Downhole wireless communication method and system based on time coding and related equipment

Abstract

The invention discloses an underground wireless communication method and system based on time coding and related equipment. The underground water distributor receives a downlink control signal sent by the ground equipment, wherein the downlink control signal comprises a function identifier for indicating the execution of the water distributor; according to a function identifier carried in the downlink control signal, determining a measurement parameter included in the function and acquiring corresponding measurement data; according to the measurement data of the measurement parameters, determining a coding time length corresponding to each measurement parameter, and according to the coding time length, generating an uplink data signal based on time coding and sending the uplink data signal to the ground equipment; the frame body of the uplink data signal comprises positive codes and negative codes of a first set time length, one positive code in the frame body is used for carrying measurement data of one measurement parameter, and the positive code time length of each positive code is the coding time length corresponding to the measurement parameter; the inverse code in the frame body is used for spacing the positive code. Therefore, the total time length of coding can be reduced according to the preset time length, the opening and closing times of the underground water nozzle are reduced, and the power consumption of the underground water distributor is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of underground communication in oil and gas exploitation, and in particular to an underground wireless communication method, system and related equipment based on time coding. Background Art

[0002] There are a large number of water injection wells in the oil industry, and these water injection wells are usually distributed in remote, unpowered field well sites, and some well sites are not even covered by mobile communication signals. Therefore, in order to establish two-way communication with these wells, especially stratified water injection wells, including sending control instructions from the ground to achieve data transmission and collecting downhole data and uploading data, supporting remote communication technology is required. In order to save project investment, it is generally necessary to develop low-cost two-way wireless remote communication technology suitable for water injection, especially stratified water injection wells based on existing facilities and objective conditions.

[0003] The two-way wireless communication technologies currently used include "pressure waves" and "flow waves". Because there is a wired power supply in the water distribution room, the wired power supply in the water distribution room can be used to power the equipment at the entrance of the water injection well. Based on the principle of efficient use of on-site resources, the ground signal generation and acquisition terminal is installed in the water distribution room; the underground signal generation and acquisition terminal is lowered with the intelligent water distributor and installed in the designed layer of the water injection well, and the underground battery is used to power each instrument in the intelligent water distributor. It can be seen that there is a huge difference in the source of power for driving the signal transmission and collection on the ground and underground, so the energy-saving demand for underground intelligent instruments is more important. At present, energy saving is mainly carried out from three aspects, namely reducing the installed power of the instrument itself, designing a low-power working system, and adopting efficient and low-power coding technology. Among them, underground wireless communication coding technology is the key to balancing underground power consumption and data transmission efficiency, and it is also the key to breaking through the bottleneck of promoting and applying underground wireless communication technology.

[0004] Considering the difference in power supply between the ground and underground, a set of codes is used for data upload and data download respectively. Because the ground power supply is sufficient, the ground data, i.e., the control instructions, are usually transmitted in binary code, and the length of each bit, i.e., the coding unit, is determined based on the set valve switch duration. The modulation method here is very mature and will not be discussed in detail. The design of underground electric control instruments needs to comprehensively consider the influence of factors such as tool size, battery capacity, battery self-discharge, normal operation energy consumption of underground instruments, and data transmission and reception energy consumption, and there is a huge gap in the power consumption of different underground electric control instruments. This is because the underground switch (generally refers to the opening or closing action of the water distributor nozzle) is in the high pressure difference state conversion of the fluid, and the underground micro motor drives the underground valve (generally refers to the water distributor nozzle) to switch to generate a flow signal, and the power consumption of completing this single switch is hundreds of times that of the underground sensor for continuous collection. The peak current of each switch can reach 1 to 2 amperes, while the working current of the sensor is in the milliampere level. Considering the problem that downhole instruments consume a lot of power during each switch process, in order to reduce energy consumption and achieve energy saving, under the condition of limited downhole battery capacity, if the number of valve switches can be reduced as much as possible, and the battery life of the downhole battery can be extended while transmitting a larger amount of data, the goal of continuous service on site for a long enough time, such as 3-5 years, can be achieved. Therefore, in practical applications, time coding is usually used for uploading downhole data.

[0005] The invention patent application with the publication number CN107503720A and the invention name is "A device and method for regulating stratified water injection using flow waves", and the invention patent application with the publication number CN109763799B and the invention name is "A method for controlling stratified water injection using flow waves", discloses the encoding method of related data transmission. Both patent applications use the duration of maintaining a certain high or low flow state as the time unit for encoding. In terms of encoding method, the latter is an improvement of the former, and claims to be able to reduce the number of times the downhole water nozzle is turned on and off in most cases. Summary of the invention

[0006] The inventor of this application has found that the existing implementation schemes for uploading data by time coding, such as the technical schemes disclosed in the above two invention patent applications, have time units related to the speed of opening or closing the faucet, and the design duration of maintaining the open or closed state. Because after opening or closing once, it is necessary to wait for the flow rate to reach stability before it can be used as a valid high or low bit of data, and then as a valid coding bit, this process usually takes several minutes or even longer, so the coding unit based on time length generally has a longer duration under the real clock benchmark; the coding efficiency of underground data upload is low and the possibility of bit errors is high.

[0007] In view of the above problems, the present invention is proposed to provide a downhole wireless communication method, system and related equipment based on time coding to overcome the above problems or at least partially solve the above problems.

[0008] The embodiment of the present invention provides a method for underground wireless communication based on time coding, comprising:

[0009] The downhole water distributor receives a downlink control signal sent by the surface equipment, wherein the downlink control signal includes a function identifier indicating the water distributor to execute;

[0010] Determine, according to the function identifier carried in the downlink control signal, the measurement parameters included in the function and obtain corresponding measurement data;

[0011] According to the measurement data of the measurement parameter, the coding duration corresponding to each measurement parameter is determined, and an uplink data signal based on time coding is generated according to the coding duration and sent to the ground equipment; the frame body of the uplink data signal includes a positive code and an inverse code of a first set duration, a positive code in the frame body is used to carry the measurement data of a measurement parameter, and the positive code duration of each positive code is the coding duration corresponding to the represented measurement parameter; the inverse code in the frame body is used to space the positive code.

[0012] In some preferred embodiments, the uplink data signal includes a frame header, a frame body, a frame tail and a blank frame, the frame header, the frame body and the frame tail include a positive code and an inverse code, and the blank frame is an inverse code of the second set duration, including:

[0013] The positive code duration in the frame header is the third set duration, and the reverse code duration is the first set duration;

[0014] The positive code duration in the frame body is the encoding duration of the measurement parameter corresponding to the positive code, and the inverse code duration is the first set duration;

[0015] The inverted code duration in the frame tail is the fourth set duration, and the positive code duration is the fifth set duration.

[0016] In some preferred embodiments, the downhole water distributor receives a downlink control signal sent by the surface equipment, and determines the measurement parameters included in the function and obtains the corresponding measurement data according to the function identifier carried in the downlink control signal, including:

[0017] The downhole flow detector in the downhole water distributor receives the downlink control signal broadcasted or sent one-to-one by the ground equipment, and decodes the downlink control signal; the downlink control signal adopts a binary-coded flow wave;

[0018] Determine whether the water distributor instruction is for itself according to the water distributor identification carried in the downlink control signal;

[0019] If yes, determine the function to be executed and the measurement parameters included in the function according to the function identifier carried in the downlink control signal, and obtain corresponding measurement data.

[0020] In some preferred embodiments, determining the coding duration corresponding to each measurement parameter according to the measurement data of the measurement parameter, and generating an uplink data signal based on time coding according to the coding duration and sending it to the ground device includes:

[0021] The downhole water distributor determines the positive code duration corresponding to each measurement parameter according to each measurement parameter and its measurement data;

[0022] Generate an uplink data signal including a frame header, a frame body and a frame tail with alternating positive codes and inverse codes according to a preset frame header positive code duration and a frame header inverse code duration, a positive code duration corresponding to each measurement parameter and an inverse code duration used to space the positive code, a preset frame tail positive code duration and a frame tail inverse code duration, and a preset blank frame duration; the frame body includes a positive code duration corresponding to each measurement parameter and the inverse codes therebetween;

[0023] The downhole water distributor controls the opening and closing of the water nozzle according to the duration of the positive code and the negative code included in the uplink data signal to form a corresponding flow wave and transmit it to the surface equipment.

