A two-way wireless communication system and method for underground mines

Abstract

The present invention provides a novel downhole two-way wireless communication system and method. The novel downhole two-way wireless communication system includes a surface part, a downhole part and a radio frequency signal ball. The radio frequency signal ball is divided into a control ball and a feedback ball. After the surface part writes control information into the control ball, the control ball sinks from the wellhead into the well. When passing through the downhole part, the downhole part reads the control information in the control ball, adjusts the opening of the downhole switch valve, writes the information required for feedback into the feedback ball, and releases the feedback ball into the well fluid. The feedback ball floats to the wellhead in the well fluid, and the surface part reads the feedback information in the feedback ball and performs signal processing. The novel downhole two-way wireless communication system and method are convenient to construct, simple in structure, can realize two-way instant communication between the well and the downhole, and provide a new technical path for oil fields to realize reliable, stable and long-life intelligent injection and production.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent stratified injection and production in oil fields, and in particular to an underground two-way wireless communication system and method. Background Art

[0002] At present, Shengli Oilfield has entered the middle and late stages of development, with a rapid increase in water content, prominent contradictions between oil layers, and serious interlayer interference. Layered injection and production of different production layers to achieve real-time allocation of production layers can effectively reduce interlayer contradictions and improve recovery. The core technology of intelligent layered injection and production is to effectively control the opening and closing of valves of each target oil layer in the well in real time. At present, intelligent injection and production is divided into two categories: cable communication and wireless communication. Cable communication has high data transmission reliability, high information data rate, and large amount of information. It is widely used on site, but there is a problem that the cable is easily broken during the construction process. The application of wireless communication technology in intelligent layered injection and production in oil fields is a great technical challenge: the well fluid is a three-phase flow of oil, gas and water, the well fluid is discontinuous, there is slug flow, the wellbore space is small, and the wireless signal will be reflected, refracted, attenuated, multipath and other effects in the transmission process of different media, which poses a challenge to the signal transmission and demodulation technology. At present, there are three main types of wireless downhole communication technologies in the world: acoustic wave, electromagnetic, and pressure pulse. Acoustic downhole wireless communication technology is currently the most mature and widely used communication technology in the downhole environment of oil fields. This technology uses sound waves as carriers and oil pipes as transmission media. Due to the attenuation of sound wave energy, the transmission distance is limited, usually only 500 meters. Compared with oil wells that are several thousand meters long, the acoustic wave wireless transmission system requires multiple repeaters to complete. Therefore, the battery power supply problem of the repeater is the key to ensuring the reliability and life of the acoustic wave communication system; electromagnetic technology is widely used in the field of communication, but it is difficult to apply in oil and water wells. The transmission distance of electromagnetic waves in liquid is inversely proportional to its frequency. Therefore, the transmission distance of electromagnetic waves in well fluid is very short, and the use of electromagnetic waves with large wavelengths consumes more power. Therefore, electromagnetic waves cannot be transmitted in well fluid. Electromagnetic waves are transmitted in oil pipes with a transmission distance of 600 meters, and repeaters are required like acoustic wave transmission technology. Pressure pulse technology is currently a commonly used downhole intelligent switch control technology on site. Its advantage is that one-way communication from the wellhead to the downhole can be achieved by hydraulic pressure according to a predetermined code. The disadvantage is that this method requires the liquid in the wellbore to be a closed and continuous pressure system, and is not suitable for use when a large amount of well fluid is lost.

[0003] In summary, the above three existing wireless measurement and control methods have their advantages and disadvantages, and are suitable for specific applications. However, for intelligent stratified injection and production, none of them fully realizes the technical requirements of two-way communication, long life, high reliability, low power consumption and low cost.

[0004] In the Chinese patent application with application number: CN201610291943.3, a wireless intelligent control system for oil wells based on radio frequency identification technology is involved, including radio frequency tags, radio frequency identification control systems, downhole measurement control systems, passive wake-up tags, sleep wake-up control systems and power management systems. The radio frequency tags and radio frequency identification control systems can perform two-way wireless communication, and the power management system supplies power to the radio frequency identification control system and the downhole measurement control system; the passive wake-up tags are connected to the radio frequency identification control system signal line, and the sleep wake-up control system is a reader and can communicate wirelessly with the passive wake-up tags. The system focuses on the wake-up process and is applied to the drilling process, and the radio frequency tags are discharged out of the well along with the drilling fluid.

