Hydraulic control water-gas dual medium separate injection tool and control method

Abstract

This invention belongs to the field of oilfield gas injection development and discloses a hydraulically controlled water-gas dual-medium injection tool and control method capable of precisely regulating the alternating injection of water and gas dual media. The tool includes a mandrel, an upper body, a middle body, and a lower body, all three forming internal channels. The mandrel is slidably connected to the channels via a gear adjustment component. An injection flow adjustment sleeve is installed inside the upper body, with multiple vent holes arranged axially thereon. An injection outlet is opened on the upper body. A water injection flow adjustment sleeve is installed inside the lower body, with multiple drainage holes arranged axially thereon. A water injection outlet is opened on the lower body. The tool has a gas injection adjustment mode: the gear adjustment component slides the mandrel towards the lower body, causing the mandrel to block different numbers of vent holes on the injection flow adjustment sleeve; and a water injection adjustment mode: in the water injection adjustment mode, the gear adjustment component slides the mandrel towards the upper body, causing the mandrel to block different numbers of drainage holes on the water injection flow adjustment sleeve.

Description

Technical Field

[0001] This invention relates to the field of oilfield gas injection development, specifically to a liquid-controlled water-gas dual-medium injection tool and control method. Background Technology

[0002] For low-permeability and tight reservoirs, gas injection development offers significant technological advantages. Firstly, it can rapidly increase reservoir pressure, replenish formation energy, and establish an effective displacement system. Secondly, it can substantially improve oil recovery by reducing interfacial tension and enhancing miscibility with crude oil. Studies show that miscible flooding can generally increase oil recovery by 10%–25%, while immiscible flooding can increase it by 7%–15%.

[0003] In practical field applications, water-gas alternation (WAG) injection is often used to suppress gas cross-flow. On the one hand, it effectively increases formation pressure and quickly reaches the miscible pressure condition. On the other hand, it can effectively control the mobility of the displacement fluid, achieving an organic combination of gas injection to improve micro-displacement efficiency and water injection to improve macro-sweep coefficient, thereby improving the recovery rate.

[0004] Most continental sedimentary reservoirs in my country are highly heterogeneous, and stratified injection can effectively improve the sweep efficiency and development results. For strata with significant gas channeling, it is necessary to increase the injection rate of low-mobility water media and decrease the injection rate of high-mobility gas media to suppress gas channeling velocity. For strata with slow pressure build-up, it is necessary to increase the gas injection rate and decrease the water injection rate to quickly establish an effective displacement system, thereby achieving uniform displacement of all reservoir strata and improving the overall swept volume.

[0005] Currently available gas stratified injection tools often use steel wires or cables to lower specialized instruments for injection adjustment. The success rate of steel wire / cable operations is significantly affected by well inclination, failing to meet the adjustment needs of highly deviated and horizontal wells; however, highly deviated and horizontal wells constitute a large proportion of offshore oilfields. Intelligent injection tools using single-core steel pipe cables are currently used in water injection wells, but have not been tested in gas injection wells, and mature technologies for downhole gas testing and control are lacking. Existing technologies cannot achieve simultaneous and precise control of water and gas injection volumes. Therefore, it is necessary to develop a dual-gas, dual-medium stratified injection tool to control and adjust the water and gas injection volumes in each stratum. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention proposes a liquid-controlled water-gas dual-medium injection tool and control method capable of precisely adjusting the alternating injection of water and gas dual media.

[0007] The hydraulically controlled water-air dual-medium dispensing tool according to the present invention includes: a mandrel, an upper body, a middle body, and a lower body connected coaxially in sequence. Channels are formed inside the upper body, the middle body, and the lower body. The mandrel is slidably connected to the channels via a gear adjustment assembly. An air injection flow regulating sleeve is installed inside the upper body between the mandrel and the upper body. An air injection outlet is provided on the upper body to cooperate with the air injection flow regulating sleeve. Multiple vent holes are spaced upwards along the axial direction of the air injection flow regulating sleeve. A water injection flow regulating device is installed inside the lower body between the mandrel and the lower body. The lower body of the sleeve has an air outlet that cooperates with the water flow regulating sleeve. The water flow regulating sleeve has multiple drainage hole groups spaced at intervals along its axial direction. The hydraulically controlled water-air dual-medium dispensing tool is constructed to have an air injection regulation mode and a water injection regulation mode. In the air injection regulation mode, the gear adjustment component slides the mandrel toward the lower body so that the mandrel blocks different numbers of air vent groups on the air flow regulating sleeve. In the water injection regulation mode, the gear adjustment component slides the mandrel toward the upper body so that the mandrel blocks different numbers of drainage hole groups on the water flow regulating sleeve.

