A liquid-electric composite layered polymer injection pipe column and device and construction method

Abstract

This invention discloses a hydraulic-electric composite layered polymer injection string, device, and construction method. The polymer injection device includes a track reversing mechanism and a flow regulation mechanism connected together; it also includes a piston control mechanism connected to the upper end of the track reversing mechanism; the piston control mechanism has a main control piston and an auxiliary guide piston. This invention solves the problem of difficult downhole switch adjustment. By monitoring the flow rate at the wellhead and using a step-by-step decreasing method, the flow rate of each layer downhole is controlled and guided, eliminating the need for a flow meter and saving cable costs.

Description

Technical Field

[0001] This invention relates to the field of single-tube layered polymer injection technology, specifically to a hydraulic-electric composite layered polymer injection tubing and device and construction method. Background Technology

[0002] To improve polymer injection efficiency, enhance displacement effects, and reduce inter-layer interference, polymer injection wells need to be subdivided for injection. Currently, subdivided polymer injection processes mainly include concentric dual-tube subdivided polymer injection and hollow single-tube subdivided polymer injection technologies. Concentric dual-tube subdivided polymer injection strings use two independent injection channels, basically meeting the field requirements for subdivided polymer injection. However, because concentric dual-tubes can only inject a maximum of two layers, and the initial investment cost is relatively high, large-scale promotion in various oilfields is limited. With continuous technological development, the hollow single-tube subdivided polymer injection process has been continuously improved in recent years, resulting in pre-installed cable direct-control electrically controlled subdivided polymer injection process strings, concentric adjustable single-tube subdivided polymer injection process strings, etc. The former achieves real-time monitoring of pre- and post-injection pressure without the need for instrument tripping during testing, direct surface reading of flow rate, direct control, and no-drop-off-injection instrumentation. Although this invention achieves no-drop-off-and-retrieve testing, the lifespan of electronic components is difficult to guarantee. Furthermore, the adjustment using the polymer injector's internal downhole motor has low self-adjustment torque, making it difficult to adjust in the later stages of polymer injection. The latter injection volume adjustment mechanism has a spiral lifting and lowering injection core to adjust the injection volume of the polymer pressure reduction and adhesion retention mechanism; the polymer pressure reduction and adhesion retention mechanism has a shuttle-shaped wave injection channel with pressure reduction and adhesion retention characteristics; the injection core has sufficient inner diameter to ensure the operation of profile testing and other operations. However, relying solely on the lowering and adjusting instrument for testing and adjustment, especially in the later stage of polymer injection, when a lot of polymer adheres to the wellbore, it is very easy to cause the instrument to not be lowered into place or to be unable to be adjusted, resulting in a low success rate of testing and adjustment.

[0003] Chinese Patent 201710028171.9 discloses a large-capacity single-tube layered polymer injection adjustable device, including a testing and adjustment tool introduction mechanism, an injection volume adjustment mechanism, and a polymer pressure reduction and adhesion retention mechanism. The testing and adjustment tool introduction mechanism has a guiding and positioning function; the injection volume adjustment mechanism has a spirally lifting and lowering injection core to adjust the injection volume of the polymer pressure reduction and adhesion retention mechanism; the polymer pressure reduction and adhesion retention mechanism has a spindle-shaped wave injection channel with pressure reduction and adhesion retention characteristics; the injection core has a sufficient inner diameter to ensure the conduct of profile testing and other operations, and the layered polymer injection testing and adjustment working cylinder has a bridge-type channel, so that when testing is carried out in the current layer, it does not affect the polymer injection of other layers. It has the characteristics of large injection volume, good adhesion retention, and adjustable injection volume, realizing multi-segment injection of single-tube layered polymer injection testing and adjustment, solving the current difficulties faced by layered polymer injection in offshore oilfields, and effectively improving polymer utilization and oil displacement effect. However, this process requires the lowering of instruments, especially in the later stage of polymer injection, due to the inner wall structure of the tubing or polymer adhesion, it is difficult to lower the testing and adjustment instruments, ultimately leading to testing and adjustment failure.