[0005] In the Chinese patent application with application number: CN202010288877.0, a petroleum downhole parameter acquisition system based on a smart chip is involved, comprising a ground control system (1), an RS485 industrial communication network (2), a ground capture device (3) and a smart chip (4); the smart chip (4) collects downhole parameters and then brings them to the ground through backflow, the ground capture device (3) collects downhole parameter information through wireless radio frequency transmission and transmits it to the ground control system through the RS485 industrial communication network (2); the smart chip (4) comprises a housing ( 5), a first radio frequency coil (6), a first microprocessor (7), a micro battery (8), a sensor (9) and a counterweight (10) integrated inside the housing (5); the first microprocessor (7) is electrically connected to the first radio frequency coil (6), the micro battery (8) and the sensor (9) respectively; the ground capture device (3) includes a ceramic pipe (12) installed on the metal pipe through a metal pipe flange (11), a second radio frequency coil (13) wound outside the ceramic pipe (12) and a second microprocessor (14) connected to the second radio frequency coil (13). This invention patent is a parameter acquisition system for a smart chip, not a two-way communication system. When the smart chip flowing out of the well with the return fluid flows through the system, the system bundled on the official road can read the information in the smart chip.

[0006] The Chinese patent application with application number: CN201710307954.0 involves a downhole pressure and temperature measurement signal transmission system and method based on radio frequency technology, including a downhole measurement device, a downhole radio frequency read-write unit, a radio frequency tag, a ground radio frequency read-write unit, and a host computer. The system is applied in the field of drilling technology, and the radio frequency tag is discharged out of the well along with the drilling fluid.

[0007] In the Chinese patent application with application number: CN201711468373.1, the present invention relates to the field of oil fracturing and testing technology, and in particular to a downhole fracturing data wireless transmission device. It includes a command tag, a ground information ball data reading device, a tag delivery device and an information ball capture device installed at the wellhead, a motor control and ball delivery short section installed on the continuous oil pipe, a main control communication short section, a data acquisition short section and a battery pack; it is applied to pressure testing technology, and the command tag is discharged out of the well through the return.

[0008] In the Chinese patent application with application number: CN201410798838.X, the present invention relates to the field of oil and gas development and exploration, and in particular to a data transmission system and method for transmitting downhole measurement data while drilling to the ground, the system comprising: a drill string equipped with a logging while drilling measurement tool; a short section while drilling, which contains a micro memory. The system has a short section while drilling installed on the drill string, and a radio frequency tag is contained in the short section. The radio frequency tag is released during the drilling process, and mud is used as the transmission medium of the radio frequency tag, and the radio frequency tag is discharged back out of the well.

[0009] The above patents all cite that the RFID tag is delivered into the well, dropped into the well, or discharged out of the well.

[0010] To this end, we have invented a new underground two-way wireless communication system and method to solve the above technical problems. Summary of the invention

[0011] The object of the present invention is to provide a downhole two-way wireless communication system and method for realizing downhole wireless communication by bidirectionally throwing signal balls based on radio frequency technology.

[0012] The purpose of the present invention can be achieved through the following technical measures: a downhole two-way wireless communication system, which includes a ground part, a downhole part and a radio frequency signal ball. The ground part and the downhole part communicate wirelessly through the radio frequency signal ball. The radio frequency signal ball is divided into a control ball and a feedback ball. The control ball can fall freely in the wellbore, and the feedback ball can automatically float to the wellhead in the well fluid. After the ground part writes control information into the control ball, the control ball sinks from the wellhead into the well. When passing through the downhole part, the downhole part reads the control information in the control ball, adjusts the opening of the downhole switch valve, writes the information that needs to be fed back into the feedback ball, and releases the feedback ball into the well fluid. When the feedback ball floats to the wellhead in the well fluid, the ground part reads the feedback information in the feedback ball and performs signal processing.

