Cooling control system for downhole instrument and central control cooling module in cooling control system

Abstract

The invention discloses a downhole instrument cooling control system and a central control cooling module therein. The downhole instrument cooling control system comprises a sleeve; the displacer accommodating part is embedded in the side wall of the sleeve; the cooling cavity is arranged in the sleeve, the upper end face of the cooling cavity is matched with the lower end face of the replacement body containing part in shape, and the cooling cavity is used for containing cooling liquid for cooling a hardware circuit of the underground measuring instrument; the high-temperature cooling liquid storage cavity is formed in the sleeve and located below the cooling cavity; the first control circuit is arranged in the cooling cavity and is used for informing the ground of putting the cooling liquid carrying module when detecting that the cooling liquid in the cooling cavity reaches a high-temperature state, and controlling the first control circuit to realize physical connection with the cooling liquid carrying module at the replacement body accommodating part when detecting that the cooling liquid carrying module arrives; and the control module is used for controlling the internal cooling liquid to be discharged into the high-temperature cooling liquid storage cavity and guiding the cooling liquid in the carrying module to the cooling cavity. The downhole instrument can be cooled, and the problem of ultra-high-temperature use is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of measurement and control while drilling, and in particular to a downhole instrument cooling control system and a central control cooling module therein. Background Art

[0002] Measurement while drilling (MWD) and logging while drilling (LWD) can provide real-time information such as directional parameters, engineering parameters, geological parameters, etc. during the drilling process, which is convenient for adjusting the wellbore trajectory and improving the drilling rate. They are key equipment for future automated and intelligent drilling.

[0003] The formation temperature increases with the increase of formation depth. The average geothermal gradient of the earth is about 3℃ / 100m. The temperature resistance of downhole instruments directly restricts the drilling of ultra-deep wells over 10,000 meters. Therefore, high temperature resistance is the main development direction of MWD / LWD instruments.

[0004] At present, the temperature resistance of hardware circuit systems is mainly improved through high-temperature circuit design and low-power design, thereby improving the temperature resistance of downhole instruments. There are three types of high-temperature circuit design methods: traditional method, hybrid circuit method, and special function circuit method. Specifically, the traditional method mainly optimizes the design of electronic components themselves by adopting high-temperature resistant design, reducing the power consumption of electronic components, and selecting heat-resistant raw materials; the hybrid circuit method uses integrated chips and thin and thick film technologies to design circuits at the same time; the special function circuit method is a special design method specifically for integrated circuit design. Low-power design methods include reducing the supply voltage, implementing frequency reduction, reducing load capacitance, and intelligent firmware control.

[0005] Limited by the existing technological level, the temperature resistance of the hardware circuit system can only be improved by optimizing the hardware circuit structure, adopting high-temperature resistant electronic components, optimizing power consumption design, etc. There are still insurmountable technical bottlenecks in further improving the temperature resistance of the instrument. It is impossible to work for a long time under ultra-high temperature conditions underground, and it is difficult to meet the needs of ultra-deep and ultra-high temperature drilling. Summary of the invention

[0006] The purpose of the present invention is to provide a control scheme for cooling downhole instruments, so as to control the operating temperature of the downhole instruments within a reasonable range by cooling the downhole instruments, thereby avoiding the temperature resistance, working safety and stability under ultra-high temperature conditions underground and extending the service life of the instruments.

[0007] In order to solve the above technical problems, an embodiment of the present invention provides a central control cooling module for a downhole instrument cooling control system, comprising: a sleeve; a displacement body accommodating portion embedded in the side wall of the sleeve; a cooling cavity arranged in the sleeve, whose upper end surface matches the shape of the lower end surface of the displacement body accommodating portion, and is used to hold coolant for cooling the hardware circuit of the downhole measuring instrument; a high-temperature coolant storage cavity arranged in the sleeve, which is located below the cooling cavity; a first control circuit arranged in the cooling cavity, which is used to notify the ground to drop a coolant carrier module when it is detected that the coolant in the cooling cavity reaches a high temperature state, and when the coolant carrier module is detected to arrive, control itself to achieve physical connection with the coolant carrier module at the displacement body accommodating portion, so as to control the coolant in the cooling cavity to drain into the high-temperature coolant storage cavity, and guide the coolant in the coolant carrier module to the cooling cavity.

[0008] Preferably, the cooling cavity includes: a circuit skeleton, whose upper end surface is formed as the upper end surface of the cooling cavity and is physically connected to the coolant carrying module through a first valve body, the first control circuit and the hardware circuit of the downhole measuring instrument are arranged inside the circuit skeleton, wherein the lower end surface of the circuit skeleton is connected to the high-temperature coolant storage cavity through a second valve body; a spare coolant storage cavity arranged on the side wall of the circuit skeleton, which is constructed as a U-shaped structure, and the two ends of the spare coolant storage cavity are connected to the circuit skeleton through a third valve body and a fourth valve body respectively, so as to realize the movement of coolant between the inside of the circuit skeleton and the spare coolant storage cavity.

[0009] Preferably, the first control circuit includes: a temperature sensor for measuring the coolant temperature in real time; a detector for emitting a detection signal to detect the position of the coolant carrier module in real time, and sending an arrival signal to the microcontroller when it is detected that the coolant carrier module moves to the detection boundary of the central control cooling module; a magnetization and demagnetization device, which is arranged at the upper end surface adjacent to the circuit skeleton, and is used to emit or stop emitting electromagnetic force under the action of the microcontroller; a microcontroller for detecting whether the current coolant has reached a high temperature state according to the real-time temperature of the coolant, and sending a delivery notification when the coolant reaches a high temperature state, and then controlling the detector to detect the coolant carrier module, and when it is detected that the coolant carrier module has arrived according to the detected feedback signal, controlling the magnetization and demagnetization device to magnetize, thereby realizing a physical connection with the coolant carrier module.

[0010] Preferably, the microcontroller is also used to control the connection between the circuit skeleton and the standby coolant storage cavity, and to control the connection between the circuit skeleton and the high-temperature coolant storage cavity after the central control cooling module is physically connected with the coolant carrier module, so that the high-temperature coolant in the cooling cavity can flow into the high-temperature coolant storage cavity, thereby controlling the disconnection between the circuit skeleton and the high-temperature coolant storage cavity after the leakage is completed.

[0011] Preferably, the first control circuit further includes: a microcontroller monitoring unit, which is used to monitor the operating status of the microcontroller to control the microcontroller to restart when the operation is abnormal; and a crystal oscillator, which is used to provide a clock signal for the operation of the microcontroller.

[0012] Preferably, the detector has an RFID reader and an antenna for periodically transmitting radio frequency signals and detecting the position of the coolant carrier module through the RFID tag carried by the coolant carrier module; the magnetization and demagnetization device has an iron core and a coil; and the microcontroller adopts an MCU device.

[0013] Preferably, the microcontroller is also used to detect whether the coolant has reached a high temperature state according to the following process: the first step is to determine whether the current coolant temperature has reached or exceeded a preset temperature threshold in the first stage according to the real-time temperature of the coolant, so as to achieve the migration of the coolant between the circuit skeleton and the standby coolant storage cavity according to the corresponding strategy based on the temperature evaluation result of the first stage, so as to enter the next step when the migration is completed; the second step is to determine whether the current coolant temperature has reached or exceeded the preset temperature threshold in the second stage according to the real-time temperature of the coolant after the migration. If yes, it indicates that the current coolant has reached a high temperature state. If not, return to the first step to continue to transfer the coolant to conduct heat for the downhole measuring instrument.

