Intelligent separate layer injection polymer pipe string for unconsolidated sandstone reservoir and construction method

Abstract

The application discloses a loose sandstone oil reservoir intelligent layered polymer injection pipe column and a construction method, the polymer injection pipe column comprises at least two layered polymer injection units connected through oil pipes, the layered polymer injection unit comprises a layered packer and an intelligent adjusting injection device, the intelligent adjusting injection device is arranged below the layered packer, and the intelligent adjusting injection device is internally provided with anti-adsorption gravel; at least two levels of intelligent adjusting injection devices are arranged in one layered polymer injection unit, and the filling coefficients of the anti-adsorption gravels in each level of intelligent adjusting injection devices are different. The application discloses the idea of abandoning the polymer flow regulation of the current throttling unit, and innovatively adopts the pre-filling technology with different filling coefficients to regulate the flow, so that the viscosity retention rate is not affected by the machining precision, and the viscosity retention rate is relatively high.

Description

Technical Field

[0001] This invention relates to the field of petroleum development technology, specifically to an intelligent layered polymer injection tubing and construction method for loose sandstone reservoirs. Background Technology

[0002] Polymer flooding is a key development method for further enhancing oil recovery after waterflooding. It has been widely applied in domestic oilfields such as Daqing, Shengli, and Dagang, making China the country with the largest scale and best results in using polymer flooding technology. With the industrialization and application of polymer flooding technology, to mitigate the adverse effects of reservoir vertical heterogeneity on polymer flooding, stratified polymer injection technology has rapidly developed, forming single-tube (concentric and eccentric) stratified injection processes, dual-tube stratified injection processes, etc. Currently, with the construction of smart oilfields, the demand for intelligent stratified polymer injection is even more urgent.

[0003] Reference 1, "Intelligent Measurement and Control Technology for Layered Polymer Injection Wells," discloses an intelligent measurement and control process. This involves placing an intelligent injector in each injection layer. Each injector contains flow, pressure, and temperature sensors, as well as a flow regulation and control device. All injectors are connected to the wellhead via a single steel cable. The continuous layered flow and pressure signals monitored by the injectors at each layer are transmitted via cable to a surface control box. The surface control box then transmits these signals to the control room via cable or wirelessly. The surface control box issues commands to each layer downhole via cable, achieving online control of the layered flow.

[0004] Reference 2, "Research and Application of Pre-installed Cable Intelligent Layered Polymer Injection Technology," discloses intelligent polymer injection technology, which consists of a computer, a wireless network, and a process tubing. The process tubing mainly comprises a surface control system, a dedicated injection wellhead for the cable, a cable packer, and a flow-reading downhole electrically controlled polymer injector. The core component is the intelligent polymer injector, which adopts a split design, is connected by a plug-in method, and is fixed by a central pipe thread.

[0005] Announcement No. CN115992695B discloses a novel intelligent downhole monitoring and control device, system, and method. The device includes a fiber optic downhole temperature, pressure, and flow sensor and a hydraulic control valve. The fiber optic downhole temperature, pressure, and flow sensor and the hydraulic control valve are connected by a threaded connection. The fiber optic downhole temperature, pressure, and flow sensor collects downhole fluid flow, temperature, and pressure data and transmits the downhole data to an external wellhead control cabinet via an optical cable. The hydraulic control valve is connected to the wellhead control cabinet via a hydraulic control pipeline. The wellhead control cabinet pressurizes the hydraulic control valve through the hydraulic control pipeline to regulate the downhole flow rate.

[0006] Publication No. CN118815430A discloses an integrated intelligent sub-injection process tubing string for water injection and profile control, including a wellhead, tubing, water distributor, packers, ball seats, screen pipes, and plugs. The lower end of the wellhead is provided with tubing sleeved inside the casing. The lower end of the tubing is fixedly installed with ball seats, screen pipes, and plugs in sequence from top to bottom. Several packers are provided at intervals on the lower outer side of the tubing above the ball seats. A water distributor is installed on the tubing below each packer.

[0007] Publication No. CN118110483A discloses a segmented intelligent polymer injection process string for horizontal wells, including a casing concentrically arranged outside the tubing, a surface control system, and an intelligent injector. The intelligent injector is electrically connected to the surface control system via a control cable. The intelligent injector is equipped with a flow regulating element. When the surface control system is configured to regulate flow, it issues a command to control the flow regulating element inside the intelligent injector to regulate the flow in each segment.