[0024] In some preferred embodiments, the downhole water distributor controls the opening and closing of the water nozzle to form a corresponding flow wave according to the duration of the positive code and the negative code included in the uplink data signal, including:

[0025] The downhole water distributor determines the flow rate based on the duration of the positive code and the negative code included in the uplink data signal and the mapping relationship between the duration and the flow rate, and controls the opening and closing durations of the water nozzles according to the flow rate to form a corresponding flow wave.

[0026] In some preferred embodiments, a method for underground wireless communication based on time coding further includes:

[0027] The downhole water distributor receives a downlink wake-up signal sent by the surface equipment before receiving the downlink control signal sent by the surface equipment, and adjusts its own state to the wake-up standby state according to the downlink wake-up signal; and / or

[0028] The downhole water distributor does not receive any signal from the surface equipment within the set monitoring time and adjusts its state to a low-power monitoring state.

[0029] An embodiment of the present invention provides a time-coding-based underground wireless communication method, which includes:

[0030] The surface equipment sends a downlink control signal to the downhole water distributor; the downlink control signal includes a function identifier instructing the water distributor to perform, so that the downhole water distributor determines the measurement parameters included in the function and obtains the corresponding measurement data according to the function identifier carried in the downlink control signal;

[0031] Receive an uplink data signal sent by a downhole water distributor; the uplink data signal is generated by the downhole water distributor based on the measurement data of the measurement parameter, determining the encoding duration corresponding to each measurement parameter, and based on the time encoding method according to the encoding duration;

[0032] The positive code and the inverse code in the uplink data signal frame body are detected, and the measurement data of the measurement parameter corresponding to each positive code is determined according to the positive code duration of each positive code detected and the mapping relationship between the positive code duration of each positive code and the measurement data of the represented measurement parameter.

[0033] In some preferred embodiments, the surface equipment sends a downlink control signal to the downhole water distributor, including:

[0034] The surface equipment determines the downhole water distributor that needs to upload data according to the layer position of the downhole water distributor and the set data upload order, generates a downlink control signal including a downhole water distributor identifier and a function identifier indicating the water distributor to be executed, and sends it one-to-one to the downhole water distributor that needs to upload data or sends it to the downhole water distributor by broadcasting.

[0035] In some preferred embodiments, the downlink control signal adopts a binary-coded flow wave, and the downlink control signal includes a frame header, an instruction frame, a check frame and a frame tail. The number of binary bits of the frame header, the instruction frame, the check frame and the frame tail is pre-set, the instruction frame includes a function identifier, and the check frame includes a downhole water distributor identifier.

[0036] In some preferred embodiments, the receiving of the uplink data signal sent by the downhole water distributor; detecting the positive code and the negative code in the uplink data signal frame body, and determining the measurement data of the measurement parameter corresponding to each positive code according to the positive code duration of each positive code detected and the mapping relationship between the positive code duration of each positive code and the measurement data of the measurement parameter represented, including:

[0037] The surface flow detector in the surface equipment receives the uplink data signal sent by the downhole water distributor, decodes the received uplink signal, and obtains the total duration of the uplink data signal, including the positive code and the positive code duration, the inverse code and the inverse code duration;

[0038] Performing error checking and adjustment on the uplink data signal according to the total duration of the uplink data signal and a preset checking rule;

[0039] The frame header, frame body, frame tail and blank frame are determined according to the positive code and its duration, the inverse code and its duration. The measurement data of the measurement parameter corresponding to each positive code in the frame body is determined according to the mapping relationship between the positive code duration of each positive code in the frame body and the measurement data of the measurement parameter represented.

[0040] In some preferred embodiments, the error checking and adjusting the uplink data signal according to the total duration of the uplink data signal and a preset checking rule includes:

[0041] The ground equipment controller compares the total duration of the uplink data signal with the total duration preset by the time code;

[0042] If the duration error between the two is within a preset duration error range, the total duration of the decoded data is corrected according to the principle of proportional correction to obtain a corrected total duration of the uplink data signal;

[0043] If the duration error between the two is not within the preset duration error range, the uplink data signal is discarded, a fault warning is issued, and the uplink data signal is received again after the fault is eliminated.

[0044] In some preferred embodiments, determining the measurement data of the measurement parameter corresponding to each positive code according to the positive code duration of each positive code detected, the mapping relationship between the positive code duration of each positive code and the measurement data of the represented measurement parameter, includes:

[0045] According to the positive code duration of each positive code detected, the measured data is read through the mapping relationship between the positive code duration of each positive code and the measured data represented. The mapping relationship between the duration and the measured data is: y=log b (ax+c)+d;

[0046] Among them, a, b, c, d are mapping parameters of the duration and the measurement data, x is the positive code duration or the reverse code duration, and y is the measurement data corresponding to x.

[0047] In some preferred embodiments, a downhole wireless communication method based on time coding further includes:

[0048] Before the surface equipment sends a downlink control signal to the downhole water distributor, the surface equipment sends a downlink wake-up signal to the downhole water distributor, so that the water distributor adjusts its own state to the wake-up standby state according to the downlink wake-up signal.

[0049] The embodiment of the present invention provides a downhole water distributor, comprising: a downhole geophone, a downhole control unit and a downhole signal generator;

[0050] The downhole geophone, the downhole water distributor receives a downlink control signal sent by the surface equipment, the downlink control signal includes a function identifier indicating the water distributor to perform;

[0051] The downhole control unit determines the measurement parameters included in the function and obtains the corresponding measurement data according to the function identifier carried in the downlink control signal; determines the encoding duration corresponding to each measurement parameter according to the measurement data of the measurement parameters

[0052] A downhole signal generator is used to generate an uplink data signal based on time coding according to the coding duration and send it to the ground equipment; the frame body of the uplink data signal includes a positive code and an inverse code of a first set duration, a positive code in the frame body is used to carry the measurement data of a measurement parameter, and the positive code duration of each positive code is the coding duration corresponding to the represented measurement parameter; the inverse code in the frame body is used to space the positive code.

[0053] An embodiment of the present invention provides a ground device, comprising: a ground flow detector, a ground signal generator and a ground control unit;

[0054] A surface signal generator, used to send a downlink control signal to the downhole water distributor, wherein the downlink control signal includes a function identifier indicating the water distributor to perform;

[0055] A surface flow detector, used to receive an uplink data signal sent by a downhole water distributor; the uplink data signal is generated by the downhole water distributor based on the measurement data of the measurement parameter, determining the encoding duration corresponding to each measurement parameter, and based on the time encoding method according to the encoding duration;

[0056] The ground control unit is used to detect the positive code and the inverse code in the uplink data signal frame body, and determine the measurement data of the measurement parameter corresponding to each positive code according to the positive code duration of each positive code detected and the mapping relationship between the positive code duration of each positive code and the measurement data of the measurement parameter represented.

[0057] An embodiment of the present invention provides a downhole wireless communication system based on time coding, comprising: the above-mentioned surface equipment and the above-mentioned downhole water distributor.

[0058] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0059] In the downhole wireless communication method based on time coding provided by the embodiment of the present invention, the ground equipment sends a downlink control signal to the downhole water distributor, and the function identifier in the downlink control signal indicates the function to be performed by the downhole water distributor. The downhole water distributor performs the corresponding function according to the function identifier, obtains the measurement parameters and corresponding measurement data involved in the function, determines the encoding duration corresponding to each measurement parameter according to the measurement data, generates an uplink data signal in a time-coded manner and sends it to the ground equipment. The uplink signal sent to the ground equipment uses different positive code durations to represent the measurement data of different measurement parameters and is spaced by reverse codes, and controls the flow wave by controlling the opening and closing of the water nozzle. The duration of the positive code and the reverse code, this method does not need to wait for the stable conversion of the high flow bit and the low flow bit as in the prior art, but only needs to control the opening and closing time of the water nozzle according to the mapping relationship between the duration and the flow, and does not need to set multiple coding units for each digit, which leads to a large amount of coding time, thereby greatly reducing the total coding duration, that is, reducing the time required for time coding to transmit data, improving the speed and efficiency of underground data transmission, and effectively reducing energy consumption, reducing the power consumption of underground water distributors, meeting the energy-saving needs of underground battery power supply, and extending the service life. At the same time, it also reduces the possibility of bit errors and reduces the bit error rate.