[0014] Preferably, in the first step, it includes: if the real-time temperature of the coolant reaches or exceeds the preset temperature threshold in the first stage, the third valve body and the fourth valve body are immediately opened to realize the movement of the coolant, so that when the duration of the movement process reaches the preset movement time, the current movement is ended by controlling the closing of the third valve body and the fourth valve body; if the real-time temperature of the coolant is lower than the preset temperature threshold in the first stage, the coolant movement is realized by opening the third valve body and the fourth valve body at a preset interval time, so that when the duration of the movement process reaches the preset movement time, the current movement is ended by controlling the closing of the third valve body and the fourth valve body.

[0015] Preferably, the first control circuit is communicatively connected to the hardware circuit of the downhole measuring instrument, and is also used to send a release instruction to the hardware circuit of the downhole measuring instrument when the coolant reaches a high temperature state, so as to use the hardware circuit of the downhole measuring instrument to notify the ground system to release the coolant carrier module, wherein the downhole measuring instrument is an MWD instrument, an EM-MWD instrument, or an LWD instrument.

[0016] On the other hand, an embodiment of the present invention provides a downhole instrument cooling control system, comprising: a central control cooling module as described above; and a coolant transport module, which is used to inject the coolant from the wellhead when the coolant inside the central control cooling module reaches a high temperature state, and after achieving physical connection with the central control cooling module, introduce the transported coolant into the central control cooling module.

[0017] Compared with the prior art, one or more embodiments of the above scheme may have the following advantages or beneficial effects:

[0018] The present invention proposes a downhole instrument cooling control system and a central control cooling module therein. The scheme includes the hardware circuit architecture, mechanical structure and cooling control method of the central control cooling module of the downhole instrument cooling control system. Under the constraints of the existing technical level of the hardware circuit structure and the temperature resistance of electronic components, after the temperature resistance of the instrument hardware circuit system reaches the design limit, through the central control cooling module and control method of the downhole instrument cooling control system provided by the present invention, the downhole instrument is integrated with the central control cooling module and goes into the well to work, and the central control cooling module cools the instrument, which can control the working temperature of the instrument within a reasonable temperature range, avoid instrument damage and reduced working stability under ultra-high temperature conditions underground, extend the service life of the instrument, meet the application requirements of ultra-deep and ultra-high temperature drilling, and improve drilling efficiency.

[0019] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0021] Figure 1 This is a schematic diagram of the overall structure of a central control cooling module for a downhole instrument cooling control system according to an embodiment of the present application.

[0022] Figure 2This is a structural schematic diagram of the first control circuit in the central control cooling module of the downhole instrument cooling control system according to an embodiment of the present application.

[0023] Figure 3 This is a schematic diagram of the implementation process of the central control cooling module of the downhole instrument cooling control system according to an embodiment of the present application.

[0024] Figure 4 This is a schematic diagram of the overall structure of a coolant carrier module for a downhole instrument cooling control system according to an embodiment of the present application.

[0025] Figure 5 This is a schematic diagram of the structure of the transport control circuit in the coolant transport module of the downhole instrument cooling control system according to an embodiment of the present application.

[0026] Figure 6 This is a schematic diagram of the implementation process of the coolant carrier module for the downhole instrument cooling control system according to an embodiment of the present application.

[0027] Figure 7 This is a schematic diagram of the structure of a downhole instrument cooling control system according to an embodiment of the present application. DETAILED DESCRIPTION

[0028] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that as long as there is no conflict, the various embodiments of the present invention and the various features in the embodiments can be combined with each other, and the technical solutions formed are all within the protection scope of the present invention.

[0029] In addition, the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions. Also, although a logical sequence is shown in the flowchart, in some cases, the steps shown or described can be performed in a sequence different from that here.

[0030] The terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "one", "one" and "item" used herein are also intended to include plural numbers. It should also be understood that the terms "include" and / or "comprise" used herein specify the existence of stated features, integers, steps, operations, units and / or components, without excluding the existence or addition of one or more other features, integers, steps, operations, units, components and / or combinations thereof.

[0031] Measurement while drilling (MWD) and logging while drilling (LWD) can provide real-time information such as directional parameters, engineering parameters, geological parameters, etc. during the drilling process, which is convenient for adjusting the wellbore trajectory and improving the drilling rate. They are key equipment for future automated and intelligent drilling.

[0032] The formation temperature increases with the increase of formation depth. The average geothermal gradient of the earth is about 3℃ / 100m. The temperature resistance of downhole instruments directly restricts the drilling of ultra-deep wells over 10,000 meters. Therefore, high temperature resistance is the main development direction of MWD / LWD instruments.

[0033] At present, the temperature resistance of hardware circuit systems is mainly improved through high-temperature circuit design and low-power design, thereby improving the temperature resistance of downhole instruments. There are three types of high-temperature circuit design methods: traditional method, hybrid circuit method, and special function circuit method. Specifically, the traditional method mainly optimizes the design of electronic components themselves by adopting high-temperature resistant design, reducing the power consumption of electronic components, and selecting heat-resistant raw materials; the hybrid circuit method uses integrated chips and thin and thick film technologies to design circuits at the same time; the special function circuit method is a special design method specifically for integrated circuit design. Low-power design methods include reducing the supply voltage, implementing frequency reduction, reducing load capacitance, and intelligent firmware control.

[0034] Limited by the existing technological level, the temperature resistance of the hardware circuit system can only be improved by optimizing the hardware circuit structure, adopting high-temperature resistant electronic components, optimizing power consumption design, etc. There are still insurmountable technical bottlenecks in further improving the temperature resistance of the instrument. It is impossible to work for a long time under ultra-high temperature conditions underground, and it is difficult to meet the needs of ultra-deep and ultra-high temperature drilling.

[0035] Therefore, in order to solve the above technical problems, the embodiment of the present application proposes a central control cooling module for a downhole instrument cooling control system. After the central control cooling module of the downhole instrument cooling control system enters the well, the central control cooling module cools the instrument and controls the working temperature of the instrument within a reasonable temperature range, thereby avoiding problems such as instrument damage and reduced working stability under ultra-high temperature conditions underground, extending the service life of the instrument, meeting the application requirements of ultra-deep and ultra-high temperature drilling, and improving drilling efficiency.

[0036] Figure 7 Schematic diagram of the structure of the downhole instrument cooling control system of the embodiment of the present application. Figure 7 As shown, the downhole instrument cooling control system (also called “cooling control system”) includes a central control cooling module 100 and a coolant carrying module 200 .

[0037] The central control cooling module 100 is integrated into the downhole measuring instrument, and is electrically and physically connected to the hardware circuit system in the downhole measuring instrument, so that it can work in the well with the downhole measuring instrument. In addition, the hardware circuit of the downhole measuring instrument is set in the coolant stored in the cooling cavity inside the central control cooling module 100. In the central control cooling module 100, a cooling cavity for storing coolant is provided, so that the coolant in the cooling cavity is used to cool the hardware circuit of the downhole measuring instrument in operation.

[0038] That is to say, the central control cooling module 100 cools the downhole measuring instrument through the coolant carried in the cooling cavity inside the module. When the coolant carried into the well cannot meet the cooling requirements of the instrument, the coolant carrier module 200 is dropped into the wellhead, and then the central control cooling module 100 controls the communication between modules, the physical connection between modules, and the introduction of (newly carried) coolant.

[0039] Specifically, a (high-temperature) coolant storage cavity is provided below the cooling cavity, so that when the coolant in the cooling cavity reaches a high-temperature state, after the physical connection between the central control cooling module 100 and the coolant carrier module 200 is realized, the high-temperature coolant in the cooling cavity is discharged into the high-temperature coolant storage cavity, so that the emptied cooling cavity can accommodate the new coolant introduced by the coolant carrier module 200, thereby using the newly introduced coolant to continue to cool the hardware circuit of the downhole measuring instrument.

