Intelligent oil extraction control method and system

Abstract

The invention relates to an intelligent oil extraction control method and system, and belongs to the technical field of oil well intelligent layered oil extraction. According to the method, a pressure generating device is arranged in an intelligent switch of each oil layer, the pressure generating devices control opening and closing of a liquid inlet channel so that different pressure signals generated by an oil sleeve annulus can be fed back to the ground, and when a certain oil layer in a well needs to transmit information to the ground, the pressure generating devices are switched on and switched off. An intelligent switch of a corresponding layer controls a liquid inlet channel of the intelligent switch to be opened and closed with set times and set duration according to a set coding rule, a pressure signal fed back to the ground is formed, a pressure detection device arranged on the ground detects the pressure signal uploaded by the oil sleeve annulus, decoding is carried out according to a set decoding rule, and the oil sleeve annulus is sent to the intelligent switch. According to the method and the system, the two-way communication of the ground information and the underground information can be realized.

Description

Technical Field

[0001] The invention relates to an intelligent oil production control method and system, belonging to the technical field of intelligent stratified oil production in oil wells. Background Art

[0002] For oil fields in the late stage of water injection development, the water content rises, the remaining oil is highly dispersed, the conventional stratified control level of oil wells is low, and the stratified oil production process has problems such as difficulty in finding water plugging, high operating costs, long operation time, and lack of effective downhole parameter monitoring methods. In order to solve these problems, intelligent stratified oil production technology came into being.

[0003] At present, intelligent stratified oil production strings are divided into two types: cabled and cableless. The cabled string transmits command information through electrical signals or optical signals. Compared with the cabled string, the cableless string has the advantages of low cost and simple operation, and has been promoted and applied in many oil fields. The existing cableless string controls the oil production process through multiple intelligent switches set in each oil layer, and uses pressure signals on the ground to control the opening and closing of the intelligent switches to achieve stratified oil production. For example, the invention patent document with publication number CN101250987A discloses a method for intelligent stratified testing and production of oil wells. The string of this method is mainly composed of a hand-free joint, a safety joint, a water plugging packer, and an intelligent switch connected from top to bottom through a short section of oil pipe. This method realizes the action of the underground intelligent switch by sending commands through ground remote control to complete the opening and closing of the layer. Although the existing methods can use the intelligent switch to receive ground information for action, they do not realize the function of feedback information from the underground to the ground, and cannot realize stratified control in a timely and effective manner. If the intelligent switch integrates various monitoring data, such as monitoring pressure, temperature, flow, switch status, etc., it is usually only possible to obtain downhole monitoring information by pulling out the intelligent switch string and replaying the ground data, and then conduct process effect analysis to guide the formulation of subsequent mining plans, which is costly and time-consuming. Summary of the invention

[0004] The purpose of the present invention is to provide an intelligent oil production control method and system, which realizes two-way communication of ground and underground information of cable-free intelligent stratified oil production wells through pressure waves, so as to solve the problem that the cable-free intelligent stratified oil production system lacks effective and timely feedback of information to the ground.

[0005] To achieve the above object, the solution of the present invention includes:

[0006] The intelligent oil production control method of the present invention is characterized by comprising the following steps:

[0007] A pressure generating device is provided in the intelligent switch of each oil layer, and the pressure generating device controls the opening and closing of the liquid inlet channel so that different pressure signals generated in the oil casing annulus are fed back to the surface;

[0008] When a certain oil layer in the well needs to transmit information to the ground, the intelligent switch of the corresponding layer controls its own liquid inlet channel to open and close for a set number of times and for a set duration according to the set coding rules, forming a pressure signal that is fed back to the ground;

[0009] The pressure detection device installed on the ground detects the pressure signal uploaded from the casing annulus, decodes it according to the set decoding rules, and obtains the transmission information of the corresponding oil layer intelligent switch in the well.

[0010] Beneficial effects: The intelligent oil production control method of the present invention can realize two-way communication and effective stratified control between the underground and the ground in the cable-free intelligent stratified oil production process of the oil well by transmitting signals through pressure waves without moving the pipe string or inserting wired equipment such as cables. It can feed back various types of information to the ground, and the construction is convenient. The pressure detection device on the ground can obtain the transmission information of the corresponding oil layer intelligent switch in this way, and understand the situation of the underground oil layer in a more timely manner.

[0011] Furthermore, the pressure signal is composed of a waveform combination of pressure drop and duration, and the waveform sequence of the pressure signal includes a feedback preparation segment, an information feedback segment and an end segment. The feedback preparation segment is used to notify the ground device that the command has been received and information feedback is about to be made; the information feedback segment is used for the intelligent switch device that needs to execute the instruction to feedback the specific information required by the instruction; the end segment is used to notify the ground device that the information feedback is completed.

[0012] Beneficial effect: According to the number of jumps and the time interval, the intelligent switch states and different instructions of different oil layers can be distinguished, and different instructions can be transmitted according to the number of jumps. The time interval of each jump can be the same or different. This method is simple and effective.

[0013] Furthermore, the feedback preparation section and information feedback in the pressure signal are distinguished according to different pressure jump times.