[0013] The purpose of the present invention can also be achieved by the following technical measures:

[0014] The ground part includes an uphole reader / writer, which includes a central processing unit, a signal processing module and an antenna. The antenna is connected to the signal processing module to read the feedback information in the feedback ball and send it to the signal processing module. The signal processing module is connected to the central processing unit, receives the feedback information transmitted by the antenna, filters and amplifies the feedback information, and then transmits it to the central processing unit. The central processing unit receives the feedback information sent by the signal processing module; the central processing unit also receives a control signal and transmits the control signal to the signal processing module. The signal processing module transmits the control signal transmitted by the central processing unit to the antenna, and the antenna writes the control information into the control ball.

[0015] The ground part also includes a host computer, which is connected to the central processor, sends a control signal to the central processor, and displays and stores feedback information transmitted from the central processor.

[0016] The ground part also includes a wireless mobile signal transceiver, which is connected to the central processor and connected to the computer through a wireless base station. The wireless mobile signal transceiver sends the control signal wirelessly transmitted from the computer to the central processor, and wirelessly transmits the feedback information transmitted from the central processor to the computer for display and storage.

[0017] The ground part also includes a clock synchronization module, which is connected to the central processor and sends a clock synchronization signal to the central processor. The central processor reads the clock synchronization signal and sets the sampling frequency.

[0018] The downhole part includes a downhole controller and a downhole antenna. The downhole controller includes a downhole central processor, a downhole signal processing module, a motor and a motor drive module, a downhole switch valve and a memory. The central processor is connected to the downhole signal processing module and sends a detection signal to the downhole signal processing module. The downhole signal processing module is connected to the downhole antenna, receives the detection signal sent by the downhole central processor, and sends the detection signal to the downhole antenna. After receiving the detection signal, the downhole antenna emits a radio frequency magnetic field to detect the control ball, reads the control signal in the control ball, and transmits the control signal to the downhole signal processing module. The downhole signal processing module filters and amplifies the control signal and then transmits it to the downhole central processor. The downhole central processor is connected to the motor and the motor drive module and the memory, stores the control signal in the memory, and sends it to the motor and the motor drive module. The motor and the motor drive module are connected to the downhole switch valve and receive the control signal transmitted by the downhole central processor to drive the downhole switch valve to operate.

[0019] The downhole part also includes a sensor and signal processing module, a feedback ball storage and signal reading and writing module and a feedback ball transmitting module. The sensor and signal processing module is connected to the downhole central processor, collects parameters of the production layer and performs signal processing, and sends the signals to the downhole central processor. The downhole central processor is connected to the feedback ball storage and signal reading and writing module, stores parameter information in the memory, and sends the parameter information to the feedback ball storage and signal reading and writing module. The feedback ball storage and signal reading and writing module is connected to the feedback ball reflection module, stores parameter information and writes information to be fed back to the feedback ball, and then sends the reading and writing completion information to the downhole central processor. After receiving the reading and writing completion information, the downhole central processor controls the feedback ball storage and signal reading and writing module to push the feedback ball to the feedback ball transmitting module, and the feedback ball transmitting module transmits the feedback ball into the well fluid.

[0020] The downhole part also includes a downhole clock synchronization module, which is connected to the downhole central processor and sends a clock synchronization signal to the downhole central processor. The downhole central processor reads the clock synchronization signal and sets the sampling frequency.

[0021] The radio frequency signal ball has a chip inside, a round shell made of a hard non-metallic material, and an inner filler made of a non-metallic material, which has the function of fixing the chip.

[0022] The control ball has a density greater than the well fluid, and the feedback ball has a density less than the well fluid.

[0023] The control ball is formed by bonding multiple feedback balls together through soluble materials. The overall density of the control ball is greater than the well fluid. When it goes down to the bottom of the well, after the communication is completed, the soluble material dissolves, and the multiple feedback balls inside float up to the wellhead to complete the two-way communication.

[0024] The object of the present invention can also be achieved by the following technical measures: a downhole two-way wireless communication method, the downhole two-way wireless communication method adopts the downhole two-way wireless communication system according to claim 1, comprising:

[0025] Step 1: The ground part writes control information into the control ball;

[0026] Step 2, controlling the ball to sink from the wellhead into the well;

[0027] Step 3, when the control ball passes through the downhole part, the downhole part reads the control information in the control ball;

[0028] Step 4: The downhole part adjusts the opening of the downhole switch valve according to the control information, and writes the information to be fed back into the feedback ball;

[0029] Step 5, the downhole part releases the feedback ball into the well fluid;

[0030] Step 6: When the feedback ball floats up to the wellhead in the well fluid, the surface part reads the feedback information in the feedback ball and performs signal processing.