[0040] The coolant carrier module 200 is built with coolant. The bottom of the coolant carrier module 200 is designed to be a concave spherical shape, which matches the concave spherical shape of the bottom of the displacement body accommodating part 120 in the central control cooling module 100. In addition, a diversion port for diverting the coolant is provided at the bottom of the coolant carrier module 200. It is dropped into the wellbore from the wellhead, moves along the wellbore under the action of its own gravity, and when it descends to the position of the downhole measuring instrument, under the control of the central control cooling module 100, the coolant in the coolant carrier module 200 is introduced into the cooling cavity in the central control cooling module 100 for instrument cooling. After all the coolant is discharged, the coolant carrier module 200 returns to the ground under the buoyancy of the drilling fluid.

[0041] Therefore, the coolant carrier module 200 described in the embodiment of the present invention is used to be dropped from the wellhead and move downward along the wellbore when the coolant inside the central control cooling module reaches a high temperature state, and after the coolant carrier module 200 is physically connected with the central control cooling module 100, the carried coolant is introduced into the central control cooling module 100. In addition, the central control cooling module 100 is used to control itself to achieve a physical connection with the coolant carrier module 200 when the arrival of the coolant carrier module is detected. Among them, the central control cooling module 100 is also used to notify the ground to drop the coolant carrier module 200 when it is detected that the internal coolant has reached a high temperature state.

[0042] In one embodiment, the downhole measurement instrument described in the embodiment of the present invention is a measurement while drilling (MWD) instrument or a logging while drilling (LWD) instrument or an EM-MWD instrument.

[0043] Figure 1 Schematic diagram of the overall structure of the central control cooling module for the downhole instrument cooling control system of the embodiment of the present application. Figure 1 As shown, the central control cooling module 100 described in the embodiment of the present invention includes: a sleeve 110, a displacement body accommodating portion 120, a cooling cavity 130, a high-temperature coolant storage cavity 140 and a first control circuit 150.

[0044] The replacement body receiving portion 120 is embedded in the side wall of the sleeve 110. The lower end surface of the replacement body receiving portion 120 forms a coolant replacement end.

[0045] The cooling cavity 130 is disposed inside the sleeve 110. The upper end surface of the cooling cavity 130 matches the shape of the lower end surface of the displacement body receiving portion 120. The cooling cavity 130 is provided with not only the first control circuit 150 and the hardware circuit of the downhole measuring instrument, but also the cooling cavity 130 is used to contain a coolant used to cool the hardware circuit of the downhole measuring instrument.

[0046] The high-temperature coolant storage chamber 140 is disposed inside the sleeve 110 , and the high-temperature coolant storage chamber 140 is also located below the cooling chamber 130 .

[0047] The first control circuit 150 is arranged inside the cooling cavity 130. The first control circuit 150 is mainly used to realize the high temperature state detection of the coolant in the cooling cavity 130, the movement and leakage control of the coolant, and the on-off control between the central control cooling module 100 and the coolant carrier module 200. Specifically, the first control circuit 150 is used to notify the ground to drop the coolant carrier module 200 when it is detected that the coolant in the cooling cavity 130 has reached a high temperature state. In addition, the first control circuit 150 is also used to control the central control cooling module 100 and the coolant carrier module 200 to achieve physical connection at the replacement body accommodating portion 120 when the arrival of the coolant carrier module 200 is detected, and then control the coolant in the cooling cavity 130 to leak into the high temperature coolant storage cavity 140, and guide the coolant in the coolant carrier module 200 to the cooling cavity 130.

[0048] Specifically, the sleeve 110 is placed outside the cooling cavity 130. The sleeve 110 is used to protect the hardware circuits of the downhole instrument and the central control cooling module, and prevent the hardware circuits of the downhole measuring instrument and the hardware circuits of the central control cooling module 100 from being directly exposed to the harsh working environment of high temperature, high pressure, strong vibration, strong impact, etc. in the well. In addition, a heat insulation coating is added to the outside of the sleeve 110 to isolate the heat of the formation and drilling fluid from being conducted to the downhole measuring instrument and the central control cooling module 100.

[0049] The displacement body accommodating portion 120 is located in the middle and upper part of the sleeve 110, and is a component of the sleeve 110. The structure of the displacement body accommodating portion 120 is an embedded type, wherein the shape of the bottom end surface of the displacement body accommodating portion 120 is designed to be a spherical shape that is concave inward, which can not only realize the physical connection between the central control cooling module 100 and the coolant carrier module 200, but also facilitate the flow of drilling fluid, and prevent the drilling fluid from adhering to the upper end of the central control cooling module 100 for a long time, thereby avoiding the drilling fluid from being left between the modules after the central control cooling module 100 and the coolant carrier module 200 are physically connected, and preventing the drilling fluid from polluting the coolant and affecting the electrical performance of the hardware circuit. In addition, at the bottom coolant replacement end of the replacement body accommodating portion 120, an electromagnetic switch valve body (first valve body) is integrated. When the coolant carrying module 200 moves to the replacement body accommodating portion 120, under the control of the first control circuit 150, the central control cooling module 100 is physically connected with the coolant carrying module 200. Since the opening and closing of the valve core of the first valve body is controlled by the microcontroller in the first control circuit, a fluid channel is provided for the introduction and replacement of the coolant.

[0050] The cooling cavity 130 includes a circuit skeleton 131 and a standby cooling liquid storage cavity 132 .

[0051] The upper end surface of the circuit skeleton 131 is formed as the upper end surface of the cooling cavity 130. Moreover, the circuit skeleton 131 is physically connected to the coolant carrier module through the first valve body. The first control circuit 150 and the hardware circuit of the downhole measuring instrument are arranged inside the circuit skeleton 131. Among them, the lower end surface of the circuit skeleton 131 is connected to the high-temperature coolant storage cavity through the second valve body.

[0052] The circuit skeleton 131 is used to install, fix and protect the hardware circuit and the first control circuit 150 of the downhole measuring instrument, and further improve the temperature resistance, pressure resistance, vibration resistance and impact resistance of the downhole measuring instrument and the central control cooling module 100. A thermal insulation coating is added to the outside of the circuit skeleton 131 to further isolate the conduction of formation and drilling fluid heat to the downhole instrument and the central control cooling module. The top of the circuit skeleton 131 is directly connected to the coolant replacement end of the replacement body accommodating part 120. Before being placed in the circuit skeleton 131, the hardware circuit and the first control circuit 150 of the downhole measuring instrument need to be potted with potting glue to improve the vibration resistance, electrical stability and safety of the hardware circuit during the downhole operation; the potted hardware circuit is placed in the circuit skeleton 131 for fixation, and the other parts of the circuit skeleton 131 except the top are sealed. Before the downhole measuring instrument is put into operation, coolant is input through the coolant replacement end so that the circuit skeleton 131 and the standby coolant storage cavity 132 are filled with coolant, which is used to cool the downhole measuring instrument and play a role in buffering and vibration reduction, protecting the hardware circuit in the circuit skeleton 131. In addition, four electromagnetic switch valve bodies (first valve body, second valve body, third valve body and fourth valve body) are integrated on the circuit skeleton 131, and the opening and closing of the four corresponding valve cores are controlled by the microcontroller in the first control circuit 150, which are respectively used to control the movement and leakage of the coolant inside the cooling cavity.