[0014] Furthermore, the control method also includes transmitting information from the ground to the underground, and the transmission process is as follows: an eccentric liquid passage channel for transmitting pressure signals is arranged on one side of the pipeline where the intelligent switch of each layer is located, and a pressure receiver is arranged inside each intelligent switch. When the pressure generating device on the ground pressurizes the underground according to the set coding rules, the pressure is transmitted to the pressure receivers in the intelligent switches of each layer through the eccentric liquid passage channel.

[0015] Furthermore, the pressure signal transmitted from the ground to the underground is composed of a waveform combination of pressure and duration, and the waveform combination sequence of the pressure signal includes an activation segment, a command segment, a layer command segment, and an end segment. The activation segment is used to wake up the intelligent switches of each oil layer; the command segment is used to convey the task commands of the intelligent switches of each layer and the all-shutdown command; the layer command segment is used to require the intelligent switch of a certain layer to feedback the task status required by the command segment.

[0016] Furthermore, the pressure signal is transmitted via a transmission medium, and the transmission medium is crude oil, water or water injected into the oil field in the well.

[0017] Beneficial effects: Wireless pressure waves are used to transmit signals between the ground and the well, and the transmission medium is liquid, which is easy to implement.

[0018] An intelligent oil production control system of the present invention comprises a surface device arranged on the ground for communicating with a downhole device and intelligent switches arranged corresponding to each intermediate oil layer. A pressure generating device is arranged inside the intelligent switch. The pressure generating device controls its own liquid inlet channel to open and close for a set number of times and for a set duration according to a set coding rule, so that different pressure signals generated in the casing annulus are fed back to the ground.

[0019] Beneficial effects: The intelligent oil production control system of the present invention can realize two-way communication and effective stratified control between the underground and the ground in the oil well without moving the pipe string or inserting wired equipment such as cables, by transmitting signals through pressure waves. It can also feed back various types of information to the ground, making construction convenient.

[0020] Furthermore, the pressure generating device includes a driving mechanism for driving the sealing piston body to move up and down inside the central oil pumping channel, a sealing piston body arranged inside the central oil pumping channel and a liquid inlet channel for connecting the oil layer with the central oil pumping channel, and the driving mechanism completes the closing and opening of the liquid inlet channel during the process of driving the sealing piston body to move up and down.

[0021] Furthermore, the intelligent switch also includes a pressure receiving device for receiving the pressure signal transmitted from the surface device. When the intelligent switch transmits the pressure signal to the downhole, the eccentric liquid channel is pressurized by the pressure generating device arranged at the wellhead. The pressure receivers of each layer are used to receive the pressure signal transmitted by the eccentric liquid channel. The eccentric liquid channel is arranged on one side of the pipeline where the intelligent switch is located.

[0022] Furthermore, the pressure receiving device is connected to the eccentric liquid passage through the pressure inlet hole.

[0023] Furthermore, the controller in the intelligent switch performs encoding and decoding according to the set encoding and decoding rules.

[0024] Furthermore, the waveform stage of the pressure signal sent by the pressure generating device on the ground is distinguished by the duration of different stages and the number of pressure application and pressure relief. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of a process string for an intelligent layered oil production well in an embodiment of the present invention;

[0026] Figure 2 is a schematic diagram of the structure of the intelligent switch in the open state in an embodiment of the present invention;

[0027] Figure 3 is a schematic diagram of the structure of the intelligent switch in the closed state in an embodiment of the present invention;

[0028] Figure 4 is a schematic diagram of an intelligent oil production system in an embodiment of the present invention;

[0029] Figure 5 Schematic diagram of the working principle of communication between the intelligent switch and the ground system in an embodiment of the present invention;

[0030] FIG6( a ) is a schematic diagram of a pressure wave formed by pressure-time in an embodiment of the present invention;

[0031] FIG6( b ) is a schematic diagram of a pressure wave formed by pressure drop-time in an embodiment of the present invention;

[0032] Figure 7 It is a schematic diagram of decoding coding of an intelligent switch device in an embodiment of the present invention;

[0033] Figure 8 is a schematic diagram of an example of encoding of a signal transmitted to the ground by an intelligent switch in an embodiment of the present invention;

[0034] Fig. 9 is a schematic diagram of a decoding and encoding example of a certain intelligent switch in an embodiment of the present invention;

[0035] Fig.10 It is a schematic diagram of a pressure waveform formed after the control signal of the intelligent switch 5 of the oil layer 2 is implemented in the embodiment of the present invention;

[0036] Reference numerals: 1-production tubing string; 2-packer; 3-intelligent switch; 4-packer; 5-intelligent switch; 6-packer; 7-intelligent switch; 8-production tubing; 9-thread plug; 10-oil layer casing; 11-surface pump truck; 12-surface circuit system;

[0037] 31-upper tube body; 32-sealing piston body; 33-connector; 34-driving mechanism; 35-upper cabin body; 36-lower tube body; 37-connector; 38-pressure inlet hole; 39-pressure sensor; 310-controller; 311-downhole power supply; 312 lower cabin body;

[0038] 3101-central oil pumping channel; 3102-eccentric liquid passage channel; 3103-liquid inlet channel. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0040] Intelligent oil production control system implementation example:

[0041] like Figure 4 An intelligent oil production control system shown mainly includes a surface device and an intelligent layered oil production well process string located underground.

