Intelligent injection tubular column with built-in cable, application method of intelligent injection tubular column and intelligent water injection system

Abstract

The invention belongs to the field of cable-controlled intelligent water injection, and discloses an intelligent injection tubular column with a built-in cable. The tubular column comprises a tubular column body, a water distribution mechanism, a waterproof packer, a cable, a wireless communication mechanism and a battery. The string body includes an outer sleeve and a central tube forming an annulus. The water distribution mechanism is arranged in the annulus and controls the water injection flow. The cable is arranged in the central pipe and extends to pass through an axial area corresponding to the water distribution mechanism. The wireless communication mechanism comprises a signal sending device and a signal receiving device which communicate through wireless signals, the signal sending device is arranged in the annulus and communicates with the water distribution mechanism, and the signal receiving device is connected to the cable to communicate with the cable. The battery supplies power to the water distribution mechanism and the signal sending device. Information transmission between the underground cable-controlled intelligent water distributor and the ground is provided by utilizing a small-range wireless transmission technology, and the adaptability of the working condition and the success rate under the complex working condition are improved by tripping in the cable from a tubular column.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of cable-controlled intelligent water injection, in particular to an intelligent injection string with a built-in cable, an application method thereof and an intelligent water injection system. BACKGROUND

[0002] China is rich in oil resources, and oil, as an important energy source for the economic development of China, has far-reaching significance for the sustainable development of the country. In recent years, with the large-scale exploitation of oilfields, most of the oilfields have reached the high water cut stage, and the difficulty of their production has also increased, and the technical requirements for separate layer water injection technology have also become higher and higher. In order to maintain the reservoir pressure and prolong the production period of the oil well, the main method currently used is to inject water into the formation in order to supplement the void volume occupied by the extracted crude oil in the oil layer, so as to keep the oil layer pressure stable or rising, so as to achieve the purpose of high and stable production of oil wells and improving the ultimate recovery rate.

[0003] From the history of domestic oilfield development, the separate layer water injection technology can be roughly divided into four generations: the first generation of injection technology represented by concentric fixed type, the second generation of injection technology represented by bridge type eccentric, the third generation of injection technology represented by high-efficiency measurement and adjustment, and the fourth generation of injection technology represented by cable-controlled intelligent.

[0004] The cable-controlled intelligent water injection technology mainly consists of the following parts: intelligent water distributor, packer, cable, ground controller, oil pipe, wellhead, etc. Its working principle is as follows: the intelligent water distributor and the packer are connected through the oil pipe to form a water injection string; the ground controller sends control instructions to the intelligent water distributor of the target layer through the cable, and the intelligent water distributor can measure and feed back the related information such as the front mouth pressure, the back mouth pressure, the injection flow, the flow control valve opening degree, etc. to the ground controller after receiving the control instructions, and can also control the opening degree of the flow control valve in the intelligent water distributor. The cable-controlled intelligent water injection technology does not need to lower the testing instrument into the wellbore, and can obtain the downhole parameters on the ground, and can also adjust the downhole parameters according to the needs. The power required for the operation of the intelligent water distributor is usually transmitted by the ground through the cable.

[0005] With the increase of the service life of oil wells, due to the action of various factors such as geological reasons, biological reasons, chemical reactions and the like, many oil well casings are damaged to different degrees. Among them, the most common one is the deformation of the oil-water well casing. In the process of oilfield development, the most common and most widely used displacement method is water flooding. Water flooding has the characteristics of high sweep efficiency. Water flooding can not only greatly improve the recovery rate, but also can supplement the formation energy. Compared with other displacement methods, water flooding also has the characteristics of wide source of displacement and low cost. Therefore, water flooding technology is widely used in most oilfields. However, during the development of oilfields, the casings of injection wells will also be deformed or even damaged to different degrees, which not only seriously affects the working efficiency of the injection well, but also the selection of the injection well is strictly calculated and screened. Once the injection well cannot work normally, it will lead to the imbalance of the injection pressure of some blocks, and low-pressure blocks are easy to appear in the formation, which will affect the stable oil control and water control of the oilfield to different degrees. Affected by the casing deformation, the conventional water injection tool cannot be lowered below the casing deformation section, so the water well of this type can only use the unified injection method or the stop injection method, and there is no separate injection measure.