[0053] Further, the standby cooling liquid storage cavity 132 is arranged on the side wall of the circuit skeleton 131. The standby cooling liquid storage cavity 132 is constructed as a U-shaped structure. The two ends of the standby cooling liquid storage cavity 132 are respectively connected to the side wall of the circuit skeleton 131 through the third valve body and the fourth valve body, so as to realize the movement of the cooling liquid between the inside of the circuit skeleton 131 and the standby cooling liquid storage cavity 132. It should be noted that, in the embodiment of the present invention, when the inside of the circuit skeleton 131 is connected with the standby cooling liquid storage cavity 132, the cavity after the two are connected constitutes the cooling cavity 130. In addition, when the inside of the circuit skeleton 131 is not connected with the standby cooling liquid storage cavity 132, only the inside of the circuit skeleton 131 constitutes the cooling cavity 130.

[0054] The standby coolant storage chamber 132 is located between the sleeve 110 and the circuit skeleton 131, and is connected to the circuit skeleton 131 through two electromagnetic switch valves (the third valve body and the fourth valve body). The standby coolant stored in the standby coolant storage chamber 132 is used for the outward conduction of the heat generated by the operation of the hardware circuit in the circuit skeleton. After the downhole measuring instrument is put into operation, before drilling into the high-temperature formation, the heat generated by the operation of the downhole measuring instrument is the main influencing factor for the increase in the operating temperature of the instrument, and causes the temperature of the coolant in the circuit skeleton to increase. Therefore, the electromagnetic switch valve needs to be controlled by the first control circuit 150 in the central control cooling module 100 to realize the movement of the coolant between the circuit skeleton 131 and the standby coolant storage chamber 132, so as to conduct the heat generated by the operation of the downhole measuring instrument. In addition, a heat-insulating coating is added to the outside of the standby coolant storage chamber 132 to isolate the conduction of the formation and drilling fluid heat to the standby coolant.

[0055] Furthermore, the underground high-temperature coolant storage chamber 140 is located below the circuit skeleton 131 and above the sleeve 110. The high-temperature coolant storage chamber 140 is connected to the circuit skeleton 131 through an electromagnetic switch valve (second valve body), and is mainly used to store the high-temperature coolant discharged from the circuit skeleton 131 and the standby coolant storage chamber 132.

[0056] Figure 2 Schematic diagram of the structure of the first control circuit in the central control cooling module of the downhole instrument cooling control system according to the embodiment of the present application. Figure 2 As shown, the first control circuit 150 at least includes: a temperature sensor 151 , a detector 152 , a magnetization and demagnetization device 153 and a microcontroller 154 .

[0057] The temperature sensor 151 is used to measure the temperature of the coolant in real time. In other words, the temperature sensor 151 is used to collect the working temperature of the downhole measuring instrument (ie, the temperature of the coolant in which the hardware circuit system of the downhole measuring instrument is immersed).

[0058] The detector 152 is used to detect the position reached by the coolant carrier module 200 in real time by emitting corresponding detection signals. In one embodiment, the detector 152 has an RFID reader and an antenna; the detector 152 is used to periodically emit radio frequency signals. In addition, the detector 152 is also used to detect the position reached by the coolant carrier module 200 after the coolant carrier module 200 is put into the wellbore through the RFID tag carried by the coolant carrier module 200. In addition, the detector 152 is also used to send an arrival signal to the microcontroller 154 when it is detected that the coolant carrier module 200 moves to the detection boundary of the central control cooling module 100.

[0059] The magnetization and demagnetization device 153 is used to generate or stop generating electromagnetic force under the action of the microcontroller 154. In one embodiment, the magnetization and demagnetization device 153 has an iron core and a coil, which is used to achieve the physical connection between the central control cooling module 100 and the coolant carrier module 200.

[0060] The microcontroller 154 is the control and processing core of the first control circuit 150 in the central control cooling module 100. The microcontroller 154 is used to detect whether the current coolant has reached a high temperature state according to the real-time temperature of the coolant, and send a notification signal to the ground to drop the coolant carrier module 200 when the coolant reaches a high temperature state, and then control the detector 152 to detect the coolant carrier module 200, and when the coolant carrier module 200 arrives (i.e., the coolant carrier module 200 moves to the detection boundary of the detector 152) according to the detected feedback signal, the magnetization and demagnetization device 153 is controlled to magnetize and emit electromagnetic force, thereby achieving physical connection with the coolant carrier module 200. In one embodiment, the microcontroller 154 adopts an MCU device.

[0061] It should be noted that the magnetization and demagnetization device 153 described in the embodiment of the present invention is arranged at the upper end surface close to the circuit frame 131. Specifically, when fixed in the circuit frame 131, the end where the magnetization and demagnetization device 153 is located should be placed close to the top of the circuit frame 131, so as to maximize the electromagnetic attraction to the coolant carrier module 200.

[0062] In addition, the first control circuit 150 further includes: a microcontroller monitoring unit 155, a crystal oscillator 156, a power conversion unit 157 and a plurality of valve bodies (a first valve body, a second valve body, a third valve body and a fourth valve body).

[0063] The microcontroller monitoring unit 155 is used to monitor the operating state of the microcontroller 154 to control the microcontroller 154 to restart when the operation is abnormal. The microcontroller monitoring unit 155 can restart the hardware circuit of the central control cooling module 100 when the program of the microcontroller 154 runs away, thereby ensuring that the central control cooling module 100 operates stably underground.

[0064] The crystal oscillator 156 is used to provide a clock signal for the operation of the microcontroller 154 .

[0065] The central control cooling module 100 is powered by the power supply of the downhole measuring instrument, and the power conversion unit 157 is used to convert the voltage provided by the power supply of the downhole measuring instrument into a specific voltage value for the operation of each component in the central control cooling module 100. In one embodiment, the power conversion unit 157 is a DC-DC unit, which is used to convert the voltage provided by the power supply of the downhole measuring instrument into a specific voltage value required for the stable operation of the analog and digital circuits of the central control cooling module 100.

[0066] Figure 3 This is a schematic diagram of the implementation process of the central control cooling module for the downhole instrument cooling control system of the embodiment of the present application. Figure 3 The specific functions and implementation process of the central control cooling module 100 described in the embodiment of the present invention are described.

[0067] like Figure 3 As shown, first, the central control cooling module 100 is integrated into the downhole measuring instrument and goes into the well with the downhole measuring instrument to work. The central control cooling module 100 starts timing after it is powered on.

[0068] The temperature sensor 151 periodically measures the temperature of the coolant in the circuit skeleton 131. The temperature measurement period is denoted as T1.

[0069] The microcontroller 154 is also used to detect whether the coolant has reached a high temperature state according to the measured temperature data after obtaining the real-time temperature data of the coolant. Specifically, in the first step, according to the real-time temperature of the coolant, it is determined in the first stage whether the current coolant temperature has reached or exceeded the preset temperature threshold, so as to realize the movement of the coolant between the circuit skeleton and the standby coolant storage cavity according to the corresponding strategy according to the temperature evaluation result of the first stage, so as to enter the next step when the movement is completed.

[0070] In the first step, in the first embodiment, if the real-time temperature of the coolant in the first stage is lower than the above-mentioned preset temperature threshold (the preset temperature threshold is determined according to the maximum temperature resistance value of the downhole measuring instrument, such as: 180°C), then under the control of the microcontroller 154, the coolant migration is realized by opening the third valve body and the fourth valve body at preset intervals, so that when the duration of the migration process reaches the preset migration time, the current migration is ended by controlling the closing of the third valve body and the fourth valve body.

[0071] Specifically, if the coolant temperature in the circuit skeleton measured in the first stage is lower than the set threshold temperature and the timing of the central control cooling module 100 reaches the set time period T2, the microcontroller 154 controls the opening of the two electromagnetic switch valve cores between the circuit skeleton 131 and the spare coolant storage chamber 132, and the heat generated by the downhole instrument is removed by the movement of the coolant; then, after the movement is started, when the timing of the central control cooling module 100 reaches the set period T3 (T3>T2) (that is, when the opening time of the two electromagnetic switch valve cores reaches (T3-T2)), the microcontroller 154 controls the closing of the two electromagnetic switch valve cores between the circuit skeleton 131 and the spare coolant storage chamber 132. At this time, the timing of the central control cooling module 100 is reset and the timing is restarted.