[0060] The above method can adopt a broadcast communication mode, where the ground equipment sends instructions to the underground parallel system at the same time, so that all water injection data of a single layer can be uploaded in one communication, which simplifies the data acquisition process and can further shorten the on-site measurement and adjustment time.

[0061] The above method can also correct the uplink data signal to avoid the uplink data signal error caused by the inconsistency between the counter of the downhole water distributor and the ground timing, thereby ensuring the accuracy of the uplink data transmission.

[0062] In the above method, the downhole water distributor is in a low power monitoring state before receiving the wake-up control signal, and enters the low power monitoring state after a specified time after completing the communication, which further reduces the power consumption of the downhole water distributor.

[0063] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0064] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0066] Figure 1 This is a flow chart of an underground wireless communication method based on time coding in Embodiment 1 of the present invention;

[0067] Figure 2 This is an example diagram of the architecture of an underground wireless communication system based on time coding in Embodiment 1 of the present invention;

[0068] Figure 3 This is a flow chart of an underground wireless communication method based on time coding in Embodiment 2 of the present invention;

[0069] Figure 4 A schematic diagram of downlink control signal encoding in an embodiment of the present invention;

[0070] Figure 5 A schematic diagram of uplink data signal encoding in an embodiment of the present invention;

[0071] Figure 6 This is a mapping relationship diagram between duration and data in an embodiment of the present invention;

[0072] Figure 7 This is a flow chart of an underground wireless communication method based on time coding in Embodiment 3 of the present invention;

[0073] Figure 8 This is a flow chart of a method for broadcast communication in Embodiment 4 of the present invention;

[0074] Fig. 9 This is a method flow chart of a one-to-one communication method according to Embodiment 5 of the present invention;

[0075] Fig.10 It is a structural schematic diagram of an underground wireless communication system in an embodiment of the present invention;

[0076] Fig.11 This is a schematic diagram of the structure of a downhole water distributor in an embodiment of the present invention;

[0077] Fig.12 Schematic diagram of the structure of ground equipment in an embodiment of the present invention. DETAILED DESCRIPTION

[0078] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0079] The technical solution disclosed in the patent application with publication number CN107503720A mentioned in the prior art adopts a conservative coding method, that is, the numbers 0-9 in the decimal system are continuously distributed in ten consecutive coding units in a certain order. Therefore, if each bit in the decimal system is to be represented, 10 consecutive coding units are required. When transmitting a two-digit number, 20 consecutive coding units are required in the data segment representing the data. For example, to transmit a flow rate of 15 cubic meters per day in a certain layer underground, the number 1 in the tens position needs to occupy 10 coding units, and a high-order flow rate is generated at the position representing 1, and the rest is a low-order flow rate; the number 5 in the ones position requires another 10 consecutive coding units, and a high-order flow rate is generated at the position representing 5, and the rest is a low-order flow rate. If it takes 2 minutes to generate a coding unit, the time required to transmit 15 cubic meters of data per day in this coding method is 2×20=40 minutes. Therefore, if the download time of the ground command and the time occupied by the complete upload coding are added, the waiting time will far exceed 40 minutes just to obtain the flow value uploaded to the ground from a certain layer underground. If more downhole data, such as pressure, temperature, etc., or relevant data of more layers are required, the communication time will be multiplied on this basis. For example, it usually takes 4-6 hours or even longer to complete the downhole data acquisition of a two-layer water injection well, which does not include the correctness check of the data (the transmitted data should include relevant coding) and the time required to resend instructions and receive data when the check is wrong.

[0080] The patent application with publication number CN109763799B slightly improved the decimal encoding method, that is, the low-order flow rate represents the tens digit, the high-order flow rate represents the ones digit, and the number of encoding units occupied by the two flow durations represents the corresponding two-digit value. Therefore, in theory, this scheme can shorten the length of the uploaded encoded data segment to a certain extent, but its effect of shortening the encoding time is not good, and the time required to complete the downhole data acquisition of a two-layer water injection well is not shortened much.

[0081] In order to solve the problems of long time consumption, low efficiency, high bit error rate and the like in the prior art in the encoding methods for uploading downhole data, an embodiment of the present invention provides a downhole wireless communication method based on time coding, which is a low-power downhole wireless communication technology suitable for the upstream field of the petroleum industry and can take into account both the amount of uploaded data and the transmission time consumption. It generates wireless remote communication time coding by controlling the change of pipeline flow and implements relevant error checking to reduce data transmission time, improve transmission efficiency, reduce energy consumption, meet downhole power supply requirements, and effectively reduce the bit error rate, thereby providing support for the promotion and application of downhole wireless communication technology.

[0082] Embodiment 1:

[0083] Embodiment 1 of the present invention provides a method for underground wireless communication based on time coding, the process of which is as follows: Figure 1 As shown, the architecture of the underground wireless communication system based on time coding that can implement this method is as follows Figure 2 As shown, the following steps are included:

[0084] Step S101: The surface equipment sends a downlink control signal to the downhole water distributor, wherein the downlink control signal includes a function identifier instructing the water distributor to execute.

[0085] Step S102: The downhole water distributor receives a downlink control signal sent by the surface equipment.

[0086] Step S103: The downhole water distributor determines the measurement parameters included in the function according to the function identifier carried in the downlink control signal and obtains the corresponding measurement data.

[0087] Step S104: the downhole water distributor determines the encoding duration corresponding to each measurement parameter according to the measurement data of the measurement parameter, generates an uplink data signal based on time encoding according to the encoding duration, and sends it to the surface equipment.

[0088] Among them, the frame body of the uplink data signal includes a positive code and an inverse code of a first set duration. A positive code in the frame body is used to carry measurement data of a measurement parameter, and the positive code duration of each positive code is the encoding duration corresponding to the represented measurement parameter; the inverse code in the frame body is used to space the positive code.

[0089] Step S105: The surface equipment receives the uplink data signal sent by the downhole water distributor.

[0090] Step S106: The ground equipment detects the positive code and the negative code in the uplink data signal frame body, and determines the measurement data of the measurement parameter corresponding to each positive code according to the positive code duration of each positive code detected and the mapping relationship between the positive code duration of each positive code and the measurement data of the measurement parameter represented.

[0091] In the downhole wireless communication method based on time coding provided by the embodiment of the present invention, the ground equipment sends a downlink control signal to the downhole water distributor, and the function identifier in the downlink control signal indicates the function to be performed by the downhole water distributor. The downhole water distributor performs the corresponding function according to the function identifier, obtains the measurement parameters and corresponding measurement data involved in the function, determines the encoding duration corresponding to each measurement parameter according to the measurement data, generates an uplink data signal in a time-coded manner and sends it to the ground equipment. The uplink signal sent to the ground equipment uses different positive code durations to represent the measurement data of different measurement parameters and is spaced by reverse codes, and controls the flow wave by controlling the opening and closing of the water nozzle. The duration of the positive code and the reverse code, this method does not need to wait for the stable conversion of the high flow bit and the low flow bit as in the prior art, but only needs to control the opening and closing time of the water nozzle according to the mapping relationship between the duration and the flow, and does not need to set multiple coding units for each digit, which leads to a large amount of coding time, thereby greatly reducing the total coding duration, that is, reducing the time required for time coding to transmit data, improving the speed and efficiency of underground data transmission, and effectively reducing energy consumption, reducing the power consumption of underground water distributors, meeting the energy-saving needs of underground battery power supply, and extending the service life. At the same time, it also reduces the possibility of bit errors and reduces the bit error rate.

[0092] Embodiment 2

[0093] Embodiment 2 of the present invention provides a method for underground wireless communication based on time coding, and describes the implementation process of an underground water distributor. The process is as follows: Figure 3 As shown, the following steps are included:

[0094] Step S201: the downhole water distributor receives a downlink control signal sent by the surface equipment, wherein the downlink control signal includes a function identifier instructing the water distributor to execute.

[0095] Step S202: The downhole water distributor determines the measurement parameters included in the function according to the function identifier carried in the downlink control signal and obtains the corresponding measurement data.

