An intelligent adjustable injection string and method of use thereof

Abstract

The application belongs to the technical field of steam flooding oil recovery, and discloses an intelligent adjustable injection pipe column and a use method thereof, wherein the pipe column comprises a casing and a tubing, the tubing is arranged inside the casing, an annular cavity is arranged between the casing and the tubing, a plug is arranged at the bottom of the tubing, and a plurality of high-temperature crossing packers are arranged on the tubing at intervals; a high-temperature injection distribution valve is arranged between the lowermost high-temperature crossing packer and the plug of the tubing and between two adjacent high-temperature crossing packers; and an optical fiber and a capillary tube are arranged on the outer side of the tubing in the axial direction. The pipe column detects downhole pressure through the capillary tube and detects downhole temperature through the optical fiber, adjusts the steam injection amount of each oil layer through the high-temperature injection distribution valve according to the downhole pressure and the downhole temperature, realizes accurate steam injection of each layer, and solves the problem of uneven longitudinal gas absorption.

Description

Technical Field

[0001] This invention belongs to the field of steam-driven oil recovery technology, and specifically relates to an intelligent adjustable injection string and its usage method. Background Technology

[0002] Steam drive, as an efficient and widely used extraction method, is of great significance for heavy oil development. However, facing complex geological conditions such as significant reservoir heterogeneity, large permeability differences, and steam overlay, existing steam drive technologies encounter some problems in practical applications, as follows:

[0003] 1. Uneven motion in both the plane and longitudinal directions severely restricts the development effect of steam drive.

[0004] 2. Problems such as limited number of layers, low success rate of steam injection nozzle adjustment, and difficulty in guaranteeing injection accuracy are particularly prominent in the later stages of oilfield development, making it difficult to meet the needs of precise control and efficient development.

[0005] To address the aforementioned issues and further improve the development efficiency and oil recovery rate of steam-driven systems, a new type of steam injection tubing technology that can flexibly adjust and precisely control the amount of steam injected is urgently needed. Summary of the Invention

[0006] To address the above problems, this invention provides an intelligent adjustable injection string and its usage method, employing the following technical solution:

[0007] An intelligent adjustable injection string includes a casing and an oil tubing. The oil tubing is disposed inside the casing, and an annular cavity exists between the casing and the oil tubing. A plug is disposed at the bottom of the oil tubing, and multiple high-temperature cross-pass packers are disposed at intervals on the oil tubing. High-temperature injection valves are disposed between the lowest high-temperature cross-pass packer and the plug, as well as between two adjacent high-temperature cross-pass packers. An optical fiber and a capillary are disposed axially on the outer side of the oil tubing.

[0008] Furthermore, each of the high-temperature passage packers is provided with a capillary channel, and the capillary extends through the capillary channel of each of the high-temperature passage packers.

[0009] Furthermore, the top of the capillary extends to the top of the oil pipe, and the bottom of the capillary extends to the bottom of the lowest high-temperature dispensing valve.

[0010] Furthermore, each of the high-temperature passage packers is also provided with an optical fiber channel, and the optical fiber passes through the optical fiber channel of each of the high-temperature passage packers.

[0011] Furthermore, the top of the optical fiber extends to the top of the oil pipe, and the bottom of the optical fiber extends to the bottom of the lowest high-temperature dispensing valve.

[0012] Furthermore, a heat insulation pipe is provided above the high-temperature passage packer at the top of the oil pipe.

[0013] Furthermore, the high-temperature dispensing valve adopts an equal-bore structure.

[0014] Furthermore, the high-temperature dispensing valve includes, from top to bottom, a magnetic positioning component, a mechanical positioning component, a transmission mechanism, and a valve body;

[0015] The valve body is provided with a nozzle, and a central flow channel is provided axially inside the valve body. The inner side of the nozzle is connected to the central flow channel, and the outer side of the nozzle is connected to the annular cavity.

[0016] Furthermore, the valve body is provided with different numbers of nozzles at different positions in the axial direction.