[0006] During the popularization of the cable-controlled intelligent injection string technology, it is found that the intelligent injection string cannot be implemented in 23% of the planned well times due to casing damage and diameter reduction, which affects the overall deployment, production management and effect analysis of the block. At the same time, there are a large number of intelligent injection string requirements for sidetracking wells in oilfields. Sidetracking wells have the characteristics of small diameter and large inclination. The existing cable-controlled process string needs to bundle a cable outside the string in order to power and communicate with the intelligent water distributor downhole. However, in the casing deformation well and the small-diameter well, the cable is easy to be broken, which can cause the failure of the string and signal loss. Moreover, the string has operation risk and cannot meet the process requirements.

[0007] Therefore, it is necessary to develop an intelligent injection process string for application in small-diameter well conditions such as casing deformation wells and sidetracking wells. SUMMARY

[0008] In view of the above problems, the present application provides an intelligent injection string with a built-in cable, an application method thereof and an intelligent water injection system comprising the intelligent injection string, so as to realize the popularization of intelligent injection technology in small-diameter well conditions such as casing deformation wells and sidetracking wells.

[0009] According to an aspect of the present application, an intelligent injection string with a built-in cable is provided, comprising: a string body, the string body comprising an outer sleeve and a central pipe with different diameters, an annulus being formed between the outer sleeve and the central pipe, a water injection channel being formed in the central pipe, and a water injection port being provided on the outer sleeve; a water distribution mechanism, the water distribution mechanism being arranged in the annulus of the string body, the water distribution mechanism being connected with the water injection channel and the water injection port and being capable of controlling the flow of water provided to the water injection port; A water isolation packer is arranged in the annulus of the tubular string body and separates the water distribution mechanism into set sections to form a water injection zone for a predetermined formation; A cable is arranged in the central pipe and extends through the axial region corresponding to the water distribution mechanism; A wireless communication mechanism includes a signal transmitting device and a signal receiving device which communicate via wireless signals, the signal transmitting device is arranged in the annulus and is in communication connection with the water distribution mechanism, and the signal receiving device is connected to the cable to communicate with the cable; A battery is arranged in the annulus and supplies power to the water distribution mechanism and the signal transmitting device.

[0010] According to one embodiment of the present application, the signal transmitting device and the signal receiving device of the wireless communication mechanism communicate by electromagnetic induction.

[0011] According to one embodiment of the present application, the working frequency of the electromagnetic induction is 3 kHz to 30 kHz.

[0012] According to one embodiment of the present application, the intelligent injection string further comprises a positioner for determining whether the signal receiving device enters the effective communication range of the signal transmitting device.

[0013] According to one embodiment of the present application, the positioner is a magnetic positioner.

[0014] According to one embodiment of the present application, the magnetic positioner comprises a Hall switch arranged near the signal transmitting device and a magnetic steel arranged near the signal receiving device.

[0015] According to one embodiment of the present application, the signal transmitting device has a sleep mode and a working mode, and when the Hall switch detects the magnetic steel, the signal transmitting device is switched from the sleep mode to the working mode.

[0016] According to one embodiment of the present application, the intelligent injection string further comprises a hydroelectric power generation device installed in the annulus, which is connected to the battery and charges the battery.

[0017] According to one embodiment of the present application, the hydroelectric power generation device is a turbine arranged in the flow passage of the water distribution mechanism.

[0018] According to one embodiment of the present application, the intelligent injection string comprises a plurality of water distribution mechanisms and a plurality of water isolation packers, and the plurality of water isolation packers separate the plurality of water distribution mechanisms from each other.

[0019] According to one embodiment of the present application, the number of the wireless communication mechanisms is consistent with the number of the water distribution mechanisms.

[0020] According to one embodiment of the present application, the water distribution mechanism comprises a housing, in which a flow meter, an actuator, a valve, a pressure sensor and a temperature sensor are arranged, and the flow meter, the actuator, the pressure sensor and the temperature sensor are in communication connection with the signal transmitting device.

[0021] According to one embodiment of the present application, the housing is provided with an inlet and an outlet, the inlet is in communication with the water injection channel of the central pipe, and the outlet is in communication with the water injection port of the outer sleeve.

[0022] According to one embodiment of the present application, the actuator can drive the valve to rotate to control the opening degree of the valve.