[0004] Chinese Patent 202010328374.1 discloses a pre-installed cable direct-control electrically controlled layered polymer injection process string and method. It relates to the field of layered polymer injection well technology, and particularly to a pre-installed cable direct-control electrically controlled layered polymer injection process string and method. The string includes a casing containing tubing. The annulus between the casing and tubing is divided into different layers by several cable-passing washable packers. A single-core steel cable passes through these cable-passing washable packers. A flow-direct reading downhole electrically controlled polymer injector is installed between adjacent packers. The injection volume of the flow-direct reading downhole electrically controlled polymer injector is controlled by a surface controller. The flow-direct reading downhole electrically controlled polymer injector contains two pressure sensors and an electromagnetic flowmeter. The provided polymer injection process string and method allow the surface control device to power and communicate with the downhole flow-direct reading electrically controlled polymer injector via a single-core steel cable. This enables interactive monitoring between the surface and the well, achieving real-time monitoring of flow rate, pre- and post-injection pressure without the need for instrument tripping during testing. While this process eliminates the need for drop-and-retrieve testing, the built-in motor torque is relatively low, making it difficult to achieve prolonged downhole adjustments.

[0005] Publication (Announcement) No.: CN112177574A, Publication (Announcement) Date: 2021-01-05 discloses a linkage-type hydraulic layer-changing switch and a linkage-type layer-changing method, including a track reversing mechanism, a piston mechanism, and a housing. The piston mechanism includes a cylinder liner, a piston, and a one-way valve. The cylinder liner has an axially penetrating cylinder liner center hole, an axially penetrating eccentric axial channel, and a radially penetrating cylinder liner lower radial hole. The lower radial hole of the cylinder liner is connected to the cylinder liner center hole, but not to the eccentric axial channel. The piston slides in a sealed manner within the cylinder liner center hole. The piston includes an upper piston cavity and a lower piston cavity, with a sealing section between the two cavities. The upper port of the upper piston cavity is connected to the one-way valve, and the upper piston cavity has an upper radial hole. The lower end of the cylinder liner is threadedly connected to the track reversing mechanism. The lower port of the lower piston cavity is connected to the upper end of the reversing track body of the track reversing mechanism to form an integral structure. It enables the coordinated replacement of upper and lower layers, meeting the needs of oil and gas field development for layer-by-layer extraction without changing the tubing string.

[0006] Publication (Announcement) No.: CN109458162B, Publication (Announcement) Date: 2021-03-26 This invention relates to a hydraulic switching device for stratified oil production in side-drilling. The technical solution is as follows: an inlet ring is connected to the upper side of the lower connector; a one-way valve is provided in the lower cavity of the inlet ring; the inlet ring is connected to a reversing track; a switch actuator valve sleeve is connected to the outer wall of the inlet ring; a rotating ring is fitted on the outer side of the reversing track; a track pin is placed in the track groove of the reversing track through the track pin hole of the rotating ring; a sealing reversing sleeve is connected to the upper end of the switch actuator valve sleeve; a pressure regulating retaining ring is connected to the upper connector; then a return spring is fitted onto the sealing short section, with one end contacting the pressure retaining ring and the other end contacting the pressure regulating retaining ring; the pressure retaining ring drives the sealing reversing sleeve to slide along the outer wall of the sealing short section; an outlet hole is provided at the lower end of the sealing short section. The beneficial effects are: the original three-layer structure is transformed into a two-layer structure, which further increases the inner diameter of the stratified oil production tool, enabling stratified oil production of multiple oil layers and making it more applicable to a wider range of applications.

[0007] How to control single-tube multi-layered polymer injection has become a challenge for polymer injection developers. Therefore, it is necessary to conduct research on single-tube multi-layered polymer injection design to improve the effective utilization of this type of reservoir. Summary of the Invention

[0008] To address the aforementioned deficiencies in existing technologies, the purpose of this invention is to provide a hydraulic-electric composite layered polymer injection string, device, and construction method that solves the problem of difficult downhole switch adjustment. By monitoring the wellhead flow rate and adopting a step-by-step decreasing method, the flow rate of each layer downhole can be controlled and guided, eliminating the need for a flow meter and saving cable costs.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A liquid-controlled stratified polymer injection device includes a track reversing mechanism and a flow regulating mechanism connected to each other.

[0011] It also includes a piston control mechanism, which is connected to the upper end of the track reversing mechanism;

[0012] The piston control mechanism has a main control piston and an auxiliary guide piston.