[0008] The aforementioned existing technologies are all controlled by hydraulic pipelines or cables. In application, the lifespan is difficult to guarantee due to the influence of pipeline or cable joints. At the same time, the installation process is also relatively cumbersome, increasing construction costs.

[0009] In summary, the technical solutions, technical problems to be solved, and beneficial effects of the above-disclosed technologies are all different from those of the present invention. Regarding the more technical features, technical problems to be solved, and beneficial effects of the present invention, the above-disclosed technical documents do not provide any technical inspiration. Summary of the Invention

[0010] To address the aforementioned deficiencies in existing technologies, the purpose of this invention is to provide an intelligent layered polymer injection tubing and construction method for loose sandstone reservoirs.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] On one hand, the present invention provides an intelligent stratified polymer injection string for loose sandstone reservoirs, including at least two stratified polymer injection units connected by tubing. Each stratified polymer injection unit includes a stratified packer and an intelligent regulating injection device. The intelligent regulating injection device is located below the stratified packer and contains anti-adsorption gravel. At least two levels of intelligent regulating injection devices are provided in one stratified polymer injection unit, and the filling coefficient of the anti-adsorption gravel in each level of intelligent regulating injection device is different.

[0013] Furthermore, the intelligent regulating injection device includes a central tube and an outer sleeve;

[0014] Specifically, a connecting ring is provided on the inner wall of the upper end of the outer sleeve, the inner wall of the connecting ring is connected to and sealed with the outer wall of the central tube, and a wireless controller, a linear driver, a pull sleeve, and a sand-proof throttling tube section are arranged sequentially from top to bottom in the annular space between the outer sleeve and the central tube.

[0015] Specifically, the output shaft of the linear actuator is connected to the pull sleeve, and an injection port is provided on the wall of the central tube. The injection port corresponds to the pull sleeve. The linear actuator receives control signals through the wireless controller, which drives the pull sleeve to move up and down to open or close the injection port. When the injection port is open, the injected fluid enters the well through the injection port, the annulus between the outer sleeve and the central tube, and the sand-proof throttling pipe section.

[0016] Specifically, anti-adsorption gravel is installed inside the sand-proof throttling pipe section.

[0017] Furthermore, the sand-control throttling pipe section includes a base pipe, a flow ring is provided on the inner wall of the upper end of the base pipe, a closing ring is provided on the lower end of the inner wall of the base pipe, the inner wall of the flow ring and the inner wall of the closing ring are connected to the outer wall of the central pipe, and the outer wall of the upper end of the base pipe is connected to the lower end of the outer sleeve;

[0018] Specifically, the flow ring is provided with an inlet D, the base pipe wall is provided with an inlet E, and the annular space between the base pipe and the central pipe is filled with anti-adsorption gravel.

[0019] Furthermore, the outer wall of the base tube is wound with wire, and a protective sleeve is fitted over the wire. The upper outer wall of the protective sleeve is connected to the lower inner wall of the outer sleeve.

[0020] Specifically, the upper inner wall of the sheath is provided with an upper sheath ring, the lower inner wall of the sheath is provided with a lower sheath ring, the inner wall of the upper sheath ring is connected to the outer wall of the base tube, the inner wall of the lower sheath ring is connected to the outer wall of the base tube, and the winding wire is located between the upper and lower sheath rings; the sheath is provided with an inlet F.

[0021] Furthermore, the central tube includes an upper central tube and a lower central tube, which are connected by a connecting assembly;

[0022] Specifically, the upper central tube is connected to the connecting ring of the outer sleeve, and the lower central tube is connected to the base tube.

[0023] Furthermore, the wireless controller includes a battery pack, a wireless receiving system, and a circuit control system; the linear driver includes a motor controller and a rotation-linear transmission system.

[0024] Specifically, a concave ring is provided on the inner wall of the lower central tube, the wireless receiving system is disposed in the concave ring, and the wireless receiving system is electrically connected to the circuit control system;

[0025] Specifically, the battery pack, circuit control system, motor controller, rotary-linear transmission system, and pull sleeve are arranged in the annulus between the upper central tube and the outer sleeve;

[0026] Specifically, the circuit control system is electrically connected to the motor controller, the rotary-linear transmission system is connected to the motor output shaft in the motor controller, and the rotary-linear transmission system is connected to the pull sleeve;

[0027] Specifically, the battery pack provides power; the wireless receiving system is responsible for receiving commands from the signal ball and transmitting them to the circuit control system; the circuit control system sends commands to the motor control system; and the motor control system drives the pull sleeve to move up and down through the rotation-linear transmission system.