[0023] According to one embodiment of the present application, the pressure sensor comprises a pre-nozzle pressure gauge for measuring pre-nozzle pressure and a post-nozzle pressure gauge for measuring post-nozzle pressure.

[0024] According to one embodiment of the present application, the water distribution mechanism further comprises a controller, which is in communication connection with the flow meter, the actuator, the pressure sensor, the temperature sensor and the signal transmitting device.

[0025] According to one embodiment of the present application, the bottom end of the cable is further provided with a counterweight.

[0026] According to one embodiment of the present application, the intelligent injection string further comprises an upper joint and a lower joint, which are respectively installed at the top end and the bottom end of the string body.

[0027] According to another aspect of the present application, there is provided an intelligent water injection system, which comprises: the intelligent injection string with the built-in cable as described above; a surface controller, which is connected with the cable to realize communication with the signal receiving device.

[0028] According to still another aspect of the present application, there is provided an application method of the intelligent injection string with the built-in cable as described above, which comprises the following steps: pre-adjusting the water distribution mechanism, and then lowering the intelligent injection string into the casing to ensure that the water distribution mechanism is lowered to the predetermined layer position; connecting the signal receiving device of the wireless communication mechanism to the cable according to the designed distance and lowering the cable from the central pipe; after the signal receiving device is lowered to the predetermined depth, performing matching test with the corresponding signal transmitting device respectively; After the test, the pack-off is carried out, and the water distribution mechanism is controlled as required.

[0029] Compared with the prior art, the intelligent injection pipe string with the built-in cable and the intelligent water injection system have at least the following advantages: (1) The wireless signal transmission mode is adopted to replace the traditional mechanical wiring mode, the external cable does not need to be connected to the pipe string annulus, the complex modification of the pipe string structure is avoided, the construction difficulty is reduced, and the construction success rate is improved; (2) The cable is built in the center pipe of the pipe string, the pipe string construction is not affected by casing deformation, the cable can be protected, and cable damage caused by casing friction and scratching is avoided; (3) The battery is arranged in the pipe string annulus to supply power to each electronic element of the water distribution mechanism, and the dependence on the external ground connecting cable is eliminated; (4) Compared with the original technology, the construction difficulty is significantly reduced, the tool cost is reduced, the intelligent injection technology is popularized in small-diameter well conditions such as casing deformation wells and sidetracking wells, and has a wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0030] The accompanying drawings are included to provide a further understanding of the present disclosure and constitute a part of the specification, and are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation on the present disclosure. In the drawings: Figure 1 a diagram of the intelligent injection pipe string with the built-in cable according to an embodiment of the present application; Figure 2 a structural schematic view of the intelligent injection pipe string with the built-in cable according to an embodiment of the present application.

[0031] LIST OF REFERENCE NUMERALS 10, pipe string body; 11, upper joint; 12, lower joint; 13, outer sleeve; 14, center pipe; 20, water distribution mechanism; 21, hydroelectric power generation device; 22, battery; 30, water isolation packer; 40, cable; 50, wireless communication mechanism; 51, signal sending device; 52, signal receiving device; 60, counterweight. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application.

[0033] The terms "comprising" and "having," and any variations thereof, used in the specification and accompanying drawings of this invention are intended to cover non-exclusive inclusion; the terms "first," "second," etc., used in the specification, claims, or accompanying drawings of this invention are used to distinguish different objects, not to describe a particular order. "A plurality of" means two or more, unless otherwise explicitly specified.

[0034] In the description of this invention and the above-described drawings, when an element is referred to as "fixed to," "mounted to," "set on," or "connected to" another element, it can be located directly or indirectly on that other element. For example, when an element is referred to as "connected to" another element, it can be directly or indirectly connected to that other element.

[0035] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0036] Figure 1 A simplified diagram of a smart injection string with an integrated cable according to an embodiment of the present invention is shown. Figure 2 A schematic diagram of a smart injection string with an integrated cable according to an embodiment of the present invention is shown.

[0037] One object of the present invention is to provide a smart injection string with an internal cable, such as Figure 1 As shown, the intelligent injection string generally includes a string body 10, a water distribution mechanism 20, a water-sealing packer 30, a cable 40, a wireless communication mechanism 50, and a battery 22 (see reference). Figure 2 ).

