Ground direct-control single-pipe separate injection process technology

Abstract

The invention relates to the technical field of ground direct-control single-pipe separate injection, in particular to a ground direct-control single-pipe separate injection process technology which comprises the following steps: 1) using a specially-made single-pipe structure which comprises an upper butt joint, a main body pipe, a single injection pipe, a connecting pressing cap, a sealing carrier and a sealing gasket, a connecting body is formed through screw thread connection, the accuracy of each layer of single injection pipe is ensured by utilizing the size limit of the single injection pipe and the upper butt joint, the whole process is safer and more reliable due to the realization of ground direct control, the ground of inspection and detection instruments is realized, the adverse effect of well conditions on the instruments is avoided, the injection data is more accurate, and the detection accuracy is improved. And fine management of water injection and polymer injection is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of ground direct-controlled single-tube dispensing, in particular to a ground direct-controlled single-tube dispensing process technology. Background Art

[0002] In the process of oil production, liquid injection is one of the commonly used methods and one of the most widely used processes. Due to the multi-layer reasons and the differences between layers, injection becomes particularly important.

[0003] At present, the commonly used injection processes include: double-tube concentric injection, eccentric injection, automatic control injection technology, mechanical injection and other processes. In order to extend the service life of these processes, the packers are all washable, such as Y341 or K341 (including K344). Due to the limitations of the process, various process packers have problems with well washing, resulting in poor sealing, which ultimately leads to poor stratification effect. To be precise, the packers in the above processes are not stratified, but throttling between layers. In this way, the stratification effect is greatly reduced.

[0004] From the above discussion, it can be seen that each of the above processes has technical and process limitations to varying degrees. For example:

[0005] Double-tube concentric injection achieves clear stratification and simple operation, which can be said to be ideal. However, since the interlayer is too long and the diameter of the coupling part is larger than the pipe diameter when the core pipe is connected, it is easy to cause major repairs due to scaling after a long period of use.

[0006] Eccentric injection: This is an older process. It can only inject the same liquid, and the injection pressure between layers cannot be adjusted. The injection amount is adjusted using a water nozzle. When replacement is required, the nozzle needs to be removed and a new one needs to be put in again.

[0007] Automated control and injection technology: Due to the influence of cables, it is prone to major repairs and accidents, and has obvious limitations.

[0008] Mechanical mixing and injection process: still needs to be operated again and is greatly affected by the well conditions. Summary of the invention

[0009] (I) Purpose of the invention

[0010] In view of this, the purpose of the present invention is to propose a ground direct-controlled single-tube injection process technology to solve the problems raised in the above background.

[0011] (II) Technical solution

[0012] The ground direct-control single-tube injection process technology includes the following steps:

[0013] 1) Use a special single-tube structure, which includes an upper butt joint, a main tube, a single injection tube, a connecting cap, a sealing carrier and a sealing gasket, which are connected by threads to form a connector, and the size limit of the single injection tube and the upper butt joint is used to ensure the accuracy of each layer of the single injection tube;

[0014] 2) Use the connecting cap and the upper joint on the other pipe to compress the sealing gasket to achieve the sealing isolation of each single injection pipe to achieve the purpose of direct control injection;

[0015] 3) Lower the III injection string into the II well casing and connect it to the flange on the upper part of the II well casing through the suspension of the III injection string manifold;

[0016] 4) Pressurize the wellhead by flushing the seat seal on the V injection manifold to seat the packer (such as Y);

[0017] 5) Injection is performed through each injection port, wherein the injection liquid is injected from a specific injection hole A, and the well flushing valve blocks the well flushing hole to ensure that all the injection liquid is injected into the injection layer;

[0018] 6) When it is necessary to wash the well, the wellhead is pressurized by the seat seal, and the well washing fluid from the C well washing hole pushes open the well washing valve, and the well washing valve goes down to block the injection nozzle, so that the well washing fluid can circulate upward, achieving the purpose of washing the well and cleaning the pipeline.

[0019] Preferably, each single injection tube in the single-tube structure has a different length, forming a memory code for the injection layer, which is easy to identify and operate.

[0020] Preferably, the packer is a non-well-washable Y packer, which has the advantages of large isolation pressure difference, easy implementation and good effect.

[0021] Preferably, the gaps between the fine injection single pipes and the gaps between the main pipes are utilized to realize the well washing of the pipe string and the setting of the Y packers of each layer, thereby saving the internal space of the pipe string and simplifying the process.