[0072] In the second embodiment, if the real-time temperature of the coolant reaches or exceeds the above-mentioned preset temperature threshold in the first stage, the third valve body and the fourth valve body are immediately opened under the control of the microcontroller 154 to realize the movement of the coolant, so that when the duration of the movement process reaches the preset movement time, the current movement is ended by controlling the closing of the third valve body and the fourth valve body.

[0073] Specifically, if the coolant temperature in the circuit skeleton measured in the first stage is higher than or equal to the set threshold temperature, the microcontroller 154 controls the immediate opening of the two electromagnetic switch valve cores between the circuit skeleton 131 and the standby coolant storage chamber 132, and the heat generated by the downhole measuring instrument is removed by the movement of the coolant; then, after the movement is started, when the opening time of the two electromagnetic switch valve cores reaches (T3-T2), the microcontroller 154 controls the closing of the two electromagnetic switch valve cores. At this time, the timing of the central control cooling module 100 is reset and the timing is restarted.

[0074] Next, in the second step, according to the real-time temperature of the coolant after migration, it is determined in the second stage whether the current coolant temperature reaches or exceeds the above-mentioned preset temperature threshold. If the real-time temperature of the coolant after migration reaches or exceeds the above-mentioned preset temperature threshold, it indicates that the current coolant has reached a high temperature state. In addition, if the real-time temperature of the coolant after migration is lower than the above-mentioned preset temperature threshold, it returns to the first step and continues to transfer heat to the downhole measuring instrument through the migration of the coolant.

[0075] Specifically, if the measured temperature of the coolant in the circuit skeleton is lower than the set threshold temperature after the coolant is moved, the process returns to the first step and continues to transfer the coolant to conduct heat to the hardware circuit of the downhole measuring instrument. If the measured temperature of the coolant in the circuit skeleton is higher than or equal to the set threshold temperature after the coolant is moved, it indicates that the current coolant has reached a high temperature state, and the ground is immediately notified to drop the coolant carrier module 200.

[0076] In addition, the microcontroller 154 in the first control circuit 150 is also connected to the hardware circuit of the downhole measuring instrument. The microcontroller 154 is also used to send a delivery instruction to the hardware circuit of the downhole measuring instrument when detecting that the coolant reaches a high temperature state, so as to use the hardware circuit of the downhole measuring instrument to notify the ground system to deliver the coolant carrier module 200.

[0077] In the embodiment of the present invention, the average density of the coolant carrier module 200 loaded with coolant is greater than the density of the drilling fluid in the wellbore, and the density of the drilling fluid in the wellbore is greater than the average density of the coolant carrier module 200 after the coolant is extracted.

[0078] In this way, the coolant carrier module 200 carrying the coolant can be dropped from the wellhead and moved underground under the control of the ground system.

[0079] like Figure 3 As shown, the microcontroller 154 is also used to immediately control the detector 152 to detect the coolant carrier module 200 when it is detected that the coolant reaches a high temperature state. At this time, the detector 152, under the control of the microcontroller 154, periodically transmits a radio frequency signal to obtain a real-time feedback signal from the coolant carrier module 200. Since the coolant carrier module carries an RFID tag, the microcontroller 154 can detect the feedback signal from the coolant carrier module, thereby obtaining the arrival position information of the coolant carrier module 200, until it is detected that the coolant carrier module 200 reaches the detection boundary of the central control cooling module 100. At this time, the microcontroller 154 in the central control cooling module 100 can detect the arrival of the coolant carrier module 200.

[0080] The microcontroller 154 is also used to control the magnetization and demagnetization device 153 to generate electromagnetic force when detecting the arrival of the coolant carrier module 200, so as to attract the coolant carrier module 200 to the replacement body accommodating portion 120, thereby realizing the physical connection between the central control cooling module 100 and the coolant carrier module 200. Specifically, the magnetization and demagnetization device 153 of the central control cooling module 100 begins to magnetize under the control of the microcontroller 154, and attracts the coolant carrier module 200 to the replacement body accommodating portion 120 through electromagnetic attraction, thereby realizing the physical connection between the central control cooling module 100 and the coolant carrier module 200.

[0081] It should be noted that since the bottom of the coolant carrier module 200 is designed to be a concave spherical shape, it matches the concave spherical shape of the bottom of the replacement body accommodating portion 120 in the central control cooling module 100. At this time, when the coolant carrier module 200 is attracted to the replacement body accommodating portion 120, the guide port at the bottom of the coolant carrier module 200 is connected to the guide port at the first valve body at the top of the circuit skeleton 131.

[0082] Furthermore, the microcontroller 154 is also used to control the connection between the circuit skeleton 131 in the cooling cavity 130 and the standby coolant storage cavity 132, and the connection between the circuit skeleton 131 and the high-temperature coolant storage cavity 140 after the central control cooling module 100 and the coolant carrier module 200 are physically connected, so that the high-temperature coolant in the cooling cavity 130 is discharged into the high-temperature coolant storage cavity 140. Then, after the discharge is completed, the microcontroller 154 is also used to control the disconnection between the circuit skeleton 131 and the high-temperature coolant storage cavity 140 to prepare for the coolant diversion.

[0083] Specifically, the central control cooling module 100 is controlled by the microcontroller 154 to open the solenoid switch valve core between the circuit skeleton 131 and the standby coolant storage chamber 132, and the solenoid switch valve core between the downhole high-temperature coolant storage chamber 140 and the circuit skeleton 131. At this time, the high-temperature coolant flows into the downhole high-temperature coolant storage chamber 140 under the action of gravity; and then the microcontroller 154 controls the solenoid switch valve core between the downhole high-temperature coolant storage chamber 140 and the circuit skeleton 131 to close.

[0084] After the preparation for the coolant diversion is completed, since the current coolant carrier module 200 is in the replacement body accommodating portion 120, the microcontroller 154 is also used to control the first valve body at the top of the circuit skeleton 131 to open, so that after the valve body at the bottom of the coolant carrier module 200 is opened, the top diversion port of the circuit skeleton 131 is connected with the bottom diversion port of the coolant carrier module 200 attracted at the replacement body accommodating portion 120, and the coolant carried by the coolant carrier module 200 is diverted to the cooling cavity by relying on the coolant's own gravity. The cooling cavity described in the embodiment of the present invention is a cooling space formed after the circuit skeleton 131 is connected to the standby coolant storage cavity 132. Then, after the diversion is completed, the microcontroller 154 is also used to control the first valve body at the top of the circuit skeleton 131 to close.

[0085] Specifically, the central control cooling module 100 is controlled by the microcontroller 154 to open the solenoid switch valve core at the coolant replacement end of the sleeve. After the solenoid switch valve core of the coolant carrier module 200 is opened, the coolant inside the coolant carrier module 200 flows into the circuit skeleton 131 and the spare coolant storage cavity 132 of the central control cooling module 100 under the action of gravity. After the coolant is introduced, the opened solenoid switch valve cores of the central control cooling module and the coolant carrier module are both closed.

[0086] Finally, after completing the control of closing the diversion port valve body, the microcontroller 154 is also used to control the magnetization and demagnetization device 153 to stop generating electromagnetic force (demagnetization), thereby disconnecting the physical connection between the central control cooling module 100 and the coolant carrier module 200. Specifically, the magnetization and demagnetization device 153 of the central control cooling module 100 is controlled by the microcontroller 154 to demagnetize, and the coolant carrier module 200 floats to the wellhead under the buoyancy of the drilling fluid and is recovered by the ground system.