[0096] Step S203: The downhole water distributor determines the coding duration corresponding to each measurement parameter based on the measurement data of the measurement parameter, generates an uplink data signal based on time coding according to the coding duration, and sends it to the ground equipment; the frame body of the uplink data signal includes a positive code and an inverse code of a first set duration, a positive code in the frame body is used to carry the measurement data of a measurement parameter, and the positive code duration of each positive code is the coding duration corresponding to the represented measurement parameter; the inverse code in the frame body is used to space the positive code.

[0097] In the above step S201, the downhole flow detector in the downhole water distributor receives the downlink control signal broadcasted or sent one-to-one by the surface equipment, and decodes the downlink control signal; the downlink control signal adopts a binary-coded flow wave.

[0098] The downhole water distributor determines whether the control instruction is for itself based on the water distributor identifier carried in the downlink control signal; if so, it determines the function to be executed and the measurement parameters included in the function based on the function identifier carried in the downlink control signal and obtains the corresponding measurement data.

[0099] The downlink control signal for ground data transmission adopts non-return zero code (NZR code). For example, high-order flow represents logic "1" and low-order flow represents logic "0". The time width t of each bit is determined by the time required to generate a stable high-low flow conversion after the flow signal generator is turned off or on.

[0100] Downlink control signals include frame header, command frame, check frame and frame tail. The signal frame structure is shown in Figure 4 As shown, the downlink control signal adopts binary coding, the peak indicates that the flow signal generator is turned on, and the trough indicates that the flow signal generator is turned off. The following is a downlink control signal encoded using non-return-to-zero coding, for example, there are 28 coding bits in total, 7 bits for the frame header, 10 bits for the instruction frame, 10 bits for the check frame, 1 bit for the frame bit, and the total number of coding bits is 28=7+10+10+1. The coding unit duration t of the downlink control signal is set according to the actual characteristics of the water injection well, for example, it can usually be 20s to 30s, and the time required to transmit a downlink control signal is 9.3min to 14min.

[0101] In the above step S201, taking the broadcast method as an example, the flow detector in the downhole water distributor receives the downlink control signal broadcasted by the ground equipment, and the downlink control signal requires the execution of function X (a function of the downhole water distributor), and function X requires each layer to upload the measured values ​​of the single layer flow, the pressure before the mouth, and the pressure after the mouth in turn; the ground signal generator in the ground equipment is activated to form a modulated binary downlink flow wave, which flows downward through the downhole water distributor of each layer in turn. The downlink control signal can include the upload order, for example, uploading in order from shallow to deep according to the distribution layer of the downhole water distributor.

[0102] Taking the one-to-one method as an example, the downhole water distributor receives a downlink control signal, which requires the downhole water distributor in the one-to-one communication layer to execute function X. Function X includes uploading the measured values ​​of the single-layer flow, the pressure before the mouth, and the pressure after the mouth at the previous recording point; the ground signal generator in the ground equipment is activated to form a modulated binary downlink flow wave, which flows to the downhole water distributor in this layer with a stronger signal strength.

[0103] In the above step S202, it is determined whether the water distributor identifier carried in the downlink control signal is a control instruction for itself; if so, the function to be executed and the measurement parameters included in the function are determined according to the function identifier carried in the downlink control signal and the corresponding measurement data is obtained.

[0104] Taking the broadcast method as an example, the downhole detector in the downhole water distributor receives the downhole control signal and transmits it to the downhole control unit. The control unit determines whether the downhole control signal is an instruction that the downhole water distributor needs to execute according to the coding rules. If not, it will not be executed; if so, it determines whether the corresponding downhole control instruction carries an identifier with function X. If not, function X will not be executed. If so, the downhole water distributor executes function X to obtain the measured values ​​of single-layer flow rate, front-mouth pressure and rear-mouth pressure. The downhole control unit controls the downhole signal generator to perform time encoding according to the measured values ​​of flow rate, front-mouth pressure and rear-mouth pressure to generate an uplink data signal.

[0105] Taking a one-to-one method as an example, the downhole detector in the downhole water distributor receives the downhole control signal and transmits it to the downhole control unit. The downhole control unit determines whether the downhole control signal is an instruction that the downhole water distributor needs to execute according to the coding rules. If not, it will not be executed; if so, it determines whether the corresponding downhole control instruction carries an identifier with function X. If not, function X will not be executed. If so, the downhole water distributor executes function X to obtain the measured values ​​of single-layer flow rate, front-mouth pressure and rear-mouth pressure. The downhole control unit controls the downhole signal generator to perform time encoding according to the measured values ​​of flow rate, front-mouth pressure and rear-mouth pressure to generate an uplink data signal.

[0106] In the above step S203, the uplink data signal adopts time coding, including positive code + reverse code, and the uplink data signal includes a frame header, a frame body, a frame tail and a blank frame. The frame header, the frame body and the frame tail include positive code and reverse code. The positive code duration in the frame header is the third set duration, and the reverse code duration is the first set duration; the positive code duration in the frame body is the coding duration of the measurement parameter corresponding to the positive code, and the reverse code duration is the first set duration; the reverse code duration in the frame tail is the fourth set duration, and the positive code duration is the fifth set duration. The duration of the positive code and reverse code of the frame header and the frame tail in the uplink data signal is pre-set, and the duration of the blank frame is also pre-set. Each positive code in the frame body represents a measurement parameter and can also be pre-agreed. The duration of each positive code is determined according to the measurement data corresponding to the measurement parameter, and different durations can represent different sizes of the measurement data. The size of the measurement data and the coding duration can be calculated according to the mapping relationship.

[0107] The signal frame structure of the uplink control signal can be found in Figure 5As shown, it includes a frame header, a frame body, a frame tail and a blank frame (containing no information). The uplink data signal can select the low-order flow to high-order flow conversion segment (curve rising edge) or the high-order flow to low-order flow conversion segment (curve falling edge) as the starting and ending points of the total upload coding time as needed, and the time contained in these two positions is used as the basis for error checking. In the time coding used in the upload data signal, except for the blank frame, the remaining components are composed of "time length + inverse code"; in addition, the end of the last data time length in the data frame directly follows the frame tail to simplify the coding.

[0108] The preset value of the time length t of the inverse code in the time coding method is also determined by the flow signal generator, for example, it can be determined by the time required for the stable flow high and low position conversion after the flow signal generator is turned off or on. Since the generation process of the underground upload flow signal is similar to the "positive pulse" form of the drilling mud pulse signal, the flow change signal responds faster, and the inverse code time length t can take a preset value, for example, it can take a value of 15s to 20s. For conservative reasons, for example, the preset time length is uniformly taken as 30s. The frame header can be designed with a preset time length of, for example, 60s, and the total time length of the inverse code is, for example, 90s; similarly, the frame tail can also be designed with a preset time length, for example, a positive code time length of 60s, and a total of 90s with the inverse code; it can also be designed with a reverse code time length of 60s, and a positive code time length of 30s, and a preset time length of 90s. The frame body part uses different positive codes to represent different measurement parameters. For example, the first positive code represents the flow rate, and the duration of the positive code represents the size of the flow rate; the second positive code represents the pressure in front of the mouth, and the duration of the positive code represents the size of the pressure in front of the mouth; the third positive code represents the pressure behind the mouth, and the duration of the positive code represents the size of the pressure behind the mouth.

[0109] In the above step S203, the downhole water distributor determines the positive code duration corresponding to each measurement parameter according to each measurement parameter and its measurement data; generates an uplink data signal including a frame header, a frame body and a frame tail with alternating positive codes and reverse codes according to the preset frame header positive code duration and frame header reverse code duration, the positive code duration corresponding to each measurement parameter and the reverse code duration used to space the positive code, the preset frame tail positive code duration and frame tail reverse code duration, and the preset blank frame duration; the frame body includes the positive code duration corresponding to each measurement parameter and the reverse codes between them; the downhole water distributor controls the opening and closing of the water nozzle according to the duration of the positive code and reverse code included in the uplink data signal to form a corresponding flow wave and transmit it to the surface equipment. Optionally, the downhole water distributor determines the flow size according to the duration of the positive code and reverse code included in the uplink data signal and the mapping relationship between the duration and the flow, and controls the opening and closing duration of the water nozzle according to the flow size to form a corresponding flow wave.