[0008] Furthermore, each vent hole group includes a plurality of vent holes spaced apart circumferentially along the air injection flow regulating sleeve, and each drain hole group includes a plurality of drain holes spaced apart circumferentially along the water injection flow regulating sleeve.

[0009] Furthermore, the gear adjustment assembly includes a track groove formed on the mandrel, a guide key fixedly installed inside the lower body and located between the lower body and the mandrel, a hydraulic drive component for driving the mandrel to slide so that the guide key travels along the track groove, and a torque transmission component for transmitting torque to the mandrel. The track groove is constructed such that, in its unfolded state, it has horizontally spaced and connected air injection gear areas and water injection gear areas. The air injection gear areas and water injection gear areas are connected by a conversion channel. The air injection gear area includes multiple air injection slots arranged at intervals from top to bottom, and the water injection gear area includes multiple water injection slots arranged at intervals from top to bottom. The lowest water injection slot... The water level slot is connected to the uppermost air level slot. In air level adjustment mode, when the hydraulic drive component drives the spindle to slide so that the guide key moves along a certain air level slot to the conversion channel, the torque transmission component drives the spindle to rotate so that the guide key moves through the conversion channel into the adjacent air level slot or water level slot. In water level adjustment mode, when the hydraulic drive component drives the spindle to slide so that the guide key moves along a certain water level slot to the conversion channel, the torque transmission component drives the spindle to rotate so that the guide key moves through the conversion channel into the adjacent water level slot or air level slot.

[0010] Furthermore, the multiple air injection slots include an uppermost slot closure slot and multiple first slots arranged at intervals from top to bottom. The multiple water injection slots include multiple second slots arranged at intervals from top to bottom. The lowermost second slot is connected to the slot closure slot. The lengths of the slot closure slot and each first slot increase from top to bottom, and the lengths of each second slot also increase from top to bottom. The central axis of the uppermost second slot is located between the slot closure slot and the adjacent first slot. The central axis of the lowermost first slot is located between its nearest adjacent second slot. The central axes of the other second slots are located between their nearest adjacent first slots. When the guide key is in the slot closure slot, both the water injection flow regulating sleeve and the air injection flow regulating sleeve are closed. When the guide key is in the first slot, the water injection flow regulating sleeve is closed and the air injection flow regulating sleeve is open. When the guide key is in the second slot, the water injection flow regulating sleeve is open and the air injection flow regulating sleeve is closed.

[0011] Furthermore, the conversion channel includes a plurality of first sidewalls for connecting adjacent gear closing slots and first gear slots and adjacent first gear slots within the air injection gear area, and a plurality of second sidewalls for connecting adjacent second gear slots within the water injection gear area. Each first sidewall is configured to be inclined away from the water injection gear area, and each second sidewall is configured to be inclined away from the air injection gear area.

[0012] Furthermore, the hydraulic drive component includes a hydraulic pump and a combined seal formed between the middle body and the spindle. The combined seal includes an upper sealing assembly and a lower sealing assembly axially fixed between the middle body and the spindle, and a middle sealing assembly located between the upper and lower sealing assemblies. An air-injection opening sealing chamber is formed between the upper and middle sealing assemblies, and a water-injection opening sealing chamber is formed between the middle and lower sealing assemblies. When the hydraulic pump pumps hydraulic oil into the air-injection opening sealing chamber, the pressure in the air-injection opening sealing chamber increases, pushing the middle sealing assembly toward the lower sealing assembly, thereby causing the spindle to move toward the lower body so that the spindle blocks different numbers of vent hole groups on the air-injection flow regulating sleeve. When the hydraulic pump pumps hydraulic oil into the water-injection opening sealing chamber, the pressure in the water-injection opening sealing chamber increases, pushing the middle sealing assembly toward the upper sealing assembly, thereby causing the spindle to move toward the upper body so that the spindle blocks different numbers of drain hole groups on the water-injection flow regulating sleeve.

[0013] Furthermore, the upper sealing assembly, the middle sealing assembly, and the lower sealing assembly each include an O-ring, two V-rings located on both sides of the O-ring, a V-ring retaining ring located outside the V-ring, and an H-ring retaining ring located outside the V-ring.

[0014] Furthermore, pipeline passage grooves are provided on the upper body, middle body, and lower body. The upper body and the middle body are threaded together, and a first torque transmission key is embedded at the end where the upper body and the middle body are connected to align the pipeline passage grooves on the two bodies. The middle body and the lower body are threaded together, and a second torque transmission key is embedded at the end where the middle body and the lower body are connected to align the pipeline passage grooves on the two bodies.

[0015] The control method for multi-layer injection using the above-mentioned liquid-controlled water-gas dual-medium injection tool according to the present invention includes: in a certain formation, controlling the guide key of the liquid-controlled water-gas dual-medium injection tool in the formation to enter a certain water injection level slot to realize gas injection at different levels, and controlling the guide key to enter different water injection level slots to realize water injection at different levels, wherein water injection and gas injection are performed alternately in cycles.