[0087] In this way, after the central control cooling module 100 is physically disconnected from the coolant carrier module 200, the coolant carrier module 200 that is not filled with coolant can actively float to the wellhead due to the buoyancy from the drilling fluid, so that the coolant carrier module 200 that is not filled with coolant can be recovered by the ground system.

[0088] In one embodiment, the central control cooling module 100 of the downhole instrument cooling control system uses ultra-high boiling point electronic fluoride liquid as the immersion coolant, and the boiling point is above 230°C, which is higher than the formation temperature of the ultra-deep formation. After the coolant in the circuit skeleton 131 and the standby coolant storage chamber 132 is introduced into the downhole high-temperature coolant storage chamber 140, its temperature rises to the formation temperature encountered during drilling, which is lower than the boiling point of the electronic fluoride liquid, thereby ensuring the safety of the central control cooling module in downhole application.

[0089] In another embodiment, the central control cooling module 100 of the downhole instrument cooling control system uses aerogel as a heat insulation coating material, and is coated on the sleeve 110, the circuit skeleton 131 and the outside of the standby coolant storage chamber 132 through a specific process, so as to isolate the conduction of formation and drilling fluid heat to the downhole instrument and the central control cooling module (including coolant), prolong the use time of the coolant in the well, and improve the temperature resistance of the downhole instrument.

[0090] Example

[0091] The temperature reduction control system described in the embodiment of the present invention is applied to an actual measurement while drilling scenario to illustrate the implementation process of the temperature reduction control system and the central control temperature reduction module therein.

[0092] The central control cooling module works with the instrument when it enters the well. The module starts timing from the time it is powered on, and the timing time is used as the reference value for the relevant time in the cooling control process.

[0093] The central control cooling module measures the coolant temperature in the circuit skeleton every T1 (e.g., 10s) period. If the measured coolant temperature in the circuit skeleton is lower than the set threshold temperature (e.g., the threshold temperature is 180°C, and the instrument has a maximum temperature resistance of 200°C), when the central control cooling module reaches the set period T2 (e.g., 10min), the heat generated by the instrument operation is removed through the coolant transfer, and when the opening time of the solenoid switch valve core reaches (T3-T2) (e.g., 1min), the solenoid switch valve core is closed; if the measured coolant temperature in the circuit skeleton is higher than or equal to the set threshold temperature, the solenoid switch valve core is immediately opened for coolant transfer, and when the opening time of the solenoid switch valve core reaches (T3-T2), the solenoid switch valve core is closed. If the coolant temperature in the circuit skeleton is lower than the set threshold temperature after the coolant is transported, the instrument will be cooled in a cycle according to the above process; if the coolant temperature after migration is still higher than or equal to the threshold temperature, the coolant carrier module must be dropped into the wellbore from the wellhead, and the central control cooling module will periodically (e.g., once every 3 seconds) transmit the radio frequency signal.

[0094] When the RFID tag carried in the coolant carrier module is detected (e.g., the maximum detection distance is 30m), the magnetization and demagnetization device of the central control cooling module begins to magnetize. The electromagnetic attraction generated attracts the coolant carrier module to the coolant replacement end of the central control cooling module when it approaches, thereby realizing the physical connection between the two modules.

[0095] The central control cooling module opens the solenoid switch valve core between the circuit skeleton and the spare coolant storage cavity, and the solenoid switch valve core between the downhole high-temperature coolant storage cavity and the circuit skeleton. After all the coolant flows into the downhole high-temperature coolant storage cavity, the solenoid switch valve core between the downhole high-temperature coolant storage cavity and the circuit skeleton is closed.

[0096] The central control cooling module and the coolant carrier module open the solenoid switch valve cores at the coolant replacement end of the sleeve respectively, and introduce the coolant inside the coolant carrier module into the circuit skeleton and the spare coolant storage cavity of the central control cooling module. After the coolant introduction is completed, the central control cooling module and the coolant carrier module close the opened solenoid switch valve cores.

[0097] The magnetization and demagnetization device of the central control cooling module is demagnetized, and the instrument is cooled down again according to the set process cycle. The coolant carrier module floats up under the buoyancy of the drilling fluid and is recovered on the ground.

[0098] Figure 4 FIG. 1 is a schematic diagram of the overall structure of a coolant carrier module for a downhole instrument cooling control system according to an embodiment of the present application. Figure 4 As shown, the cooling liquid carrying module 200 described in the embodiment of the present invention includes: a shell 210, a cooling liquid guide port 220 and a carrying control circuit 230.

[0099] In the embodiment of the present invention, the cooling liquid carrier module 200 is put into the well and moves down the wellbore. The housing 210 is used to hold the cooling liquid. The lower end surface of the housing 210 matches the shape of the lower end surface of the displacement body receiving portion 120 in the central control cooling module 100. The lower end surface of the displacement body receiving portion 120 forms the cooling liquid displacement end of the central control cooling module 100.

[0100] The carrier control circuit 230 is arranged in the internal space of the housing 210. The carrier control circuit 230 is used to send a feedback signal indicating the position of the coolant carrier module 200 after receiving the radio frequency signal sent from the central control cooling module 100. Among them, the carrier control circuit 230 is also used to control the opening of the coolant guide port when it detects that the coolant carrier module 200 (coolant carrier module 200) has reached a stationary state, so as to guide the carried coolant into the central control cooling module 100 when its coolant guide port and the guide port of the central control cooling module are in a docking state, so as to replace the high-temperature coolant with a low-temperature coolant that can continue to cool the hardware circuit of the downhole measuring instrument when the coolant in the central control cooling module 100 is in a high-temperature state.

[0101] Specifically, the module housing 210 is used to load the coolant and the carrier control hardware circuit 230, and provide mechanical and chemical protection for the coolant and the carrier control hardware circuit 230 when the coolant carrier module 200 moves along the wellbore.

[0102] In one embodiment, a heat-insulating coating is added to the outside of the module housing 210 to isolate the heat of the formation and the drilling fluid from being conducted to the coolant in the module when the coolant carrier module 200 moves downward along the wellbore. Specifically, the coolant carrier module 200 uses aerogel as the heat-insulating coating material, which is applied to the outside of the module housing 210 through a specific process.

[0103] In one embodiment, the bottom of the module shell 210 is made of metal material, and the other parts of the module shell 210 are made of low-density organic material, so that when the central control cooling module 100 emits electromagnetic force, the cooling liquid carrier module 200 and the central control cooling module 100 are docked by relying on the adsorption force of the central control cooling module 100. At this time, the guide port of the cooling liquid carrier module 200 and the guide port of the central control cooling module 100 reach a docking state; or, when the central control cooling module 100 stops emitting electromagnetic force, the docking state between the cooling liquid carrier module 200 and the central control cooling module 100 is disconnected.

[0104] In order to meet the requirement that the coolant carrier module 200 can be attracted by the electromagnetic attraction of the central control cooling module 100, the bottom of the module housing 210 is made of a metal material with iron as the main component; and the other parts of the module housing 210 are made of a low-density organic material that is not affected by electromagnetic attraction. In one embodiment, the housing 210 of the coolant carrier module 200 is made of a fluoroelastomer material. In this way, while providing mechanical and chemical protection for the carrier control hardware circuit 230 and the coolant in the coolant carrier module 200, it also ensures that the density of the coolant carrier module 200 can meet the process requirements of sinking when fully loaded with coolant and floating after the coolant is drained.

[0105] In one embodiment, the body of the module housing 210 is constructed as a spherical structure, and the bottom of the module housing 210 is constructed as a concave sphere. Limited by the wellbore size, in order to maximize the single carrying capacity of the coolant, the body of the module housing 210 adopts a spherical structure, and considering the spherical structure of the sleeve coolant replacement end of the central control cooling module 100, in order to improve the fit of the two modules after physical connection, the bottom of the module housing 210 is designed as a concave sphere.

