Layered water injection tubular column and testing and deploying method thereof

Abstract

The invention discloses a layered water injection tubular column and a testing and deploying method thereof. The layered water injection tubular column comprises an oil pipe, a water distributor and a packer. At least two water distributors are arranged on the oil pipe, one packer is arranged between every two water distributors, each water distributor corresponds to one water injection layer, and the flow velocity amplifying device comprises a water distributor flow velocity amplifying device and a pipe column flow velocity amplifying device; a water distributor flow velocity amplifying device is arranged above each water distributor, and the tubular column flow velocity amplifying device is arranged above the uppermost water distributor flow velocity amplifying device. Parameters of the measuring and adjusting instrument are not changed, the flow speed of a certain area in the pipe column is amplified, the flow range capable of being accurately measured by the measuring and adjusting instrument is achieved, and the flow measuring range is expanded.

Description

Technical Field

[0001] The present invention relates to the technical field of oil well water injection equipment, and specifically relates to a layered water injection pipe string and a testing and adjustment method thereof. Background Art

[0002] At present, layered water injection mainly adopts the electro-mechanical integration measurement and adjustment method, which greatly improves the measurement and adjustment efficiency and the adjustment accuracy, and has remarkable effects in medium and high permeability oil reservoirs. However, in low permeability oil reservoirs, the injection volume of injection wells is small, and the injection volume of each water injection layer section is mainly 10-20 m 3 / d, and the injection volume of some layer sections is only 5 m 3 / d, which is close to or even lower than the flow rate test limit of the measurement and adjustment instrument. Whether the flow rate test is accurate depends entirely on the test accuracy of the measurement and adjustment instrument. When the test instrument measures at a small flow rate, there are problems such as large data fluctuations, long measurement and adjustment cycles, and low accuracy. In addition, the mainstream flow rate measurement method of the decreasing method further amplifies the error, and the layered adjustment cannot ensure that the actual injection volume of each layer meets the requirements of the planned injection volume, affecting the water flooding development effect of low permeability oil reservoirs.

[0003] Publication (Announcement) No.: CN115012888A discloses a layered water injection method and a layered water injection device without a downhole flowmeter. The method includes connecting a plurality of packers and intelligent water distributors on the water injection pipe string, and setting water nozzles with adjustable channel sizes on each intelligent water distributor; lowering the water injection pipe string into the well, using the packers to separate multiple downhole water injection layer sections, and each water injection layer section corresponds to an intelligent water distributor; opening the water nozzles of the required water injection layer section and closing the water nozzles of other water injection layer sections, and changing the channel size of the water nozzles to adjust the injection pressure to adjust the injection flow rate; and injecting water layer by layer for multiple water injection layer sections. The invention does not need to lower a layered flowmeter, adjusts the layered injection volume by adjusting the size of the water nozzles of each water injection layer section, has a simple structure and a fast method, reduces the operation process, reduces the layered water injection cost, can accurately judge the water absorption difference and change trend of different layers, provides an important basis for formulating water injection adjustment policies, and improves the water injection development level.

[0004] When this prior art is used, it has high requirements for the coordinated work of the water nozzles of each layer. If there is no coordinated work, the injection volume of some injection layers will be incorrect.

[0005] Publication (Announcement) Number: CN111075412A discloses a real-time monitoring and automatic allocation process system and method for downhole layered water injection, including a ground intelligent control device, a downhole intelligent layered water injection pipe string, and a measurement and control instrument. The downhole intelligent layered water injection pipe string includes a casing protection packer, an intelligent water distributor, a preset working barrel, a double-acting valve, a screen pipe, and a plug, which are connected in sequence from top to bottom. The intelligent water distributor is one or more, and an interlayer packer is provided between two adjacent intelligent water distributors; the ground intelligent control device is used to send a flow command to the intelligent water distributor, and the intelligent water distributor adjusts the size of the water outlet according to the flow command. The measurement and control instrument is communicatively connected to the intelligent water distributor to record the downhole flow rate and pressure. After receiving the command, the intelligent water distributor is powered by a motor battery pack to open or close the water nozzle assembly, performing the automatic adjustment process of the water nozzle to ensure that the layered water injection volume meets the requirements of layered water injection allocation, realizing downhole monitoring of layered dynamic parameters and automatic allocation of layered flow rates.