[0016] Furthermore, during gas injection: the hydraulically controlled water-gas dual-medium injection tools at each layer are positioned at the gas injection setting. When it is necessary to adjust the gas injection rate at a certain layer, the hydraulically controlled water-gas dual-medium injection tools at other layers are shut down via the surface controller. The pressure-flow rate variation curve of the injection at that layer is measured using pressure gauges and flow meters on the wellhead gas injection process. Based on the measured pressure-flow rate variation curve of the injection at that layer and the nozzle wear characteristic curve of the hydraulically controlled water-gas dual-medium injection tool, the target gas injection setting that meets the gas injection rate requirement is calculated. The gas injection in the hydraulically controlled water-gas dual-medium injection tool at that layer is adjusted according to the target gas injection setting. During water injection: ensure that the hydraulically controlled water-gas dual-medium injection tools at each layer are in the water injection position. When it is necessary to adjust the water injection rate at a certain layer, the hydraulically controlled water-gas dual-medium injection tools at other layers are shut down via the ground controller. The water injection pressure versus flow rate curve at that layer is measured using pressure gauges and flow meters on the wellhead gas injection process. Based on the measured water injection pressure versus flow rate curve at that layer and the nozzle wear characteristic curve of the hydraulically controlled water-gas dual-medium injection tool, the target water injection position that meets the water injection rate requirement is calculated. Adjust the water injection position in the hydraulically controlled water-gas dual-medium injection tool at that layer according to the target water injection position.

[0017] Compared with existing technologies, the hydraulically controlled water-gas dual-medium injection tool of this invention uses a gear adjustment component to drive the axial movement of the mandrel, thereby enabling the mandrel to block different drainage and venting hole groups on the gas injection flow adjustment sleeve and the water injection flow adjustment sleeve respectively. This allows for separate adjustment of gas and water injection. The gear adjustment component uses a mechanical hydraulic control method to achieve the movement of the mandrel, contains no electronic components, has superior high-temperature resistance, and is suitable for high-temperature gas and water injection wells. At the same time, the hydraulic adjustment thrust is large, which is beneficial for removing scale or blockage at the downhole valve. The hydraulically controlled water-gas dual-medium injection tool of this invention can simultaneously meet the needs of stratified water and gas injection. The venting and drainage hole groups on the gas injection flow adjustment sleeve and the water injection flow adjustment sleeve can be precisely designed according to the injection volume requirements, meeting the technical requirements of oilfield water-gas alternating injection process. Simultaneously, the valve opening of the downhole injection tool can be controlled in real time from the ground, and the adjustment does not occupy the wellhead or is not limited by well inclination, meeting the needs of offshore oilfield gas injection development. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the liquid-controlled water-gas dual-medium injection tool according to an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of the structure of the mandrel and guide key mating;

[0020] Figure 3 This is a schematic diagram of the unfolded structure of the guide groove;

[0021] Figure 4 This is a diagram illustrating gear shifting.

[0022] Figure 5 This is a schematic diagram of the combined seal.

[0023] Figure 6 This is a structural schematic diagram of the central sealing assembly;

[0024] Figure 7 This is a schematic diagram illustrating the installation of a multi-layer injection system using a liquid-controlled water-gas dual-medium injection tool according to an embodiment of the present invention. Detailed Implementation

[0025] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0026] Figure 1 The structure of a liquid-controlled water-gas dual-medium dispensing tool 100 according to an embodiment of the present invention is shown. For example... Figure 1As shown, the hydraulically controlled water-air dual-medium dispensing tool 100 may include: a mandrel 4, an upper body 1, a middle body 2, and a lower body 3 connected coaxially in sequence. Channels are formed inside the upper body 1, middle body 2, and lower body 3. The mandrel 4 is slidably connected to the channels via a gear adjustment assembly 7. An air injection flow regulating sleeve 5 is installed inside the upper body 1, located between the mandrel 4 and the upper body 1. An air injection outlet 11 that cooperates with the air injection flow regulating sleeve 5 is opened on the upper body 1. Multiple vent holes (not shown in the figure) are spaced upwards along the axial direction of the air injection flow regulating sleeve 5. A water injection flow regulating sleeve 5 is installed inside the lower body 3, located between the mandrel 4 and the lower body 3. The volume regulating sleeve 6 has an air outlet 21 on its lower body 3 that cooperates with the water flow regulating sleeve 6. The water flow regulating sleeve 6 has multiple drainage hole groups (not shown in the figure) spaced apart axially. The hydraulic water-air dual-medium dispensing tool 100 is constructed to have an air injection regulating mode and a water injection regulating mode. In the air injection regulating mode, the gear adjusting component 7 slides the spindle 4 toward the lower body 3 so that the spindle 4 blocks different numbers of vent hole groups on the air flow regulating sleeve 5. In the water injection regulating mode, the gear adjusting component 7 slides the spindle 4 toward the upper body 1 so that the spindle 4 blocks different numbers of drainage hole groups on the water flow regulating sleeve 6.