[0038] The tubing body 10 forms a water injection channel and a sealed cavity. The water injection channel is used to inject water into the tubing from the outside, and the sealed cavity is used to install various electronic components and sensors. For example... Figure 2 As shown, the main body 10 of the tubing column may include an outer sleeve 13 and a central tube 14 of different diameters. An annular space is formed between the outer sleeve 13 and the central tube 14, and the two ends of the annular space are sealed with O-rings to form a ring-shaped sealed cavity. The two ends of the cavity are an upper connector 11 and a lower connector 12, respectively. Various electronic components and sensors are installed in this sealed cavity. The hollow area inside the central tube 14 forms a water injection channel, and the injected water mainly flows inside the central tube 14, thus not affecting the operation of the electrical components. A water inlet is provided on the central tube 14, and a water injection port is provided on the outer sleeve 13.

[0039] The water distribution mechanism 20 can control the amount of water injected into the formation according to external control commands while monitoring various parameters during water injection. The water distribution mechanism 20 is disposed within the annulus of the tubular string body 10. The water distribution mechanism 20 is capable of controlling the flow rate of water provided to the water injection ports of the outer sleeve 13. For example, in some embodiments, the water distribution mechanism 20 includes a housing having a flow meter, an actuator, a valve, a pressure sensor, and a temperature sensor disposed therein. The housing has an inlet port in communication with the water injection channel of the center pipe 14 and an outlet port in communication with the water injection ports of the outer sleeve 13. The actuator can be a DC motor, and the valve can include a rotating valve and a fixed valve, with the DC motor connected to and controlling the rotation of the rotating valve via a transmission shaft. The rotating valve and the fixed valve have fan-shaped or circular flow passages opened on their end faces, which are sealed together to form a closed adjustable water nozzle. The fixed valve is fixedly connected to the housing of the water distribution mechanism 20. When the flow passages on the rotating valve and the fixed valve are connected, the inlet port can be connected to the outlet port via the flow passages. When the fan-shaped or circular flow passages on the rotating valve are rotated to completely coincide with the non-passage face on the fixed valve, the water nozzle is closed, and the inlet port and the outlet port are not connected, and the water injection channel is closed. Therefore, the area of overlap of the flow passages of the rotating valve and the fixed valve can be changed by operating the rotating valve to rotate, thereby changing the water injection flow rate.

[0040] In some embodiments, the water distribution mechanism 20 further includes a controller in communication with the flow meter, the actuator, the pressure sensor, and the temperature sensor, and receives information collected by these devices or controls the operation of these devices.

[0041] In some embodiments, the pressure sensor can include a pre-nozzle pressure gauge for measuring the pre-nozzle pressure and a post-nozzle pressure gauge for measuring the post-nozzle pressure. The pre-nozzle pressure corresponds to the pressure inside the tubing corresponding to the layer section, and the post-nozzle pressure corresponds to the pressure inside the casing corresponding to the layer section. Since the casing annulus is in communication with the formation perforations, the post-nozzle pressure is also equal to the formation pressure. By comparing the pre-nozzle and post-nozzle pressure values, the pressure loss caused by the water nozzle can be calculated. This pressure loss is crucial for evaluating the efficiency and performance of the water nozzle. Understanding the difference between the pre-nozzle and post-nozzle pressures helps optimize flow allocation by controlling the degree of opening of the water nozzle, thereby adjusting the flow rate and reducing unnecessary pressure loss. At the same time, it can also timely detect abnormal conditions in the system, such as blockage, leakage, etc. This is crucial for ensuring the safe operation of the system. By timely detecting and addressing these issues, potential failures and accidents can be avoided.

[0042] In some embodiments, the water distribution mechanism 20 is further provided with a hydroelectric power generation device 21 and a battery 22. The hydroelectric power generation device 21 is connected to the battery 22 and charges the battery 22. Specifically, the hydroelectric power generation device 21 can be a turbine generator installed in the water flow passage of the water distribution mechanism 20 and generates electricity under the driving of the water flow. The hydroelectric power generation device 21 is connected to the battery 22 via a wire to supply power to the battery 22. The battery 22 can be a battery pack including a plurality of battery cells. By providing the hydroelectric power generation device 21 and the battery 22, the electrical components in the water distribution mechanism 20 can be powered without relying on external cables. Moreover, compared with the water distribution mechanism without the power generation device, the water distribution mechanism 20 of the present application can autonomously generate electricity, so that it can transmit data to the ground at a higher frequency.