[0017] Furthermore, the lateral and longitudinal spacing between two adjacent nozzles is the same.

[0018] Furthermore, the number of nozzles in the valve body first increases and then decreases in the direction gradually moving away from the transmission mechanism.

[0019] Furthermore, the diameter of the steam injection valve orifice of the nozzle gradually increases from the inside to the outside.

[0020] Furthermore, the centerline of each of the steam injection valve holes forms an angle with the centerline of the central flow channel.

[0021] Furthermore, the transmission mechanism includes an outer cylinder, a lead screw, and a nut. The two ends of the outer cylinder are fixedly connected to the mechanical positioning component and the valve body, respectively. The lead screw and the nut are disposed inside the outer cylinder. The external thread of the lead screw is threadedly connected to the internal thread of the nut. An inner cylinder is disposed inside the central flow channel. The inner cylinder is slidably connected to the central flow channel. The end of the inner cylinder near the transmission mechanism is fixedly connected to the lead screw.

[0022] Furthermore, the nut is disposed inside the outer cylinder at one end near the mechanical positioning component.

[0023] Furthermore, the high-temperature through-packer includes an upper connector, a seal, an unsealing mechanism, and a setting mechanism connected in sequence, with the upper connector connected to the oil pipe.

[0024] Furthermore, the capillary channel extends axially through the upper connector, the seal, the unsealing mechanism, and the setting mechanism.

[0025] Furthermore, the optical fiber channel extends axially through the upper connector, the seal, the unsealing mechanism, and the setting mechanism.

[0026] The present invention also provides a method for using the aforementioned intelligent adjustable injection string, comprising the following steps:

[0027] Two adjacent oil layers are isolated by a high-temperature packer. Downhole pressure is detected by capillary tube and downhole temperature is detected by optical fiber. Based on the downhole pressure and temperature, the steam injection rate of each oil layer is adjusted by a high-temperature injection valve.

[0028] Furthermore, the steam injection rate of each oil layer is adjusted through the high-temperature injection valve, including the following steps:

[0029] The linear motion of the lead screw of the control transmission mechanism along the nut drives the inner cylinder to slide along the central flow channel, thereby controlling the number of nozzles opened and adjusting the amount of steam injected into each oil layer.

[0030] The beneficial effects of this invention are:

[0031] 1. In this embodiment of the invention, the tubing string detects downhole pressure through a capillary tube and downhole temperature through an optical fiber. Based on the downhole pressure and temperature, the steam injection volume of each oil layer is adjusted through a high-temperature injection valve to achieve precise steam injection in each layer and solve the problem of uneven vertical gas intake.

[0032] 2. The high-temperature penetration packer of this invention is equipped with a capillary channel and an optical fiber channel, which effectively protects the capillary and optical fiber during construction, avoids the risk of breakage, and ensures smooth construction.

[0033] 3. The high-temperature injection valve of this invention adopts an equal-diameter structure to support injection of countless layers, thus solving the problem of limited number of layers in the prior art.

[0034] 4. In this embodiment of the invention, the high-temperature injection valve drives the inner cylinder to slide along the central flow channel by the linear movement of the screw along the nut, thereby controlling the number of nozzles opened. This achieves precise control of the injection volume required for each stage, solving the problems of low success rate of steam nozzle adjustment and difficulty in guaranteeing injection accuracy in the prior art.

[0035] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 A schematic diagram of a smart adjustable injection string according to an embodiment of the present invention is shown;

[0038] Figure 2 A schematic diagram of the structure of a high-temperature dispensing valve according to an embodiment of the present invention is shown;

[0039] Figure 3 A schematic diagram of the nozzle arrangement of a high-temperature dispensing valve according to an embodiment of the present invention is shown.

[0040] Figure 4 A schematic diagram of a high-temperature passage packer according to an embodiment of the present invention is shown.