[0027] The hydraulically controlled water-air dual-medium injection tool 100 of this invention uses the gear adjustment component 7 to drive the spindle 4 to move axially, thereby enabling the spindle 4 to block different drainage hole groups and vent hole groups on the air injection flow adjustment sleeve 5 and the water injection flow adjustment sleeve 6 respectively, thus realizing the separate adjustment of air injection and water injection. By designing the vent hole groups and drainage hole groups on the air injection flow adjustment sleeve 5 and the water injection flow adjustment sleeve 6, the specific arrangement and number of vent hole groups and drainage hole groups can be precisely designed according to the air intake capacity and air injection volume of the layer to be injected, as well as the water intake capacity and water injection volume, so as to achieve fine adjustment of alternating water-air dual-medium injection.

[0028] Preferably, each vent hole group may include a plurality of vent holes spaced circumferentially along the air injection flow regulating sleeve 5, and each drain hole group includes a plurality of drain holes spaced circumferentially along the water injection flow regulating sleeve 6. Specifically, in conjunction with Figure 3As shown, the air injection flow regulating sleeve 5 has circular holes of different diameters along the axial direction, with a total of 6 rows of holes corresponding to 6 air injection levels. Each row can have 4 holes circumferentially. All the holes in each circumferential direction form an exhaust hole group, and the number of exhaust hole groups is the number of air injection levels. By moving the spindle 4 axially to block different numbers of exhaust hole groups, the air injection level can be adjusted. Similarly, the water injection flow regulating sleeve 6 has circular holes of different diameters along the axial direction, with a total of 7 rows of holes corresponding to 7 water injection levels. Each row can have 4 holes circumferentially. All the holes in each circumferential direction form a drain hole group, and the number of drain hole groups is the number of water injection levels. By moving the spindle 4 axially to block different numbers of drain hole groups, the water injection level can be adjusted.

[0029] According to the present invention, in such Figure 1 As for Figure 3 In the preferred embodiment shown, the gear adjustment assembly 7 may include a track groove 72 formed on the spindle 4, a guide key 71 fixedly mounted inside the lower body 3 and located between the lower body 3 and the spindle 4, a hydraulic drive component (not shown) for driving the spindle 4 to slide so that the guide key 71 travels along the track groove 72, and a torque transmission component (not shown) for transmitting torque to the spindle 4, wherein, as Figure 3 As shown, the track groove 72 can be constructed as having horizontally spaced and connected air injection zone A and water injection zone B in a planar unfolded state. Air injection zone A and water injection zone B are connected via a conversion channel 724. Air injection zone A includes multiple air injection slots arranged at intervals from top to bottom, and water injection zone B includes multiple water injection slots arranged at intervals from top to bottom. The lowest water injection slot is connected to the highest air injection slot. In air injection adjustment mode, the hydraulic drive component drives the spindle 4 to slide so that the guide key 71 moves along a certain... When the guide key 71 travels from the air injection slot to the conversion channel 724, the torque transmission component drives the spindle 4 to rotate, causing the guide key 71 to enter the adjacent air injection slot or water injection slot via the conversion channel 724. In water injection mode, when the hydraulic drive component drives the spindle 4 to slide, causing the guide key 71 to travel from a water injection slot to the conversion channel 724, the torque transmission component drives the spindle 4 to rotate, causing the guide key 71 to enter the adjacent water injection slot or air injection slot via the conversion channel 724. Through this embodiment, arbitrary switching of the air injection level within the air injection zone A, arbitrary switching of the water injection level within the water injection zone B, and alternating switching between the air injection and water injection levels can be achieved.

[0030] In such Figure 2 and Figure 3In the preferred embodiment shown, the plurality of air injection slots may include an uppermost slot closure slot 721 and a plurality of first slots 722 arranged sequentially from top to bottom. The plurality of water injection slots may include a plurality of second slots 723 arranged sequentially from top to bottom. The lowermost second slot 723 is connected to the slot closure slot 721. The lengths of the slot closure slot 721 and each of the first slots 722 increase sequentially from top to bottom, and the lengths of each of the second slots 723 increase sequentially from top to bottom. The central axis of the uppermost second slot 723 is located at and adjacent to the slot closure slot 721. Between adjacent first gear slots 722, the central axis of the lowest first gear slot 722 is located between the adjacent second gear slots 723, and the central lines of the other second gear slots 723 are located between the adjacent first gear slots 722. When the guide key 71 is located in the gear closing slot 721, both the water flow regulating sleeve 6 and the air flow regulating sleeve 5 are closed. When the guide key 71 is located in the first gear slot 722, the water flow regulating sleeve 6 is closed and the air flow regulating sleeve 5 is open. When the guide key 71 is located in the second gear slot 723, the water flow regulating sleeve 6 is open and the air flow regulating sleeve 5 is closed.