[0042] like Figure 4 As shown, the surface device includes a surface pump truck 11 for pressure pumping and a surface circuit system 12. The surface pump truck is connected to the annulus of the oil layer casing 10, and water is injected into the annulus of the oil layer casing 10 to "pressure pump-decompress" and generate a pressure signal in the wellbore and transmit it to the downhole.

[0043] The ground circuit system (i.e., ground device) 12 is connected to the pipelines of the wellhead and the pump shop, and includes a receiver, a decoder, and a control circuit. The receiver includes a ground pressure sensor, which can receive and decode the pressure signal generated in the casing annulus by the intelligent switch opening and closing the inlet channel through the driving mechanism. Preferably, the ground circuit system can be connected to a device with a display function to display the decoded information. The power supply of the ground circuit system can be powered by a power system or a battery.

[0044] The ground pump truck and the ground circuit system may be independent or integrated.

[0045] The process string of the intelligent stratified oil production well is arranged in the oil layer casing 10, including the production string 1 and the release string. The upper part of the release string is lowered into the production string, which can be any kind of artificial lifting process such as a rod pump, a screw pump, an electric pump, etc.

[0046] The release string includes a device assembled with multiple packers and intelligent switches (intelligent switch 3, intelligent switch 5, intelligent switch 7) (each oil layer is provided with an intelligent switch, and packers (packer 2, packer 4, packer 6) are provided between each oil layer, a production tubing 1, a plug 9, and each device is threadedly connected in sequence. The number of intelligent switches can be multiple, which are respectively arranged at the corresponding positions of each oil layer, and packers are provided between each oil layer to separate each oil layer. The packer and the intelligent switch are connected by a production tubing 8. The end of the deepest production tubing is plugged with a plug 9. After the release string is released, the production tubing can be lowered.

[0047] like Figure 2 , Figure 3 As shown, a pressure generating device is provided in the intelligent switch 3 (same for intelligent switch 5 and intelligent switch 7), and the pressure generating device controls the opening and closing of its own liquid inlet channel to set times and set duration according to the set coding rules, so that different pressure signals generated by the oil casing annulus are fed back to the ground, and the pressure detection device provided on the ground detects the pressure signal uploaded by the oil casing annulus, decodes it according to the set decoding rules, and obtains the transmission information of the oil layer intelligent switch corresponding to the well. The pressure generating device includes a driving mechanism 34 for driving the sealing piston body to move up and down inside the central oil pumping channel, a sealing piston body 32 provided inside the central oil pumping channel, and a liquid inlet channel 3103 for connecting the oil layer with the central oil pumping channel 3101, and the driving mechanism completes the closing and opening of the liquid inlet channel in the process of driving the sealing piston body to move up and down.

[0048] Specifically, the intelligent switch 3 (similar to the intelligent switch 5 and the intelligent switch 7) includes an upper tube body 31, which includes a central oil pumping channel 3101 extending vertically through the middle, an eccentric liquid passage channel 3102 and a liquid inlet channel 3103. The lower outer part of the upper tube body is connected to a lower tube body 36, and the lower tube body has a lower connecting end for connecting to a lower pipe column. The lower inner side of the upper tube body is connected to a closed control cabin through a connector. A driving mechanism is arranged in the closed control cabin, and the driving mechanism can drive a sealing piston body 32 arranged in the central oil pumping channel to move up and down to connect or disconnect the liquid inlet channel and the upper end port of the upper tube body. An external thread section is arranged on the top of the upper tube body, and the external thread section forms an upper connecting end for connecting to an upper pipe column.

[0049] like Figure 2 As shown, the liquid inlet channel 3103 is arranged on the side of the upper pipe body and is connected to the central oil pumping channel 3101. When the driving structure 34 drives the sealing piston body 32 downward to open the liquid inlet channel 3103, the oil can flow into the central oil pumping channel 3101 (in the direction of arrow O) along the liquid inlet channel, and then pass through the central oil pumping channel upward to the upper pipe column to be pumped out. The liquid inlet channel plays a throttling role, and the flow area can be adjusted by the driving mechanism.

[0050] The sealing control cabin is sealingly connected to the lower end of the central oil pumping channel, and the sealing control cabin includes an upper cabin body 35 and a lower cabin body 312 connected by a second connector 37 .

[0051] The upper cabin body 35 and the first connecting head 33 form a driving mechanism installation cavity, and the driving mechanism 34 is arranged in the driving mechanism installation cavity. The lower cabin body and the second connecting head 37 form a control part installation cavity, and the control part is arranged in the control part installation cavity. The control part has a pressure sensor 39, a controller 310, and a downhole power supply 311, wherein the driving mechanism, the pressure sensor, the controller, and the downhole power supply are all arranged on the corresponding ends of the connecting head.

[0052] The upper cabin is connected to the upper tube body 31 through the first connector 33, and the lower end of the first connector is threadedly sealed with the upper cabin. The first connector 33 is threadedly sealed with the lower end of the central oil pumping passage of the upper tube body, and the middle part of the first connector 33 is also provided with a through passage extending up and down for the sealing piston body to move up and down, so that the driving mechanism drives the sealing piston body to move up and down more stably.