[0022] Preferably, the deformable ball basket formed by the well-washing valve, water injection nozzle and reset spring can catch the sealing ball seat, which not only achieves the purpose of sealing the packer, but also reduces the pollution to the oil and water wells. It is a mature process and is safe and reliable.

[0023] Preferably, the single tube can be designed to have different lengths, and the process is completed as a mechanical structure, with a wide range of implementation and good economic benefits.

[0024] Preferably, it also includes preparation steps before going down the well, including replacing the upper joint on the direct layered single pipe to form a single pipe injection short joint, and replacing the main pipe on the direct layered single pipe with a Y packer to form a special packer for ground direct control single pipe injection.

[0025] Preferably, it also includes a tool inspection step before going down the well, including verifying the sealing of the upper joint and the sealing carrier behind the packer, inspecting the pressure, tension and sealing of the direct-controlled layered single pipe, as well as inspecting the sealing of the injection short joint, the discharge volume of the injection water nozzle and the shear force of the packer shear pins.

[0026] Preferably, the method further includes the steps of lowering the III injection pipe column into the casing according to the design requirements after the well scraping is completed, installing the wellhead, connecting the manifold, and pressurizing the packer to seal it.

[0027] Preferably, it also includes the step of performing injection according to the process requirements after the sealing of the packer is completed. When a single pipe in a certain layer needs to be flushed, it is only necessary to stop the current layer and pressurize the wellhead through the sealing and flushing on the III injection string to achieve circulation of the current layer without affecting the injection process of other layers.

[0028] It can be seen from the above technical solutions that the present application has the following beneficial effects:

[0029] 1. The implementation of direct ground control in this invention makes the entire process safer and more reliable, realizes the ground-based inspection and testing instruments, avoids the adverse effects of well conditions on instruments, makes injection data more accurate, and is conducive to the refined management of water injection and polymer injection.

[0030] 2. The invention realizes single-tube injection for each layer without affecting each other, and realizes special treatment for each layer. That is, the injection liquid, injection pressure, liquid temperature, etc. of the layer can be selected according to the actual situation. In this way, the situation that only the same liquid can be injected, such as partial matching, can be avoided.

[0031] 3. The public well-washing passage of the invention makes the process clean and space-saving. The process has a larger expansion space and can be designed with more layers. At the same time, each injection layer will not be affected by well washing. For example, double-tube concentric injection requires a passage, so when one layer is washed, the other layer must be stopped.

[0032] 4. The invention realizes the single-tube internal circulation well washing method, which will not corrode the casing due to well washing and expand the application scope of the process.

[0033] 5. The invented packer adopts the non-washable well, making the interlayer stratification safer and more reliable, avoiding the original process that affects the effect in order to extend the service life.

[0034] 6. The use of the length code of the invention makes the determination of the layer position by this process more clear.

[0035] 7. The single-tube design of the invention realizes the disassembly of each tube during operation, thus avoiding major repairs due to scaling. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1This is a schematic diagram of the direct-controlled single-tube injection principle of the present invention;

[0037] Figure 2 This is a schematic diagram of a directly controlled layered single tube according to the present invention;

[0038] Figure 3 This is a schematic diagram of the main pipe connection of the present invention;

[0039] Figure 4 This is a schematic diagram of the structure of the first injector of the present invention;

[0040] Figure 5 It is a schematic diagram of the structure of the injector body of the present invention.

[0041] In the figure: 1. V injection manifold; 2. III injection string; 3. II wellbore casing; 411. upper joint; 412. main pipe; 413. single injection pipe; 414. connecting pressure cap; 415. sealing carrier; 416. sealing gasket; 511. a upper pipe; 512. b lower pipe; 611. injector body; 612. injection nozzle; 613. packer seat seal shear pin; 614. well washing valve; 615. reset spring; 711. A injection hole; 712. C well washing hole. DETAILED DESCRIPTION

[0042] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, and use. It should be understood that in all of these figures, the same or similar reference numerals indicate the same or similar parts and features. The various drawings only schematically represent the concepts and principles of the embodiments of the present disclosure, and do not necessarily show the specific dimensions and proportions of the various embodiments of the present disclosure. Specific parts in specific drawings may be exaggerated to illustrate the relevant details or structures of the embodiments of the present disclosure.