[0013] Furthermore, the piston control mechanism includes a sealing sleeve, a cylindrical piston one, and a cylindrical piston two; the cylindrical piston one is the main control piston, and the cylindrical piston two is the auxiliary guide piston.

[0014] The sealing sleeve has three axial channels, namely the main channel, piston channel one, and piston channel two, wherein cylindrical piston one is installed in piston channel one and cylindrical piston two is installed in piston channel two.

[0015] The upper end of the sealing sleeve is connected to the upper connector, the upper connector has a hydraulic control channel, the hydraulic control channel is connected to the piston channel, and the lower end of the cylindrical piston is connected to the track sleeve of the track reversing mechanism.

[0016] Furthermore, the track reversing mechanism includes a track sleeve, a limiting sleeve, and a track pin;

[0017] The track sleeve is placed inside the outer sleeve, which is composed of an upper outer sleeve and a lower outer sleeve connected together. The upper end of the upper outer sleeve is connected to the sealing sleeve of the piston control mechanism.

[0018] The limiting sleeve is fixed inside the lower outer sleeve;

[0019] The track pin is fixed to the limiting sleeve, and the track pin extends into the track opened on the outer wall of the track sleeve.

[0020] Furthermore, it also includes a spring reset mechanism, which includes an adjusting shim, an upper spring, and an inner central tube;

[0021] The inner central tube is located inside the lower outer sleeve, and the upper end of the inner central tube is connected to the track sleeve. The upper spring is placed between the inner central tube and the lower outer sleeve. The upper end of the upper spring is pressed against the lower end of the track sleeve by an adjusting shim, and the lower end of the upper spring is pressed against the recessed shoulder opened on the inner wall of the lower outer sleeve.

[0022] Furthermore, the flow regulating mechanism includes a thrust bearing, an inner adjusting core, a lower spring, an outer adjusting core, and a polymer injection sleeve;

[0023] The upper end of the adjusting inner core is connected to the lower end of the inner central tube via a thrust bearing.

[0024] The adjusting outer core is placed outside the adjusting inner core, and the adjusting outer core is located inside the polymer injection sleeve. The upper end of the polymer injection sleeve is connected to the lower outer sleeve, and the lower end of the polymer injection sleeve is connected to the lower connector.

[0025] The upper end of the lower spring is connected to the adjusting inner core, and the lower end of the lower spring abuts against the upper end face of the lower connector.

[0026] Furthermore, the upper end of the polymer injection sleeve abuts against the lower outer sleeve, and the lower end of the polymer injection sleeve abuts against the lower connector. The inner diameter of the polymer injection sleeve is larger than the outer diameter of the adjusting outer core, that is, there is an annular gap channel between them.

[0027] Furthermore, the polymer injection sleeve has a polymer injection hole, the adjusting outer core has an outer injection hole, and the adjusting inner core has at least two inner injection holes. The diameter of the inner injection hole is smaller than that of the outer injection hole. The first polymer injection hole and the second polymer injection hole are not at the same height, that is, their axes are not aligned.

[0028] To achieve the above objectives, the present invention adopts the following technical solution:

[0029] A hydraulic-electric composite layered polymer injection string includes an outer sand-proof string, an inner sub-injection string, and a ground control cabinet;

[0030] The injection tubing includes a liquid-controlled stratified polymer injection device and an electronically controlled liquid distribution device.

[0031] The hydraulically controlled stratified polymer injection device corresponds to a specific oil layer location, and both the hydraulically controlled stratified polymer injection device and the electro-hydraulic circuit distribution device are connected to the oil pipe.

[0032] The electro-hydraulic distribution device is provided with a main hydraulic control pipeline interface and an upper armored cable interface at the upper end, and multiple branch hydraulic control pipeline interfaces and a lower armored cable interface at the lower end.

[0033] The electronic pressure gauge and flow meter are connected to the liquid-controlled stratified polymerization device and are connected to the corresponding lower armored cable interface at the lower end of the electronically controlled liquid distribution device through the armored cable.

[0034] The hydraulically controlled stratified polymer injection devices corresponding to different oil layers are connected to the corresponding hydraulically controlled pipeline interfaces at the lower end of the electronically controlled liquid distribution device through their respective hydraulically controlled pipelines.