[0106] In addition, in order to ensure that the coolant carrier module 200 can move downward along the wellbore under the action of gravity after being dropped from the wellhead, and at the same time ensure that the coolant carrier module 200 can float up under the buoyancy of the drilling fluid and be recovered on the ground after the coolant is drained out underground, the following design conditions must be met: the average density of the coolant carrier module 200 loaded with coolant is greater than the density of the drilling fluid in the wellbore, and the density of the drilling fluid in the wellbore is greater than the average density of the coolant carrier module 200 after the coolant is drained out.

[0107] In addition, the coolant diversion port 220 is arranged on the lower end surface of the module housing 210. Among them, a diversion valve body is arranged at the coolant diversion port 220. The carrier control circuit 230 controls the opening and closing state of the coolant diversion port by controlling the switch state of the diversion valve body. An electromagnetic switch valve body is integrated at the bottom of the module housing 210. Since the density of the material used for the bottom is much higher than that of other parts, when the coolant carrier module 200 moves downward along the wellbore, the bottom is stably at the lower end. When it is subjected to the electromagnetic attraction of the central control cooling module 100, it can ensure that the bottom (but not other parts) with the electromagnetic switch valve body is in contact with the central control cooling module 100. After the coolant carrier module 200 is physically connected with the central control cooling module 100, the corresponding coolant diversion port 220 and the diversion port of the central control cooling module reach a docking state; moreover, the opening and closing of the corresponding valve core is controlled by the microprocessor in the carrier control circuit 230 in the coolant carrier module 200 to provide a fluid channel for the coolant to be discharged.

[0108] In addition, the coolant carrier module 200 further includes: a hardware circuit fixing device 240. The hardware circuit fixing device 240 is connected to the module housing 210. The hardware circuit fixing device 240 is used to fix the carrier control circuit 230 in the module housing 210. When the coolant carrier module 200 moves along the wellbore, the hardware circuit (carrier control circuit 230) is protected, and the acceleration sensor measurement value of the hardware circuit is ensured to maintain good consistency with the coolant carrier module 200. After data processing, it is used to control the opening and closing of the electromagnetic switch valve core according to the control process, and then the coolant is discharged.

[0109] Figure 5Schematic diagram of the structure of the transport control circuit in the coolant transport module of the downhole instrument cooling control system according to the embodiment of the present application. Figure 5 As shown, the transport control circuit 230 at least includes: an acceleration sensor 231 , a position feedback device 232 and a microprocessor 233 .

[0110] The acceleration sensor 231 is used to measure in real time the running acceleration of the cooling liquid carrier module 200. In other words, the acceleration sensor 231 is used to collect the real-time acceleration of the cooling liquid carrier module 200 during the movement along the wellbore after the cooling liquid carrier module 200 is dropped from the wellhead.

[0111] The position feedback device 232 is used to output a feedback signal indicating its position after receiving a detection signal sent from a detector in the central control and cooling module 100. In one embodiment, the position feedback device 232 has an RFID tag and an antenna; the position feedback device 232 is used to receive a radio frequency signal sent by a detector (especially a reader) in the central control and cooling module 100; in addition, the position feedback device 232 is also used to send tag information to the outside after receiving the radio frequency signal, so that the central control and cooling module 100 can determine the position of the coolant carrier module 200.

[0112] The microprocessor 233 is the control and processing core of the transport control circuit 230 in the coolant carrier module 200. The microprocessor 233 is used to determine the acceleration evaluation index at each unit time interval according to the real-time operation acceleration, and detect the operation state of the coolant carrier module 200 according to the acceleration evaluation index, so that when it is in a stationary state (indicating that the physical connection between the central control cooling module 100 and the coolant carrier module 200 has been achieved), the coolant diversion port 220 is first controlled to open, and then the coolant diversion port 220 is controlled to close after the coolant diversion is completed. In addition, the microprocessor 233 in the transport control circuit 230 is also used to control the opening and closing of the coolant diversion port 220 by controlling the switch state of the diversion valve body at the bottom of the module housing 210.

[0113] In one embodiment, the microprocessor 233 is an MCU device.

[0114] In addition, the carrier control circuit 230 further includes a microprocessor monitoring unit 234 , a crystal oscillator 235 , a battery 236 and a power conversion unit 237 .

[0115] The microprocessor monitoring unit 234 is used to monitor the operating state of the microprocessor 233 to control the microprocessor 233 to restart when the operation is abnormal. The microcontroller monitoring unit 234 can restart the hardware circuit of the coolant carrier module 200 when the program of the microprocessor 233 runs away, thereby ensuring that the coolant carrier module 200 operates stably underground.

[0116] The crystal oscillator 235 is used to provide a clock signal for the operation of the microprocessor 233 .

[0117] The coolant carrier module 200 is powered by a battery 236. The power conversion unit 237 is used to convert the voltage provided by the battery 236 into a specific voltage value for the operation of various components in the coolant carrier module 200. In one embodiment, the power conversion unit 237 is a DC-DC unit, which is used to convert the voltage provided by the battery 236 into a specific voltage value required for the stable operation of the analog and digital circuits of the coolant carrier module 200.

[0118] Figure 6 Schematic diagram of the implementation process of the coolant carrier module for the downhole instrument cooling control system in the embodiment of the present application. Figure 6 As shown, first, when the central control cooling module 100 detects that the current internal coolant is in a high temperature state, it sends a coolant carrier module 200 delivery instruction to the ground, and the coolant carrier module 200 is dropped from the wellhead and moves downward along the wellbore.

[0119] When the RFID tag of the position feedback device 232 inside the coolant carrier module 200 receives the radio frequency signal sent by the reader of the central control cooling module 100, it sends out a feedback signal (RFID tag information) indicating the arrival position.

[0120] Under the action of the microprocessor 233 , the measurement values ​​collected in real time by the acceleration sensor 231 are periodically read, with a period of T1 .

[0121] The microprocessor 233 is also used to determine the acceleration evaluation index at each unit time interval based on the real-time operating acceleration measurement value, and to detect whether the operating state of the coolant carrier module 200 is converted from a moving state to a stationary state based on the acceleration evaluation index.

[0122] In one embodiment, the microprocessor 233 is further used to calculate the acceleration evaluation index at each unit time interval according to the running acceleration measurement value. Specifically, the mean of the acceleration element data of each axis is calculated according to the running three-axis acceleration sequence obtained in the unit time; the arithmetic mean of the acceleration change in each axial direction is calculated according to the absolute value of the difference between each three-axis acceleration element data and the acceleration mean of the corresponding axis; finally, the arithmetic mean of the acceleration change in each axial direction is subjected to square, summation and square root operations to obtain the acceleration evaluation index.

[0123] Specifically, in the process of processing the acquired acceleration measurement values, the mean of the acceleration values ​​of each axis within a unit time (for example: 1 second) is first calculated; then the absolute value of the difference between the acceleration value of each axis and the mean of the corresponding axis is calculated; finally, the arithmetic mean of the absolute value of the difference of the above-mentioned axes is calculated, and then after squaring, summing, and square rooting the arithmetic means of the above-mentioned axes, the acceleration evaluation index △g is calculated and obtained, and the acceleration evaluation index △g is used as a characterization of the movement or stillness of the coolant carrier module 200.