[0041] In the diagram: 1. Casing; 2. Oil pipe; 3. Annular cavity; 4. Plug; 5. High-temperature through packer; 6. High-temperature injection valve; 7. Optical fiber; 8. Capillary tube; 9. Capillary channel; 10. Optical fiber channel; 11. Insulation tube; 12. Magnetic positioning component; 13. Mechanical positioning component; 14. Transmission mechanism; 15. Valve body; 16. Nozzle; 17. Central flow channel; 18. Steam injection valve orifice; 19. Outer cylinder; 20. Lead screw; 21. Nut; 22. Inner cylinder; 23. Upper connector; 24. Seal; 25. Unsealing mechanism; 26. Sealing mechanism. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] It should be noted that the terms "first," "second," etc., used in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," "longitudinal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings.

[0044] This invention provides an intelligent adjustable injection string and its usage method, addressing key issues in current heavy oil development such as low steam drive efficiency, uneven horizontal and vertical utilization, limited number of strata, low steam injection adjustment precision, and inability to meet fine-tuning requirements. This invention enables precise adjustment of steam injection volume for different oil layers, improving the success rate and accuracy of steam injection nozzle adjustment, and allows for unlimited strata injection, providing strong technical support for heavy oil development in oil fields.

[0045] like Figure 1 As shown, an intelligent adjustable injection string includes a casing 1 and an oil pipe 2. The oil pipe 2 is located inside the casing 1. There is an annular cavity 3 between the casing 1 and the oil pipe 2. A plug 4 is provided at the bottom of the oil pipe 2. Multiple high-temperature penetration packers 5 are arranged at intervals on the oil pipe 2. The high-temperature penetration packers 5 are used to isolate two adjacent oil layers.

[0046] Among them, the oil pipe 2 is equipped with a high temperature injection valve 6 between the lowest high temperature crossing packer 5 and the plug 4, as well as between two adjacent high temperature crossing packers 5, to adjust the amount of steam injected into each oil layer.

[0047] An optical fiber 7 and a capillary tube 8 are arranged axially on the outer side of the oil pipe 2, such as... Figure 4 As shown, each high-temperature crossing packer 5 is provided with a capillary channel 9 and an optical fiber channel 10. The capillary 8 passes through the capillary channel 9 of each high-temperature crossing packer 5. The top of the capillary 8 extends to the top of the tubing 2 and connects to the external system. The bottom of the capillary 8 extends to the bottom of the lowest high-temperature injection valve 6. The capillary 8 is used to detect downhole pressure.

[0048] Fiber 7 runs through the fiber optic channel 10 of each high-temperature packer 5. The top of fiber 7 extends to the top of tubing 2 and connects to the external system. The bottom of fiber 7 extends to the bottom of the lowest high-temperature injection valve 6. Fiber 7 is used to detect downhole temperature. For example, fiber 7 and capillary tube 8 are arranged parallel to each other.

[0049] In this embodiment of the invention, a capillary tube 8 and an optical fiber 7 are provided on the column. The capillary tube 8 is used to detect pressure, and the optical fiber 7 is used to detect temperature, thereby realizing the real-time acquisition of temperature and pressure parameters and improving the effect of steam drive development.

[0050] The high-temperature penetration packer 5 of this invention is provided with a capillary channel 9 and an optical fiber channel 10, which effectively protects the capillary 8 and optical fiber 7 during construction, avoids the risk of breakage, and ensures smooth construction.

[0051] For example, the oil pipe 2 is provided with a heat insulation pipe 11 above the high temperature passing packer 5 at the top to prevent heat transfer and maintain the temperature inside the pipe string.

[0052] like Figure 2 As shown, for example, the high-temperature injection valve 6 adopts an equal-bore structure to support injection of countless layers. The high-temperature injection valve 6 includes a magnetic positioning component 12, a mechanical positioning component 13, a transmission mechanism 14 and a valve body 15 connected sequentially from top to bottom.

[0053] The magnetic positioning component 12 is used to position and adjust the position of the high-temperature dispensing valve 6 through electromagnetic signals, ensuring that it accurately controls the flow rate and pressure of the fluid.