[0043] See also Figure 1-5 , an embodiment provided by the present invention:

[0044] The ground direct-control single-tube injection process technology includes the following steps:

[0045] 1) Use a special single-tube structure, which includes an upper butt joint 411, a main tube 412, a single injection tube 413, a connecting cap 414, a sealing carrier 415 and a sealing gasket 416, which are connected by threads to form a connection body, and the size limit of the single injection tube 413 and the upper butt joint 411 is used to ensure the accuracy of each layer of the single injection tube 413, such as Figure 2 As shown;

[0046] 2) Using the connecting cap 414 and the upper joint 411 on the other pipe to compress the sealing gasket 416, the sealing isolation of each single injection pipe 413 is realized to achieve the purpose of direct control injection;

[0047] 3) Lower the III injection string 2 into the II well casing 3, and connect it to the flange on the upper part of the II well casing 3 through the suspension of the III injection string 2;

[0048] 4) Pressurize the wellhead by flushing the seat seal on the V injection manifold 1 to set the packer such as Y341;

[0049] 5) The injection is carried out through each injection port, wherein the injection liquid is injected from a specific injection hole A711, and the well flushing valve 614 blocks the well flushing hole to ensure that the injection liquid is fully injected into the injection layer. Figure 1 As shown;

[0050] 6) When the well needs to be washed, the wellhead is pressurized by sealing the wellhead, and the washing fluid from the well-washing hole 712 pushes the well-washing valve 614, and the well-washing valve 614 moves downward to block the injection nozzle 612, so that the washing fluid can circulate upward, achieving the purpose of washing the well and cleaning the pipeline. Figure 4 As shown in the figure, the packer seat seal shear pin (613) on one of the layers is cut off, causing a sudden drop in pressure. At this time, the packer has been set and can be injected. Since there is pressure during injection, the other unbroken packer seat seal shear pins (613) can be easily cut off during well washing, which will not affect the performance of the entire pipe string. Figure 5 As shown, the injection liquid is injected from the A injection hole (711), and the well washing valve blocks the C well washing hole 712, so that the injection liquid is completely injected into the injection layer. When the well needs to be washed, the well washing liquid from the C well washing hole 712 pushes the well washing valve open, and the well washing valve goes down to block the injection nozzle 612, so that the well washing liquid can circulate upward, and finally the purpose of washing the well and cleaning the pipeline is achieved.

[0051] Further, each single injection tube 413 in the single tube structure has a different length, forming a memory code for the injection layer, which is easy to identify and operate, such as Figure 3 As shown: a connection between the upper pipe and b lower pipe. In this way, due to the different lengths of each single injection pipe, a memory code for the injection layer is formed. After the pipe string is lowered, the wellhead is washed and pressurized through the seat seal on the V injection manifold, and the packers of each layer are seated at the same time.

[0052] Furthermore, the packer is a non-well-flushing Y341 packer, which has the advantages of large isolation pressure difference, easy implementation and good effect.

[0053] Furthermore, the gaps between the precision-injected single pipes and the gaps between the main pipes 412 are utilized to realize the well washing of the pipe string and the setting of the Y341 packers of each layer, thereby saving the internal space of the pipe string and simplifying the process.

[0054] Furthermore, the deformed ball basket formed by the well washing valve 614, the water injection nozzle 612 and the return spring 615 can catch the sealing ball seat, which not only achieves the purpose of sealing the packer, but also reduces the pollution to the oil and water wells. It is a mature process and is safe and reliable.

[0055] Furthermore, the single tube can be designed into different lengths, and the process is completed as a mechanical structure, which has a wide implementation range and good economic benefits.

[0056] Furthermore, it also includes preparation steps before going down the well, including replacing the upper joint 411 on the direct layered single pipe to form a single pipe injection short joint, and replacing the main pipe 412 on the direct layered single pipe with a Y341 packer to form a special packer for ground direct control single pipe injection.

[0057] Furthermore, it also includes a tool inspection step before going downhole, including verifying the sealing of the upper joint 411 and the sealing carrier 415 behind the packer, inspecting the pressure, tension and sealing of the direct-controlled layered single pipe, as well as inspecting the sealing of the injection short joint, the discharge volume of the injection water nozzle 612 and the shear force of the packer shear pin 613.

[0058] Furthermore, it also includes the steps of lowering 2 columns of III injection pipe strings into the casing according to design requirements after the well scraping is completed, installing the wellhead, connecting the manifold, and pressurizing to seal the packer.