[0043] The water isolation packer 30 is used to separate different oil layers and water layers. The water isolation packer 30 is also arranged in the annulus of the pipe string body 10. The water isolation packer 30 separates the water distribution mechanism 20 into a set of sections to form a water injection area for injecting water into a predetermined formation. The water isolation packer 30 mainly has three working processes of setting, testing and unsetting. The commonly used types of water isolation packers for water injection mainly include expansion packers and compression packers. The expansion packer is widely used in water injection operations and mainly consists of an upper joint, an upper rubber seat, a rubber sleeve, a central tube, a lower rubber seat, a lower joint and other components. The working principle is that the internal and external pressure difference is formed by pressurizing in the tubing, the high-pressure liquid enters the rubber sleeve through the filter screen cover, the lower joint hole and the central tube water tank, so that the rubber sleeve is forced to expand, the setting process is realized, and the annular space outside the tubing is closed. The compression packer generally consists of an end connection mechanism, a setting mechanism, a sealing unit, a shoulder protection mechanism, an unsetting mechanism and a locking mechanism. The working principle is that when the liquid pressure in the piston cavity increases to the starting pressure of the packer through the central tube, the anti-midway setting shear pin on the packer is sheared off, the packer starts to set, and as the piston moves towards the rubber sleeve end, the rubber sleeve is continuously compressed. When the rubber sleeve is compressed to the maximum compression distance, the piston no longer rises, and at this time the locking mechanism in the packer locks the compressed rubber sleeve, completing the setting process of the packer.

[0044] The cable 40 is used to provide power and data transmission channels for the signal receiving device 52 of the wireless communication mechanism 50. The cable 40 is arranged in the central tube 14 and extends through the axial area corresponding to each water distribution mechanism 20. Optionally, in some embodiments, in order to keep the cable 40 in a vertical state when it is lowered into the central tube 14, a counterweight 60 is connected to the bottom end of the cable 40. By embedding the cable 40 in the pipe string central tube 14, the pipe string construction is not affected by casing deformation, the cable can be protected, and damage to the cable caused by friction and scratching of the casing can be avoided.

[0045] The wireless communication mechanism 50 is used to realize the communication between the water distribution mechanism 20 and the ground equipment. As shown in FIG. 1, the wireless communication mechanism 50 is arranged in the central tube 14 and extends through the axial area corresponding to each water distribution mechanism 20.Figure 2 As shown, the wireless communication mechanism 50 can include a signal transmitting device 51 and a signal receiving device 52 that communicate via wireless signals. The signal transmitting device 51 is disposed in the annulus of the pipe column body 10 and is proximate to the water distribution mechanism 20. The flow meter, actuator, pressure sensor, and temperature sensor of the water distribution mechanism 20 are communicatively connected to the signal transmitting device 51, for example, by a cable. Alternatively, the signal transmitting device 51 can be communicatively connected (e.g., by a wired connection) to the controller of the water distribution mechanism 20 to receive data collected by the various sensors of the water distribution mechanism 20 or to provide control signals to the controller to adjust the valve opening. The signal receiving device 52 is connected to the cable 40 to communicate with and be powered by the cable. The signal transmitting device 51 and the signal receiving device 52 use one-to-one, short-range wireless transmission to avoid interference between different groups of signal transmitting devices 51 and signal receiving devices 52.

[0046] For example, in some embodiments, the signal transmitting device 51 and the signal receiving device 52 communicate using electromagnetic induction. Wireless communication using electromagnetic waves is that when an alternating signal passes through a conductor coil, an alternating electric field is generated in the conductor coil, thereby generating an alternating magnetic field. According to the theory of electromagnetic fields, as long as there is an alternating electric field, an alternating magnetic field will be generated, and the electric field and the magnetic field will alternately generate and propagate into space, forming an electromagnetic field. An induced electromotive force is generated in the conductor, and a closed loop will generate an induced current, thus forming the required carrier signal for wireless transmission. Using this principle, the data to be transmitted is modulated onto such a carrier, and the modulated signal is propagated out, and the required data is demodulated at the receiving end. In this way, wireless data transmission is achieved. If it is low-frequency induction communication, the data to be transmitted is modulated by a low-frequency carrier, amplified, and power amplified, and a certain alternating current is generated at the transmitter. The alternating current generates an alternating magnetic field, and the alternating magnetic field generates an electric field, thereby generating an induced electromotive force in the receiver. After filtering, demodulation, decoding, and other signal processing, the transmitted information can be accurately received at the receiving end, and the data transmission process is completed.