[0035] The electro-hydraulic distribution device is connected to the ground control cabinet via a main hydraulic control pipeline and an armored cable.

[0036] Furthermore, the injection string also includes small plugs, injection packers, and positioning devices all connected to the tubing. The injection packers are used for sealing the inside of the sand control string, and the positioning devices are used for positioning the injection string.

[0037] To achieve the above objectives, the present invention adopts the following technical solution:

[0038] A construction method for a hydraulic-electric composite layered polymer injection column includes the following steps: During routine injection, a command is sent from the ground control cabinet to the electrically controlled liquid distribution device to open the liquid control channel of the upper-layer hydraulic-controlled layered polymer injection device. Then, the hydraulic control switch of the ground control cabinet pressurizes the upper-layer hydraulic-controlled layered polymer injection device through the main hydraulic control pipeline. The cylindrical piston drives the track sleeve, the track sleeve drives the inner central tube, and the inner central tube drives the adjusting inner core to move up and down, adjusting the size of the injection hole. The track sleeve continuously changes direction under the action of the track pin. The lower the adjusting inner core goes, the smaller the injection hole becomes, until the required flow rate is achieved.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] (1) The use of a hydraulic-electric composite layered polymer injection string enables flow control and testing of the downhole polymer injection switch by a main hydraulic control line and an armored cable, simplifying most of the pipelines in the wellbore.

[0041] (2) The hydraulically controlled layered polymer injection device uses a combination of cylindrical piston one and cylindrical piston two to achieve safe deep well switching;

[0042] (4) The liquid-controlled layered polymer injection device adopts a multi-track design and achieves multi-level control by pressurization and depressurization (the pressure is transmitted to the ground after being tested by a pressure transmitter);

[0043] (5) The water nozzle mating surface is sealed with metal, and multiple throttling pressure differentials can be controlled by adjusting the multi-stage injection holes. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the hydroelectric composite layered polymer injection column structure of the present invention;

[0045] Figure 2 This is a schematic diagram of the structure of the liquid-controlled layered polymerization device of the present invention.

[0046] 1. Filter sand pipe, 2. Sub-injection packer, 3. Sand prevention packer, 4. Hydraulic control layered polymer injection device, 5. T-joint, 6. Suspended packer, 7. Positioning device, 8. Hydraulic control line one, 9. Hydraulic control line two, 10. Electrically controlled hydraulic distribution device, 11. Armored cable, 12. Sleeve, 13. Oil pipe, 14. Ground control cabinet, 15. Large plug, 16. Small plug, 17. Main hydraulic control line;

[0047] 401 Coupling, 402 Upper Connector, 403 Sealing Sleeve, 404 Cylindrical Piston I, 405 Upper Outer Sleeve, 406 Track Sleeve, 407 Limiting Sleeve, 408 Track Pin, 409 Adjusting Shim, 410 Lower Outer Sleeve, 411 Upper Spring, 412 Thrust Bearing, 413 Adjusting Inner Core, 414 Lower Spring, 415 Adjusting Outer Core, 416 Polymer Injection Sleeve, 417 Lower Connector, 418 Rubber Ring, 419 Cylindrical Piston II, 420 Inner Center Tube. Detailed Implementation

[0048] 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.

[0049] Example 1:

[0050] like Figure 1As shown, a hydraulic-electric composite layered polymer injection string includes an external sand control string, an internal sub-injection string, and a ground control cabinet 14. The sand control string includes a large plug 15, a sand filter tube 1, a sand packer 3, a sleeve 12, and a suspended packer 6. The sub-injection string includes a small plug 16, a sub-injection packer 2, a hydraulically controlled layered polymer injection device 4, a positioning device 7, an oil pipe 13, and an electro-hydraulic distribution device 10. The sand filter tube corresponds to a specific oil layer. The packer seals two oil layers. The suspended packer is used to suspend the entire sand control string. The large plug, filter pipe, sand control packer, and suspended packer are connected through the sleeve. The injection packer is used for sealing inside the sand control string. The hydraulically controlled stratified polymer injection device corresponds to the corresponding oil layer. The positioning device is used for positioning the injection string. The small plug, injection packer, hydraulically controlled stratified polymer injection device, positioning device, and electro-hydraulic distribution device are connected through oil pipes.