[0031] The purpose of the present invention can also be achieved by the following technical measures:

[0032] The underground two-way wireless communication method also includes, before step 1, the ground part reads the information of the inserted radio frequency signal ball, and enters step 1 for controlling the ball; and enters step 6 for feeding back the ball.

[0033] In step 1, the control information includes layer position, valve opening degree, requested temperature, and requested pressure.

[0034] In step 4, the feedback information includes the temperature, pressure, and flow rate of the corresponding layer in the well.

[0035] The downhole two-way wireless communication system and method of the present invention can realize two-way communication between the wellhead and the downhole without moving the pipe string: it can realize wireless control of the downhole intelligent layered switch from the ground, and can also realize the feedback of data such as downhole formation parameters and switch valve status to the wellhead. This method has low production and maintenance costs, convenient operation, and flexible and fast communication methods. It is an effective and feasible method for downhole wireless measurement and control. The downhole two-way wireless communication system and method of the present invention fully utilize the structural characteristics of the wellbore, effectively overcome the defects of the existing three types of downhole wireless communications, namely pulse, acoustic and electromagnetic, in the application of oil wells, and can ensure the reliability and integrity of the signal during the transmission process between the well and the downhole. It is convenient to construct, simple in structure, and can realize two-way instant communication between the well and the downhole, providing a new technical path for oil fields to achieve reliable, stable and long-life intelligent injection and production. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural diagram of a specific embodiment of the underground two-way wireless communication system of the present invention;

[0037] Figure 2 It is a general structural block diagram of the ground part of a downhole two-way wireless communication system in a specific embodiment of the present invention;

[0038] Figure 3 It is a structural block diagram of the ground part of a downhole two-way wireless communication system in a specific embodiment of the present invention;

[0039] Figure 4 It is a general structural block diagram of the downhole part of a downhole two-way wireless communication system in a specific embodiment of the present invention;

[0040] Figure 5It is a block diagram of the subdivided structure of the downhole part of a downhole two-way wireless communication system in a specific embodiment of the present invention;

[0041] Figure 6 It is a flow chart of a ground operation method in a specific embodiment of the present invention;

[0042] Figure 7 It is a flow chart of a downhole operation method in a specific embodiment of the present invention;

[0043] Figure 8 This is a schematic diagram of the structure of an information ball in a specific embodiment of the present invention;

[0044] Fig. 9 It is a schematic diagram of the structure of a soluble radio frequency ball in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0045] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0046] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations and / or combinations thereof.

[0047] like Figure 1 As shown, a downhole two-way wireless communication system provided by the present invention comprises: a surface part 100, a downhole part 200 and a signal ball 300. The surface part 100 and the downhole part 200 perform wireless communication via the radio frequency signal ball 300.

[0048] The signal ball is divided into a control ball 310 and a feedback ball 320. The control ball 310 has a density greater than the well fluid and can fall freely in the wellbore; the feedback ball 320 has a density less than the well fluid and can automatically float to the wellhead in the oil-gas-water three-phase mixed flow well fluid. The signal ball 300 uses radio frequency wireless communication with the ground part 100 and the downhole part 200. The ground part 100 is used to read the signal in the feedback ball 320, write the signal to the control ball 310, and realize human-computer interaction through the host computer. The downhole part 200 is used to read the signal in the control ball 310, write the signal to the feedback ball 320, read and store the sensor signal of the corresponding layer, transmit the feedback ball 320, and control the downhole switch valve 214.

[0049] like Figure 2 As shown, the ground part 100 is composed of a host computer 110 and an uphole reader / writer 120. The host computer 110 is used for human-computer interaction; the uphole reader / writer 120 is used for reading and writing the signal ball 300.

[0050] like Figure 3 As shown, the well reader 120 is composed of a central processor 121, a signal processing module 122, an antenna 123, and a clock synchronization module 124. The antenna 123 is connected to the central processor 121 through the signal processing module 122, and the clock synchronization module 124 is connected to the central processor 121. The host computer 110 is connected to the central processor 121. The antenna 123 is connected to the signal ball 300 through a wireless radio frequency signal.