[0054] The mechanical positioning component 13 is used to fix and adjust the position of the high-temperature dispensing valve 6, providing stable support and adjustment functions. The transmission mechanism 14 is used to convert the control signal into mechanical motion, driving the high-temperature dispensing valve 6 to open and close, thereby achieving precise fluid control.

[0055] The valve body 15 is provided with a nozzle 16, and a central flow channel 17 is provided axially inside the valve body 15. The inner side of the nozzle 16 is connected to the central flow channel 17, and the outer side of the nozzle 16 is connected to the annular cavity 3.

[0056] like Figure 2 and Figure 3 As shown, for example, multiple nozzles 16 are provided, and the valve body 15 has different numbers of nozzles 16 at different axial positions. For example, the number of nozzles 16 on the valve body 15 first increases and then decreases in the direction gradually moving away from the transmission mechanism 14. For example, one nozzle 16 is provided at the position of the valve body 15 closest to the transmission mechanism 14, and then the number of nozzles 16 on the valve body 15 gradually moves away from the transmission mechanism 14, which are 2, 3, 4, 3, and 2 respectively. For example, the lateral spacing and longitudinal spacing between two adjacent nozzles 16 are the same.

[0057] For example, the nozzle 16 adopts FCD nozzle 16 technology. The steam injection valve orifice 18 of the nozzle 16 is designed with a Venturi tube flow pattern. The orifice diameter of the steam injection valve orifice 18 gradually increases from the inside to the outside. The center line of each steam injection valve orifice 18 has an angle with the center line of the central flow channel 17. For example, the angle can be an acute angle.

[0058] In this embodiment of the invention, the steam injection valve orifice 18 of the nozzle 16 adopts a Venturi flow pattern. The fluid velocity increases as the orifice diameter of the steam injection valve orifice 18 decreases. However, when the velocity at the throat of the nozzle 16 reaches the speed of sound, a blockage occurs. By controlling the flow velocity at the throat of the nozzle 16 to always be the speed of sound, the injection flow rate is not limited by the reservoir pressure.

[0059] like Figure 2As shown, for example, the transmission mechanism 14 includes an outer cylinder 19, a lead screw 20, and a nut 21. The two ends of the outer cylinder 19 are fixedly connected to the mechanical positioning component 13 and the valve body 15, respectively. The lead screw 20 and the nut 21 are disposed inside the outer cylinder 19. The nut 21 is disposed inside the outer cylinder 19 near the mechanical positioning component 13. The external thread of the lead screw 20 is threadedly connected to the internal thread of the nut 21. An inner cylinder 22 is disposed inside the central flow channel 17 of the valve body 15. The inner cylinder 22 is slidably connected to the central flow channel 17. The end of the inner cylinder 22 near the transmission mechanism 14 is fixedly connected to the lead screw 20. The linear movement of the lead screw 20 along the nut 21 drives the inner cylinder 22 to slide along the central flow channel 17, thereby controlling the number of nozzles 16 that are opened. This achieves precise control of the required injection volume for each layer, ensuring the efficient development of the oilfield.

[0060] like Figure 4 As shown, for example, the high-temperature pass-through packer 5 ensures stable setting by hydraulic setting. The high-temperature pass-through packer 5 includes an upper connector 23, a seal 24, a release mechanism 25, and a setting mechanism 26 connected in sequence. The upper connector 23 is connected to the oil pipe 2, and the setting mechanism 26 is equipped with a locking mechanism to ensure that the seal 24 is stable and does not retract.

[0061] The upper connector 23 ensures that the high-temperature penetration packer 5 is securely fixed in the downhole position. Through the threaded connection, the upper connector 23 can transmit pressure and torque, ensuring the stable operation of the high-temperature penetration packer 5.

[0062] The seal 24 is the core component of the high-temperature passage packer 5, and is typically made of an elastic material, such as rubber or a special synthetic material. Under external force, the seal 24 undergoes radial deformation, thereby sealing the annular gap and preventing fluid passage.