[0006] This prior art has the problem of being unable to work after a power outage.

[0007] Publication (Announcement) Number: CN113323638A discloses a regulation and control layered water injection system and control method using infrasound waves. The system includes a ground control device, a downhole intelligent water distributor, a packer, a water injection wellhead, a water injection pipe string, a casing, a screen, and a ball seat. The ground control device is connected to the downhole intelligent water distributor, the downhole intelligent water distributor is connected to the downhole water injection pipe string, the casing is arranged on the inner wall of the well, several packers are arranged at intervals on the water injection pipe string, and the downhole intelligent water distributor is arranged on the water injection pipe string between any two packers. A screen and a ball seat are arranged at the end of the water injection pipe string. This invention adopts infrasound wave communication technology to achieve real-time wireless two-way fast communication between the ground control device and the downhole intelligent water distributor, with stable and reliable transmission, long transmission distance, low system power consumption, long service life, and strong data real-time performance. This invention is simple in construction, easy to operate, pollution-free, and low in cost, and can support real-time online one-key seal verification and one-key remote allocation.

[0008] When using this prior art, there are high requirements for the coordinated work of each layer of water nozzles. If there is no coordinated work, the water injection allocation volume of some injection allocation layers will be incorrect.

[0009] In summary, the technical solutions, the technical problems to be solved, and the beneficial effects of the above disclosed technologies are all different from those of the present invention. Regarding more technical features, the technical problems to be solved, and the beneficial effects of the present invention, none of the above disclosed technical documents provide technical inspiration. Summary of the Invention

[0010] In view of the above-mentioned defects existing in the prior art, the object of the present invention is to provide a layered water injection string and its testing and adjustment method. By using existing flow measurement instruments, the flow rate is amplified by changing the test conditions, and the actual flow rate is calculated to achieve small flow rate testing and adjustment, which is different from the above-mentioned invention.

[0011] To achieve the above object, the present invention adopts the following technical solutions:

[0012] A layered water injection string includes a tubing string, a water distributor, and a packer; at least two water distributors are provided on the tubing string, a packer is provided between every two water distributors, and each water distributor corresponds to a water injection layer.

[0013] It further includes a flow rate amplification device, and the flow rate amplification device includes a water distributor flow rate amplification device and a string flow rate amplification device.

[0014] A water distributor flow rate amplification device is provided above each water distributor, and the string flow rate amplification device is provided above the uppermost water distributor flow rate amplification device.

[0015] A washing well valve is provided at the bottom of the tubing string.

[0016] The flow rate amplification device and the string flow rate amplification device have the same structure, and both include a coupling and a thick-walled short section.

[0017] The coupling and the thick-walled short section are connected by threads, and the inner diameter of the thick-walled short section is smaller than the inner diameter of the tubing string.

[0018] In an embodiment of the present invention, the water distributor flow rate amplification device is designed as a bridge-type flow rate amplification device.

[0019] The bridge-type flow rate amplification device includes an upper joint, an outer sleeve, a flow rate amplification short section, a lower joint, and an adjusting ring.

[0020] The flow rate amplification short section is connected to the inner wall of the upper joint, and the outer sleeve is connected to the outer wall of the upper joint; the flow rate amplification short section is connected to the upper joint of the water distributor, the inner diameter of the flow rate amplification short section is smaller than the inner diameter of the tubing string, and the flow rate amplification short section is provided with an upper diversion hole.

[0021] The middle part of the outer sleeve adopts a bridge-type diversion structure.

[0022] The lower joint is connected to the lower joint of the water distributor, the lower joint is provided with a lower diversion hole, the adjusting ring is connected to the outer wall of the lower joint, and the adjusting ring is in contact with and presses the lower end face of the outer sleeve.

[0023] The middle part of the outer sleeve is provided with a bridge-type diversion hole, and the bridge-type diversion hole is independent of and does not interfere with the water injection hole of the water distributor.