[0051] The electro-hydraulic distribution device is provided with a main hydraulic control pipeline interface and an armored cable interface at the upper end, and multiple hydraulic control pipeline interfaces and an armored cable interface at the lower end.

[0052] The electronic pressure gauge and flow meter are embedded inside the liquid-controlled stratified polymer injection device and are connected to the corresponding armored cable interface at the lower end of the electronically controlled liquid distribution device via the armored cable. Although the electronic pressure gauge and flow meter are not shown in the figure, they are monitoring devices installed in the liquid control channel of the polymer injection device and are conventional technology in this field.

[0053] The liquid-controlled layered polymer injection device corresponding to different oil layers is connected to the corresponding liquid control line interface at the lower end of the electro-hydraulic circuit distribution device through liquid control line 8 and liquid control line 9 respectively.

[0054] The upper end of the electro-hydraulic distribution device is connected to the ground control cabinet via a main hydraulic control pipeline 17 and an armored cable 11. The main hydraulic control pipeline is a pipeline with a diameter of φ9.53mm or larger. The electro-hydraulic distribution device controls the internal motor through the armored cable to realize the channels of each hydraulic control pipeline in the well, and pressurizes each hydraulic control pipeline in the well through the main hydraulic control pipeline.

[0055] Example 2:

[0056] like Figure 2As shown, the liquid-controlled layered polymer injection device includes a coupling 401, an upper connector 402, a piston control mechanism, a track reversing mechanism, a spring return mechanism, a flow regulating mechanism, a lower connector 417, and a rubber ring 418. The piston control mechanism includes a sealing sleeve 403, a cylindrical piston one 404, a cylindrical piston two 419, etc. The track reversing mechanism includes an upper outer sleeve 405, a track sleeve 406, a limiting sleeve 407, and a track pin 408, etc. The spring return mechanism includes a lower outer sleeve 410, an adjusting shim 409, an upper spring 411, and an inner central tube 420, etc. The flow regulating mechanism includes a thrust bearing 412, an adjusting inner core 413, an adjusting outer core 415, a polymer injection sleeve 416, and a lower spring 414, etc. The coupling is threadedly connected to the upper connector, and the upper connector is threadedly connected to the sealing sleeve. The sealing sleeve is threaded to the upper outer sleeve, the upper outer sleeve is threaded to the lower outer sleeve, the lower outer sleeve is threaded to the injection sleeve, and the injection sleeve is threaded to the lower connector. Cylindrical piston one and cylindrical piston two are symmetrically placed inside the sealing sleeve. The track sleeve is actively connected to cylindrical piston one and cylindrical piston two. The limiting sleeve is placed in the steps of the upper and lower outer sleeves. The track pin is placed inside the limiting sleeve and simultaneously in the track outside the track sleeve. The track sleeve is threaded to the inner center tube. The adjusting shim and upper spring are placed inside the annular space between the lower outer sleeve and the inner center tube. The thrust bearing is placed between the inner center tube and the adjusting inner core. The adjusting outer core is placed outside the adjusting inner core. The lower spring is placed at the lower end of the adjusting inner core.

[0057] The upper connector and sealing sleeve, cylindrical pistons one and two and the piston hole of the upper connector, sealing sleeve and upper outer sleeve, upper outer sleeve and lower outer sleeve, lower outer sleeve and injection sleeve, and injection sleeve and lower connector are sealed and connected by the rubber rings.

[0058] The sealing sleeve is symmetrically provided with two sealing holes;

[0059] The limiting sleeve has two through holes arranged symmetrically for placing two track pins;

[0060] The aforementioned upper connector is equipped with a hydraulic control pipeline pressure hole, i.e., a hydraulic control channel;

[0061] The piston hole at one location of the cylindrical piston is connected to the hydraulic control line, while the piston hole at the other location of the cylindrical piston is not connected to the hydraulic control line.

[0062] The lower end of the adjustment core is evenly arranged with multiple injection holes, namely inner injection holes 421, and the outer surface is smooth.

[0063] The upper end of the adjusting outer core is provided with an injection hole, namely an external injection hole, and the outer surface is smooth;

[0064] The inner adjusting core and the outer adjusting core form a metal self-sealing structure;

[0065] The polymer injection sleeve has a large polymer injection hole on its exterior.