[0053] The driving mechanism is driven by a motor, and the output end of the driving mechanism is an upward external screw connected to the lower part of the sealing piston body with a downward internal thread, so that the driving mechanism drives the sealing piston body to move up and down.

[0054] The sealing piston body 32 includes an upper large diameter section and a lower small diameter section. The upper large diameter section is provided with a sealing groove to cooperate with the inner side of the central oil pumping channel 3101 of the upper tube body 31 to form a seal, and the lower small diameter section passes through the inside of the connector and is sealed with an O-ring. The bottom of the lower small diameter section is also provided with a downward internal thread to connect with the drive mechanism. The outer side of the bottom of the lower small diameter section is non-circular and is arranged in the middle diameter reduction section of the upper cabin body, so that the sealing piston body can only move up and down but not rotate.

[0055] The controller 310 is arranged at the lower end of the second connector 37. Specifically, the controller is actually a circuit board, which is threadedly mounted at the lower end of the connector. The lower end of the controller is connected to the downhole power supply, and the upper end of the controller is provided with a pressure sensor. The pressure sensor is a prior art and will not be described here. The lower end of the second connector 37 is provided with a cavity connected to the outer pressure-introducing hole 38. The pressure sensor is placed in the cavity and can receive the pressure change outside the connector. The controller commands the start and stop of the driving mechanism according to the different pressure signals.

[0056] Among them, the intelligent switch also includes a pressure receiving device (pressure sensor) to receive the pressure signal transmitted from the ground device. When the intelligent switch transmits the pressure signal to the well, the pressure generating device arranged at the wellhead pressurizes the eccentric liquid channel. The pressure receivers at each layer are used to receive the pressure signal transmitted by the eccentric liquid channel. The eccentric liquid channel is arranged on one side of the pipeline where the intelligent switch is located.

[0057] Specifically, the eccentric liquid passage 3102 extends along the up and down directions of the oil pipe until it extends to the screw plug. The eccentric liquid passage of each intelligent switch is connected with the "U"-shaped channel arranged at the bottom of the lower cabin of the switch. The other end of the "U"-shaped channel is connected with the pressure-inducing hole. The fluid in the eccentric liquid passage passes through the "U"-shaped channel to reach the pressure-inducing hole, and the fluid transmits the generated pressure to the sensing part of the pressure sensor through the pressure-inducing hole.

[0058] Specifically, when the surface device at the wellhead pressurizes downward, the liquid passes through the eccentric liquid passage downward through the pressure-inducing hole 38 to transmit the pressure to the pressure sensor, and the pressure sensor transmits the pressure signal to the controller to command the drive mechanism to start and stop. The pressure can be transmitted vertically downward along the pipe wall (in the direction of arrow I).

[0059] The controller 310 includes a receiver, an encoder, a decoder and a control circuit, which can receive the pressure signal generated by the ground pump truck received by the pressure sensor 39, convert the pressure signal into an electrical signal and then decode it to obtain information instructions and execute the instructions; further, the controller can integrate the functions of temperature monitoring, switch status monitoring and data storage. Preferably, the controller can monitor information according to a pre-set program or instruction. Preferably, other types of sensors such as flow can be set, and their monitoring data can be transmitted to the controller of the intelligent switch.

[0060] The downhole power supply 311 may be a battery pack or a self-powered device that generates electricity from, for example, flow, vibration and / or temperature of a process. The downhole power supply provides power for the controller, drive mechanism and pressure sensor.

[0061] In this embodiment, the surface device and the intelligent switch device in the well need to use the pressure wave transmission medium to transmit the pressure signal (pressure wave). The pressure wave transmission medium is a liquid, which can be crude oil, water and oil field injection water in the well. When the intelligent switches are all closed, the transmission medium is continuous and closed from the liquid surface in the wellbore to the plug 9; when the intelligent switches are opened, the fluid in the wellbore and the fluid in the oil layer can flow to each other.

[0062] In this embodiment, the instructions transmitted by the ground pump truck mainly include two types, one is the command to turn on or off the intelligent switch (first type of instruction), and the other is the instruction to require the intelligent switch to feedback downhole information (second type of instruction). Figure 5 As shown, for the command to open or close the intelligent switch, the intelligent switch directly drives the driving mechanism to open or close the liquid inlet channel through the controller to execute; for the instruction of the intelligent switch to feedback downhole information, the controller collects the information to be fed back, encodes it, and forms a control signal. The control driving mechanism is controlled according to the code. When the ground pump truck pressurizes to the design pressure and maintains the pressure holding state, the pressure signal is formed in the wellbore by opening and closing the liquid inlet channel different times. The ground circuit system receives the pressure signal and decodes it to obtain the information fed back by the intelligent switch.

[0063] Among them, according to specific actual needs, the communication code can be the first type of instructions, the second type of instructions, or a combination of the two types of instructions. The instructions transmitted by the ground pump truck can be concurrent or sequential, that is, the pressure signal generated by the ground pump truck can be given to all intelligent switches or to a certain intelligent switch. It should be noted that concurrent instructions are only applicable to the generated command to open or close the intelligent switch (first type of instructions), but not to the second type of instructions. The intelligent switches of each oil layer execute instructions sequentially and cannot execute concurrently.