[0024] In an embodiment of the present invention, the number of water distributors is two, which are divided into a first water distributor and a second water distributor; a first water distributor flow rate amplification device is provided on the first water distributor, and a second water distributor flow rate amplification device is provided on the second water distributor.

[0025] A testing and adjusting method for a layered water injection string includes the following steps:

[0026] S1. Measure the total well flow rate and adjust the wellhead flow rate through the injection pump and the wellhead gate;

[0027] Lower the testing and adjusting instrument above the flow rate amplification device of the string to measure the total well flow rate value Q 实 , and continue to lower the testing and adjusting instrument into the inner cavity of the flow rate amplification device at the top of the string to measure the total well amplified flow rate value Q 放 ;

[0028] By changing the injection flow rate, multiple groups of Q 实 , Q 放 values are obtained, denoted as Q 实1 , Q 放1 , Q 实2 , Q 放2 , Q 实3 , Q 放3 , ……, Q 实i , Q 放i , and the number of values taken is at least 3 groups; according to the measured Q 实1 , Q 放1 , Q 实2 , Q 放2 , Q 实3 , Q 放3 , ……, Q 实i , Q 放i , based on the data discrete distribution situation, the relationship formula between Q 实 and Q 放 is obtained;

[0029] The relationship formula between Q 实 and Q 放 is a linear term formula Q 放 = A·Q 实 + B, or a quadratic term formula Q 放 = A·Q 实 2 + B·Q 实 + C, or a linear formula that can reflect the relationship trend between Q 实 and Q 放 .

[0030] S2. Measure the flow rate of the water distributor. The injection volume q 实 of the water distributor is a known number according to the geological plan. According to Q 实 , Q 放The relational formula is used to calculate the value of q 放 value;

[0031] Lower the measurement and adjustment instrument. The deployment manipulator of the instrument locates the water distributor of the water injection layer and adjusts the flow rate. The measurement and adjustment section of the instrument is in the inner cavity of the flow rate amplification device corresponding to the water distributor. At this time, the flow rate data measured by the measurement and adjustment instrument is the amplified flow rate;

[0032] Adjust the injection volume on the ground so that the flow rate data measured by the measurement and adjustment instrument is q 放 , then the actual injection volume of the water distributor is q 实 , meeting the injection allocation requirements of the geological plan and realizing the flow rate allocation of the water distributor.

[0033] In an embodiment of the present invention, step S2 is adjusted

[0034] S2. Measure and adjust the flow rate of the water distributor. The injection volume q 实 of the water distributor is a known number according to the geological plan. According to the relational formula of Q 实 , Q 放 , calculate the value of q 放 ;

[0035] Lower the measurement and adjustment instrument. The deployment manipulator of the instrument locates the water distributor of the water injection layer and adjusts the flow rate. The measurement and adjustment section of the instrument is in the flow rate amplification short section of the corresponding bridge-type flow rate amplification device. At this time, the flow rate data measured by the measurement and adjustment instrument is the amplified flow rate;

[0036] Adjust the injection volume on the ground so that the flow rate data measured by the measurement and adjustment instrument is q 放 , then the actual injection volume of the water distributor is q 实 , meeting the injection allocation requirements of the geological plan and realizing the flow rate allocation of the water distributor.

[0037] Use the difference method to obtain the actual flow rates of different water injection layers;

[0038] Based on the known injection volume q 1实 of the bottom water injection layer, according to the relational formula of Q 实 , Q 放 , calculate the value of q 1放 ; Lower the measurement and adjustment instrument to the bottom water distributor, and adjust the injection volume on the ground so that the measured value of the measurement and adjustment instrument is q 1放 , then the actual flow rate of the bottom water distributor injecting into the bottom water injection layer is q 1实 , realizing the flow rate allocation of the bottom water injection layer;

[0039] Similarly, the injection volume of the upper water injection layer is q 2实 , according to the relational formula of Q 实 , Q 放 , calculate the value of q 2放Value; Lower the measurement and adjustment instrument to the upper-layer water distributor, and adjust the injection volume on the ground so that the measured value of the measurement and adjustment instrument is q 1放 +q 2放 , then the flow rate through the upper water distributor is q 1实 +q 2实 , through the difference method, it can be known that the flow rate injected into the upper-layer water injection layer through the upper-layer water distributor is q 1实 ;

