Sandwich mode annulus plugging system, structure and method

Abstract

The invention discloses a sandwich mode annulus leaking stoppage system, structure and method, the sandwich mode annulus leaking stoppage system comprises an injection pipe, a traction assembly and an injection assembly, and the cross section of the injection pipe is flat; the traction assembly is arranged at one end of the injection pipe and used for pulling the injection pipe into the annulus. The output end of the injection assembly is connected and communicated with the other end of the injection pipe, and the injection assembly is used for injecting one or more of liquid, gas and colloid into the injection pipe. According to the sandwich mode annulus leaking stoppage system provided by the invention, under the traction of the traction assembly, the sandwich mode annulus leaking stoppage system is matched with the flat injection pipe, so that the sandwich mode annulus leaking stoppage system can be drooped to the corresponding depth in an annulus in a basically non-winding, non-curling, accurate and controllable manner, and the stability and the safety of construction are improved.

Description

Technical Field

[0001] The invention relates to the technical field of annular space plugging, and in particular to a sandwich mode annular space plugging system, structure and method. Background Art

[0002] The main purpose of annulus plugging is to solve the problem of fluid leakage in the annular space between the wellbore and the casing (referred to as "annulus") during drilling, completion or production. Annular cross-pressure causes the annular pressure to exceed the design pressure, which is easy to cause gas to leak out. At present, plugging structures are often used to prevent gas and liquid leakage. For example, Chinese patent 201710190571.X discloses a plugging material, a plugging device and a plugging method for the annulus between casings. The plugging device includes an oil and gas tree device, which is symmetrical along the central axis. The oil and gas tree device is encapsulated at the wellhead of the oil well for oil production; wherein a sealing drain flange is installed on one side of the casing four-way of the oil and gas tree device; a steel wire pipeline, which enters the annulus of the casing through the sealing drain flange, and the steel wire pipeline is used to pass the plugging material.

[0003] Although the above-mentioned prior art has certain effects on annular space plugging, there is still a problem that the injection pipe is easily curled and entangled during the insertion of the injection pipe into the annulus during the construction of the annular space plugging, resulting in the displacement of the injection position and the problem of pressure interruption. Summary of the invention

[0004] The purpose of the present invention is to overcome the above technical deficiencies and propose a sandwich mode annulus plugging system, structure and method to solve the technical problem that the injection pipe in the prior art is prone to twisting and entanglement during the insertion into the annulus.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a sandwich mode annular space plugging system, comprising: An injection tube having a flat cross-sectional shape; A pulling assembly, which is arranged at one end of the injection pipe and is used to pull the injection pipe downward into the annulus; and The injection assembly has an output end connected to and communicated with the other end of the injection pipe, and is used to inject one or more of liquid, gas and colloid into the injection pipe.

[0006] In some embodiments, both side walls of the injection tube cross section are provided with circular support layers, and the upper and lower inner walls in the middle of the injection tube cross section are provided with semicircular support layers, and the two semicircular support layers are separable.

[0007] In some embodiments, the traction assembly includes a visualized hydraulic traction head, which is arranged 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 respectively used for visualized traction and providing traction power.

[0008] In some embodiments, the traction assembly includes a chain weight, which is disposed at one end of the injection pipe and hangs down into the annulus by its own weight.

[0009] In some embodiments, the visualized hydraulic traction head is provided with three reverse hydraulic injection holes and an electromagnetic reversing injection device, wherein the electromagnetic reversing injection device has two horizontally opposed injection holes that can be opened and closed and switched.

[0010] In a second aspect, the present invention further provides a sandwich mode annular space plugging structure, comprising: Production of oil pipes; A production casing, which is sleeved on the outside of the production oil pipe to form a first annulus; an inner technical casing, which is sleeved on the outer side of the production casing to form a second annulus therebetween, wherein a first annulus cement stone and a second annulus cement stone are respectively arranged in the first annulus and the second annulus; and The plugging layer group includes a plugging structural adhesive layer and a foaming colloid layer stacked in sequence from bottom to top on the top of the first annulus cement stone of the first annulus.