[0064] In this embodiment, the pressure signal is a combination of various waveforms consisting of pressure and duration, or pressure drop and duration. As shown in Figure 6(a), when the ground information instruction is implemented, it can be a pressure wave transmission consisting of pressure and duration formed by "pressurizing-relieving" the ground several times. As shown in Figure 6(b), when the intelligent switch uploads information, it is a pressure wave transmission consisting of pressure drop and duration formed by the driving mechanism opening or closing the liquid inlet channel several times. In the process of two-way communication using pressure signal transmission, it is necessary to set rules for the intelligent switch in each oil layer to identify the oil layer and communicate, and the coding rules of communication correspond to the pressure signal and are pre-designed.

[0065] The coding rule is to control the number of pressure jumps within a certain time interval, and transmit different layers of instructions according to the number of jumps. The time interval of each jump can be the same or different. In order to ensure the effectiveness and integrity of information transmission, the transmitted data can use integer values ​​or simplified numbers to facilitate encoding and data transmission. The coding code can be implemented using binary "0" and "1" two-level codes, where logic "1" represents a high level or idle state, and logic "0" represents a low level or response state.

[0066] The decoding code of the intelligent switch is a combination of activation segment, command segment, layer command segment and end segment. The activation segment is used to wake up the intelligent switches of each oil layer; the command segment is used to convey the task commands and all shutdown commands of the intelligent switches of each layer; the layer command segment is used to require the intelligent switch of a certain layer to feedback the task status required by the "command segment"; the end segment is used to notify the intelligent switches of each oil layer that the command has ended and wait for the feedback signal from the downhole. The end segment needs to maintain a high level state. Figure 7 The schematic diagram of the example of signal encoding transmitted from the ground to the intelligent switch is shown. The activation segment and the command segment are designed to jump once respectively, the layer command segment is designed to jump twice, and the end segment remains in a high level state. The waveform stage of the pressure signal sent by the ground pressure generating device is distinguished by the duration of different stages and the number of pressure-release times.

[0067] The encoding of information transmitted from underground to the surface adopts a combination of feedback preparation segment, information feedback segment, and end segment. The feedback preparation segment is used to notify the surface that the command has been received and information feedback will be made soon; the information feedback segment is used for the intelligent switch that needs to execute the command to feedback the specific information required by the command; the end segment is used to notify the surface circuit system that the information feedback has been completed, and the end segment needs to remain idle. Figure 8 This is a schematic diagram of an example of signal encoding transmitted from an intelligent switch to the ground. The feedback preparation section is designed with one jump, the information feedback section is designed with two jumps, and the end section remains idle. The feedback preparation section and information feedback in the pressure signal are distinguished according to the different pressure jump times.

[0068] The coding and decoding programs of the ground device (including the pressure generating device and the pressure receiving device) and the intelligent switch need to be designed in advance. The decoding program designed for the ground device is solidified into the ground circuit system; the controller coding and decoding programs of the intelligent switch corresponding to each oil layer, as well as the temperature monitoring, the switch state monitoring rules of the intelligent switch and the data transmission rules are designed and solidified into the controllers of the intelligent switch of each layer. Then connect the hand-off string (such as Figure 1 When the control of the present invention is needed, a surface device is installed behind the wellhead casing annulus valve in the stop production state. The driving mechanism switches the liquid inlet channel to form a corresponding pressure signal in the wellbore, and the surface circuit system of the surface device detects and decodes in real time, and finally obtains the required information.

[0069] It should be noted that currently the intelligent switch can only feedback information according to the command after the ground device sends the command, and cannot actively send information to the ground device.

[0070] Through the system of this embodiment, the method for realizing intelligent stratified oil production well control is as follows:

[0071] First, the ground pump truck must transmit instructions to the intelligent switch in the well. According to the required instructions and the designed code, the pressure signal is sent out by "pressurizing, releasing or holding pressure". All intelligent switches can receive the signal and decode, identify and judge the information instructions at the same time. If the instruction is to order all intelligent switches to open (or close), all intelligent switches will analyze and judge their respective switch states. Those in the open (or closed) state will maintain the original state, and those in the closed (or open) state will open (or close) the corresponding oil layer's inlet channel through their respective drive mechanisms; if the instruction is to a certain layer of intelligent switches, all intelligent switches will analyze and judge whether the instruction is for "themselves", and the intelligent switches that are "not for themselves" will stand by, and the intelligent switches that are "for themselves" will execute the instruction. If the instruction given to a certain layer of intelligent switch is an open (or close) command, the intelligent switch of this layer will open (or close) the liquid inlet channel of the oil layer through the driving mechanism; if the instruction given to a certain layer of intelligent switch is to require feedback of downhole information, the controller of the intelligent switch will encode the corresponding stored information to form a control signal, and "open-close" the liquid inlet channel through the driving mechanism in a sequence of different time lengths and times, so as to form a pressure signal in the wellbore.

[0072] The ground circuit system monitors and decodes the pressure signal, and ultimately obtains the required information, realizing two-way information transmission from underground to the ground, thus achieving effective stratified control of cable-free intelligent stratified oil production wells.

[0073] The embodiment of the present invention takes an intelligent stratified oil production well with two oil layers as an example to illustrate the present invention in detail. The described embodiment is only exemplary and intended to be used to explain the present invention, and cannot be understood as limiting the present invention.