[0040] Similarly, the injection volume allocation of the upper n-layer water injection layers is q n实 , according to the relational formula of Q 实 , Q 放 , calculate the q n放 value; Lower the measurement and adjustment instrument to the upper n-layer water distributor, and adjust the injection volume on the ground so that the measured value of the measurement and adjustment instrument is q 1放 +q 2放 +……+q n放 , then the flow rate through the upper water distributor is q 1实 +q 2实 +……+q n实 , through the difference method, it can be known that the flow rate injected into the upper n-layer water injection layer through the upper n-layer water distributor is q n实 .

[0041] The present invention has the following beneficial effects compared with the prior art:

[0042] 1. The parameters of the measurement and adjustment instrument itself are not changed in this invention patent. By magnifying the flow rate in a certain area of the pipe string, the flow rate range that can be accurately measured by the measurement and adjustment instrument is achieved, and the flow rate measurement range is expanded.

[0043] 2. By designing a bridge-type flow rate amplification device in this invention and enclosing the water distributor in it, single-layer flow rate measurement is realized, with good versatility. There is no need to redesign or replace the existing water distributor, which can save design time and capital investment.

[0044] 3. The method of this invention is applicable to all water distributors. Through the layered water injection pipe string and the measurement and adjustment method, the layered measurement and adjustment of low-injection volume water injection wells are realized. Description of the Drawings

[0045] Figure 1 is a schematic structural diagram of a layered water injection pipe string of the present invention;

[0046] Figure 2 is a schematic structural diagram of a flow rate amplification device of a layered water injection pipe string of the present invention;

[0047] Figure 3 is a schematic structural diagram of a bridge-type flow rate amplification device of a layered water injection pipe string of the present invention;

[0048] In the figure: 1-1, tubing string flow rate amplification device; 1-2, flow rate amplification device for the first water distributor; 1-3, flow rate amplification device for the second water distributor; 301, upper joint; 302, outer sleeve; 303, upper flow splitting hole; 304, flow rate amplification short section; 305, upper joint of the water distributor; 306, central tube of the water distributor; 307, anti-backflow spring of the water distributor; 308, water injection hole of the water distributor; 309, bridge-type flow splitting hole; 3010, piston of the water distributor; 3011, fixed core of the water distributor; 3012, rotating core of the water distributor; 3013, compression spring of the water distributor; 3014, lower joint of the water distributor; 3015, lower joint; 3016, lower flow splitting hole; 3017, adjusting ring. Detailed implementation manners

[0049] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0050] Embodiment 1:

[0051] Please refer to Figures 1 to 2 , a layered water injection tubing string and its testing and adjustment method provided by the present invention include a tubing string, a water distributor, and a packer; at least two water distributors are arranged on the tubing string, a packer is arranged between every two water distributors, each water distributor corresponds to a water injection layer, and a washing well valve is arranged at the bottom of the tubing string;

[0052] It further includes a flow rate amplification device, and the flow rate amplification device includes a flow rate amplification device for the water distributor and a tubing string flow rate amplification device 1-1. A flow rate amplification device for the water distributor is arranged above each water distributor, and the tubing string flow rate amplification device 1-1 is arranged above the flow rate amplification device for the water distributor at the topmost layer. All the flow rate amplification devices have the same structure, and the sizes can be different according to actual requirements.

[0053] The packer realizes layered sealing, the water distributor realizes layered water injection, and the washing well valve 5 realizes reverse washing of the well.

[0054] The flow rate amplification device at the uppermost part of the tubing string is used to amplify the total well flow rate, and the remaining flow rate amplification devices of the tubing string are used to amplify the single-layer flow rate.

[0055] The structures of the flow rate amplification device and the tubing string flow rate amplification device 1-1 are as Figure 2 shown, and include a coupling 101 and a thick-walled short section 102; the coupling 101 and the thick-walled short section 102 are connected by threads, and the inner through diameter of the thick-walled short section 102 is smaller than the inner through diameter of the tubing string.