[0031] In this embodiment, when the guide key 71 is located in the gear closing slot 721, the hydraulic control water-air dual-medium dispensing tool 100 neither dispenses air nor water; when the guide key 71 is located in the first gear slot 722, the hydraulic control water-air dual-medium dispensing tool 100 dispenses only air; and when the guide key 71 is located in the second gear slot 723, the hydraulic control water-air dual-medium dispensing tool 100 dispenses only water.

[0032] In such Figure 4 In the preferred embodiment shown, when the guide key 71 moves from the gear stop groove 721 to the adjacent second gear groove 723, water is injected at the water injection level 1. As the guide key 71 continues to move from the second gear groove 723 to the adjacent first gear groove 722, air is injected at the air injection level 1. With the guide key 71 alternating between the air injection area A and the water injection area B, until the guide key 71 moves back from the lowermost second gear groove 723 to the gear stop groove 721, the water injection at the water injection level 7 is completed, ending the water and air injection process. Of course, the above water and air injection process can be either water injection first followed by air injection, or air injection first followed by water injection.

[0033] According to the present invention, such as Figure 3As shown, the switching channel 724 may include a plurality of first sidewalls 7221 for connecting adjacent gear closing slots 721 and first gear slots 722 and adjacent first gear slots 722 within the air injection zone A, and a plurality of second sidewalls 7231 for connecting adjacent second gear slots 723 within the water injection zone B. Each first sidewall 7221 is constructed to be inclined away from the water injection zone B, and each second sidewall 7231 is constructed to be inclined away from the air injection zone A. This configuration provides a guiding slope for the guide key 71 to switch between the water injection zone A and the water injection zone B, thereby making the switching process smoother and more reliable. Preferably, to ensure the uniformity of switching, the inclination angles of each first sidewall and each second sidewall can be set to be the same. More preferably, the inclination angle can be 45°.

[0034] According to the present invention, combined Figure 1 and Figure 5 As shown, the hydraulic drive component may include a hydraulic pump (not shown) and a combined seal 73 formed between the middle body 2 and the spindle 4. The combined seal 73 may include an upper sealing assembly 731 and a lower sealing assembly 733 axially fixed between the middle body 2 and the spindle 4, and a middle sealing assembly 732 located between the upper sealing assembly 731 and the lower sealing assembly 733. An air-injection opening sealing cavity is formed between the upper sealing assembly 731 and the middle sealing assembly 732, and a water-injection opening sealing cavity is formed between the middle sealing assembly 732 and the lower sealing assembly 733. When the hydraulic pump... When the hydraulic pump injects hydraulic oil into the gas injection opening and sealing chamber, the pressure in the gas injection opening and sealing chamber increases, pushing the middle sealing assembly 732 towards the lower sealing assembly 733, thereby causing the mandrel 4 to move towards the lower body 3 so that the mandrel 4 blocks different numbers of vent hole groups on the gas injection flow regulating sleeve 5; when the hydraulic pump injects hydraulic oil into the water injection opening and sealing chamber, the pressure in the water injection opening and sealing chamber increases, pushing the middle sealing assembly 732 towards the upper sealing assembly 731, thereby causing the mandrel 4 to move towards the upper body 1 so that the mandrel 4 blocks different numbers of drain hole groups on the water injection flow regulating sleeve 6. In this embodiment, the movement of the middle sealing assembly 732 is driven by hydraulic drive to drive the movement of the mandrel 4. This mechanical hydraulic control method is not only more reliable, but also allows the internal components of the hydraulically controlled water-gas dual-medium injection tool 100 to be free of electronic components, thus providing better high-temperature resistance and making it more suitable for application in high-temperature gas injection and water injection wells.

[0035] Preferably, the cross-sectional area of ​​the intermediate sealing assembly 732 can be 1489.03 mm². 2 When the ground hydraulic pipeline is pressurized to 20MPa, it is equivalent to a thrust of about 3 tons. The thrust is relatively large, which is also helpful in removing scale or blockage at the downhole valve nozzle.

[0036] In such Figure 6In the preferred embodiment shown, the upper sealing assembly 731, the middle sealing assembly 732, and the lower sealing assembly 733 each include an O-ring 7321, two V-rings 7322 located on either side of the O-ring 7321, a V-ring retaining ring 7323 located outside the V-ring 7322, and an H-ring retaining ring 7324 located outside the V-ring retaining ring 7323. This arrangement reduces the friction between the combined sealing member 73 and the channel, allowing the combined sealing member 73 to slide more smoothly relative to the channel, thus improving the accuracy and smoothness of gear shifting. Furthermore, it effectively enhances the sealing strength of the combined sealing member 73, ensuring that hydraulic oil does not leak from the air-injected and water-injected sealing chambers.