[0011] In some embodiments, a nano-leakage plugging glue layer is also inserted in the leak-plugging structural glue layer.

[0012] In some embodiments, a cleaning liquid layer is further inserted into the foaming colloid layer.

[0013] In some embodiments, a first annulus wing valve communicating with the first annulus is disposed on the production casing, and a second annulus wing valve communicating with the second annulus is disposed on the inner technical casing.

[0014] In a third aspect, the present invention further provides a sandwich mode annular space plugging method, comprising the following steps: S1. The plugging 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 displacement; S2, inject strong cleaning fluid to clean the inner wall of the annulus and inject appropriate amount of inert gas to bubble and clean the wall; S3, inject the foaming colloid again, isolate the strong cleaning liquid and rub and squeeze the brush to clean the wall surface; S4, inject cementation and plugging structural adhesive; S5, injecting an unsolidified adhesive containing nanoparticles; S6. Inject an appropriate amount of bonding and plugging structural adhesive again.

[0015] In some embodiments, the shear strength of the bonding plugging structural adhesive with the clean annulus wall is ≥30MPA, and at an ambient temperature of 0°C, the viscosity of the bonding plugging structural adhesive is ≤2000mpas, and the shear strength between the bonding plugging structural adhesive and the unclean annulus pipe wall is ≥0.5MPA.

[0016] In some embodiments, the material particle size of the nanoparticle unsolidified colloid is 50-800nm.

[0017] Compared with the prior art, the sandwich mode annulus plugging system provided by the present invention can be drooped to the corresponding depth in the annulus basically without entanglement or curling and in a precisely controllable manner by cooperating with a flat injection pipe under the traction of a traction assembly, thereby improving the stability and safety of construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a sandwich mode annular space plugging system provided by an embodiment of the present invention; Figure 2 It is a structural schematic diagram of the injection pipe of the sandwich mode annular space plugging system provided by an embodiment of the present invention penetrating into the annular space; Figure 3 It is a structural schematic diagram of a sandwich mode annular space plugging structure provided in an embodiment of the present invention; Figure 4 It is a schematic diagram of the injection structure of step 1 of the sandwich mode annular space plugging method provided by an embodiment of the present invention; Figure 5 It is a schematic diagram of the injection structure of step 2 of the sandwich mode annular space plugging method provided by an embodiment of the present invention; Figure 6 It is a schematic diagram of the injection structure of step three of the sandwich mode annular space plugging method provided by an embodiment of the present invention; Figure 7 It is a schematic diagram of the injection structure of step 4 of the sandwich mode annular space plugging method provided by an embodiment of the present invention; Figure 8 It is a schematic diagram of the injection structure of step five of the sandwich mode annular space plugging method provided by an embodiment of the present invention; Fig. 9 It is a schematic diagram of the injection structure of step six of the sandwich mode annular space plugging method provided by an embodiment of the present invention; Fig.10 is a schematic diagram of the cross-sectional structure of an injection pipe of a sandwich mode annular leak plugging system provided in an embodiment of the present invention; Fig.11 It is a schematic diagram of the structure of a visualized hydraulic traction head of a sandwich mode annular space plugging system provided by an embodiment of the present invention; Fig.12 It is a schematic cross-sectional structure diagram of a visualized hydraulic traction head of a sandwich mode annular space plugging system provided by an embodiment of the present invention, in which the first-direction injection holes and the second-direction injection holes are both closed; Fig.13 It is a schematic cross-sectional structure diagram of a visualized hydraulic traction head of a sandwich mode annulus plugging system provided by an embodiment of the present invention, in which the first-direction injection hole is opened and the second-direction injection hole is closed; Fig.14 It is a schematic cross-sectional structure diagram of a visualized hydraulic traction head of a sandwich mode annulus plugging system provided by an embodiment of the present invention, in which the first direction injection hole is closed and the second direction injection hole is opened.