[0056] Flow test method:

[0057] S1. Measure the total well flow rate: Adjust the wellhead flow rate through the injection pump and wellhead gate, and require it to be greater than the lower limit of the flow rate that the measurement and adjustment instrument can accurately measure and adjust;

[0058] Lower the measurement and adjustment instrument above the flow rate amplification device of the pipe string to measure the total well flow rate value Q 实 , and continue to lower the measurement and adjustment instrument into the inner cavity of the flow rate amplification device at the top of the pipe string to measure the total well amplified flow rate value Q 放 ;

[0059] By changing the injection flow rate, obtain multiple groups of Q 实 、Q 放 values, denoted as Q 实1 、Q 放1 ,Q 实2 、Q 放2 ,Q 实3 、Q 放3 ,……,Q 实i 、Q 放i , and the number of values taken is at least 3 groups;

[0060] According to the discrete distribution of the measured Q 实1 、Q 放1 ,Q 实2 、Q 放2 ,Q 实3 、Q 放3 ,……,Q 实i 、Q 放i data, obtain the relationship formula between Q 实 and Q 放 , that is, the error correction formula of the measurement and adjustment instrument;

[0061] The relationship formula between Q 实 and Q 放 is a linear term formula Q 放 =A·Q 实 +B, or a quadratic term formula Q 放 =A·Q 实 2 +B·Q 实 +C, or a linear formula that can reflect the relationship trend between Q 实 and Q 放 ;

[0062] S2. Measure the flow rate of the water distributor. The injection volume q 实 of the water distributor is a known number according to the geological plan. According to the relationship formula between Q 实 、Q 放 , calculate the q 放 value;

[0063] Lower the survey and adjustment instrument. The deployment manipulator of the instrument locates the water distributor of the water injection layer and adjusts the flow rate. The survey and adjustment section of the instrument is inside the flow rate amplification device cavity of the corresponding water distributor. At this time, the flow rate data measured by the survey and adjustment instrument is the amplified flow rate;

[0064] Adjust the injection volume on the ground so that the flow rate data measured by the survey and adjustment instrument is q 放 , then the actual injection volume of the water distributor is q 实 , meeting the injection allocation requirements of the geological plan and realizing the flow rate allocation of the water distributor.

[0065] Take two water distributors as an example for explanation. The tubing is sequentially provided with a string flow rate amplification device 1-1, a first water distributor flow rate amplification device 1-2, a first water distributor 3-1, a packer 4, a second water distributor flow rate amplification device 1-3, a second water distributor 3-2, and a backwashing well valve 5 from top to bottom;

[0066] According to the known injection volume q 2实 of the second water injection layer, calculate the value of q 2实 according to the relational formula of Q 2放 ; Lower the survey and adjustment instrument to the second water distributor 3-2, and adjust the injection volume on the ground so that the measured value of the survey and adjustment instrument is q 2放 . Then the actual flow rate injected into the second water injection layer by the lower water distributor is q 2放 , realizing the flow rate allocation of the second water injection layer; 2实

[0067] Similarly, the injection volume of the first water injection layer is q 1实 . According to the relational formula of Q 1实 and Q 1放 , calculate the value of q 1放 ; Lower the survey and adjustment instrument to the first water distributor 3-1, and adjust the injection volume on the ground so that the measured value of the survey and adjustment instrument is q 1放 +q 2放 . Then the flow rate flowing through the upper water distributor is q 1实 +q 2实 . Through the difference method, it can be known that the flow rate injected into the first water injection layer through the upper water distributor is q 1实 .

[0068] In theory, the actual flow rate and the amplified measurement flow rate are equal. However, the measurement instrument will have errors at low flow rates. This invention patent obtains the actual flow rate and the amplified measurement flow rate under the same conditions by measuring in the downhole tubing string, establishes the relational formula between the actual flow rate and the amplified measurement flow rate, realizes flow rate measurement under the condition of flow rate amplification, and calculates the actual flow rate to eliminate the errors of the measurement instrument.