[0028] Furthermore, a straightening block is connected to the outer wall of the lower central tube below the base tube.

[0029] Furthermore, an upper connector is provided at the upper end of the upper central tube, and a lower connector is provided at the lower end of the lower central tube.

[0030] Furthermore, the connection assembly includes a converter head, a connecting sleeve, and a support sleeve;

[0031] Specifically, the outer wall of the converter head is connected to the inner wall of the outer sleeve, the upper outer wall of the lower central tube is connected to the lower inner wall of the converter head, and the lower outer wall of the connecting sleeve is connected to the upper inner wall of the converter head.

[0032] Specifically, the inner wall of the connecting sleeve is provided with an upward-facing first stepped surface, the outer wall of the upper central tube is provided with a downward-facing second stepped surface, and the lower end of the lower central tube and its outer wall are fitted together with the upper end of the connecting sleeve.

[0033] Specifically, the inner wall of the support sleeve is provided with a flow-through protrusion ring, the flow-through protrusion ring is provided with an inlet B, the flow-through protrusion ring is located between the second step surface and the upper end surface of the connecting sleeve, and the upper central tube is provided with an inlet A corresponding to the inlet B;

[0034] Specifically, a first sealing component is provided between the upper end face of the flow-through convex ring and the second step surface, and between the lower end face of the flow-through convex ring and the upper end face of the connecting sleeve;

[0035] Specifically, the pull sleeve is fitted between the support sleeve and the outer sleeve, and a limiting ring is provided on the upper inner wall of the pull sleeve. The limiting ring can contact and limit the upper end face of the support sleeve. The outer wall and inner wall of the pull sleeve are provided with a second sealing component, which can seal the inlet B.

[0036] Furthermore, the first sealing assembly includes V-shaped polytetrafluoroethylene and rubber ring B;

[0037] Specifically, the second sealing assembly includes a rectangular polytetrafluoroethylene lining, a rubber ring C, and a support ring. The inner and outer walls of the lower end of the pull sleeve are provided with mounting grooves. The second sealing assembly is disposed in the mounting grooves, and a fixing ring is connected to the opening of the mounting grooves to press the second sealing assembly.

[0038] Furthermore, the lower end of the bottom layered polymerization unit is connected to a backwash valve, and the lower end of the backwash valve is connected to a plug.

[0039] Secondly, this invention provides a construction method for an intelligent layered polymer injection string in a loose sandstone reservoir, comprising the following steps:

[0040] S1. Set up layered polymer injection units according to the number of oil layers. Set up at least two levels of intelligent adjustable injection devices in each layered polymer injection unit. The filling coefficient of anti-adsorption gravel in each intelligent adjustable injection device is different. Connect the tubing string and run it into the well to complete the setting of each level of layered packer.

[0041] S2. By inserting information spheres equipped with entry position codes and opening codes into the well, the intelligent adjustment injection device in the layered polymer injection unit is controlled.

[0042] Furthermore, in step S2, based on the water absorption index of each oil layer and combined with the indoor throttling pressure difference-flow test curve of the intelligent adjustment injection device, the layered polymer injection unit is adjusted from bottom to top;

[0043] During adjustment, refer to the test results of the ground flow meter for auxiliary adjustment. After the adjustment of each layer is completed, lower the wire-drop flow meter for retesting.

[0044] Compared with the prior art, the present invention has the following advantages:

[0045] 1. This invention abandons the current approach of simply relying on throttling units to regulate polymer flow rate. Instead, it innovatively adopts pre-filling technology with different filling coefficients to regulate flow rate. The viscosity retention rate is not affected by machining precision and has a relatively high viscosity retention rate.

[0046] 2. This invention utilizes a signal ball to communicate with the downhole intelligent regulating injection device, and switches it on and off via a downhole motor. It employs gravel with pre-set different filling coefficients to achieve multi-level downhole pressure regulation and realize the purpose of downhole layered flow regulation. It features large-channel injection, simple downhole construction, and integrated prevention and injection.