[0019] Description of reference numerals: 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 equipment; 32. Glue injection machine; 4. Production oil pipe; 5. Production casing; 501. First annulus wing valve; 6. Inner technical casing; 601. Second annulus wing valve; 7. First annulus; 701. First annulus cement stone; 702. Leakage plugging structural glue layer; 703. Foaming colloid layer; 704. Nano-leakage plugging glue layer; 705. Cleaning liquid layer; 706. Gas and liquid channeling layer; 8. Second annulus; 801. Second annulus cement stone; 9. Formation. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] In order to solve the technical problem that the injection tube is easily twisted and entangled during the process of inserting into the annulus, the present invention provides a sandwich mode annulus plugging system, structure and method, which can realize the insertion of the injection tube into the annulus without twisting and entanglement.

[0022] It should be noted that the sandwich mode annulus plugging system, structure and method described in the present invention are used for but not limited to annulus plugging construction, etc. For the convenience of explanation, in the present invention, only the sandwich mode annulus plugging system, structure and method are applied to annulus plugging construction as an example for explanation, and the principles of applying the sandwich mode annulus plugging system, structure and method to other types of annular space plugging operations are essentially the same as those applied to annulus plugging construction, which will not be elaborated here.

[0023] First, see Figure 1 and Figure 2 , Figure 1 The schematic diagram of the structure of the sandwich mode annulus plugging system in one embodiment of the present invention 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, and is used to inject one or more of liquid, gas and colloid into the injection pipe 1, and is discharged from the end close to the visual hydraulic traction head 2 through the injection pipe 1, and the plugging material is injected into the annulus to form a corresponding plugging structure.

[0024] In one of the embodiments, in order to achieve a basic vertical insertion effect of the injection pipe 1 into the annulus, the traction assembly 2 adopts a chain weight, which can be bent and pass through the wing valve on the annulus into the annulus space, and vertically pull the injection pipe 1 vertically downward, thereby playing the role of traction drilling.

[0025] In order to achieve a controllable effect, since the chain weight is pulled vertically downward, the depth of exploration can be determined according to the unwinding length of the injection pipe 1, thereby achieving controllable depth.

[0026] In another embodiment, in order to achieve the purpose of visualized and controllable traction drilling, the traction assembly 2 adopts a visualized hydraulic traction head, which is arranged at one end of the injection pipe 1, and has an ultra-fine camera probe 205 and a hydraulic injection device at the front end, which can be guided in a visual and controllable manner, and is used to hydraulically inject and pull the injection pipe 1 vertically into the annulus, and can enter the annulus space through the wing valve on the annulus, and inject and pull the injection pipe 1 vertically downward, and through hydraulic controllable direction guidance, the liquid injection device includes a liquid supply pump and three reverse hydraulic injection holes 201 opened on the outside of the visualized hydraulic traction head 2, and the liquid supply pump is connected to the visualized hydraulic traction head 2 through a pipeline, and is used to supply liquid as a power source.

[0027] For further information, see Fig.10 and Fig.11The 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 to a data receiving device for visual guidance.