[0047] According to the different working frequency of wireless communication, wireless communication can be divided into long wave communication, medium wave communication, short wave communication, microwave communication. According to the frequency spectrum of radio signal, the frequency spectrum can be divided into very low frequency VLF, low frequency LF, medium frequency MF, high frequency HF, very high frequency VHF, ultra high frequency UHF, super high frequency SHF, extremely high frequency EHF, infrared, visible light, ultraviolet. In the harsh environment of high pressure and high temperature in the well, when the high frequency signal is accessed, due to its large change rate, it will lead to uneven distribution of signal, and the charge will concentrate on the surface of the conductor, which will produce the maximum induced electromotive force. According to the principle of electromagnetic induction, the induced current will be generated in the closed loop nearby, and the direction of the induced current is opposite to that of the high frequency signal current, which will form the opposite effect with the original current, reduce the direction of the original current, and lead to the current limited to the surface of the conductor. In this way, because the signal transmission is greatly attenuated, the skin effect makes the efficiency of the conductor in transmitting high frequency (microwave) signal very low, and with the increase of frequency, the skin effect is more obvious, and the signal attenuation is faster.

[0048] Due to the harsh environment of high temperature, high pressure and limited space in the well, the adjustable water nozzle placed in the well can only be powered by battery or weakly charged in the well. At the same time, considering the influence of water conductivity and mineralization on signal, the high frequency signal is greatly attenuated in the well, so the mode of wireless communication in the well is locked in the low frequency communication using electromagnetic induction. The working frequency of electromagnetic induction wireless communication technology is in the very low frequency band (VLF about 3kHz~30kHz), which uses low frequency electromagnetic wave as carrier to transmit data, and is suitable for low frequency communication in the well.

[0049] The signal sending device 51 is provided with a transmitting coil T, and the signal receiving device 52 is provided with a receiving coil R. The transmitting coil T and the receiving coil R are separated by a certain distance. If the alternating current i is supplied to the transmitting coil T, the alternating current will generate an alternating electromagnetic field around the receiving coil R, which is called the primary field. The induced electromotive force E is generated in the receiving coil R, and the induced current I is generated in the closed loop. The electromagnetic coupling of the two coils realizes the communication and wireless signal transmission of the two. It should be noted that although "signal sending device" and "signal receiving device" are used here to describe the two components, in fact, the signal sending device 51 and the signal receiving device 52 can communicate bidirectionally, that is, the signal sending device 51 can also be used for signal receiving, and the signal receiving device 52 can also be used for signal transmission. Therefore, the functions of the two are to realize the wireless communication of the two, rather than to limit them to only one-way communication.

[0050] In some embodiments, the intelligent injection string includes a plurality of water distribution mechanisms 20 and a plurality of water isolation packers 30 that separate the plurality of water distribution mechanisms 20 from each other. With the separation by the packers 30 and the precise control of the water distribution mechanisms 20, uniform displacement can be achieved, the recovery of the oilfield can be improved, and the intelligent injection string can be suitable for different geological conditions and well depths and can be flexibly adjusted to meet various injection requirements.

[0051] In some embodiments, the intelligent injection string further includes a locator for determining whether the signal receiving device 52 enters the effective communication range of the signal transmitting device 51. The locator can specifically be a magnetic locator, which can include a Hall switch arranged near the signal transmitting device 51 and a magnetic steel arranged near the signal receiving device 52. The magnetic steel can be a permanent magnet, which has stable magnetic field characteristics. When the magnetic steel moves close to the Hall switch, the Hall element will generate a Hall effect, i.e., a potential difference, which will trigger a change in the internal circuit state of the Hall switch. By measuring the change in the electrical signal output by the Hall switch, the position of the magnetic steel relative to the Hall switch can be determined. For example, when the magnetic steel moves close to the Hall switch, the Hall switch will output a signal indicating that the magnetic steel has reached a certain position. Further, the signal transmitting device 51 can have a sleep mode and a working mode. When the Hall switch detects the magnetic steel, the signal transmitting device 51 is switched from the sleep mode to the working mode, so that wireless communication is established between the signal transmitting device 51 and the signal receiving device 52. By setting the magnetic locator, on the one hand, the position of the signal receiving device 52 relative to the signal transmitting device 51 can be determined, and on the other hand, the signal transmitting device 51 can be woken up, thereby reducing energy consumption.