[0110] The uplink data signal contains information on multiple data, such as single-layer flow, pressure before or after the mouth, etc. Similarly, each data is compiled in the form of "duration + reverse code" and can also contain other downhole data (just add the corresponding "duration + reverse code" data frame). That is, this type of coding realizes the one-time transmission of multiple data of a certain injection layer in the well. For details, see Figure 5 As shown, the peak represents the opening action of the water spout, and the trough represents the closing action of the water spout. For example, a single upload of the flow rate, the pressure in front of the spout, and the pressure behind the spout of a certain injection layer requires driving the water spout to move a total of 11 times, including 6 times of opening and 5 times of closing. The blank frame represents a coding segment that does not contain information in the total duration, that is, the timing continues after the end of the frame until the set total duration.

[0111] The mapping relationship between the positive code duration and the measurement data in the uplink data signal can be found in Figure 6 As shown, the mapping relationship between duration and measurement data is: y = log b (ax+c)+d; wherein a, b, c, d are mapping parameters of the duration and the measurement data, x is the positive code duration or the reverse code duration, and y is the measurement data corresponding to x.

[0112] After the downhole water distributor completes the corresponding downlink control signal, if the downhole water distributor does not receive a signal sent by the surface equipment within the set monitoring time, it adjusts its own state to a low-power monitoring state.

[0113] In some optional embodiments, the above method further includes:

[0114] Before receiving the downlink control signal sent by the surface equipment, the downhole water distributor receives the downlink wake-up signal sent by the surface equipment, and adjusts its own state to the wake-up standby state according to the downlink wake-up signal.

[0115] Embodiment 3

[0116] Embodiment 2 of the present invention provides a method for underground wireless communication based on time coding, and describes the implementation process of the surface equipment side. The process is as follows: Figure 7 As shown, the following steps are included:

[0117] Step S301: The surface equipment sends a downlink control signal to the downhole water distributor. The downlink control signal includes a function identifier instructing the water distributor to perform, so that the downhole water distributor determines the measurement parameters included in the function and obtains the corresponding measurement data according to the function identifier carried in the downlink control signal.

[0118] The surface equipment determines the downhole water distributor that needs to upload data according to the layer position of the downhole water distributor and the set data upload order, generates a downlink control signal including the downhole water distributor identification and the function identification indicating the water distributor to be executed, and sends it one-to-one to the downhole water distributor that needs to upload data or sends it to the downhole water distributor by broadcasting.

[0119] The downlink control signal adopts a binary-coded flow wave. The downlink control signal includes a frame header, a command frame, a check frame and a frame tail. The binary bits of the frame header, the command frame, the check frame and the frame tail are preset. The command frame includes a function identifier, and the check frame includes a downhole water distributor identifier.

[0120] Step S302: The surface equipment receives the uplink data signal sent by the downhole water distributor. The uplink data signal is generated by the downhole water distributor based on the measurement data of the measurement parameters, determining the encoding duration corresponding to each measurement parameter, and based on the encoding duration based on the time encoding method. Referring to step S203, the downhole water distributor generates the uplink data signal based on the time encoding method according to the encoding duration.

[0121] Step S303: The ground equipment detects the positive code and the negative code in the uplink data signal frame body, and determines the measurement data of the measurement parameter corresponding to each positive code according to the positive code duration of each positive code detected and the mapping relationship between the positive code duration of each positive code and the measurement data of the measurement parameter represented.

[0122] The ground flow detector in the ground equipment receives the uplink data signal sent by the downhole water distributor, decodes the received uplink signal, and obtains the total duration of the uplink data signal, including the positive code and the positive code duration, and the reverse code and the reverse code duration; performs error check and adjustment on the uplink data signal according to the total duration of the uplink data signal and a preset verification rule; determines the frame header, frame body, frame tail and blank frame according to the positive code and the positive code duration, and the reverse code and the reverse code duration, and determines the measurement data of the measurement parameter corresponding to each positive code in the frame body according to the positive code duration of each positive code in the frame body, the mapping relationship between the positive code duration of each positive code and the measurement data of the measurement parameter represented.

[0123] According to the positive code duration of each positive code detected, the measured data is read through the mapping relationship between the positive code duration of each positive code and the measured data represented. The mapping relationship between the duration and the measured data is: y = log b (ax+c)+d; wherein a, b, c, d are mapping parameters of the duration and the measurement data, x is the positive code duration or the reverse code duration, and y is the measurement data corresponding to x.

[0124] Among them, the uplink data signal is error-checked and adjusted according to the total duration of the uplink data signal and a preset verification rule, including: the ground equipment controller compares the total duration of the uplink data signal with the preset total duration of the time code; if the duration error between the two is within the preset duration error range, the total duration of the decoded data is corrected according to the principle of proportional correction to obtain the corrected total duration of the uplink data signal; if the duration error between the two is not within the preset duration error range, the uplink data signal is discarded, a fault warning is issued, and the uplink data signal is received again after the fault is eliminated.

[0125] The uplink data signal encoding is all asynchronous communication, and the encoding does not include a clock line. This design, on the one hand, takes into account the actual needs, that is, the field only needs to be able to retrieve data, and there is no need for strict synchronization of information flow in wireless remote communication; on the other hand, it can simplify the transceiver system, and there is no need to add a clock (external crystal oscillator) to the downhole instrument, further reducing the power consumption of the instrument while also simplifying the execution code. Therefore, the ground equipment needs to perform time error verification on the uploaded data.

[0126] Uplink data signal error checking process:

[0127] The uplink data signal is encoded with a preset total encoding time, for example, the preset total encoding time is t0 = 2400s, that is, the downhole water distributor times the single data upload for 2400s according to the internal clock of the microcontroller. When performing a single continuous data upload, without external crystal calibration, the internal clock of the microcontroller jumps in the same direction.

[0128] After receiving the uplink data signal, the surface equipment obtains the detection curve of the uploaded data based on the clock of the downhole water distributor. Due to the internal clock of the microcontroller, a cumulative positive error based on the software clock of the host computer may be formed. For details, see Figure 5 As shown, the actual receiving upload data time of the upload data curve received on the ground is t", the designed upload data curve is the total single upload encoding time t0 (true value curve), and the positive error (ΔS1) is the difference between t” and t0; the actual receiving upload data time of the upload data curve received on the ground is t', and the negative error (ΔS2) is the difference between t0 and t'.

[0129] Preset error judgment based on positive or negative error;

[0130] If the positive error or negative error is not within the preset error range, the error check data is discarded;

[0131] If the positive error or negative error is within the preset error range, the error check data is read;

[0132] The uploaded data detection curve is proportionally corrected by the ground equipment according to the preset total encoding time, for example, t0=2400s, to obtain the true value of the curve based on the accurate clock of the ground equipment.

[0133] According to the positive code duration of each positive code detected, and the mapping relationship between the positive code duration of each positive code and the measured data of the measured parameter represented, the measured data of the measured parameter corresponding to each positive code is determined; according to the positive code duration of each positive code detected, the measured data is read through the mapping relationship between the positive code duration of each positive code and the measured data represented, and the mapping relationship between the duration and the measured data is: y=log b (ax+c)+d; wherein a, b, c, d are mapping parameters of the duration and the measurement data, x is the positive code duration or the reverse code duration, and y is the measurement data corresponding to x.

[0134] According to the obtained true value curve, the flow and pressure values ​​are read through the ground equipment. For the mapping relationship between time and data, please refer to Figure 6 , the horizontal axis represents time and the vertical axis represents data.

[0135] Specifically, take time and flow as an example. The mapping relationship between time and flow is y = log b (ax+c)+d, where x represents time t, y represents flow rate Q, and parameters a, b, c, and d are obtained through data planning and coordination. The mapping relationship curve between time and flow rate is in the first quadrant of the coordinate system. Figure 5 In this example, Q0, Q1, t1', and t1" represent the boundaries of the mapping curve. For example, t1' represents the minimum flow rate Q0 to be measured. Therefore, the measurement resolution can be reflected by the interval of t1 and Q. For example, if t1 is taken in [0s, 100s] to map the flow rate Q of [0 cubic meters / day, 10 cubic meters / day], 10 cubic meters / day is divided into 100 equal parts, and the resolution is 0.1 cubic meters / day; if the t1 value range is changed to [0s, 200s], the resolution is 0.05 cubic meters / day. In actual application, it should be adjusted according to the site requirements.