[0047] 3. The present invention integrates layered sand control and layered polymer injection tubing design, eliminating the need for cables or hydraulic control lines, simplifying the construction process; the overall tubing diameter is significantly increased compared to the original step-by-step tubing, further improving viscosity retention rate. Attached Figure Description

[0048] Figure 1This is a schematic diagram of the structure of an intelligent layered polymer injection string for loose sandstone reservoirs according to the present invention;

[0049] Figure 2 This is a schematic diagram of the intelligent adjustment injection device in this invention;

[0050] Figure 3 This is a schematic diagram of the intelligent adjustment injection device in the present invention.

[0051] In the diagram: 1. Plug, 2. Backwash valve, 3. Oil pipe, 4A. First-stage intelligent regulating injection device, 4B. Second-stage intelligent regulating injection device, 4C. Third-stage intelligent regulating injection device, 5. Layered packer, 6. Signal ball, 7. Casing;

[0052] 4 Intelligent adjustment injection device, 401 coupling, 402 upper central tube, 403 rubber ring A, 404 outer sleeve, 405 battery pack, 406 wireless receiving system, 407 circuit control system, 408 motor control system, 409 rotary-linear transmission system, 410 V-shaped polytetrafluoroethylene, 411 rubber ring B, 412 washer, 413 rectangular polytetrafluoroethylene, 414 rubber ring C, 415 support ring, 416 fixing ring, 417 pull sleeve, 418 support sleeve, 419 connecting sleeve, 420 conversion head, 421 lower central tube, 422 base tube, 423 upper end ring of sheath, 424 winding wire, 425 sheath, 426 anti-adsorption gravel, 427 lower end ring of sheath, 428 straightening block, 429 inlet A, 430 inlet B, 431 channel A, 432 inlet C, 433 inlet D, 434 inlet F, 435 inlet E. Detailed Implementation

[0053] 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, and 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.

[0054] Example 1:

[0055] Please see Figures 1 to 3This invention provides an intelligent stratified polymer injection string for loose sandstone reservoirs, comprising at least two stratified polymer injection units connected by tubing. Each stratified polymer injection unit includes a stratified packer 5 and an intelligent regulating injection device 4. The intelligent regulating injection device 4 is located below the stratified packer 5 and contains anti-adsorption gravel 426. Each stratified polymer injection unit contains at least two stages of intelligent regulating injection devices 4, with different filling coefficients of the anti-adsorption gravel 426 in each stage, resulting in different injection pressure differentials. The lower end of the lowest stratified polymer injection unit is connected to a backwash valve 2, and the lower end of the backwash valve 2 is connected to a plug 1.

[0056] Among them, the layered packer 5 separates the oil layers, so that one layered polymer injection unit corresponds to one oil layer.

[0057] Furthermore, the intelligent regulating injection device 4 includes a central tube and an outer sleeve 404. A connecting ring is provided on the inner wall of the upper end of the outer sleeve 404. The inner wall of the connecting ring is threadedly connected to the outer wall of the central tube and sealed by a rubber ring A403. A wireless controller, a linear actuator, a pull sleeve 417, and a sand control throttling pipe section are arranged sequentially from top to bottom in the annular space between the outer sleeve 404 and the central tube. The output shaft of the linear actuator is connected to the pull sleeve 417. An injection port is provided on the wall of the central tube, and the injection port corresponds to the pull sleeve 417. The wireless controller receives control signals to cause the linear actuator to drive the pull sleeve 417 to move up and down, opening or closing the injection port. When the injection port is open, the injected fluid enters the well through the injection port, the annular space between the outer sleeve 404 and the central tube, and the sand control throttling pipe section. Anti-adsorption gravel 426 is provided inside the sand control throttling pipe section. By making the anti-adsorption gravel 426 filling coefficients of different intelligent regulating injection devices 4 in a layered polymer injection unit different, different injection pressure differentials are formed.