[0028] For further information, see Fig.11 , Fig.12 , Fig.13 and Fig.14 The visualized hydraulic traction head is provided with three reverse hydraulic injection holes 201, and liquid is supplied by a liquid supply pump. The inner side of the visualized hydraulic traction head has a cavity connected with the liquid supply pump infusion pipeline. Liquid enters the cavity through liquid force and is ejected from the reverse hydraulic injection hole to form a driving force for downward pushing. The visualized hydraulic traction head is provided with an electromagnetic reversing injection device 202, which has two horizontally opposite injection holes that can be opened and closed. The electromagnetic reversing injection device 202 includes an electromagnetic reversing driver 2021, a spring 2022 and a reversing sleeve 2023. The electromagnetic reversing driver 2021, the spring 2022 and the reversing sleeve 2023 are connected end to end in sequence, and the electromagnetic reversing driver 2021 is installed at the cavity end of the visualized hydraulic traction head. The reversing sleeve is controlled by the electromagnetic reversing driver to move axially along the cavity in the visualized hydraulic traction head. The position is switched by moving the magnetic reversing sleeve 2023 to align the first through hole 2024 with the first direction injection hole 203, or to align the second through hole 2025 with the second direction injection hole 204. By switching the opening and closing of the first direction injection hole 203 and the second direction injection hole 204, the visualized hydraulic traction head is guided to deviate left and right.

[0029] It can be understood that the electromagnetic commutation drive can adopt a bistable electromagnetic commutation drive, which can switch between two stable positions and does not require continuous power supply to maintain these positions. Each time, only a short period of power supply is required to complete the conversion from one position to another, which is an existing mature device.

[0030] In one embodiment, see Fig.10 In order to ensure the minimum flow cross-sectional area without interruption and structural strength when winding during the injection of plugging materials, circular support layers 101 are provided on both side walls of the cross section of the injection pipe 1 to provide structural strength on both sides and further weaken its bendability toward both sides to reduce the probability of winding and curling. Semicircular support layers 102 are provided on the upper and lower inner walls in the middle of the cross section of the injection pipe 1 to provide support for the middle part to avoid excessive extrusion of the winding part on the release winding machine, resulting in pressure interruption, and the two semicircular support layers 102 are separable.

[0031] In one embodiment, see Figure 3The 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 on 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 reels the injection pipe 1 and releases and unwinds it. At the same time, the plugging material is discharged through the injection pipe 1 by the glue injection machine 32 and injected into the annular space to plug the leak.

[0032] It can be understood that the pipeline release equipment 31 can adopt the existing mature electric or hydraulic winding machine to achieve the winding and releasing of the injection pipe 1, and no sole limitation is made here; the glue injection machine 32 can adopt the existing mature high-pressure grouting machine, or it can adopt a high-pressure plunger pump or a high-pressure gear pump two-component controllable proportional glue injection pump to achieve the purpose of high-pressure injection of plugging materials into the annular space, and no sole limitation is made here.

[0033] Second, see Figure 2 and Figure 3 The present invention also provides a sandwich-mode annulus plugging structure, including a production oil pipe 4, a production casing 5, an inner technical casing 6 and a plugging layer group. The production oil pipe 4 is mainly used to extract crude oil or natural gas from underground oil reservoirs to surface facilities; the production casing 5 is sleeved on the outside of the production oil pipe 4, and is mainly used to protect the wellbore structure, isolate different geological layers and provide a fluid transmission channel, and a first annulus 7 is formed between the production casing 5 and the production oil pipe 4; the inner technical casing 6 is sleeved on the outside of the production casing 5, and the inner technical casing 6 is usually a layer of casing placed after the production casing 5 has been inserted, and a second annulus 8 is formed between the inner technical casing 6 and the production casing 5, and the first annulus 7 and the second annulus 8 are respectively provided with a first annulus cement stone 701 and a second annulus cement stone 8. 01, the first annulus cement stone 701 and the second annulus cement stone 801 are both annulus cement stones. The annulus cement stone is a solid cement layer formed by injecting cement slurry into the annulus between the casing and the wellbore wall in the wellbore and hardening it to provide basic wellbore wall support; the plugging layer group includes a plugging structural adhesive layer 702 and a foamed colloid layer 703 stacked from bottom to top on the top of the first annulus cement stone 701 in the first annulus 7. During the plugging operation, the foamed colloid layer 703 injected first has the purpose of isolation and liquid displacement, reducing the obstruction of retained liquid in the annulus. On this basis, the plugging structural adhesive layer 702 is injected to obtain a better plugging effect.