[0074] The well process string comprises a production string 1 and a release string, wherein the release string comprises a packer 2, an intelligent switch 3, a packer 4, an intelligent switch 5, a production tubing 8, and a threaded plug 9, which are threadedly connected in sequence.

[0075] The hand-off string is lowered to the designed position in the well so that the two intelligent switches are located in the corresponding oil layers 1 and 2, and the two oil layers are separated by a packer. After the upper part of the hand-off string is lowered into the production string 1, the oil pumping process is adopted.

[0076] The specific structures of the intelligent switch 3 and the intelligent switch 5 have been described in detail above and will not be repeated here.

[0077] If the well is in production before implementation, and it is assumed that oil layer 1 is produced and oil layer 2 is closed, the intelligent switch 3 and the intelligent switch 5 of the hand-off string have been pre-set with encoding and decoding programs, downhole switch status monitoring and transmission rule programs; further, the switch status of the intelligent switch 3 and the intelligent switch 5 is stored each time, and the last state of the most recent state is fed back to the surface device when the state needs to be fed back.

[0078] The ground device includes a ground pump truck 11 and a ground circuit system 12. The ground pump truck is a 700-type pump truck commonly used in oil fields. It is installed behind the wellhead casing annulus valve. The ground pump truck 11 generates a pressure signal in the wellbore by injecting water into the casing annulus to "pressurize and release pressure" and transmit it to the wellbore. The ground circuit system 12 is connected to the wellhead casing annulus valve and the pipeline of the pump workshop. Before the connection, the decoding and encoding program is solidified into its circuit. The circuit system also integrates a device with a display function, which is used to receive the pressure signal generated in the casing annulus by the intelligent switch through the driving mechanism to open and close the liquid inlet channel, and decode and display the information.

[0079] The pressure signal sent by the ground pump truck to the intelligent switch is formed by the ground pump truck's "pressure-pressure relief" sequence. The pressure signal is composed of a waveform composed of pressure and duration. This embodiment designs the ground pump truck's "pressure-pressure relief" sequence as follows Fig. 9 As shown, the entire sequence is divided into activation section, command section, layer command section, and end section, each section is 10 minutes apart. The activation section is used to wake up the intelligent switch of each oil layer. The pressure is designed to be raised to 10MPa, and the pressure is released after stabilizing the pressure for 10 minutes; the command section is used to convey the task command and all shutdown command of the intelligent switch of each layer. The pressure is designed to be raised to 10MPa, and the pressure is released after stabilizing the pressure for 10 minutes; the layer command section is used to require a certain layer of intelligent switch to feedback the task situation required by the "command section". The pressure is designed to be raised to 10MPa, and the pressure is released after stabilizing the pressure for 10 minutes. After 10 minutes, the pressure is raised to 10MPa again, and the pressure is released after stabilizing the pressure for 10 minutes; the end section is used to notify the intelligent switch of each oil layer that the command has ended and wait for the feedback signal from the downhole. The end section presses to 10MPa, stops the pump and holds the pressure.

[0080] The pressure signal fed back by the intelligent switch is formed by the sequence of switching the liquid inlet channel, and is composed of a waveform composed of pressure drop and duration. After the control signal of the intelligent switch 5 of the oil layer 2 is implemented, the pressure waveform received by the ground circuit system is shown in FIG. Fig.10. The entire sequence is divided into a feedback preparation section, an information feedback section, and an end section, each with an interval of 10 minutes. The feedback preparation section is used to notify the ground that the command has been received and that information feedback will be given soon. The design opens the liquid inlet channel of the intelligent switch 5 until the pressure drops to 0.5MPa, and then closes the liquid inlet channel; the information feedback section is used for the intelligent switch that needs to execute the command to feedback the specific information required by the command. The design opens and closes the liquid inlet channel of the intelligent switch 5 twice, with a pressure drop of 0.5MPa each time, and an interval of 10 minutes between the two times; the end section is used to notify the ground circuit system that the information feedback has been completed, and the end section continues the pressure holding state.

[0081] The communication coding rules are pre-designed and correspond to the pressure signal. The coding rules are designed as the number of pressure jumps within a certain time interval, and instructions are transmitted according to the number of jumps. The coding code is implemented using two-level codes "1" and "0". Logical "1" represents a high level or idle state, and logical "0" represents a low level or response state.

[0082] Corresponding to the transmission of pressure signals from the ground to the downhole, the controller decoding code of the intelligent switch includes an activation segment, a command segment, a layer command segment, and an end segment. The decoding code of the intelligent switch 5 is designed as follows: the activation segment is a jump, which lasts for 10 minutes and is used to wake up the intelligent switches of each oil layer; the second jump is a command segment, which lasts for 10 minutes, indicating that the intelligent switches of each layer monitor their switch status and transmit it to the controller, encode the switch status, and then judge the execution of the switch action according to the switch status. If the monitoring status is "on", the closing work is executed; if the monitoring status is "off", the off state is maintained; within the next 40 minutes, it is the layer command segment, which is designed with two jumps, indicating that the switch status of the intelligent switch of this layer that needs to be fed back by the oil layer 2 for monitoring; the end segment maintains a high level state, waiting for the intelligent switch of the oil layer 2 to feedback the pressure signal. Each segment is 10 minutes apart. The difference between the decoding code design of the intelligent switch 3 and the intelligent switch 5 is that the layer command segment (within 40 minutes) is designed with 1 jump.