[0051] The central processing unit 121 is used to set the sampling frequency, receive data transmitted by the signal processing module 122, and transmit it to the host computer 110, receive instructions sent by the host computer 110, transmit them to the signal processing module 122, and read the clock synchronization signal; the signal processing module 122 is used to filter and amplify the signal of the antenna 123, and transmit it to the central processing unit 121, receive the signal of the central processing unit 121, and send it to the antenna 123; the antenna 123 is used to read and write the signal ball 300; the clock synchronization module 124 is used to send a clock signal to the central processing unit 121.

[0052] like Figure 4 As shown, the downhole part 200 includes a downhole controller 210 and a downhole antenna 220. The downhole controller 210 is used to control the downhole switch valve 214, read the sensor and signal processing module 216, write the signal to the feedback ball and transmit the feedback ball, and read the signal of the downhole antenna 220. The downhole antenna 220 is used to read the signal in the control ball 310 and transmit it to the signal processing module 212.

[0053] like Figure 5As shown, the downhole controller 210 includes: the downhole controller 210 includes: a central processor 211, a signal processing module 212, a motor and a motor driving module 213, a downhole switch valve 214, a memory 215, a sensor and a signal processing module 216, a feedback ball storage and signal reading and writing module 217, a feedback ball transmitting module 218, and a clock synchronization module 219. The feedback ball transmitting module 218 is connected to the central processor 211 through the feedback ball signal reading and writing module 217; the downhole switch valve 214 is connected to the central processor 211 through the motor and the motor driving module 213; the downhole antenna 220 is connected to the central processor 211 through the signal processing module 212; the sensor and the signal processing module 216, the clock synchronization module 219, and the memory 215 are directly connected to the central processor 211. The feedback ball signal reading and writing module 217 is connected to the feedback ball 320 through a wireless radio frequency signal. The feedback ball transmitting module 218 releases the feedback ball 320 into the well fluid. The downhole antenna 220 is connected to the control ball 310 via a radio frequency signal.

[0054] The central processor 211 is used to read the sensor and signal processing module 216 and store them in the memory 215, read the signal of the signal processing module 212 and store the execution instruction, control the switch of the downhole switch valve 214, control the downhole antenna 220 to transmit the radio frequency magnetic field for detecting the control ball 310, control the feedback ball reading and writing module 217 to write information to the feedback ball, and control the feedback ball transmitting module 218 to transmit the feedback ball 320 into the well fluid; the signal processing module 212 is used to filter and amplify the signal of the downhole antenna 220 and transmit it to the central processor 211, and receive the signal of the central processor 211 to the downhole antenna 220 for transmitting the radio frequency magnetic field; the motor and motor driving module 213 are used to receive the central processor 211 The control signal drives the downhole switch 214 to switch; the downhole switch valve 214 is used to receive information from the motor and the motor drive module 213, and perform the switch action; the memory 215 is used to store the storage information from the central processing unit 211; the sensor and signal processing module 216 is used to test the parameters of the production layer and perform signal processing, and send it to the central processing unit 211; the feedback ball storage and signal reading and writing module 217 is used to store and write information to the feedback ball, push the ball to the feedback ball transmitting module 218, and send the reading and writing completion information to the central processing unit 211; the feedback ball transmitting module 218 is used to transmit the feedback ball 320 into the well fluid; the clock synchronization module 219 is used to provide a clock signal for the central processing unit 211.

[0055] The signal transmission process of the signal ball is as follows: On the ground, the uphole read-write module 120 pre-writes the control information in the chip in the control ball 310 through the radio frequency signal, and the control ball 310 is dropped from the wellhead into the well, and sinks into the well under the action of gravity. When the control ball 310 passes through the sensing area of ​​the downhole antenna 220, the downhole controller 210 is switched from the low-power standby mode to the working mode, and the instructions in the control ball 310 are read through the radio frequency signal, transmitted to the central processor 211, and the next action is executed. The control ball falls to the bottom of the well under the action of gravity. Downhole, the feedback ball signal reading and writing module 217 in the downhole controller 210 stores a plurality of feedback balls 320 in advance. The feedback ball signal reading and writing module 217 writes the parameters to be fed back (including layer position, formation temperature, pressure, flow, downhole switch valve opening, number of remaining feedback balls, etc.) into the feedback ball 320 pre-placed in the downhole controller through radio frequency signals. The feedback ball transmitting module 218 in the downhole controller 210 releases the feedback ball 320 to the well fluid. The density of the feedback ball 320 is less than that of the well fluid. Under the action of buoyancy and electric pumping, it rises from the downhole to the wellhead. When the feedback ball 320 reaches the wellhead, the information is read out by the uphole reader 120 and displayed and stored in the host computer 110.