[0059] Furthermore, it also includes that after the sealing of the packer is completed, injection is carried out according to the process requirements. When a single pipe in a certain layer needs to be washed, it is only necessary to stop the layer and pressurize the wellhead through the sealing and washing wellhead on the III injection string 2 to realize the circulation of the layer without affecting the injection process of other layers.

[0060] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. Ground direct control single pipe injection process technology, characterized by: The process technology includes the following steps: 1) A special single-tube structure is used, which includes an upper butt joint (411), a main tube (412), a single injection tube (413), a connection cap (414), a sealing carrier (415) and a sealing gasket (416), which are connected by threads to form a connection body, and the size limit of the single injection tube (413) and the upper butt joint (411) is used to ensure the accuracy of each layer of the single injection tube (413); 2) Using the connecting pressure cap (414) and the upper joint (411) on another pipe to compress the sealing gasket (416) to achieve the sealing isolation of each single injection pipe (413) to achieve the purpose of direct control injection; 3) lowering the III injection string (2) into the II well casing (3), and connecting the III injection string (2) to the flange on the upper part of the II well casing (3) through the suspension of the III injection string (2); 4) Pressurize the wellhead through the seal wash on the V injection manifold (1) to set the packer (such as Y341); 5) Injection is performed through each injection port, wherein the injection liquid is injected from a specific injection hole A (711), and the well flushing valve (614) blocks the well flushing hole to ensure that the injection liquid is fully injected into the injection layer; 6) When the well needs to be washed, the wellhead is pressurized by sealing the wellhead, and the well washing fluid from the well washing hole (712) pushes the well washing valve (614) open, and the well washing valve (614) moves downward to block the injection nozzle (612), so that the well washing fluid can circulate upward, thereby achieving the purpose of washing the well and cleaning the pipeline.

2. The ground direct-control single-tube injection process technology according to claim 1 is characterized by: Each single injection tube (413) in the single tube structure has a different length, forming a memory code for the injection layer, which is easy to identify and operate.

3. The ground direct-control single-tube injection process technology according to claim 1 is characterized by: The packer is a non-well-flushing Y341 packer, which has the advantages of large isolation pressure difference, easy implementation and good effect.

4. The ground direct-control single-tube injection process technology according to claim 1 is characterized by: The invention also includes utilizing the gaps between the fine injection single pipes and the gaps between the main pipes (412) to realize the well washing of the pipe string and the setting of the Y341 packers of each layer, thereby saving the internal space of the pipe string and simplifying the process.

5. The ground direct-control single-tube injection process technology according to claim 1 is characterized by: The deformable ball basket formed by the well-washing valve (614), the water injection nozzle (612) and the return spring (615) can receive the sealing ball seat, thereby achieving the purpose of sealing the packer and reducing the pollution to the oil and water wells. The process is mature and safe and reliable.

6. The ground direct-control single-tube injection process technology according to claim 1 is characterized by: The single tube can be designed to have different lengths, and the process is completed as a mechanical structure, with a wide implementation range and good economic benefits.

7. The ground direct-control single-tube injection process technology according to claim 1 is characterized by: The method also includes preparation steps before going down the well, including replacing the upper joint (411) on the direct layered single pipe to form a single pipe injection short joint, and replacing the main pipe (412) on the direct layered single pipe with a Y341 packer to form a special packer for ground direct control single pipe injection.

8. The ground direct-control single-tube injection process technology according to claim 7 is characterized by: The method also includes a tool inspection step before going down the well, including verifying the sealing performance of the upper joint (411) and the sealing carrier (415) behind the packer, inspecting the pressure bearing, tension bearing and sealing performance of the direct-controlled layered single pipe, and inspecting the sealing performance of the injection nipple, the discharge volume of the injection nozzle (612) and the shear force of the packer sealing shear pins (613).

9. The ground direct-control single-tube injection process technology according to claim 8 is characterized by: The method also includes the steps of lowering the III injection pipe column (2) into the casing after the scraping of the wellbore is completed according to the design requirements, installing the wellhead, connecting the manifold, and pressurizing the packer to seal it.

10. The ground direct-control single-tube injection process technology according to claim 9 is characterized in that: The method also includes the steps of performing injection according to the process requirements after the packer is set and when a single pipe in a layer needs to be flushed, it is only necessary to stop the layer and pressurize the wellhead through the seal flushing well on the III injection string (2) to realize the circulation of the layer without affecting the injection process of other layers.

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