[0069] Embodiment 2:

[0070] On the basis of Embodiment 1, combined with Figure 3 ​, the water distributor is a bridge-type split-flow water distributor. When the flow rate can be measured layer by layer, the flow velocity amplification device of the water distributor is designed as a bridge-type flow velocity amplification device. The bridge-type flow velocity amplification device includes an upper joint 301, an outer sleeve 302, an upper split hole 303, a flow velocity amplification short section 304, a bridge-type split hole 309, a lower joint 3015, a lower split hole 3016, and an adjusting ring 3017;

[0071] The water distributor includes a water distributor upper joint 305, a water distributor central pipe 306, a water distributor anti-backflow spring 307, a water distributor injection hole 308, a water distributor piston 3010, a water distributor fixed core 3011, a water distributor rotating core 3012, a water distributor compression spring 3013, and a water distributor lower joint 3014. The water distributor is not the innovative content of the present invention and is only used to facilitate the explanation of the principle.

[0072] The outer sleeve 302 is connected to the outer wall of the upper joint 301. The flow velocity amplification short section 304 is connected to the inner wall of the upper joint 301. The flow velocity amplification short section 304 is threadedly connected to the water distributor upper joint 305. The inner diameter of the flow velocity amplification short section 304 is smaller than the inner diameter of the oil pipe, which can increase the fluid flow velocity. The flow velocity amplification short section 304 is provided with an upper split hole 303; The middle part of the outer sleeve 302 adopts a bridge-type split-flow structure and is provided with a bridge-type split hole 309 to achieve independence and non-interference with the water distributor injection hole 308.

[0073] The lower joint 3015 is threadedly connected to the water distributor lower joint 3014. The lower joint 3015 is provided with a lower split hole 3016. The outer surface of the lower joint 3015 is sleeved with an outer sleeve 302 and an adjusting ring 3017; The adjusting ring 3017 is threadedly connected to the lower joint 3015, and the adjusting ring 3017 is in contact with and pressed against the lower end surface of the outer sleeve 302.

[0074] By designing a bridge-type flow velocity amplification device and sleeving the water distributor inside, single-layer flow measurement is realized, with good versatility. There is no need to redesign or replace the existing water distributor, which can save design time and capital investment.

[0075] Correspondingly, the flow rate test method is adjusted:

[0076] S2. Measure the flow rate of the water distributor, and the injection volume q of the water distributor 实 Based on the geological plan as a known number, according to Q 实 、Q 放 The relationship formula is used to calculate the q 放 value;

[0077] Lower the measuring and adjusting instrument. The adjusting manipulator of the instrument positions the water distributor of the injection layer and adjusts the flow rate. The measuring and adjusting section of the instrument is in the flow rate amplification short section 4 of the corresponding bridge-type flow velocity amplification device. At this time, the flow rate data measured by the measuring and adjusting instrument is the amplified flow rate;

[0078] Adjust the injection volume on the ground so that the flow rate data measured by the flow rate measuring and adjusting instrument is q 放 , then the actual injection volume of the water distributor is q 实 , meeting the injection requirement of the geological plan and realizing the flow rate allocation of the water distributor.

[0079] Two water distributors are set for explanation. From top to bottom in the tubing string, a tubing string flow rate amplification device 1-1, a first water distributor flow rate amplification device 1-2, a first water distributor 3-1, a packer 4, a second water distributor flow rate amplification device 1-3, a second water distributor 3-2, and a backwashing well valve 5 are set in sequence;

[0080] Based on the known injection volume q of the second injection layer 2实 , according to the relational formula of Q 2实 , Q 2放 , calculate the value of q 2放 ; Lower the flow rate measuring and adjusting instrument to the second water distributor 3-2, and adjust the injection volume on the ground so that the measured value of the flow rate measuring and adjusting instrument is q 2放 , then the actual flow rate of the lower water distributor injecting into the second injection layer is q 2实 , realizing the flow rate allocation of the second injection layer;

