the first annular cement stone in the first annular space.

2. The sandwich-mode annular sealing method according to claim 1, characterized in that, The injection tube has circular support layers on both sides of its cross-section, and semi-circular support layers on the upper and lower inner walls in the middle of its cross-section. The two semi-circular support layers are separable.

3. The sandwich-mode annular sealing method according to claim 1, characterized in that, The traction assembly includes a visual hydraulic traction head, which is located at one end of the injection pipe, and has an ultra-fine camera probe and a hydraulic injection device at the front end, which are used to visualize traction and provide traction power, respectively.

4. The sandwich-mode annular sealing method according to claim 1, characterized in that, The traction assembly includes a chain weight, which is disposed at one end of the injection tube and hangs into the annulus by its own weight.

5. The sandwich-mode annular sealing method according to claim 3, characterized in that, The visualized hydraulic traction head is equipped with three reverse hydraulic jet holes and an electromagnetic reversing jet device, which has two horizontally opposing jet holes that can be opened and closed.

6. The sandwich-mode annular sealing method according to claim 1, characterized in that, The leak-stopping structural adhesive layer is further interposed with a nano-leaking adhesive layer, the foamed colloid layer is further interposed with a cleaning liquid layer, the production sleeve is provided with a first annulus wing valve communicating with the first annulus, and the inner layer technical sleeve is provided with a second annulus wing valve communicating with the second annulus.

7. The sandwich-mode annular sealing method according to claim 1, characterized in that, The particle size of the non-consolidated nanoparticle adhesive is 50-800 nm.

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