[0136] Specifically, taking a single-layer flow rate, pressure before the mouth and pressure after the mouth as examples, the corresponding times of the flow rate, pressure before the mouth and pressure after the mouth are t1, t2 and t3 respectively. The preset upper limits of t1, t2 and t3, such as 600s, can meet the requirements. The preset blank frame duration is equal to the preset inverse code duration, such as 30s. The total duration required for a single upload is 90s+600s+30s+600s+30s+600s+90s+30s=2070s=34.5min. The wireless communication time coding technology can complete the acquisition of multiple water injection data such as single-layer flow rate, pressure before the mouth and pressure after the mouth within <50min, greatly improving the transmission efficiency, while reducing downhole energy consumption and extending the service life of downhole tools.

[0137] After the downhole water distributor completes the corresponding downlink control signal, if the downhole water distributor does not receive a signal sent by the surface equipment within the set monitoring time, it adjusts its own state to a low-power monitoring state.

[0138] In some optional embodiments, the above method also includes: before the surface equipment sends a downlink control signal to the downhole water distributor, the surface equipment sends a downlink wake-up signal to the downhole water distributor so that the downhole water distributor adjusts its own state to a wake-up standby state.

[0139] The methods described in the first, second and third embodiments of the present invention include joint encoding of two sets of encoding for downlink and uplink. Figure 2 The typical three-layer stratified water injection system shown in the figure performs two-way communication. The downlink control signal is sent from the signal generator of the surface equipment, and the flow signal is transmitted to the designated downhole water distributor through the pipeline in a "broadcast" or "one-to-one" manner, and the flow signal is received by the downhole geophone, and then decoded by the control unit. According to the downlink control instruction, the downhole signal generator is controlled to work to form an uplink carrier signal, which is received and decoded by the surface flow geophone and converted into corresponding data.

[0140] Figure 2 The schematic diagram of a typical three-layer flow wave controlled stratified water injection system is shown in FIG. It includes a water pump, surface equipment and a downhole water distributor. The downhole water distributor is located in the wellbore and can be multiple. At least one is set in each injection layer. The injection layers are separated by packers. The water pump and the surface equipment are connected by a surface pipeline. The surface equipment is provided with a signal generator, a flow detector and a control unit (hereinafter referred to as the surface signal generator, the surface flow detector and the surface control unit, respectively). The surface pipeline is lowered from the wellhead into the wellbore and connected to the water distributor of each layer. As shown in the figure, a packer 1 and a water distributor 1 are provided in the injection layer 1, a packer 2 and a water distributor 2 are provided in the injection layer 2, and a packer 3 and a water distributor 3 are provided in the injection layer 3. The water distributor includes a signal generator, a flow detector and a control unit (hereinafter referred to as the downhole signal generator, the downhole flow detector and the downhole control unit, respectively). In this system, the system components added on the basis of the original facilities include: a surface signal generator, a surface flow detector, a surface control unit, and a downhole water distributor. Among them, the downhole water distributor includes a downhole signal generator (usually an electric-controlled water nozzle), a downhole flow detector, other instruments and a downhole control unit, etc. The rest is composed of a typical stratified water injection well structure, such as a packer, a one-way valve, a tubing, and a surface pipeline.

[0141] The method provided by the embodiment of the present invention has two communication modes, one is broadcast communication and the other is one-to-one communication; broadcast communication refers to the communication between the ground and the underground water distributor when the water distributors in each layer of the underground are in normal working state, which can be communication with only one water distributor at a time, or communication with multiple or even all water distributors at a time; one-to-one communication refers to data communication between the ground and only the intelligent water distributor of a single layer of the underground, while the intelligent water distributors of other layers do not participate and are in a temporarily closed state. The following embodiments 4 and 5 respectively describe these two modes.

[0142] Embodiment 4

[0143] Embodiment 4 of the present invention provides a specific implementation process of the underground wireless communication method based on time coding. Taking broadcast communication as an example, the communication system for implementing the method is shown in FIG. Figure 2 As shown, the method flow is shown in Figure 8 shown.

[0144] The downlink control signal is sent from the ground signal generator in the water distribution room in the form of a flow signal. The flow signal is transmitted to the downhole water distributor through the ground pipeline in a "broadcast" manner, and the flow signal is received by the downhole flow detector. It is then decoded by the downhole control unit and the downhole signal generator is controlled according to the downlink control signal to form an uplink carrier signal (i.e., uplink data signal), which is received and decoded by the ground flow detector and converted into corresponding data.

[0145] Before communication, all water distributors are in the wake-up standby state (the rest of the time they are in the low-power monitoring state).

[0146] The broadcast communication starts, and the relevant information for executing function X is input. The ground signal generator sends a downlink control signal in the form of a binary instruction, requiring each layer to upload the measured values ​​of the single-layer flow, the pressure before the mouth, and the pressure after the mouth in turn (a function of the intelligent water distributor, set as function X); the lower computer of the ground control unit controls the action of the ground signal generator to form a modulated binary downlink flow wave, which flows downward through the underground intelligent water distributor of each layer in turn. The process of the ground equipment signal generator sending the downlink control signal is shown in step S301.

[0147] The flow detector in the downhole water distributor receives the instruction sent by the surface equipment. As shown in the figure, downhole water distributor 1, downhole water distributor 2, and downhole water distributor 3 receive the instruction respectively. One of them is used as an example for explanation below. The downhole water distributor transmits the instruction to the downhole control unit. The downhole control unit determines whether the instruction is an instruction according to the coding rule (whether it is an instruction means whether it is a downlink control signal indicating that it uploads data). If not, it will not be executed and an error will be displayed. The layer where the downhole water distributor is located completes this communication, and the water nozzle resumes its opening and enters the standby state; if it is, it determines whether it is an instruction of function X; if not, function X will not be executed and an error will be displayed. The layer where the downhole water distributor is located completes this communication, and the water nozzle resumes its opening and enters the standby state; if it is, the downhole control unit controls the downhole signal generator to perform the time coding data upload of function X, and sends an uplink data signal, wherein the instruction includes the upload order, such as uploading in sequence from shallow to deep according to the distribution layer of the intelligent water distributor. The process of uploading the signal is shown in step S203.

[0148] The ground flow detector detects the data stream uploaded by the downhole water distributor and obtains the uplink data signal, which is decoded by the ground control unit for error checking and whether the data is true. If so, the measurement data is displayed on the control panel of the software; if not, the data is discarded and an error is displayed. After the fault is eliminated, the data is uploaded again. The process of data verification and reading of the uplink data signal is shown in step S303.

[0149] After completing the broadcast communication, the water nozzles in all underground water distributors will resume their original water injection openings and will all be in a wake-up standby state. If there is no instruction within the next N hours, they will enter a low-power monitoring state.

[0150] If the instruction involves multiple water distributors and needs to be uploaded in order, the water distributor that has not yet uploaded data will determine that the instruction is for itself and determine to execute function X. It can enter the waiting period according to the set waiting time. After the waiting period is over, that is, after the previous water distributor finishes uploading data, it will execute the corresponding function.

[0151] Embodiment 5

[0152] Embodiment 5 of the present invention provides a specific implementation process of the underground wireless communication method based on time coding. Taking one-to-one communication as an example, the communication system for implementing the method is shown in FIG. Figure 4 As shown, the method flow is shown in Fig. 9 shown.

[0153] When a certain layer or a certain injection well has a large interference and broadcast communication cannot be transmitted effectively, one-to-one communication is used instead, that is, the change in total flow is used as the signal, which has a strong signal and strong anti-interference ability.

[0154] The downlink control signal is sent from the ground signal generator in the water distribution room in the form of a flow signal. The flow signal is transmitted to the designated downhole water distributor through the ground pipeline in a "one-to-one" manner, and the flow signal is received by the downhole flow detector. It is then decoded by the downhole control unit and the downhole signal generator is controlled according to the downlink control signal to form an uplink carrier signal (i.e., uplink data signal), which is received and decoded by the ground flow detector and converted into corresponding data.

[0155] Before communication, all water distributors are in the wake-up standby state (the rest of the time they are in the low-power monitoring state).