[0081] Similarly, the injection volume of the first injection layer is q 1实 , according to the relational formula of Q 1实 , Q 1放 , calculate the value of q 1放 ; Lower the flow rate measuring and adjusting instrument to the first water distributor 3-1, and adjust the injection volume on the ground so that the measured value of the flow rate measuring and adjusting instrument is q 1放 + q 2放 , then the flow rate flowing through the upper water distributor is q 1实 + q 2实 . Through the difference method, it can be known that the flow rate of the upper water distributor injecting into the first injection layer is q 1实 , and another part of the injected water continues to flow downward through the upper shunt hole 303, the inner cavity of the outer sleeve 302, the bridge shunt hole 309, and the lower shunt hole 3016, and is injected into the second injection layer through the second water distributor 3-2.

[0082] In this application, all components that are not elaborated and the connection methods of each component in this application belong to the well-known technologies in the technical field. They can be directly applied and will not be elaborated further.

[0083] In the present invention, the term "a plurality of" refers to two or more, unless otherwise clearly defined. Terms such as "installed", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "coupled" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0084] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention.

[0085] In the description of this specification, the descriptions of terms such as "one embodiment", "some embodiments", "specific embodiments", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0086] The foregoing is only the preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A layered water injection string, comprising an oil pipe, a water distributor, and a packer; at least two water distributors are arranged on the oil pipe, a packer is arranged between every two water distributors, and each water distributor corresponds to a water injection layer. It is characterized in that it further comprises a flow rate amplification device, and the flow rate amplification device comprises a water distributor flow rate amplification device and a string flow rate amplification device; A water distributor flow rate amplification device is arranged above each water distributor, and the string flow rate amplification device is arranged above the uppermost water distributor flow rate amplification device.

2. The layered water injection string according to claim 1, It is characterized in that a washing well valve is arranged at the bottom of the oil pipe.

3. The layered water injection string according to claim 1, It is characterized in that the flow rate amplification device and the string flow rate amplification device have the same structure, and both comprise a coupling and a thick-walled short section; The coupling and the thick-walled short section are connected by threads, and the inner diameter of the thick-walled short section is smaller than the inner diameter of the oil pipe.

4. The layered water injection string according to claim 1, It is characterized in that the water distributor flow rate amplification device is designed as a bridge-type flow rate amplification device; The bridge-type flow rate amplification device comprises an upper joint, an outer sleeve, a flow rate amplification short section, a lower joint, and an adjusting ring; The flow rate amplification short section is connected to the inner wall of the upper joint, and the outer sleeve is connected to the outer wall of the upper joint; the flow rate amplification short section is connected to the upper joint of the water distributor, the inner diameter of the flow rate amplification short section is smaller than the inner diameter of the oil pipe, and the flow rate amplification short section is provided with upper diversion holes; The middle part of the outer sleeve adopts a bridge-type diversion structure; The lower joint is connected to the lower joint of the water distributor, the lower joint is provided with lower diversion holes, the adjusting ring is connected to the outer wall of the lower joint, and the adjusting ring is in contact with and presses against the lower end face of the outer sleeve.

5. The layered water injection string according to claim 4, It is characterized in that the middle part of the outer sleeve is provided with bridge-type diversion holes, and the bridge-type diversion holes are independent of and do not interfere with the water injection holes of the water distributor.

6. The layered water injection string according to claim 1, It is characterized in that the number of water distributors is two, which are divided into a first water distributor and a second water distributor; a first water distributor flow rate amplification device is arranged on the first water distributor, and a second water distributor flow rate amplification device is arranged on the second water distributor.