[0056] The present invention provides an underground two-way wireless communication method, which includes a ground operation method and an underground operation method.

[0057] like Figure 6 As shown, the ground operation method includes the following steps:

[0058] Step 1) Identify the properties of the ball

[0059] The upper computer 110 reads the information of the information ball 300 placed in the well reader 120. If it is a control ball 310, it goes to step 2); if it is a feedback ball 320, it goes to step 5); (usually the size and weight of the control ball 310 and the feedback ball 320, as well as the marking marks in the pre-implanted chip are different)

[0060] Step 2) Write control information

[0061] The host computer 110 is controlled to write control information into the control ball 310 through the well reader 120. The control information includes but is not limited to: layer position, valve opening and closing degree, requested temperature, requested pressure, etc.;

[0062] Step 3) Confirm whether the control information is written correctly

[0063] The host computer 110 reads the information written in the control ball 310 and compares whether it is written correctly. If it is correct, it will display the completion and go to step 4). If it is wrong, repeat step 2);

[0064] Step 4) taking out the ball, the host computer 110 is in standby mode;

[0065] Step 5) Read feedback information

[0066] The host computer 110 reads the information in the feedback ball 320 through the well reader 120 to the host computer 110 , and displays and stores the information in the host computer 110 .

[0067] Step 6) Confirm whether the feedback information is read correctly

[0068] Read the information in the feedback ball 320 again and compare it with the information read in step 5). If they are consistent, proceed to step 4). If the comparison results are different, repeat step 5);

[0069] like Figure 7 As shown, the downhole operation method includes the following steps:

[0070] Step 1) Standby mode

[0071] The downhole controller 210 is in standby mode, and according to the pre-defined working system, actively tests the downhole layer temperature, pressure and other information and stores them in the memory 215. The downhole controller 210 actively reads the downhole antenna 220 signal to determine whether the control ball 310 passes through the identifiable area of ​​the downhole antenna 220; if yes, execute step 2), if not, continue with step 1);

[0072] Step 2) Read the control ball 310 information

[0073] The central processor 211 reads the information of the control ball 310, stores the information in the memory 215 in the downhole controller 210, and determines whether the information reading of the control ball 310 is correct and feasible. If yes, execute step 3); if not, write the failure information into the memory 215. Execute step 1);

[0074] Step 3) Adjust the downhole switch valve 214

[0075] The CPU 211 determines whether it is necessary to adjust the opening of the downhole switch valve 214 according to the control information. If yes, the CPU 211 controls the motor and the motor driving module 213 to adjust the opening of the downhole switch valve 214 and stores the downhole switch valve 214 adjustment completion instruction in the memory 215.

[0076] If no, go to step 4;

[0077] Step 4) Read downhole parameter information

[0078] The central processing unit 211 determines whether it is necessary to read downhole parameter information from the downhole memory 215 based on the control information. If so, it reads data from the sensor and signal processing module 216 and saves it to the memory 215; if not, it executes step 5; the downhole parameter information includes but is not limited to the temperature, pressure, and flow rate of the corresponding layer in the downhole.

[0079] Step 5) Write feedback

[0080] The central processor 211 determines whether it is necessary to send the feedback ball 320 according to the control information. If yes, the central processor 211 reads the information in the memory 215 and writes it into the feedback ball 320 through the feedback ball reading and writing module 217. If no, the central processor 211 executes step 1).