[0156] One-to-one communication begins, the ground equipment signal generator generates a downlink control signal, and the upper computer of the ground control unit sends a downlink control signal, requiring that except for the downhole water distributor on the layer to be communicated (one of the layers), all other layers of downhole water distributors are closed; the ground equipment controller controls the action of the ground equipment signal generator to form a modulated binary downlink flow wave, which flows downward through the downhole water distributors of each layer in turn. The process of the ground equipment signal generator sending the downlink control signal is shown in step S301.

[0157] The flow detector in the underground water distributor receives the command sent by the surface equipment. As shown in the figure, underground water distributor 1, underground water distributor 2, and underground water distributor 3 receive the command respectively. One of them is used as an example for explanation. The underground water distributor transmits the command to the underground control unit. The underground control unit determines whether the command is a command according to the coding rules (whether it is a command means whether it is a downlink control signal indicating its own action). If not, it will not be executed and an error will be displayed. The layer where the underground water distributor is located completes this communication, and the water nozzle resumes its opening and enters the standby state; if it is, it determines whether it is a water nozzle closing command of the corresponding address. If not, the water nozzle remains open and stands by. If it is, an error will be displayed, and the lower computer of the underground control unit controls the underground signal generator to close the water nozzle. The layer where the underground water distributor is located completes this communication, and the water nozzle resumes its opening and enters the standby state. This command can be designed to automatically open the water nozzle after the water nozzle remains closed for n data upload times, and the opening degree is the same as before closing.

[0158] At this time, the closed and open status verification can be carried out, that is, the ground sends a command to the communication layer, requiring the layer to upload the current flow. If the uploaded flow is equivalent to the steady-state flow of the ground pumping (within the error range of 2%), it is considered that the state adjustment of the "one-to-one" communication is completed; if the flow error exceeds the specified range, the above work will be carried out after the fault is eliminated.

[0159] After the one-to-one status verification is completed, the relevant information for executing function X is input, and the surface signal generator sends a downlink control signal in the form of a binary instruction, requiring the "one-to-one" communication layer to upload the measured values ​​of the single-layer flow, the pressure before the mouth, and the pressure after the mouth of the previous recording point (a function of the intelligent water distributor, set as function Y); the surface control unit controls the action of the surface signal generator to form a modulated binary downlink flow wave, which flows to the downhole water distributor of this layer with a strong signal strength.

[0160] The flow detector in the downhole water distributor receives the instruction and transmits it to the downhole control control unit. The control unit determines whether the instruction is an instruction according to the coding rules. If not, it will not be executed and an error will be displayed. The layer where the communication is completed, the water nozzle will return to its original opening, and the state will be switched to standby. If so, it determines whether it is function Y. If not, function Y will not be executed and an error will be displayed. The layer where the communication is completed, the water nozzle will return to its original opening, and the state will be switched to standby. If so, the downhole control unit lower computer controls the downhole signal generator to upload the time-coded data of function Y. The process of uploading the signal is shown in step S203.

[0161] The ground flow detector obtains the uploaded data curve, that is, the ground flow detector detects the data stream, and the upper computer of the ground equipment control unit decodes it for error checking and determines whether the data is true. If it is true, the measurement data is displayed on the control panel of the software; if not, the data is discarded and an error is displayed. The layer completes the communication, the faucet returns to its original opening, and enters the standby state; after the fault is eliminated, data is uploaded again. The data verification and reading process of the uplink data signal refer to step S303.

[0162] After the communication is completed, all water distributor nozzles resume the original water filling opening and are in the wake-up standby state. If there is no instruction in the next N hours, they will enter the low-power monitoring state.

[0163] The above method is a low-power wireless communication time coding technology and error checking method that can take into account both the uploaded data volume and the transmission time consumption, providing support for the promotion and application of underground wireless communication technology.

[0164] Based on the same inventive concept, the embodiment of the present invention also provides a downhole wireless communication system based on time coding, the structure of the system is as follows Fig.10 As shown, it includes: a downhole water distributor 100 and surface equipment 200.

[0165] The structure of the underground water distributor 100 is as follows: Fig.11 As shown, it includes: a downhole geophone 11, a downhole control unit 12 and a downhole signal generator 13;

[0166] The downhole geophone 11, the downhole water distributor receives the downlink control signal sent by the surface equipment, the downlink control signal includes a function identifier indicating the water distributor to perform;

[0167] The downhole control unit 12 determines the measurement parameters included in the function and obtains the corresponding measurement data according to the function identifier carried in the downlink control signal; determines the encoding duration corresponding to each measurement parameter according to the measurement data of the measurement parameters

[0168] The downhole signal generator 13 is used to generate an uplink data signal based on time coding according to the coding duration and send it to the ground equipment; the frame body of the uplink data signal includes a positive code and an inverse code of a first set duration, a positive code in the frame body is used to carry the measurement data of a measurement parameter, and the positive code duration of each positive code is the coding duration corresponding to the represented measurement parameter; the inverse code in the frame body is used to space the positive code.

[0169] The structure of the above-mentioned ground equipment 200 is as follows: Fig.12 As shown, it includes: a ground flow detector 21, a ground signal generator 22 and a ground control unit 23;

[0170] A surface signal generator 21, used to send a downlink control signal to the downhole water distributor, wherein the downlink control signal includes a function identifier indicating the water distributor to execute;

[0171] The surface flow detector 22 is used to receive the uplink data signal sent by the downhole water distributor; the uplink data signal is generated by the downhole water distributor based on the measurement data of the measurement parameters, determining the encoding duration corresponding to each measurement parameter, and based on the encoding duration based on the time encoding method;

[0172] The ground control unit 23 is used to detect the positive code and the reverse code in the uplink data signal frame body, and determine the measurement data of the measurement parameter corresponding to each positive code according to the positive code duration of each positive code detected and the mapping relationship between the positive code duration of each positive code and the measurement data of the measurement parameter represented.

[0173] Regarding the downhole water distributor, surface equipment, and downhole wireless communication system based on time coding in the above-mentioned embodiments, the specific manner in which each module performs operations has been described in detail in the embodiments of the method and will not be elaborated here.

[0174] Unless otherwise specifically stated, terms such as processing, computing, calculating, determining, displaying, etc. may refer to the actions and / or processes of one or more processing or computing systems, or similar devices, which operate and convert data represented as physical (e.g., electronic) quantities within registers or memories of a processing system into other data similarly represented as physical quantities within memories, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0175] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0176] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0177] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the embodiments herein can all be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above around their functions. Whether such functions are implemented as hardware or software depends on specific applications and the design constraints imposed on the entire system. A skilled person can implement the described functions in an alternative manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of the present disclosure.

[0178] The steps of the method or algorithm described in conjunction with the embodiments herein may be directly embodied as hardware, a software module executed by a processor, or a combination thereof. The software module may be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a mobile disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and the storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and the storage medium may also be present in a user terminal as discrete components.

[0179] For software implementation, the techniques described in this application can be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described in this application. These software codes can be stored in a memory unit and executed by a processor. The memory unit can be implemented within the processor or outside the processor. In the latter case, it is coupled to the processor in a communication manner via various means, which are well known in the art.

[0180] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

Claims

1. A method for underground wireless communication based on time coding, characterized in that: include: The downhole water distributor receives a downlink control signal sent by the surface equipment, wherein the downlink control signal includes a function identifier indicating the water distributor to execute; Determine, according to the function identifier carried in the downlink control signal, the measurement parameters included in the function and obtain corresponding measurement data; According to the measurement data of the measurement parameter, the coding duration corresponding to each measurement parameter is determined, and an uplink data signal based on time coding is generated according to the coding duration and sent to the ground equipment; the frame body of the uplink data signal includes a positive code and an inverse code of a first set duration, a positive code in the frame body is used to carry the measurement data of a measurement parameter, and the positive code duration of each positive code is the coding duration corresponding to the represented measurement parameter; the inverse code in the frame body is used to space the positive code.

2. The method according to claim 1, characterized in that The uplink data signal includes a frame header, a frame body, a frame tail and a blank frame, wherein the frame header, the frame body and the frame tail include a positive code and an inverse code, and the blank frame is an inverse code of a second set time length; The positive code duration in the frame header is the third set duration, and the reverse code duration is the first set duration; The positive code duration in the frame body is the encoding duration of the measurement parameter corresponding to the positive code, and the inverse code duration is the first set duration; The inverted code duration in the frame tail is the fourth set duration, and the positive code duration is the fifth set duration.