[0066] Therefore, the mating surfaces of the water tap (adjusting inner core and adjusting outer core) are sealed with metal. By adjusting the multi-stage injection holes (injection holes of the adjusting inner core), multiple throttling pressure differential controls are achieved, including control from multiple inner injection holes to outer injection holes, and control from outer injection holes to polymer injection holes.

[0067] Example 3:

[0068] The method of using the aforementioned hydraulic-electric composite layered polymer injection pipe column includes: sequentially lowering the sand-proof pipe column on the outer wall and the layered polymer injection pipe column on the inner wall; when connecting each stage of the hydraulically controlled layered polymer injection device, connecting to the pressure port of each stage of the hydraulically controlled layered polymer injection device through a hydraulically controlled pipeline and a tee connector; connecting to the ground control cabinet through an electrically controlled liquid distribution device; and similarly, connecting the armored cable to the ground control cabinet through the electrically controlled liquid distribution device.

[0069] During routine injection, the ground control cabinet sends a command to the electrically controlled liquid distribution device to open the liquid control channel of the upper-level liquid-controlled stratified polymer injection device. Then, the liquid control switch of the ground control cabinet pressurizes the upper-level liquid-controlled stratified polymer injection device through the main liquid control pipeline. The cylindrical piston drives the track sleeve, the track sleeve drives the inner central tube, and the inner central tube drives the adjusting inner core to move, adjusting the switch size. The track sleeve continuously changes direction under the action of the track pin. The lower the adjusting inner core goes, the smaller the injection channel becomes until the required flow rate is reached (after depressurization, it automatically changes direction under the action of the upper and lower springs).

[0070] In this invention, a command is sent from the ground control cabinet to the electrically controlled liquid distribution device to open the liquid control channel of the upper-level polymer injection device. Then, the liquid control switch in the ground control cabinet pressurizes the upper-level polymer injection device through the main liquid control pipeline. The control process of this control cabinet and the control components used are all existing technologies in the field and can be directly applied without further description. The track reversing mechanism's track reversing principle is also a conventional technology in the field and will not be described further. However, some specific structural features of the track reversing mechanism in this invention differ from existing technologies.

[0071] Taking three-layer polymer injection as an example, the specific flow rate adjustment method is as follows: Based on the geological injection plan and combined with the display of the ground flow meter, the lowest-level hydraulically controlled stratified polymer injection device is adjusted to the required injection volume by changing the track through ground pressure. Then, a command is sent to the electrically controlled liquid distribution device to close the liquid control channel of this layer of hydraulically controlled stratified polymer injection device. Then, the middle electro-hydraulic controlled stratified polymer injection device is adjusted to the required injection volume (again, referring to the ground flow meter, calculated in a decreasing manner). Then, a command is sent to the electrically controlled liquid distribution device to close the liquid control channel of this layer of hydraulically controlled stratified polymer injection device. Finally, the highest-level electro-hydraulic integrated polymer injector is adjusted to the required injection volume (again, referring to the ground flow meter, calculated in a decreasing manner). Then, a command is sent to the electrically controlled liquid distribution device to close the liquid control channel of this layer of hydraulically controlled stratified polymer injection device. In this way, the hydraulically controlled stratified polymer injection devices at each level will not affect each other's operation.