[0034] In one embodiment, see Figure 3A nano-leakage plugging glue layer 704 is also inserted in the plugging structural glue layer 702. A portion of the plugging structural glue is injected, then the nano-leakage plugging glue is injected, and then the plugging structural glue is injected, so as to form the purpose of inserting the nano-leakage plugging glue layer 704 in the plugging structural glue layer 702. The plugging structural glue of the plugging structural glue layer 702 has cracks after a long time. Under the action of pressure difference, nano-particle materials and high-viscosity unsolidified glue are squeezed into the cracks to plug the leaks.

[0035] It can be understood that the nano-leakage plugging glue contains nano-particles but does not solidify the glue.

[0036] In one embodiment, see Figure 3 In order to clean the inner wall of the annulus and avoid the influence of retained liquid and gas and liquid leakage on cleaning, as well as to reduce the influence of the cleaning part on the plugging structure, a cleaning liquid layer 705 is also inserted in the foaming colloid layer 703. A part of the foaming colloid is injected to achieve the purpose of isolation and liquid expulsion, and then a strong cleaning liquid is injected to achieve a better cleaning effect. The foaming colloid is injected again to achieve the purpose of isolating the strong cleaning liquid and rubbing and brushing the wall surface to clean it, and a structure in which the cleaning liquid layer 705 is inserted in the foaming colloid layer 703 is formed.

[0037] In one embodiment, see 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 casing 5 is provided with a first annulus wing valve 501 connected with the first annulus 7, and the inner technical casing 6 is provided with a second annulus wing valve 601 connected with the second annulus 8.

[0038] In a third aspect, the present invention further provides a sandwich mode annular space plugging method, comprising the following steps: S1. The plugging injection point is located at the top of the annular cement stone. First, a proper amount of foaming colloid is injected to achieve the purpose of isolation and liquid displacement. The foaming colloid is the main component of the foaming colloid layer 703. S2, injecting a strong cleaning liquid to clean the inner wall of the annulus and injecting an appropriate amount of inert gas to bubble and clean the wall, the strong cleaning liquid is the main component of the cleaning liquid layer; S3, injecting the foaming colloid again, isolating the strong cleaning liquid and rubbing and squeezing the wall surface to form a structural feature in which a cleaning liquid layer 705 is inserted in the foaming colloid layer 703; S4, injecting cementing plugging structural adhesive, the cementing plugging structural adhesive is the main component of the plugging structural adhesive layer 702; S5, injecting the non-consolidating adhesive containing nanoparticles, which is the main component of the nano-leakage plugging adhesive layer 704. The cementing plugging structural adhesive has cracks after a long time. Under the action of pressure difference, the nano-particle material and the high-viscosity non-consolidating adhesive are squeezed into the cracks to plug the leak; S6. Inject an appropriate amount of bonding and plugging structural adhesive again to prevent gas and liquid leakage from the bonding gaps that appear over time and provide plugging pressure difference.

[0039] It is understandable that when the pump body is used for glue injection, the pump body can also be used to inject the cleaning liquid mixed with nitrogen.

[0040] The shear strength of the bonding plugging structural adhesive with the clean annulus wall is ≥30MPA, and the viscosity of the bonding plugging structural adhesive is ≤2000mpas at an ambient temperature of 0°C, and the shear strength between the bonding plugging structural adhesive and the unclean annulus pipe wall is ≥0.5MPA.

[0041] Furthermore, the material particle size of the nanoparticles that do not solidify the colloid is 50-800nm.