[0081] Step 6) Determine whether the feedback information is written correctly

[0082] The central processing unit 211 reads the feedback information in the feedback ball 320 in step 5. If it is consistent with the information in the memory 215, the writing is correct and step 7) is executed; otherwise, step 5) is executed;

[0083] Step 7) Launch the feedback ball

[0084] Push the feedback ball 320 from the feedback ball signal reading and writing module 217 into the feedback ball transmitting module 218 and release it into the well fluid. The downhole controller 210 enters the standby state. Execute step 1);

[0085] After the feedback ball 320 floats up to the wellhead, the signal in the feedback ball 320 is read by the reader / writer 120 on the well and sent to the host computer 110 for processing and interpretation, thereby realizing wireless transmission of the downhole signal.

[0086] The information ball 300 used in the present invention has a structure as follows: Figure 8 As shown, there are two types of balls: control ball 310 and feedback ball 320. The shell of information ball 300 is round in shape and made of hard non-metallic material, which has a sealing and protective effect and can be used in high temperature, high pressure and corrosive environment underground. The filler inside the information ball 300 is non-metallic material, which has the function of fixing the chip. The chip is usually in the form of a sheet, square or round. Both control balls 310 and feedback balls 320 are equipped with chips, which can be used for writing and reading radio frequency signals, but they should meet the underground temperature, pressure, corrosion and other environments. The difference between the two balls: the density of the control ball 310 is greater than the well fluid, so it can fall freely in the well fluid to the bottom of the well, and the density of the feedback ball 320 is less than the well fluid, so it can automatically float to the wellhead in the well fluid. To ensure the reliability of information transmission, the information ball 300 carrying the same information, that is, the control ball 310 or the feedback ball 320, can be sent 1-N at a time.

[0087] In a specific embodiment of the present invention, an alternative solution of information balls is adopted: a soluble radio frequency ball having a structure as follows Fig. 9 As shown: the control ball is made of multiple feedback balls bonded by soluble materials. The overall density of the control ball is greater than the well fluid. When it goes down to the bottom of the well, the soluble material dissolves after the communication is completed, and the internal feedback ball floats up to the wellhead, completing two-way communication.

[0088] In another specific embodiment of the present invention, an alternative solution to the host computer 110 is adopted: a wireless mobile signal transceiver is used to replace the host computer, and the signal is sent to the wireless base station, and finally to the office indoor computer, in which the production well management software is pre-installed to realize the processing of downhole signals and the determination and sending of new control instructions. The control instruction is sent back from the indoor computer to the wellhead wireless signal transceiver via the wireless mobile base station, and further sent to the well reader, throwing the signal ball to the well to realize the control of the downhole controller.

[0089] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0090] Except for the technical features described in the specification, all other technical features are known technologies to those skilled in the art.

Claims

1. A two-way wireless communication system for underground mines, characterized in that: The underground two-way wireless communication system includes a surface part, an underground part and a radio frequency signal ball. The surface part and the underground part perform wireless communication through the radio frequency signal ball. The radio frequency signal ball is divided into a control ball and a feedback ball. The control ball can fall freely in the wellbore, and the feedback ball can automatically float to the wellhead in the well fluid. After the surface part writes control information into the control ball, the control ball sinks from the wellhead into the well. When passing through the underground part, the underground part reads the control information in the control ball, adjusts the opening of the underground switch valve, writes the information required for feedback into the feedback ball, and releases the feedback ball into the well fluid. When the feedback ball floats to the wellhead in the well fluid, the surface part reads the feedback information in the feedback ball and performs signal processing. The control ball is formed by bonding multiple feedback balls together through soluble materials. The overall density of the control ball is greater than the well fluid. When it goes down to the bottom of the well, after the communication is completed, the soluble material dissolves, and the multiple feedback balls inside float up to the wellhead to complete the two-way communication.

2. The underground two-way wireless communication system according to claim 1, characterized in that: The ground part includes an uphole reader / writer, which includes a central processing unit, a signal processing module and an antenna. The antenna is connected to the signal processing module to read the feedback information in the feedback ball and send it to the signal processing module. The signal processing module is connected to the central processing unit, receives the feedback information transmitted by the antenna, filters and amplifies the feedback information, and then transmits it to the central processing unit. The central processing unit receives the feedback information sent by the signal processing module; the central processing unit also receives a control signal and transmits the control signal to the signal processing module. The signal processing module transmits the control signal transmitted by the central processing unit to the antenna, and the antenna writes the control information into the control ball.