[0063] The function of the unsealing mechanism 25 is to release the sealing state of the high-temperature penetration packer 5 when needed, allowing the oil pipe 2 to be connected, thereby retracting the slips and restoring the seal 24 to its original state, facilitating the removal of the high-temperature penetration packer 5. The unsealing mechanism 25 consists of components such as a split joint and an unsealing and retrieval sleeve.

[0064] The function of the setting mechanism 26 is to maintain a sealed state after the high temperature packer 5 is set in the target layer. During setting, the setting mechanism 26 pushes the cone, forcing the slips to open and press against the wall of the sleeve 1, while compressing the sealing element 24 to expand and seal it.

[0065] For example, the capillary channel 9 passes through the upper connector 23, the seal 24, the unsealing mechanism 25, and the setting mechanism 26 along the axial direction, and the optical fiber channel 10 passes through the upper connector 23, the seal 24, the unsealing mechanism 25, and the setting mechanism 26 along the axial direction. Through the capillary channel 9 and the optical fiber channel 10, the capillary 8 and the optical fiber 7 are effectively protected during the construction process, avoiding the risk of breakage and ensuring the smooth progress of the construction.

[0066] This invention also provides a method for using an intelligent adjustable injection string, comprising the following steps: sealing two adjacent oil layers with a high-temperature packer 5, detecting downhole pressure with a capillary tube 8, detecting downhole temperature with an optical fiber 7, and adjusting the steam injection volume of each oil layer according to the downhole pressure and temperature with a high-temperature injection valve 6 to achieve precise steam injection in each layer and solve the problem of uneven vertical gas intake.

[0067] For example, detecting downhole pressure through capillary tube 8 includes the following steps: filling capillary tube 8 with nitrogen gas, transmitting downhole pressure to the surface through nitrogen-filled capillary tube 8, and then converting the pressure signal into an electrical signal through a pressure sensor to obtain the downhole pressure.

[0068] For example, adjusting the steam injection volume of each oil layer through the high-temperature injection valve 6 includes the following steps: controlling the linear movement of the lead screw 20 of the transmission mechanism 14 along the nut 21 to drive the inner cylinder 22 to slide along the central flow channel 17, thereby controlling the number of nozzles 16 opening, adjusting the steam injection volume of each oil layer, and improving the development efficiency of steam drive and the oil recovery rate.

[0069] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A smart adjustable injection string, characterized in that, The device includes a casing (1) and an oil pipe (2). The oil pipe (2) is located inside the casing (1). There is an annular cavity (3) between the casing (1) and the oil pipe (2). A plug (4) is provided at the bottom of the oil pipe (2). Multiple high-temperature crossing packers (5) are arranged at intervals on the oil pipe (2). High-temperature injection valves (6) are provided between the lowest high-temperature crossing packer (5) and the plug (4) and between two adjacent high-temperature crossing packers (5). An optical fiber (7) and a capillary tube (8) are arranged axially on the outside of the oil pipe (2).

2. The intelligent adjustable injection string according to claim 1, characterized in that, Each of the high-temperature passage packers (5) is provided with a capillary channel (9), and the capillary (8) passes through the capillary channel (9) of each of the high-temperature passage packers (5).

3. The intelligent adjustable injection string according to claim 2, characterized in that, The top of the capillary tube (8) extends to the top of the oil pipe (2), and the bottom of the capillary tube (8) extends to the bottom of the lowest high-temperature dispensing valve (6).

4. The intelligent adjustable injection string according to claim 2, characterized in that, Each of the high-temperature passage packers (5) is also provided with an optical fiber channel (10), and the optical fiber (7) passes through the optical fiber channel (10) of each of the high-temperature passage packers (5).

5. The intelligent adjustable injection string according to claim 4, characterized in that, The top of the optical fiber (7) extends to the top of the oil pipe (2), and the bottom of the optical fiber (7) extends to the bottom of the lowest high-temperature injection valve (6).