[0058] Specifically, the sand-control and throttling pipe section includes a base pipe 422. A flow-through ring is provided on the inner wall of the upper end of the base pipe 422, and a closing ring is provided on the lower end of the inner wall of the base pipe 422. The inner walls of the flow-through ring and the closing ring are threadedly connected to the outer wall of the central pipe. The flow-through ring has an axially penetrating inlet D433, and the pipe wall of the base pipe 422 has an inlet E435. The annular space between the base pipe 422 and the central pipe is filled with anti-adsorption gravel 426. A wire 424 is wound around the outer wall of the base pipe 422, and a sheath 425 is fitted over the wire 424. The upper outer wall of the sheath 425 is threadedly connected to the lower inner wall of the outer sleeve. An upper ring 423 is provided on the upper inner wall of the sheath 425. The lower inner wall of the sheath 425 is provided with a lower sheath ring 427. The inner wall of the upper sheath ring 423 is threaded to the outer wall of the base pipe 422. The inner wall of the lower sheath ring 427 is threaded to the outer wall of the base pipe 422. The winding wire 424 is located between the upper sheath ring 423 and the lower sheath ring 427. The sheath 425 is provided with an inlet F434. The injected liquid enters the formation through inlet D433, anti-adsorption gravel 426, inlet E435, winding wire 424, and inlet F434. By adjusting the filling coefficient of the anti-adsorption gravel 426, different injection pressure differentials are formed. The winding wire 424 and the anti-adsorption gravel 426 play a role in preventing formation sand from entering the tubing.

[0059] Furthermore, the central tube includes an upper central tube 402 and a lower central tube 421, which are connected by a connecting assembly.

[0060] Specifically, the upper central tube 402 is connected to the outer sleeve 404 via a connecting ring. The wireless controller includes a battery pack 405, a wireless receiving system 406, and a circuit control system 407. The linear driver includes a motor controller 408 and a rotary-linear transmission system 409. A concave ring is provided on the inner wall of the lower central tube 421. The wireless receiving system 406 is disposed in the concave ring and is electrically connected to the circuit control system 407. The battery pack 405, circuit control system 407, motor controller 408, rotary-linear transmission system 409, and pull sleeve 417 are disposed in the annular space between the upper central tube 402 and the outer sleeve 404. The circuit control system 407 is electrically connected to the motor controller 408. The rotary-linear transmission system 409 is connected to the motor output shaft of the motor controller 408 and is connected to the pull sleeve 417.

[0061] The battery pack 405 provides power to the wireless receiving system 406, the circuit control system 407, and the motor control system 408.

[0062] Among them, the wireless receiving system 406 is responsible for receiving the commands issued by the signal ball 6, which has its address code and adjustment code pre-set on the ground.

[0063] Among them, the circuit control system 407 is the main control system, which is responsible for issuing commands to the motor control system 408.

[0064] The motor control system 408 is connected to the rotary-linear transmission system 409, which can drive the pull sleeve 417 to move up and down.

[0065] Preferably, the motor control system 408 is a hollow motor that can provide high torque output, and the rotary-linear transmission system 408 is a hollow lead screw. The hollow lead screw is connected to the hollow output shaft of the hollow motor, and the hollow lead screw is threadedly connected to the pull sleeve 417. The pull sleeve 417 can be moved up and down by driving the hollow lead screw through the hollow motor.

[0066] It should be noted that the battery pack 405, wireless receiving system 406, circuit control system 407, motor control system 408, and rotation-linear transmission system 408 are conventional systems and will not be described in detail here.

[0067] Specifically, the lower central tube 421 is connected to the base tube 422, and the outer wall of the lower central tube 421 is welded to the straightening block 428 below the base tube 422.

[0068] Specifically, the upper end of the upper central tube 402 is provided with an upper connector, the lower end of the lower central tube 421 is provided with a lower connector, and the upper end of the upper connector is threadedly connected to a coupling 401.