[0037] Preferably, the O-ring 7321 can be made of fluororubber to improve the high-temperature sealing pressure difference; the V-ring 7322 can be made of polyetheretherketone (PEEK) to improve the seal's high-temperature resistance and acid corrosion resistance; the V-ring retaining ring 7323 can be made of polytetrafluoroethylene (PTFE) with 5% molybdenum disulfide added to improve the seal's strength and lubrication performance; and the H-ring retaining ring 7324 can be made of PEEK to improve the seal's high-temperature resistance and acid corrosion resistance. Therefore, the overall structure of the combined sealing element 73 possesses both strength and lubricity, and can also satisfy the directional requirements of left-right movement dynamic sealing, with a sealing temperature resistance up to 175°C.

[0038] According to the present invention, return Figure 1 In the preferred embodiment shown, the upper body 1, the middle body 2, and the lower body 3 are all provided with pipeline passage grooves (not shown in the figure). The upper body 1 and the middle body 2 are threaded together, and the ends of the upper body 1 and the middle body 2 connected together can also be embedded with a first torque transmission key 91 for aligning the pipeline passage grooves on them. The middle body 2 and the lower body 3 are threaded together, and the ends of the middle body 2 and the lower body 3 connected together can also be embedded with a second torque transmission key 92 for aligning the pipeline passage grooves on them. When connecting the upper body 1 and the middle body 2, the alignment of the pipeline passage grooves at their ends is achieved by adjusting the threaded connection between the upper body 1 and the middle body 2 and embedding the first torque transmission key 91. When connecting the middle body 2 and the lower body 3, the alignment of the pipeline passage grooves at their ends is achieved by adjusting the threaded connection between the middle body 2 and the lower body 3 and embedding the second torque transmission key 92.

[0039] This invention also proposes a control method for multi-layer injection using the aforementioned liquid-controlled water-gas dual-medium injection tool 100, comprising: controlling the guide key 71 of the liquid-controlled water-gas dual-medium injection tool 100 within a certain formation to enter a certain water injection level slot to achieve gas injection at different levels, and controlling the guide key 72 to enter different water injection level slots to achieve water injection at different levels, wherein, for example... Figure 4As shown, water injection and air injection cycles alternate.

[0040] Figure 7 A schematic diagram of the installation of a multi-layer dispensing tool 100 for water-gas dual-medium dispensing according to an embodiment of the present invention is shown. Figure 7 As shown, firstly, hydraulically controlled water-gas dual-medium injection tools 100 are installed in each layer downhole. Layers 1, 2, and 3 are sealed together by positioning seal 105, first insertion seal 106, and second insertion seal 107. Preferably, positioning seal 35 and hydraulically controlled water-gas dual-medium injection tool 100 of layer 1, first insertion seal 106 and hydraulically controlled water-gas dual-medium injection tool 100 of layer 2, and second insertion seal 107 and hydraulically controlled water-gas dual-medium injection tool 100 of layer 3 can be prefabricated into tool assemblies, with hydraulic pipelines passing through them and joints left at the upper and lower ends for connection. Then, the water injection opening and sealing chamber of each hydraulically controlled water-gas dual-medium injection tool 100 is connected to the wellhead surface controller through the first hydraulic control line 101, and the gas injection opening and sealing chamber of each hydraulically controlled water-gas dual-medium injection tool 100 is connected to the wellhead surface controller separately through a second hydraulic control line. For example, the gas injection opening and sealing chamber of the uppermost hydraulically controlled water-gas dual-medium injection tool 100 is connected to the wellhead surface controller through the first second hydraulic control line 102, the gas injection opening and sealing chamber of the middle hydraulically controlled water-gas dual-medium injection tool 100 is connected to the wellhead surface controller through the second second hydraulic control line 103, and the gas injection opening and sealing chamber of the lowermost hydraulically controlled water-gas dual-medium injection tool 100 is connected to the wellhead surface controller through the third second hydraulic control line 104.

[0041] According to the present invention, during gas injection: the hydraulically controlled water-gas dual-medium injection tool 100 of each layer is positioned at the gas injection setting. When it is necessary to adjust the gas injection volume of a certain layer, the hydraulically controlled water-gas dual-medium injection tool 100 of other layers is shut down by the ground controller. The gas injection pressure versus flow rate curve of that layer is measured by the pressure gauge and flow meter on the wellhead gas injection process. Based on the tested gas injection pressure versus flow rate curve of that layer and the nozzle wear characteristic curve of the hydraulically controlled water-gas dual-medium injection tool, the target gas injection setting that meets the gas injection volume requirement is calculated. The gas injection setting in the hydraulically controlled water-gas dual-medium injection tool of that layer is adjusted according to the target gas injection setting.