[0083] The feedback signal coding of the intelligent switch 5 includes a feedback preparation section, an information feedback section, and an end section. The feedback coding of the intelligent switch 5 is designed as follows: Figure 8 , Fig.10As shown. The feedback preparation section is used to notify the ground that the command has been received and information feedback will be given. It is designed to jump once, with a pressure drop of 0.5MPa and a duration of Δt1. The length of this period of time is related to the pressure level in the wellbore, the physical properties of the oil layer and the formation pressure, and it is not a fixed value; the information feedback section is used for the intelligent switch that needs to execute the command to feedback the specific information required by the command. The "off state" of the intelligent switch is designed to jump twice, with a pressure drop of 0.5MPa each time, and an interval of 10 minutes each time. The duration of the jump is Δt2 and Δt3 respectively. The length of time is related to the pressure level in the wellbore, the physical properties of the oil layer and the formation pressure, and it is not a fixed value; the end section is used to notify the ground circuit system that the information feedback has been completed, and the end section remains idle. Each section is 10 minutes apart.

[0084] The specific implementation steps are:

[0085] First, stop the well pumping unit. Connect the 700 pump truck to the ground circuit system, and use the ground pump truck to fill the wellbore with oilfield injection water through the casing annulus. Then operate the ground pump truck according to the pressure-time sequence of "pressurization-pressure relief", and repeat "pressurization for 10 minutes-pressure relief for 10 minutes" four times in a row, and then stop the pump to hold the pressure after the pressure reaches 10MPa, completing the instruction requiring the intelligent switch of oil layer 2 to feedback the monitoring status.

[0086] After receiving the instruction, both the intelligent switch 3 and the intelligent switch 5 are activated. After decoding and analysis, the intelligent switch 3 closes its liquid inlet channel and stores its closed state in its controller; the intelligent switch 5 stores its closed state in its controller, and its controller encodes the "closed state" (such as Figure 8 As shown), and form a control signal to control its driving mechanism to switch the liquid inlet channel and form a pressure signal in the wellbore.

[0087] The ground circuit system will receive the feedback pressure signal, decode it, and display on the display screen that the intelligent switch 5 of the oil layer 2 is in the "off state", completing the target implementation.

[0088] Through the above system, the two-way communication between the underground and the ground of the cable-free intelligent stratified oil production process of the oil well can be realized without moving the pipe string and without inserting wired equipment such as cables, thus realizing the effective stratified control of the cable-free intelligent stratified oil production well, which is convenient for construction. In addition, wireless pressure waves are used to transmit signals between the ground and the underground in this embodiment, and the transmission medium is liquid, which is easy to implement; the information transmitted from the ground to the underground may include instructions to open or close the intelligent switch and instructions to feedback the underground information; the information uploaded from the underground to the ground may include information such as pressure, temperature, flow, state, etc. collected by various sensors in the underground, and the types of information transmitted are diverse. The system and method of this embodiment are not limited to use in the cable-free intelligent stratified oil production process of oil wells, and can be promoted and applied to oil wells with intelligent flow limiting tools in the underground, such as intelligently controlled throttle valves, sleeves, switches, etc. It can also be used as a preventive measure for the inability of underground intelligent tools to communicate with the ground after the cable of the cable-free intelligent stratified oil production process is damaged. With the increasing degree and level of intelligence in oil and gas production, the demand for low-cost development is increasing, and it has broad application prospects.

[0089] Intelligent oil production control method embodiment:

[0090] The intelligent oil production control method in this embodiment is implemented in the following steps:

[0091] A pressure generating device is provided in the intelligent switch of each oil layer, and the pressure generating device controls the opening and closing of the liquid inlet channel so that different pressure signals generated in the oil casing annulus are fed back to the surface;

[0092] When a certain oil layer in the well needs to transmit information to the ground, the intelligent switch of the corresponding layer controls its own liquid inlet channel to open and close for a set number of times and for a set duration according to the set coding rules, forming a pressure signal that is fed back to the ground;

[0093] The pressure detection device installed on the ground detects the pressure signal uploaded from the casing annulus, decodes it according to the set decoding rules, and obtains the transmission information of the corresponding oil layer intelligent switch in the well.

[0094] The pressure signal is composed of a waveform composed of pressure drop and duration. The waveform sequence of the pressure signal includes a feedback preparation segment, an information feedback segment and an end segment. The feedback preparation segment is used to notify the ground device that the command has been received and information feedback is about to be made; the information feedback segment is used for the intelligent switch to execute the command to feedback the specific information required by the command. The end segment is used to notify the ground device to complete the information feedback. The feedback preparation segment and information feedback in the pressure signal are distinguished according to the different pressure jump times.