[0069] Specifically, the connecting assembly includes a converter head 420, a connecting sleeve 419, and a support sleeve 418. The outer wall of the converter head 420 is threadedly connected to the inner wall of the outer sleeve 404 and positioned by a step, and sealed by a rubber ring. The upper outer wall of the lower central tube 421 is threadedly connected to the lower inner wall of the converter head 420. The lower outer wall of the connecting sleeve 419 is threadedly connected to the upper inner wall of the converter head 420. The inner wall of the connecting sleeve 419 has an upward-facing first step surface, and the outer wall of the upper central tube has a downward-facing second step surface. The lower end and outer wall of the lower central tube 421 fit into the upper outer wall of the connecting sleeve 419. The inner wall of the support sleeve 418 is provided with a flow-through protrusion ring. The flow-through ring is provided with a radially penetrating inlet B430. The flow-through ring is located between the second step surface and the upper end surface of the connecting sleeve 419. The upper central tube 402 is provided with an inlet A429 corresponding to the inlet B. A first sealing assembly is provided between the upper end surface of the flow-through ring and the second step surface, and between the lower end surface of the flow-through ring and the upper end surface of the connecting sleeve 419. The pull sleeve 417 is sleeved between the support sleeve 418 and the outer sleeve 404. A limiting ring is provided on the upper inner wall of the pull sleeve 417. The limiting ring can contact and limit the upper end surface of the support sleeve 418. A second sealing assembly is provided on the outer and inner walls of the pull sleeve 417. The second sealing assembly can seal the inlet B.

[0070] Specifically, the annular space between the outer sleeve 404 and the support sleeve 418 is a channel A431.

[0071] Specifically, the pull sleeve 417 is provided with rubber rings on the inner and outer walls of the limiting ring, so that the limiting ring is sealed with the upper central tube 402 and the outer sleeve 404 to protect the internal electrical equipment.

[0072] Specifically, the first sealing assembly includes V-shaped polytetrafluoroethylene 410 and rubber ring B411. At least two sets of V-shaped polytetrafluoroethylene 410 and rubber ring B411 are arranged in sequence, and the first sealing assembly is pressed by support sleeve 418 and connecting sleeve 419.

[0073] Specifically, the second sealing assembly includes a rectangular polytetrafluoroethylene 413, a rubber ring C414, a support ring 415, and a fixing ring 416. The lower inner and outer walls of the pull sleeve 417 are provided with mounting grooves. At least two sets of the rectangular polytetrafluoroethylene 413, rubber ring C414, and support ring 415 are arranged sequentially in the mounting grooves. The fixing ring 416 is threadedly connected to the groove opening of the mounting groove to press the second sealing assembly.

[0074] It should be noted that in this embodiment, the connection where the sealing method is not specified is either a threaded seal or a seal using a rubber ring.

[0075] Specifically, the direction of fluid flow is as follows: inlet A429, inlet B430, channel A431, inlet C432, inlet D433, inlet E435, and inlet F434.

[0076] Example 2:

[0077] Based on Example 1, this example provides a construction method for an intelligent layered polymer injection string in a loose sandstone reservoir. Taking two oil layers and three intelligent regulating injection devices 4 set in each layered polymer injection unit as an example, the method includes the following steps:

[0078] S1. During on-site construction, in accordance with Figure 1 As shown, two layered polymer injection units are prepared. Each layered polymer injection unit is equipped with a layered packer 5, a first-stage intelligent adjustable injection device 4A, a second-stage intelligent adjustable injection device 4B, and a third-stage intelligent adjustable injection device 4C. The filling coefficient of the anti-adsorption gravel 426 in each stage of the intelligent adjustable injection device 4 is different. A backwash valve 2 and a plug 1 are set below the tubing string. The tubing string is lowered into the well to complete the setting of each stage of the layered packer 5.

[0079] S2. Based on the water absorption index of each oil layer, and combined with the indoor throttling pressure difference-flow test curves of the first-stage intelligent adjustment injection device, the second-stage intelligent adjustment injection device, and the third-stage intelligent adjustment injection device, adjust from bottom to top.

[0080] First, activate the intelligent adjustment injection device 4 in the bottommost layered polymer injection unit;

[0081] If the second-level intelligent adjustment injection device 4B in the lowest-level layered polymer injection unit is activated, the signal ball 6 is set to the second-level layer with the layer code set to the second level and the opening code set to "open". The signal ball 6 is then inserted into the wellbore. The signal ball 6 transmits a signal to the wireless receiving system 406. Upon receiving the adjustment command, the circuit control system 407 receives the command. The motor control system 408 and the rotary-linear transmission system 409 then begin to drive the pull sleeve 417 upwards. When the pull sleeve 417 moves to... Figure 3 At this location, inlet A429, inlet B430, channel A431, inlet C432, inlet D433, inlet E435, and inlet F434 form an integrated channel, enabling the connection between the inside of tubing 3 and the formation. The polymer flows out after passing through inlet A429, inlet B430, channel A431, inlet C432, inlet D433, inlet E435, and inlet F434.