[0042] During water injection: ensure that the hydraulically controlled water-gas dual-medium injection tool 100 at each layer is in the water injection position. When it is necessary to adjust the water injection rate at a certain layer, the hydraulically controlled water-gas dual-medium injection tool 100 at other layers is shut down via the ground controller. The water injection pressure versus flow rate curve at that layer is measured using pressure gauges and flow meters on the wellhead gas injection process. Based on the measured water injection pressure versus flow rate curve at that layer and the nozzle wear characteristic curve of the hydraulically controlled water-gas dual-medium injection tool, the target water injection position that meets the water injection rate requirement is calculated. The water injection position in the hydraulically controlled water-gas dual-medium injection tool at that layer is adjusted according to the target water injection position.

[0043] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0044] In the description of this application, it should be understood that the terms "axial", "circumferential", "outer", "above", "below", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0045] Furthermore, the terms “first”, “second”, etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. 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 or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A liquid-controlled water-gas dual-medium dispensing tool, characterized in that, include: The system comprises a mandrel, an upper body, a middle body, and a lower body, all coaxially connected in sequence. Channels are formed inside each of the upper, middle, and lower bodies. The mandrel is slidably connected to these channels via a gear adjustment assembly. An air injection flow regulating sleeve is installed inside the upper body, located between the mandrel and the upper body. The upper body has an air injection outlet that mates with the air injection flow regulating sleeve. Multiple vent holes are spaced upwards along the axial direction of the air injection flow regulating sleeve. A water injection flow regulating sleeve is installed inside the lower body, located between the mandrel and the lower body. The lower body has a water injection flow regulating sleeve that mates with the water injection outlet. The flow regulating sleeve is equipped with an air injection outlet. The water injection flow regulating sleeve has multiple drainage hole groups spaced axially upwards. The liquid-controlled water-air dual-medium injection tool is configured with an air injection mode and a water injection mode. In the air injection mode, the gear adjustment component slides the mandrel towards the lower body, causing the mandrel to block different numbers of the air injection flow regulating sleeve's vent hole groups. In the water injection mode, the gear adjustment component slides the mandrel towards the upper body, causing the mandrel to block different numbers of the water injection flow regulating sleeve's drainage hole groups. The gear adjustment assembly includes a track groove formed on the mandrel, a guide key fixedly installed inside the lower body and located between the lower body and the mandrel, a hydraulic drive component for driving the mandrel to slide so that the guide key moves along the track groove, and a torque transmission component for transmitting torque to the mandrel. The track groove is configured to have horizontally spaced and connected air injection gear areas and water injection gear areas in a planar unfolded state. The air injection gear area and the water injection gear area are connected by a conversion channel. The air injection gear area includes multiple air injection slots arranged at intervals from top to bottom, and the water injection gear area includes multiple water injection slots arranged at intervals from top to bottom. The lowest water injection slot is connected to the one located at intervals from top to bottom. The uppermost air injection slots are connected. In the air injection adjustment mode, when the hydraulic drive component drives the spindle to slide so that the guide key travels along a certain air injection slot to the conversion channel, the torque transmission component drives the spindle to rotate so that the guide key enters the adjacent air injection slot or water injection slot through the conversion channel within the air injection slot. In the water injection adjustment mode, when the hydraulic drive component drives the spindle to slide so that the guide key travels along a certain water injection slot to the conversion channel, the torque transmission component drives the spindle to rotate so that the guide key enters the adjacent water injection slot or air injection slot through the conversion channel within the water injection slot.

2. The hydraulically controlled water-gas dual-medium dispensing tool according to claim 1, characterized in that, Each of the vent hole groups includes a plurality of vent holes spaced apart circumferentially along the air injection flow regulating sleeve, and each of the drain hole groups includes a plurality of drain holes spaced apart circumferentially along the water injection flow regulating sleeve.

3. The hydraulically controlled water-gas dual-medium dispensing tool according to claim 1, characterized in that, The plurality of air injection slots include an uppermost slot for closing and a plurality of first slots arranged at intervals from top to bottom. The plurality of water injection slots include a plurality of second slots arranged at intervals from top to bottom. The lowermost second slot is connected to the slot for closing. The lengths of the slot for closing and each of the first slots increase from top to bottom, and the lengths of each of the second slots also increase from top to bottom. The central axis of the uppermost second slot is located between the slot for closing and the first slot adjacent to the slot for closing. The central axis of the lowest first gear slot is located between the adjacent second gear slots, and the central lines of the other second gear slots are located between the adjacent first gear slots. When the guide key is located in the gear closing slot, both the water flow regulating sleeve and the air flow regulating sleeve are closed; when the guide key is located in the first gear slot, the water flow regulating sleeve is closed and the air flow regulating sleeve is open; when the guide key is located in the second gear slot, the water flow regulating sleeve is open and the air flow regulating sleeve is closed.