6. The intelligent adjustable injection string according to any one of claims 1-5, characterized in that, The oil pipe (2) is provided with a heat insulation pipe (11) above the high temperature through packer (5) at the top.

7. The intelligent adjustable injection string according to claim 1, characterized in that, The high-temperature dispensing valve (6) adopts an equal-bore structure.

8. The intelligent adjustable injection string according to any one of claims 1-5, characterized in that, The high-temperature dispensing valve (6) includes a magnetic positioning component (12), a mechanical positioning component (13), a transmission mechanism (14), and a valve body (15) connected sequentially from top to bottom; The valve body (15) is provided with a nozzle (16), and a central flow channel (17) is provided axially inside the valve body (15). The inner side of the nozzle (16) is connected to the central flow channel (17), and the outer side of the nozzle (16) is connected to the annular cavity (3).

9. The intelligent adjustable injection string according to claim 8, characterized in that, The valve body (15) has a different number of nozzles (16) at different positions in the axial direction.

10. The intelligent adjustable injection string according to claim 9, characterized in that, The lateral and longitudinal spacing between two adjacent nozzles (16) is the same.

11. The intelligent adjustable injection string according to claim 9, characterized in that, The number of nozzles (16) on the valve body (15) first increases and then decreases in the direction that gradually moves away from the transmission mechanism (14).

12. The intelligent adjustable injection string according to claim 8, characterized in that, The diameter of the steam injection valve hole (18) of the nozzle (16) gradually increases from the inside to the outside.

13. The intelligent adjustable injection string according to claim 12, characterized in that, The centerline of each of the steam injection valve holes (18) forms an angle with the centerline of the central flow channel (17).

14. The intelligent adjustable injection string according to claim 8, characterized in that, The transmission mechanism (14) includes an outer cylinder (19), a lead screw (20), and a nut (21). The two ends of the outer cylinder (19) are fixedly connected to the mechanical positioning component (13) and the valve body (15), respectively. The lead screw (20) and the nut (21) are arranged inside the outer cylinder (19). The external thread of the lead screw (20) is threadedly connected to the internal thread of the nut (21). An inner cylinder (22) is arranged inside the central flow channel (17). The inner cylinder (22) is slidably connected to the central flow channel (17). The end of the inner cylinder (22) near the transmission mechanism (14) is fixedly connected to the lead screw (20).

15. The intelligent adjustable injection string according to claim 14, characterized in that, The nut (21) is located inside the outer cylinder (19) at one end near the mechanical positioning component (13).

16. The intelligent adjustable injection string according to claim 4, characterized in that, The high-temperature through-sealing packer (5) includes an upper connector (23), a seal (24), a release mechanism (25), and a setting mechanism (26) connected in sequence. The upper connector (23) is connected to the oil pipe (2).

17. The intelligent adjustable injection string according to claim 16, characterized in that, The capillary channel (9) extends axially through the upper connector (23), the seal (24), the unsealing mechanism (25), and the setting mechanism (26).

18. The intelligent adjustable injection string according to claim 16, characterized in that, The fiber optic channel (10) passes axially through the upper connector (23), the seal (24), the unsealing mechanism (25), and the setting mechanism (26).

19. A method for using an intelligent adjustable injection string, characterized in that, The intelligent adjustable injection string according to any one of claims 1-18 comprises the following steps: The high-temperature packer (5) is used to seal two adjacent oil layers. The downhole pressure is detected by the capillary (8) and the downhole temperature is detected by the optical fiber (7). Based on the downhole pressure and downhole temperature, the steam injection amount of each oil layer is adjusted by the high-temperature injection valve (6).

20. The method of using the intelligent adjustable injection string according to claim 19, characterized in that, The steam injection rate of each oil layer is adjusted by the high-temperature injection valve (6), including the following steps: The lead screw (20) of the control transmission mechanism (14) moves linearly along the nut (21), causing the inner cylinder (22) to slide along the central flow channel (17), thereby controlling the number of nozzles (16) opening and adjusting the amount of steam injected into each oil layer.

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