[0042] It can be understood that the foaming colloid can be a foaming resin colloid, and the height of the resin to be injected can be calculated based on the maximum pressure of the annulus that is ≤ MPa, the inner and outer diameters of the annulus, and the safety factor; the type of cleaning fluid can be selected according to the cleanliness of the inner surface of the annulus, whether there is liquid accumulation on the top of the annulus cement stone, and whether the accumulated liquid is water-based or oily, and no sole limitation is made here; the overinjection margin required for resin injection can be calculated based on the distance between the sealing cement stone in the target annulus and the ground surface; in addition, when injecting the colloid, according to actual conditions, the amount of catalyst added can be calculated based on the formation temperature range of the target annulus construction section and the expected curing time, and the appropriate type of plugging glue can be determined, and no sole limitation is made here. If necessary, an appropriate amount of diluent can be added to improve fluidity.

[0043] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A sandwich mode annulus plugging system, characterized in that: include: An injection tube having a flat cross-sectional shape; A traction assembly, which is arranged at one end of the injection pipe and is used to traction the injection pipe to drop into the annulus; as well as The injection assembly has an output end connected to and communicated with the other end of the injection pipe, and is used to inject one or more of liquid, gas and colloid into the injection pipe.

2. The sandwich mode annulus plugging system according to claim 1 is characterized in that: Both side walls of the injection pipe cross section are provided with circular support layers, and the upper and lower inner walls in the middle of the injection pipe cross section are provided with semicircular support layers, and the two semicircular support layers are separable.

3. The sandwich mode annulus plugging system according to claim 1 is characterized in that: The traction assembly comprises a visualized hydraulic traction head, which is arranged at one end of the injection pipe, and an ultra-fine camera probe and a hydraulic injection device are provided at the front end, which are respectively used for visualized traction and providing traction power.

4. The sandwich mode annulus plugging system according to claim 1 is characterized in that: The traction assembly comprises a chain weight, which is arranged at one end of the injection pipe and hangs down into the annulus by its own weight.

5. The sandwich mode annulus plugging system according to claim 3 is characterized in that: The visualized hydraulic traction head is provided with three reverse hydraulic injection holes and an electromagnetic reversing injection device, wherein the electromagnetic reversing injection device has two horizontally opposite injection holes that can be opened and closed.

6. A sandwich-type annular plugging structure, characterized in that: include: Production of oil pipes; A production casing, which is sleeved on the outside of the production oil pipe to form a first annulus therebetween; an inner technical casing, which is sleeved on the outer side of the production casing to form a second annulus therebetween, wherein a first annulus cement stone and a second annulus cement stone are respectively arranged in the first annulus and the second annulus; and The plugging layer group includes a plugging structural adhesive layer and a foaming colloid layer stacked in sequence from bottom to top on the top of the first annulus cement stone of the first annulus.

7. The sandwich-mode annular space plugging structure according to claim 6 is characterized in that: A nanometer plugging glue layer is inserted in the plugging structural glue layer, a cleaning liquid layer is inserted in the foaming colloid layer, a first annular space wing valve connected to the first annular space is arranged on the production casing, and a second annular space wing valve connected to the second annular space is arranged on the inner technical casing.

8. A sandwich mode annulus plugging method, characterized in that: The following steps are involved: S1. The plugging 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 displacement; S2, inject strong cleaning fluid to clean the inner wall of the annulus and inject appropriate amount of inert gas to bubble and clean the wall; S3, inject the foaming colloid again, isolate the strong cleaning liquid and rub and squeeze the brush to clean the wall surface; S4, inject cementation and plugging structural adhesive; S5, injecting an unsolidified adhesive containing nanoparticles; S6. Inject an appropriate amount of bonding and plugging structural adhesive again.

9. The sandwich mode annulus plugging method according to claim 8, characterized in that: The shear strength of the bonding plugging structural adhesive and the clean annulus wall is ≥30MPA, and when the ambient temperature is 0°C, the viscosity of the bonding plugging structural adhesive is ≤2000mpas, and the shear strength between the bonding plugging structural adhesive and the unclean annulus pipe wall is ≥0.5MPA.

10. The sandwich mode annulus plugging method according to claim 8, characterized in that: The material particle size of the nanoparticle unsolidified colloid is 50-800nm.

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