[0082] Adjust the ball from bottom to top in sequence according to the above throwing method. When adjusting, refer to the test results of the ground flow meter for auxiliary adjustment. After the adjustment of each layer is completed, put down the wire-drop flow meter for retesting.

[0083] Since the entire process involves large-channel injection, the flow rate of polymer injection in each layer is adjusted by relying on the filling coefficient of the anti-adsorption gravel, resulting in a low degree of shear throughout the process.

[0084] S3. All layered polymer injection units can be opened at once. For example, the first-level intelligent adjustment injection device 4A in each oil layer can be opened. The signal ball 6 is set with the layer code as the first level of the first layer and the first level of the second layer, and the opening code as open and open. The signal ball 6 is then inserted into the wellbore, and the signal ball 6 opens the first-level intelligent adjustment injection device 4A in each oil layer.

[0085] It should be noted that the signal ball 6 is existing technology, which is clear to those skilled in the art, and therefore will not be elaborated upon.

[0086] All components not discussed in detail in this application, as well as the connection methods of these components, are well-known technologies in this field. They can be directly applied and will not be elaborated further.

[0087] In this invention, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0088] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0089] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0090] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A smart layered polymer injection string for loose sandstone reservoirs, comprising at least two layered polymer injection units connected by tubing, characterized in that, The layered polymer injection unit includes a layered packer and an intelligent regulating injection device. The intelligent regulating injection device is located below the layered packer and contains anti-adsorption gravel. A layered polymer injection unit is equipped with at least two levels of intelligent adjustable injection devices, and the filling coefficient of anti-adsorption gravel in each level of intelligent adjustable injection device is different.

2. The intelligent layered polymer injection string for loose sandstone reservoirs according to claim 1, characterized in that, The intelligent regulating injection device includes a central tube and an outer casing; A connecting ring is provided on the inner wall of the upper end of the outer sleeve. The inner wall of the connecting ring is connected to and sealed with the outer wall of the central tube. A wireless controller, a linear driver, a pull sleeve, and a sand-proof throttling tube section are arranged sequentially from top to bottom in the annular space between the outer sleeve and the central tube. The output shaft of the linear actuator is connected to the pull sleeve. An injection port is provided on the wall of the central tube. The injection port corresponds to the pull sleeve. The linear actuator receives control signals through the wireless controller, which causes the pull sleeve to move up and down to open or close the injection port. When the injection port is open, the injected fluid enters the well through the injection port, the annulus between the outer sleeve and the central tube, and the sand-proof throttling pipe section. The sand-proof throttling pipe section is equipped with anti-adsorption gravel.

3. The intelligent layered polymer injection string for loose sandstone reservoirs according to claim 2, characterized in that, The sand-control throttling pipe section includes a base pipe, a flow ring is provided on the inner wall of the upper end of the base pipe, a closing ring is provided on the lower end of the inner wall of the base pipe, the inner wall of the flow ring and the inner wall of the closing ring are connected to the outer wall of the central pipe, and the outer wall of the upper end of the base pipe is connected to the lower end of the outer sleeve. The flow ring is provided with inlet D, the base pipe wall is provided with inlet E, and the annular space between the base pipe and the central pipe is filled with anti-adsorption gravel.

4. The intelligent layered polymer injection string for loose sandstone reservoirs according to claim 3, characterized in that, The outer wall of the base tube is wound with wire, and a protective sleeve is fitted over the wire. The upper outer wall of the protective sleeve is connected to the lower inner wall of the outer sleeve. The upper inner wall of the sheath is provided with an upper sheath ring, and the lower inner wall of the sheath is provided with a lower sheath ring. The inner wall of the upper sheath ring is connected to the outer wall of the base tube, and the inner wall of the lower sheath ring is connected to the outer wall of the base tube. The winding wire is located between the upper sheath ring and the lower sheath ring. The sheath is provided with an inlet F.

5. The intelligent layered polymer injection string for loose sandstone reservoirs according to claim 3, characterized in that, The central tube includes an upper central tube and a lower central tube, and the upper central tube and the lower central tube are connected by a connecting component. The upper central tube is connected to the outer sleeve via a connecting ring, and the lower central tube is connected to the base tube.