3. The method according to claim 1, characterized in that The downhole water distributor receives the downlink control signal sent by the surface equipment, determines the measurement parameters included in the function and obtains the corresponding measurement data according to the function identifier carried in the downlink control signal, including: The downhole flow detector in the downhole water distributor receives the downlink control signal broadcasted or sent one-to-one by the ground equipment, and decodes the downlink control signal; the downlink control signal adopts a binary-coded flow wave; Determine whether the water distributor instruction is for itself according to the water distributor identification carried in the downlink control signal; If yes, determine the function to be executed and the measurement parameters included in the function according to the function identifier carried in the downlink control signal, and obtain corresponding measurement data.

4. The method according to claim 1, characterized in that Determining, according to the measurement data of the measurement parameters, a coding duration corresponding to each measurement parameter, and generating, according to the coding duration, an uplink data signal based on time coding and sending it to a ground device, including: The downhole water distributor determines the positive code duration corresponding to each measurement parameter according to each measurement parameter and its measurement data; Generate an uplink data signal including a frame header, a frame body and a frame tail with alternating positive codes and inverse codes according to a preset frame header positive code duration and a frame header inverse code duration, a positive code duration corresponding to each measurement parameter and an inverse code duration used to space the positive code, a preset frame tail positive code duration and a frame tail inverse code duration, and a preset blank frame duration; the frame body includes a positive code duration corresponding to each measurement parameter and the inverse codes therebetween; The downhole water distributor controls the opening and closing of the water nozzle according to the duration of the positive code and the negative code included in the uplink data signal to form a corresponding flow wave and transmit it to the surface equipment.

5. The method according to claim 4, characterized in that The downhole water distributor controls the opening and closing of the water nozzle according to the duration of the positive code and the negative code included in the uplink data signal to form a corresponding flow wave, including: The downhole water distributor determines the flow rate based on the duration of the positive code and the negative code included in the uplink data signal and the mapping relationship between the duration and the flow rate, and controls the opening and closing durations of the water nozzles according to the flow rate to form a corresponding flow wave.

6. The method according to claim 1, characterized in that Also includes: The downhole water distributor receives a downlink wake-up signal sent by the surface equipment before receiving the downlink control signal sent by the surface equipment, and adjusts its own state to the wake-up standby state according to the downlink wake-up signal; and / or The downhole water distributor does not receive any signal from the surface equipment within the set monitoring time and adjusts its state to a low-power monitoring state.

7. A method for underground wireless communication based on time coding, characterized in that: include: The surface equipment sends a downlink control signal to the downhole water distributor; the downlink control signal includes a function identifier instructing the water distributor to perform, so that the downhole water distributor determines the measurement parameters included in the function and obtains the corresponding measurement data according to the function identifier carried in the downlink control signal; Receive an uplink data signal sent by a downhole water distributor; the uplink data signal is generated by the downhole water distributor based on the measurement data of the measurement parameter, determining the encoding duration corresponding to each measurement parameter, and based on the time encoding method according to the encoding duration; The positive code and the inverse code in the uplink data signal frame body are detected, and the measurement data of the measurement parameter corresponding to each positive code is determined according to the positive code duration of each positive code detected and the mapping relationship between the positive code duration of each positive code and the measurement data of the represented measurement parameter.

8. The method according to claim 7, characterized in that The surface equipment sends a downlink control signal to the downhole water distributor, including: The surface equipment determines the downhole water distributor that needs to upload data according to the layer position of the downhole water distributor and the set data upload order, generates a downlink control signal including a downhole water distributor identifier and a function identifier indicating the water distributor to be executed, and sends it one-to-one to the downhole water distributor that needs to upload data or sends it to the downhole water distributor by broadcasting.

9. The method according to any one of claims 7-8, characterized in that: The downlink control signal adopts a binary-coded flow wave, and the downlink control signal includes a frame header, an instruction frame, a check frame and a frame tail. The binary bits of the frame header, the instruction frame, the check frame and the frame tail are preset. The instruction frame includes a function identifier, and the check frame includes a downhole water distributor identifier.

10. The method according to claim 8, characterized in that Receiving an uplink data signal sent by a downhole water distributor; detecting a positive code and an inverse code in a frame body of the uplink data signal, and determining the measurement data of the measurement parameter corresponding to each positive code according to the positive code duration of each positive code detected, and a mapping relationship between the positive code duration of each positive code and the measurement data of the measurement parameter represented, including: The surface flow detector in the surface equipment receives the uplink data signal sent by the downhole water distributor, decodes the received uplink signal, and obtains the total duration of the uplink data signal, including the positive code and the positive code duration, the inverse code and the inverse code duration; Performing error checking and adjustment on the uplink data signal according to the total duration of the uplink data signal and a preset checking rule; The frame header, frame body, frame tail and blank frame are determined according to the positive code and its duration, the inverse code and its duration. The measurement data of the measurement parameter corresponding to each positive code in the frame body is determined according to the mapping relationship between the positive code duration of each positive code in the frame body and the measurement data of the measurement parameter represented.

11. The method according to claim 10, characterized in that Performing error checking and adjustment on the uplink data signal according to the total duration of the uplink data signal and a preset checking rule, including: The ground equipment controller compares the total duration of the uplink data signal with the total duration preset by the time code; If the duration error between the two is within a preset duration error range, the total duration of the decoded data is corrected according to the principle of proportional correction to obtain a corrected total duration of the uplink data signal; If the duration error between the two is not within the preset duration error range, the uplink data signal is discarded, a fault warning is issued, and the uplink data signal is received again after the fault is eliminated.

12. The method according to claim 11, characterized in that Determining the measurement data of the measurement parameter corresponding to each positive code according to the positive code duration of each positive code detected and the mapping relationship between the positive code duration of each positive code and the measurement data of the represented measurement parameter, including: According to the positive code duration of each positive code detected, the measured data is read through the mapping relationship between the positive code duration of each positive code and the measured data represented. The mapping relationship between the duration and the measured data is: y=log b (ax+c)+d; Among them, a, b, c, d are mapping parameters of the duration and the measurement data, x is the positive code duration or the reverse code duration, and y is the measurement data corresponding to x.

13. The method according to claim 7, characterized in that Also includes: Before the surface equipment sends a downlink control signal to the downhole water distributor, the surface equipment sends a downlink wake-up signal to the downhole water distributor, so that the water distributor adjusts its own state to the wake-up standby state according to the downlink wake-up signal.

14. A downhole water distributor, characterized in that: include: Downhole geophone, downhole control unit and downhole signal generator; The downhole geophone, the downhole water distributor receives a downlink control signal sent by the surface equipment, the downlink control signal includes a function identifier indicating the water distributor to perform; The downhole control unit determines the measurement parameters included in the function and obtains the corresponding measurement data according to the function identifier carried in the downlink control signal; determines the encoding duration corresponding to each measurement parameter according to the measurement data of the measurement parameters A downhole signal generator is used to generate an uplink data signal based on time coding according to the coding duration and send it to the ground equipment; the frame body of the uplink data signal includes a positive code and an inverse code of a first set duration, a positive code in the frame body is used to carry the measurement data of a measurement parameter, and the positive code duration of each positive code is the coding duration corresponding to the represented measurement parameter; the inverse code in the frame body is used to space the positive code.

15. A ground device, characterized in that: include: Surface flow detector, surface signal generator and surface control unit; A surface signal generator, used to send a downlink control signal to the downhole water distributor, wherein the downlink control signal includes a function identifier indicating the water distributor to perform; A surface flow detector, used to receive an uplink data signal sent by a downhole water distributor; the uplink data signal is generated by the downhole water distributor based on the measurement data of the measurement parameter, determining the encoding duration corresponding to each measurement parameter, and based on the time encoding method according to the encoding duration; The ground control unit is used to detect the positive code and the inverse code in the uplink data signal frame body, and determine the measurement data of the measurement parameter corresponding to each positive code according to the positive code duration of each positive code detected and the mapping relationship between the positive code duration of each positive code and the measurement data of the measurement parameter represented.

16. A time-coding-based underground wireless communication system, characterized in that: include: The surface equipment as claimed in claim 15 and the downhole water distributor as claimed in claim 14.

Images