[0095] The process of transmitting information from the ground to the underground is as follows: an eccentric liquid passage channel for transmitting pressure signals is set on one side of the pipeline where the intelligent switch of each layer is located, and a pressure receiver is set inside each intelligent switch. When the pressure generating device on the ground pressurizes the underground according to the set coding rules, the pressure is transmitted to the pressure receiver in the intelligent switch of each layer through the eccentric liquid passage channel. The pressure signal transmitted from the ground to the underground is composed of a waveform combination consisting of pressure and duration. The waveform combination sequence of the pressure signal includes an activation segment, a command segment, a layer command segment, and an end segment. The activation segment is used to wake up the intelligent switches of each oil layer; the command segment is used to convey the task commands and all shutdown commands of the intelligent switches of each layer; the layer command segment is used to require the intelligent switch of a certain layer to feedback the task situation required by the command segment. It should be noted that the intelligent switch can only send information to the ground device according to the command feedback information after the ground device sends the command. The specific description has been described in detail in the intelligent oil production control system and will not be repeated here.

Claims

1. An intelligent oil production control method, characterized in that: The following steps are involved: A pressure generating device is provided in the intelligent switch of each oil layer, and the pressure generating device controls the opening and closing of the liquid inlet channel so that different pressure signals generated in the oil casing annulus are fed back to the surface; When a certain oil layer in the well needs to transmit information to the ground, the intelligent switch of the corresponding layer controls its own liquid inlet channel to open and close for a set number of times and for a set duration according to the set coding rules, forming a pressure signal that is fed back to the ground; The pressure detection device installed on the ground detects the pressure signal uploaded from the casing annulus, decodes it according to the set decoding rules, and obtains the transmission information of the corresponding oil layer intelligent switch in the well.

2. The intelligent oil production control method according to claim 1, characterized in that: The pressure signal is composed of a waveform combination of pressure drop and duration, and the waveform sequence of the pressure signal includes a feedback preparation segment, an information feedback segment and an end segment. The feedback preparation segment is used to notify the ground device that the command has been received and information feedback is about to be made; the information feedback segment is used for the intelligent switch device that needs to execute the command to feedback the specific information required by the command; the end segment is used to notify the ground device that the information feedback is completed.

3. The intelligent oil production control method according to claim 2, characterized in that: The feedback preparation section and information feedback in the pressure signal are distinguished according to different pressure jump times.

4. The intelligent oil production control method according to claim 1, characterized in that: The control method also includes transmitting information from the ground to the underground, and the transmission process is as follows: an eccentric liquid passage channel for transmitting pressure signals is provided on one side of the pipeline where the intelligent switch of each layer is located, and a pressure receiver is provided inside each intelligent switch. When the pressure generating device on the ground pressurizes the underground according to the set coding rules, the pressure is transmitted to the pressure receivers in the intelligent switches of each layer through the eccentric liquid passage channel.

5. The intelligent oil production control method according to claim 4, characterized in that: The pressure signal transmitted from the ground to the underground is composed of a waveform combination of pressure and duration. The waveform combination sequence of the pressure signal includes an activation segment, a command segment, a layer command segment, and an end segment. The activation segment is used to wake up the intelligent switches of each oil layer; the command segment is used to convey the task commands of the intelligent switches of each layer and the all-shutdown command; the layer command segment is used to require the intelligent switch of a certain layer to feedback the task status required by the command segment.

6. The intelligent oil production control method according to claim 3, characterized in that: The pressure signal is transmitted through the transmission medium, which is crude oil, water in the well or water injected into the oil field.

7. An intelligent oil production control system, comprising a surface device arranged on the ground for communicating with a downhole device and intelligent switches arranged corresponding to each intermediate oil layer, characterized in that: A pressure generating device is provided in the intelligent switch, and the pressure generating device controls the opening and closing of its own liquid inlet channel to a set number of times and for a set duration according to a set coding rule, so that different pressure signals generated in the casing annulus are fed back to the ground. A pressure detection device arranged on the ground detects the pressure signal uploaded from the casing annulus, decodes it according to the set decoding rule, and obtains the transmission information of the corresponding oil layer intelligent switch in the well.

8. The intelligent oil production control system according to claim 7, characterized in that: The pressure generating device includes a driving mechanism for driving the sealing piston body to move up and down inside the central oil pumping channel, a sealing piston body arranged inside the central oil pumping channel and a liquid inlet channel for connecting the oil layer with the central oil pumping channel. The driving mechanism completes the closing and opening of the liquid inlet channel during the process of driving the sealing piston body to move up and down.

9. The intelligent oil production control system according to claim 7, characterized in that: The intelligent switch also includes a pressure receiving device for receiving the pressure signal transmitted from the surface device. When the intelligent switch transmits the pressure signal to the downhole, the pressure generating device arranged at the wellhead pressurizes the eccentric liquid passage. The pressure receivers at each layer are used to receive the pressure signal transmitted by the eccentric liquid passage. The eccentric liquid passage is arranged on one side of the pipeline where the intelligent switch is located.

10. The intelligent oil production control system according to claim 9, characterized in that: The pressure receiving device is connected with the eccentric liquid through the pressure inlet hole.

11. The intelligent oil production control system according to claim 7, characterized in that: The controller in the intelligent switch performs encoding and decoding according to the set encoding and decoding rules.

12. The intelligent oil production control system according to claim 9, characterized in that: The waveform stage of the pressure signal sent by the pressure generating device on the ground is distinguished by the duration of different stages and the number of pressure application and pressure relief.

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