3. The underground two-way wireless communication system according to claim 2, characterized in that: The ground part also includes a host computer, which is connected to the central processor, sends a control signal to the central processor, and displays and stores feedback information transmitted from the central processor.

4. The underground two-way wireless communication system according to claim 2, characterized in that: The ground part also includes a wireless mobile signal transceiver, which is connected to the central processor and connected to the computer through a wireless base station. The wireless mobile signal transceiver sends the control signal wirelessly transmitted from the computer to the central processor, and wirelessly transmits the feedback information transmitted from the central processor to the computer for display and storage.

5. The underground two-way wireless communication system according to claim 2, characterized in that: The ground part also includes a clock synchronization module, which is connected to the central processor and sends a clock synchronization signal to the central processor. The central processor reads the clock synchronization signal and sets the sampling frequency.

6. The underground two-way wireless communication system according to claim 1, characterized in that: The downhole part includes a downhole controller and a downhole antenna. The downhole controller includes a downhole central processor, a downhole signal processing module, a motor and a motor drive module, a downhole switch valve and a memory. The central processor is connected to the downhole signal processing module and sends a detection signal to the downhole signal processing module. The downhole signal processing module is connected to the downhole antenna, receives the detection signal sent by the downhole central processor, and sends the detection signal to the downhole antenna. After receiving the detection signal, the downhole antenna emits a radio frequency magnetic field to detect the control ball, reads the control signal in the control ball, and transmits the control signal to the downhole signal processing module. The downhole signal processing module filters and amplifies the control signal and then transmits it to the downhole central processor. The downhole central processor is connected to the motor and the motor drive module and the memory, stores the control signal in the memory, and sends it to the motor and the motor drive module. The motor and the motor drive module are connected to the downhole switch valve and receive the control signal transmitted by the downhole central processor to drive the downhole switch valve to operate.

7. The underground two-way wireless communication system according to claim 6, characterized in that: The downhole part also includes a sensor and signal processing module, a feedback ball storage and signal reading and writing module. The sensor and signal processing module is connected to the downhole central processor, collects parameters of the production layer and performs signal processing, and sends them to the downhole central processor. The downhole central processor is connected to the feedback ball storage and signal reading and writing module, stores parameter information in the memory, and sends the parameter information to the feedback ball storage and signal reading and writing module. After storing the parameter information and writing the information to be fed back to the feedback ball, the reading and writing completion information is sent to the downhole central processor.

8. The underground two-way wireless communication system according to claim 6, characterized in that: The downhole part also includes a downhole clock synchronization module, which is connected to the downhole central processor and sends a clock synchronization signal to the downhole central processor. The downhole central processor reads the clock synchronization signal and sets the sampling frequency.

9. The underground two-way wireless communication system according to claim 1, characterized in that: The radio frequency signal ball has a chip inside, a round shell made of a hard non-metallic material, and an inner filler made of a non-metallic material, which has the function of fixing the chip.

10. A method for two-way wireless communication in a well, characterized in that: The underground two-way wireless communication method adopts the underground two-way wireless communication system according to claim 1, comprising: Step 1: The ground part writes control information into the control ball; Step 2, controlling the ball to sink from the wellhead into the well; Step 3, when the control ball passes through the downhole part, the downhole part reads the control information in the control ball; Step 4: The downhole part adjusts the opening of the downhole switch valve according to the control information, and writes the information to be fed back into the feedback ball; Step 5, the soluble material of the control ball dissolves, releasing the feedback ball into the well fluid; Step 6: When the feedback ball floats up to the wellhead in the well fluid, the surface part reads the feedback information in the feedback ball and performs signal processing.

11. The underground two-way wireless communication method according to claim 10, characterized in that: The underground two-way wireless communication method also includes, before step 1, the ground part reads the information of the inserted radio frequency signal ball, and enters step 1 for controlling the ball; and enters step 6 for feeding back the ball.

12. The underground two-way wireless communication method according to claim 10, characterized in that: In step 1, the control information includes layer position, valve opening degree, requested temperature, and requested pressure.

13. The underground two-way wireless communication method according to claim 10, characterized in that: In step 4, the feedback information includes the temperature, pressure, and flow rate of the corresponding layer in the well.

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