[0052] When the intelligent injection string includes a plurality of water distribution mechanisms 20 spaced apart, a corresponding wireless communication mechanism 50 needs to be provided for each water distribution mechanism 20. The signal receiving devices 52 on the cable 40 are arranged according to the installation spacing of the plurality of water distribution mechanisms 20 in the string. The Hall switch can be provided for the uppermost signal transmitting device 51, and the magnetic steel can be provided for the uppermost signal receiving device 52. Since the distance between the water distribution mechanisms 20 and the distance between the signal receiving devices 52 are corresponding, as long as the last signal receiving device 52 lowered into the string is aligned with the position of the uppermost signal transmitting device 51, and the cable 40 is in a vertical state, the other signal receiving devices 52 are also aligned with the signal transmitting devices 51 at the same time.

[0053] Another object of the present application is to provide an intelligent injection system comprising the intelligent injection string with built-in cable and the ground controller as described above. The ground controller is connected with the cable 40 to realize communication with the signal receiving device 52. In use, the sensors in the distribution mechanism 20 transmit the collected pressure information, temperature information and flow information to the controller of the distribution mechanism 20, which then transmits the information to the signal receiving device 52 via the signal sending device 51, and the signal receiving device 52 transmits the information to the ground controller via the cable 40. The ground controller generates control instructions for adjusting the flow based on the information collected by the sensors, and transmits the control instructions to the signal receiving device 52 via the cable 40. The signal receiving device 52 then transmits the control instructions to the signal sending device 51 through wireless communication, and the signal sending device 51 transmits the control instructions to the controller of the distribution mechanism 20. The controller of the distribution mechanism 20 controls the operation of the linear motor according to the control instructions to change the flow area of the water nozzle, thereby realizing control of the injection volume.

[0054] Still another object of the present application is to provide a method for using the intelligent injection string with built-in cable as described above, which comprises the following steps: The distribution mechanism 20 is pre-adjusted to ensure that each electronic device on the circuit board can work normally after the circuit board is powered on, and the motor control circuit works normally. Then the intelligent injection string is lowered into the casing to ensure that the distribution mechanism 20 is lowered to the predetermined layer position. The lowering depth and position need to be accurately calculated to ensure that the distribution mechanism 20 is lowered to the predetermined layer position and the data accuracy is ensured. Then the signal receiving device 52 of the wireless communication mechanism 50 is connected to the cable 40 at the designed distance and lowered into the central pipe 14 together with the cable 40. After the signal receiving device 52 is lowered to the predetermined depth, it is matched and tested with the corresponding signal sending device 51. After the test is normal, the pressure is pressed and set, and the distribution mechanism 20 is controlled as needed.

[0055] The present application uses small-range wireless transmission technology to provide information transmission between the downhole cable-controlled intelligent water distributor and the ground, to achieve downhole layered injection, and to monitor parameters such as flow, pressure, water nozzle opening and temperature in real time. The water nozzle can be controlled in real time, and the injection volume of each layer can be adjusted in real time. The cable is lowered from the string to improve the adaptability of the working condition and the success rate in complex conditions, and to improve the situation that casing deformation wells and sidetracked wells cannot be constructed.

[0056] The above embodiments only express the implementation of the present application, which is described in more detail and in more detail, but cannot be understood as a limitation on the scope of the patent of the present application. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application.

Claims

1. An intelligent injection string with built-in cables, characterized in that, The smart injection string comprises: a pipe string body comprising an outer sleeve and a central pipe with different diameters, an annulus being formed between the outer sleeve and the central pipe, a water injection channel being formed in the central pipe, and a water injection port being provided on the outer sleeve; a water distribution mechanism arranged in the annulus of the pipe string body, the water distribution mechanism being connected with the water injection channel and the water injection port and capable of controlling the flow rate of water supplied to the water injection port; a water isolation packer arranged in the annulus of the pipe string body and separating the water distribution mechanism into a set section to form a water injection area for a predetermined formation; a cable arranged in the central pipe and extending through an axial area corresponding to the water distribution mechanism; a wireless communication mechanism comprising a signal transmitting device and a signal receiving device for wireless signal communication, the signal transmitting device being arranged in the annulus and being in communication connection with the water distribution mechanism, and the signal receiving device being connected to the cable for communication with the cable; a battery arranged in the annulus and supplying power to the water distribution mechanism and the signal transmitting device.