[0072] 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 and will not be elaborated upon further. Examples include welding and threaded connections.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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 liquid-controlled stratified polymer injection device, comprising a track reversing mechanism and a flow regulating mechanism connected to each other; Its features are, It also includes a piston control mechanism, which is connected to the upper end of the track reversing mechanism; The piston control mechanism has a main control piston and an auxiliary guide piston; The piston control mechanism includes a sealing sleeve, a cylindrical piston one, and a cylindrical piston two; the cylindrical piston one is the main control piston, and the cylindrical piston two is the auxiliary guide piston. The sealing sleeve has three axial channels, namely the main channel, piston channel one, and piston channel two, wherein cylindrical piston one is installed in piston channel one and cylindrical piston two is installed in piston channel two. The upper end of the sealing sleeve is connected to the upper connector, the upper connector has a hydraulic control channel, the hydraulic control channel is connected to the piston channel, and the lower end of the cylindrical piston is connected to the track sleeve of the track reversing mechanism. The track reversing mechanism includes a track sleeve, a limiting sleeve, and a track spike; The track sleeve is placed inside the outer sleeve, which is composed of an upper outer sleeve and a lower outer sleeve connected together. The upper end of the upper outer sleeve is connected to the sealing sleeve of the piston control mechanism. The limiting sleeve is fixed inside the lower outer sleeve; The track pin is fixed to the limiting sleeve, and the track pin extends into the track opened on the outer wall of the track sleeve; It also includes a spring reset mechanism, which comprises an adjusting shim, an upper spring, and an inner central tube; The inner central tube is located inside the lower outer sleeve, and the upper end of the inner central tube is connected to the track sleeve. The upper spring is placed between the inner central tube and the lower outer sleeve. The upper end of the upper spring is pressed against the lower end of the track sleeve by an adjusting shim, and the lower end of the upper spring is pressed against the recessed shoulder opened on the inner wall of the lower outer sleeve. The flow regulation mechanism includes a thrust bearing, an inner regulating core, a lower spring, an outer regulating core, and a polymer injection sleeve; The upper end of the adjusting inner core is connected to the lower end of the inner central tube via a thrust bearing. The adjusting outer core is placed outside the adjusting inner core, and the adjusting outer core is located inside the polymer injection sleeve. The upper end of the polymer injection sleeve is connected to the lower outer sleeve, and the lower end of the polymer injection sleeve is connected to the lower connector. The upper end of the lower spring is connected to the adjusting inner core, and the lower end of the lower spring abuts against the upper end face of the lower connector. The upper end of the injection sleeve abuts against the lower outer sleeve, and the lower end of the injection sleeve abuts against the lower connector. The inner diameter of the injection sleeve is larger than the outer diameter of the adjusting outer core, that is, there is an annular gap channel between them. The polymer injection sleeve has a polymer injection hole, the outer adjusting core has an outer injection hole, and the inner adjusting core has at least two inner injection holes. The diameter of the inner injection hole is smaller than that of the outer injection hole, and the outer injection hole and the polymer injection hole are not at the same height, that is, their axes are not aligned.

2. A hydraulic-electric composite layered polymer injection string, comprising an external sand-proof string, an internal sub-injection string, and a ground control cabinet; Its features are, The injection tubing includes the liquid-controlled layered polymer injection device and the electro-controlled liquid distribution device as described in claim 1. The hydraulically controlled stratified polymer injection device corresponds to a specific oil layer location, and both the hydraulically controlled stratified polymer injection device and the electro-hydraulic circuit distribution device are connected to the oil pipe. The electro-hydraulic distribution device is provided with a main hydraulic control pipeline interface and an upper armored cable interface at the upper end, and multiple branch hydraulic control pipeline interfaces and a lower armored cable interface at the lower end. Electronic pressure gauges and flow meters are connected to the liquid-controlled stratified polymerization device and are connected to the corresponding lower armored cable interface at the lower end of the electronically controlled liquid distribution device via armored cables. The hydraulically controlled stratified polymer injection devices corresponding to different oil layers are connected to the corresponding hydraulically controlled pipeline interfaces at the lower end of the electro-hydraulic distribution device through their respective hydraulically controlled pipelines. The electro-hydraulic distribution device is connected to the ground control cabinet via a main hydraulic control pipeline and an armored cable.

3. The electrohydraulic composite layered polymer injection string according to claim 2, characterized in that, The injection string also includes small plugs, injection packers, and positioning devices, all connected to the tubing. The injection packers are used for sealing inside the sand control string, and the positioning devices are used for positioning the injection string.

4. A construction method for a hydroelectric composite layered polymer injection tubing, characterized in that, Using the electrohydraulic composite layered polymer injection string as described in claim 2 includes the following steps: During routine injection, a command is sent from the ground control cabinet to the electrically controlled liquid distribution device to open the liquid control channel of the upper-layer liquid-controlled layered polymer injection device. Then, the liquid control switch of the ground control cabinet pressurizes the upper-layer liquid-controlled layered polymer injection device through the main liquid control pipeline. The cylindrical piston drives the track sleeve, the track sleeve drives the inner central tube, and the inner central tube drives the adjusting inner core to move up and down, adjusting the size of the injection hole. The track sleeve continuously changes direction under the action of the track pin. The lower the adjusting inner core goes, the smaller the injection hole becomes, until the required flow rate is achieved.

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