4. The liquid-controlled water-gas dual-medium injection tool according to claim 3, characterized in that, The conversion channel includes a plurality of first sidewalls for connecting adjacent gear shut-off slots and first gear slots within the air injection gear area, and a plurality of second sidewalls for connecting adjacent second gear slots within the water injection gear area. Each first sidewall is configured to be inclined away from the water injection gear area, and each second sidewall is configured to be inclined away from the air injection gear area.

5. The hydraulically controlled water-gas dual-medium dispensing tool according to claim 1, characterized in that, The hydraulic drive component includes a hydraulic pump and a combined seal formed between the middle body and the mandrel. The combined seal includes an upper sealing assembly and a lower sealing assembly axially fixed between the middle body and the mandrel, and a middle sealing assembly located between the upper sealing assembly and the lower sealing assembly. An air-injection opening sealing cavity is formed between the upper sealing assembly and the middle sealing assembly, and a water-injection opening sealing cavity is formed between the middle sealing assembly and the lower sealing assembly. When the hydraulic pump pumps hydraulic oil into the air-injection opening sealing cavity, the pressure in the air-injection opening sealing cavity increases to push the middle sealing assembly toward the lower sealing assembly, thereby driving the mandrel to move toward the lower body so that the mandrel blocks different numbers of the vent hole groups on the air injection flow regulating sleeve. When the hydraulic pump injects hydraulic oil into the water injection opening and sealing chamber, the pressure in the water injection opening and sealing chamber increases, pushing the middle sealing assembly toward the upper sealing assembly, thereby driving the mandrel toward the upper body so that the mandrel blocks different numbers of the drain hole groups on the water injection flow regulating sleeve.

6. The hydraulically controlled water-gas dual-medium dispensing tool according to claim 5, characterized in that, The upper sealing assembly, the middle sealing assembly, and the lower sealing assembly each include an O-ring, two V-rings located on both sides of the O-ring, a V-ring retaining ring located outside the V-ring, and an H-ring retaining ring located outside the V-ring.

7. The hydraulically controlled water-gas dual-medium dispensing tool according to claim 1 or 2, characterized in that, The upper body, the middle body, and the lower body are all provided with pipeline passage grooves. The upper body and the middle body are threaded together. The end of the upper body connected to the middle body is also embedded with a first torque transmission key for aligning the pipeline passage grooves on the two. The middle body and the lower body are threaded together. The end of the middle body connected to the lower body is also embedded with a second torque transmission key for aligning the pipeline passage grooves on the two.

8. A control method for water-gas dual-medium injection using a hydraulically controlled water-gas dual-medium injection tool according to any one of claims 1 to 7, characterized in that, include: Within a certain formation, the guide key of the liquid-controlled water-gas dual-medium injection tool within that formation is controlled to enter a certain water injection level slot to achieve gas injection at different levels, and the guide key is controlled to enter different water injection level slots to achieve water injection at different levels, wherein water injection and gas injection are carried out alternately in cycles.

9. The control method for water-gas dual-medium injection using a liquid-controlled water-gas dual-medium injection tool according to claim 8, characterized in that, During gas injection: ensure that the hydraulically controlled water-gas dual-medium injection tools at each layer are in the gas injection position. When it is necessary to adjust the gas injection rate at a certain layer, the hydraulically controlled water-gas dual-medium injection tools at other layers are shut down via the ground controller. The gas injection pressure versus flow rate curve at that layer is measured using pressure gauges and flow meters on the wellhead gas injection process. Based on the measured gas injection pressure versus flow rate curve at that layer and the nozzle wear characteristic curve of the hydraulically controlled water-gas dual-medium injection tool, the target gas injection position that meets the gas injection rate requirement is calculated. Adjust the gas injection level in the liquid-controlled water-gas dual-medium injection tool at this layer according to the target gas injection level; During water injection: the hydraulically controlled water-gas dual-medium injection tools at each layer are all positioned at the water injection level. When it is necessary to adjust the water injection rate at a certain layer, the hydraulically controlled water-gas dual-medium injection tools at other layers are shut down via the ground controller. The water injection pressure versus flow rate curve at that layer is measured using pressure gauges and flow meters on the wellhead gas injection process. Based on the measured water injection pressure versus flow rate curve at that layer and the nozzle wear characteristic curve of the hydraulically controlled water-gas dual-medium injection tool, the target water injection level that meets the water injection rate requirement is calculated. Adjust the water injection level in the liquid-controlled water-air dual-medium injection tool for that layer according to the target water injection level.

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