2. The smart injection string with a built-in electrical cable of claim 1, wherein, The signal transmitting device and the signal receiving device of the wireless communication mechanism communicate by electromagnetic induction.

3. The smart injection string with a built-in electrical cable of claim 2, wherein, The working frequency of the electromagnetic induction is 3 kHz-30 kHz.

4. The smart injection string with a built-in electrical cable of claim 2, wherein, The smart injection string further comprises a locator for determining whether the signal receiving device enters the effective communication range of the signal transmitting device.

5. The smart injection string with a built-in electrical cable of claim 4, wherein, The locator is a magnetic locator.

6. The smart injection string with a built-in electrical cable of claim 5, wherein, The magnetic locator comprises a Hall switch arranged near the signal transmitting device and a magnetic steel arranged near the signal receiving device.

7. The smart injection string with a built-in electrical cable of claim 6, wherein, The signal transmitting device has a sleep mode and a working mode, and when the Hall switch detects the magnetic steel, the signal transmitting device is switched from the sleep mode to the working mode.

8. The smart injection string with a built-in electrical cable of claim 1, wherein, The smart injection string further comprises a hydroelectric power generation device installed in the annulus, the hydroelectric power generation device being connected with the battery and charging the battery.

9. The smart injection string with a built-in electrical cable of claim 8, wherein, The hydroelectric power generation device is a turbine arranged in a water flow channel of the water distribution mechanism.

10. The smart injection string with a built-in electrical cable of claim 1, wherein, The smart injection string comprises a plurality of water distribution mechanisms and a plurality of water isolation packers, the plurality of water isolation packers separating the plurality of water distribution mechanisms from each other.

11. The smart injection string with a built-in electrical cable of claim 10, wherein, The number of the wireless communication mechanisms is consistent with the number of the water distribution mechanisms.

12. The smart injection string with a built-in electrical cable of claim 1, wherein, The water distribution mechanism comprises a housing, a flow meter, an actuator, a valve, a pressure sensor and a temperature sensor being arranged in the housing, and the flow meter, the actuator, the pressure sensor and the temperature sensor are in communication connection with the signal transmitting device.

13. The smart injection string with a built-in electrical cable of claim 12, wherein, The housing is provided with an inlet and an outlet, the inlet being in communication with the water injection channel of the central pipe, and the outlet being in communication with the water injection port of the outer sleeve.

14. The smart injection string with a built-in electrical cable of claim 12, wherein, The actuator can drive the valve to rotate to control the opening degree of the valve.

15. The smart injection string with a built-in electrical cable of claim 12, wherein, The pressure sensor comprises a pre-nozzle pressure gauge for measuring pre-nozzle pressure and a post-nozzle pressure gauge for measuring post-nozzle pressure.

16. The smart injection string with a built-in electrical cable of claim 12, wherein, The water distribution mechanism further comprises a controller in communication connection with the flow meter, the actuator, the pressure sensor, the temperature sensor and the signal transmitting device.

17. The intelligent wireline-in-cable drillstring of claim 1, wherein, The bottom end of the cable is further provided with a counterweight.

18. The intelligent wireline-in-cable injection string of claim 1, wherein, The intelligent injection string further comprises an upper joint and a lower joint, which are respectively installed at the top end and the bottom end of the string body.

19. A smart water injection system characterized in that, Comprising: The intelligent injection string with built-in cable according to any one of claims 1-18; A surface controller connected with the cable to realize communication with the signal receiving device.

20. A method of using the smart injection string with a built-in cable according to any one of claims 1-18, characterized in that, Comprising the following steps: Pre-adjust the water distribution mechanism, then lower the intelligent injection string into the casing, and ensure that the water distribution mechanism is lowered to the predetermined horizon; Connect the signal receiving device of the wireless communication mechanism to the cable at the designed distance and lower it into the central pipe together with the cable; After the signal receiving device is lowered to the predetermined depth, match test is conducted with the corresponding signal sending device respectively; After normal test, carry out pressure setting and sealing, and control the water distribution mechanism as needed.

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