6. The intelligent layered polymer injection string for loose sandstone reservoirs according to claim 5, characterized in that, The wireless controller includes a battery pack, a wireless receiving system, and a circuit control system; the linear driver includes a motor controller and a rotary-linear transmission system. A concave ring is provided on the inner wall of the lower central tube, and the wireless receiving system is disposed in the concave ring. The wireless receiving system is electrically connected to the circuit control system. The battery pack, circuit control system, motor controller, rotary-linear transmission system, and pull sleeve are arranged in the annular space between the upper central tube and the outer sleeve; The circuit control system is electrically connected to the motor controller, the rotary-linear transmission system is connected to the motor output shaft in the motor controller, and the rotary-linear transmission system is connected to the pull sleeve; The battery pack provides power; the wireless receiving system is responsible for receiving commands from the signal ball and transmitting them to the circuit control system. The circuit control system sends commands to the motor control system, and the motor control system drives the pull sleeve to move up and down through the rotation-linear transmission system.

7. The intelligent layered polymer injection string for loose sandstone reservoirs according to claim 5, characterized in that, The outer wall of the lower central tube is connected to a straightening block below the base tube.

8. The intelligent layered polymer injection string for loose sandstone reservoirs according to claim 5, characterized in that, The upper central tube is provided with an upper connector at its upper end, and the lower central tube is provided with a lower connector at its lower end.

9. The intelligent layered polymer injection string for loose sandstone reservoirs according to claim 5, characterized in that, The connection assembly includes an adapter, a connecting sleeve, and a support sleeve; The outer wall of the converter head is connected to the inner wall of the outer sleeve, and the upper outer wall of the lower central tube is connected to the lower inner wall of the converter head. The inner wall of the connecting sleeve is provided with an upward-facing first step surface, the outer wall of the upper central tube is provided with a downward-facing second step surface, and the lower end of the lower central tube and its outer wall are fitted together with the upper end of the connecting sleeve. The inner wall of the support sleeve is provided with a flow-through protrusion ring, the flow-through protrusion ring is provided with inlet B, the flow-through protrusion ring is located between the second step surface and the upper end surface of the connecting sleeve, and the upper central tube is provided with inlet A corresponding to inlet B; A first sealing component is provided between the upper end face of the flow-through convex ring and the second step surface, and between the lower end face of the flow-through convex ring and the upper end face of the connecting sleeve. The pull sleeve is fitted between the support sleeve and the outer sleeve. A limiting ring is provided on the upper inner wall of the pull sleeve. The limiting ring can contact and limit the upper end face of the support sleeve. A second sealing component is provided on the outer wall and inner wall of the pull sleeve. The second sealing component can seal the inlet B.

10. The intelligent layered polymer injection string for loose sandstone reservoirs according to claim 9, characterized in that, The first sealing assembly includes V-shaped polytetrafluoroethylene and rubber ring B; The second sealing assembly includes a rectangular polytetrafluoroethylene lining, a rubber ring C, and a support ring. The inner and outer walls of the lower end of the pull sleeve are provided with mounting grooves. The second sealing assembly is disposed in the mounting grooves, and a fixing ring is connected to the opening of the mounting grooves to press the second sealing assembly.

11. A smart layered polymer injection string for loose sandstone reservoirs according to any one of claims 1-10, characterized in that, The bottom layered polymer injection unit is connected to a backwash valve, and the bottom of the backwash valve is connected to a plug.

12. A construction method for an intelligent layered polymer injection tubing system in a loose sandstone reservoir, characterized in that, Includes the following steps: S1. Set up layered polymer injection units according to the number of oil layers. Set up at least two levels of intelligent adjustable injection devices in each layered polymer injection unit. The filling coefficient of anti-adsorption gravel in each intelligent adjustable injection device is different. Connect the tubing string and run it into the well to complete the setting of each level of layered packer. S2. By inserting information spheres equipped with entry position codes and opening codes into the well, the intelligent adjustment injection device in the layered polymer injection unit is controlled.

13. The construction method of a smart layered polymer injection string for loose sandstone reservoirs according to claim 12, characterized in that, In step S2, based on the water absorption index of each oil layer and combined with the indoor throttling pressure difference-flow test curve of the intelligent adjustment injection device, the layered polymer injection unit is adjusted from bottom to top; During adjustment, refer to the test results of the ground flow meter for auxiliary adjustment. After the adjustment of each layer is completed, lower the wire-drop flow meter for retesting.

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