7. A test and adjustment method for a layered water injection string, It is characterized in that it comprises the following steps: S1. Measure the total well flow rate, and adjust the wellhead flow rate through an injection pump and a wellhead gate; Lower the survey and adjustment instrument above the string flow rate amplification device to measure the total well flow rate value Q 实 , continue to lower the survey and adjustment instrument into the inner cavity of the flow rate amplification device at the top of the string to measure the total well amplified flow rate value Q 放 ; By changing the injection flow rate, multiple sets of Q 实 and Q 放 values are obtained, denoted as Q 实1 and Q 放1 , Q 实2 and Q 放2 , Q 实3 and Q 放3 , ……, Q 实i and Q 放i , and the number of values taken is at least 3 sets; According to the measured Q 实1 , Q 放1 , Q 实2 , Q 放2 , Q 实3 , Q 放3 , ……, Q 实i , Q 放i Based on the discrete distribution of the data, the relational formula between Q 实 and Q 放 is obtained; S2. Measure the flow rate of the water distributor, and the injection volume q of the water distributor 实 According to the geological plan, which is a known number, based on Q 实 and Q 放 Using the relational formula, calculate the value of q 放 value; Lower a test and adjustment instrument, the adjustment manipulator of the instrument locates the water distributor of the water injection layer and adjusts the flow rate, and the test and adjustment section of the instrument is in the inner cavity of the corresponding water distributor flow rate amplification device. At this time, the flow rate data measured by the test and adjustment instrument is the amplified flow rate; Adjust the injection volume on the ground so that the flow rate data measured by the flow measurement and adjustment instrument is q 放 , then the actual injection volume of the water distributor is q 实 , meeting the injection allocation requirements of the geological plan and realizing the flow rate allocation of the water distributor.

8. The test and adjustment method for a layered water injection string according to claim 7, It is characterized in that make an adjustment to step S2, S2. Measure the flow rate of the water distributor, and the injection volume q of the water distributor 实 According to the geological plan as a known number, based on Q 实 , Q 放 The relationship formula is used to calculate the value of q 放 value; Lower a test and adjustment instrument, the adjustment manipulator of the instrument locates the water distributor of the water injection layer and adjusts the flow rate, and the test and adjustment section of the instrument is in the flow rate amplification short section of the corresponding bridge-type flow rate amplification device. At this time, the flow rate data measured by the test and adjustment instrument is the amplified flow rate; Adjust the injection volume on the ground so that the flow rate data measured by the flow measurement and adjustment instrument is q 放 , then the actual injection volume of the water distributor is q 实 , meeting the injection allocation requirements of the geological plan and realizing the flow rate allocation of the water distributor.

9. The test and adjustment method for a layered water injection string according to claim 7 or 8, It is characterized in that The actual flow rates of different water injection layers are obtained by using the difference method; According to the known injection rate q of the bottom water injection layer 1实 , based on the relational formula of Q 实 , Q 放 , calculate the value of q 1放 ; Lower the measurement and adjustment instrument to the bottom water distributor, and adjust the injection rate on the ground so that the measured value of the measurement and adjustment instrument is q 1放 , then the actual flow rate injected by the bottom water distributor into the bottom water injection layer is q 1实 , realizing the flow rate allocation of the bottom water injection layer; Similarly, the injection allocation volume of the upper water injection layer is q 2实 , according to the relational formula of Q 实 , Q 放 , the value of q 2放 is calculated; lower the flow measurement and adjustment instrument to the upper water distributor, and adjust the injection volume on the ground so that the measured value of the flow measurement and adjustment instrument is q 1放 +q 2放 , then the flow rate through the upper water distributor is q 1实 +q 2实 . It can be known through the difference method that the flow rate injected into the upper water injection layer through the upper water distributor is q 1实 ; Similarly, the injection allocation rate for the upper n water injection layers is q n实 , according to the relational formula of Q 实 , Q 放 , the value of q n放 is calculated; Lower the measurement and adjustment instrument to the upper n layer water distributors, and adjust the injection volume on the ground so that the measurement value of the measurement and adjustment instrument is q 1放 + q 2放 + …… + q n放 , then the flow rate through the upper water distributors is q 1实 + q 2实 + …… + q n实 . It can be known through the difference method that the flow rate injected into the upper n water injection layers through the upper n layer water distributors is q n实 .

10. A test and adjustment method for a layered water injection pipe string according to claim 7, characterized in that Q 实 and Q 放 The relational formula for is a linear term formula Q 放 = A·Q 实 + B, or a quadratic term formula Q 放 = A·Q 实 2 + B·Q 实 + C, or a linear formula that can reflect the relational trend of Q 实 and Q 放 and the relational trend of Q

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