[0124] Next, the microprocessor 233 is also used to detect the operating state of the coolant carrier module 200 according to the acceleration evaluation index at a number of consecutive unit time intervals. In one embodiment, if the value of each element in the acceleration evaluation index sequence at a number of consecutive unit time intervals changes from exceeding the preset acceleration threshold to not exceeding the preset acceleration threshold, and the duration of not exceeding the preset acceleration threshold exceeds the preset first time, it is determined that the current coolant carrier module 200 changes from a moving state to a stationary state, thereby realizing the physical connection between the coolant carrier module 200 and the central control cooling module 100.

[0125] Specifically, if the △g sequence changes from being greater than the set threshold g1 to being less than or equal to the set threshold g1, and the duration of being less than or equal to the threshold g1 exceeds the set threshold time T2, it is determined that the coolant transport module 200 changes from a moving state to a stationary state. At this time, the coolant transport module 200 and the central control cooling module 100 have been physically connected.

[0126] Continue to refer Figure 3 The microprocessor 233 is also used to guide the carried coolant into the central control cooling module 100 by controlling the opening of the coolant guide port 220 when the coolant carrier module 200 reaches a stationary state.

[0127] In one embodiment, the microprocessor 233 is further used to control the opening of the coolant diversion port after a preset second time when the coolant carrier module 200 reaches a stationary state. The preset second time is slightly longer than the discharge time of the high-temperature coolant of the central control cooling module 100. Then, the microprocessor 233 is further used to control the closing of the coolant diversion port 220 when the opening time of the coolant diversion port 220 reaches a preset third time. The preset third time is slightly longer than the opening time of the diversion port of the central control cooling module 100.

[0128] Specifically, the hardware circuit inside the coolant carrier module 200 is controlled by the microprocessor 233, and the timing starts. When the set threshold time T3 is reached (the preset second time T3 is based on the leakage time of the high-temperature coolant inside the central control cooling module 100 and is slightly greater than the leakage time), the microprocessor 233 controls the opening of the solenoid switch valve core of the diversion valve body inside the coolant carrier module 200, and the timing time is reset and restarted. At this time, the coolant inside the module shell 210 is diverted to the interior of the central control cooling module 100; when the opening time of the diversion valve body reaches the set threshold time T4 (the preset third time T4 is based on the opening time of the solenoid switch valve core of the diversion port inside the central control cooling module 100 when the coolant is introduced and replaced, and is slightly greater than the opening time of the valve core), the microprocessor 233 controls the closing of the solenoid switch valve core of the diversion valve body inside the coolant carrier module 200.

[0129] Finally, after the magnetization and demagnetization device of the central control cooling module 100 completes demagnetization, the electromagnetic attraction of the central control cooling module 100 to the coolant carrier module 200 disappears. At this time, the coolant carrier module 200 floats to the ground under the buoyancy of the drilling fluid and is captured and recovered by the ground system.

[0130] Example

[0131] The coolant carrier module 200 described in the embodiment of the present invention is applied to an actual measurement while drilling scenario, so as to illustrate the implementation process of the temperature reduction control system and the coolant carrier module 200 therein.

[0132] The transport control circuit is installed into the coolant transport module 200 and fixed, and after the coolant is injected into the module housing 210, the module is sealed and stored for future use.

[0133] When the temperature of the downhole coolant is too high to cool the instrument, a coolant carrier module 200 is dropped from the wellhead, and the module moves downward along the wellbore.

[0134] When the RFID tag of the coolant carrier module 200 receives the radio frequency signal sent by the reader of the central control cooling module 100, it sends the tag information to the outside, and the central control cooling module 100 receives the tag information, thereby determining the position of the coolant carrier module 200.

[0135] Since the tag information is sent, the coolant carrying module 200 reads the acceleration sensor measurement value once every T1 (eg, 0.1 s). In particular, taking a three-axis acceleration sensor as an example, the acceleration measurement values ​​of each axis per second are ax[0], ax[1], ..., ax[9], ay[0], ay[1], ..., ay[9], az[0], az[1], ..., az[9]; the average values ​​of the acceleration values ​​of the x, y, and z axes per second are (ax[0]+ax[1]+...+ax[9]) / 10, (ay[0]+ay[1]+...+ay[9]) / 10, and (az[0]+az[1]+...+az[9]) / 10, respectively; the differences between the acceleration values ​​of the x, y, and z axes and the above average values ​​are ax[0]-(ax[0]+ax[1]+...+ax[9]) / 10, ax[1]-(ax[0]+ax[1]+...+ax[9]) / 10, ..., ax[9]-(ax[0]+ax[1]+...+ax[9]) / 10, respectively. + ax[9]) / 10, ay[0]-(ay[0]+ay[1]+...+ay[9]) / 10, ay[1]-(ay[0]+ay[1]+...+ay[9]) / 10, ..., ay[9]-(ay[0]+ay[1]+...+ay[9]) / 10, az[0]-(az[0]+az[1]+...+az[9]) / 10, az[1]-(az[0]+az[1]+...+az[9]) / 10, ..., az[9]-(az[0]+az[1]+...+az[9]) / 10; then take the absolute values ​​of the above differences on the x, y, and z axes respectively and calculate the arithmetic mean; finally, square, sum, and square root the above arithmetic means on the x, y, and z axes to obtain △g, which is the characterization of the module's motion or stillness.

[0136] If △g changes from being greater than the set threshold g1 (such as 0.02g) to being less than or equal to the set threshold g1, and the duration of being less than or equal to the threshold g1 exceeds the set threshold time T2 (such as 5s), it is determined that the coolant carrier module 200 has changed from a moving state to a stationary state, and the two modules have been physically connected.

[0137] After determining that the physical connection is achieved, the transport control circuit 230 in the coolant transport module 200 starts timing. When the set threshold time T3 is reached (such as 70s, which is slightly longer than the leakage time of the high-temperature coolant inside the central control cooling module 100 (such as 1min) as a reference), the solenoid switch valve core inside the coolant transport module 200 is opened, the timing time is reset and restarted; when the opening time of the solenoid switch valve core reaches the set threshold time T4 (such as 70s, which is slightly longer than the opening time of the solenoid switch valve core inside the central control cooling module 100 when the coolant is introduced and replaced (such as 1min) as a reference), the solenoid switch valve core inside the coolant transport module 200 is closed.

[0138] After the introduction and replacement of the coolant is completed, the magnetization and demagnetization device 153 of the central control cooling module 100 is demagnetized, the electromagnetic attraction disappears, and the coolant carrier module 200 floats up under the buoyancy of the drilling fluid and is recovered by the ground.

[0139] The present invention discloses a downhole instrument cooling control system and a central control cooling module therein. The scheme includes a hardware circuit architecture, a mechanical structure and a cooling control method of the central control cooling module of the downhole instrument cooling control system. Under the constraints of the existing technical level of the hardware circuit structure and the temperature resistance of electronic components, after the temperature resistance of the instrument hardware circuit system reaches the design limit, through the central control cooling module and the control method of the downhole instrument cooling control system provided by the present invention, the downhole instrument is integrated with the central control cooling module and then put into the well for work, and the central control cooling module is used to cool the instrument, so that the working temperature of the instrument can be controlled within a reasonable temperature range, avoiding problems such as instrument damage and reduced working stability under ultra-high temperature conditions underground, extending the service life of the instrument, meeting the application requirements of ultra-deep and ultra-high temperature drilling, and improving drilling efficiency.

[0140] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any person familiar with the technology within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0141] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0142] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0143] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should be extended to equivalent substitutions of these features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

[0144] The "one embodiment" or "embodiment" mentioned in the specification means that the specific features, structures or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment" or "embodiment" appearing in various places throughout the specification do not necessarily refer to the same embodiment.

[0145] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A central control cooling module for a downhole instrument cooling control system, characterized in that: include: Sleeve; a replacement body receiving portion embedded in the side wall of the sleeve; A cooling cavity disposed in the sleeve, the upper end surface of which matches the shape of the lower end surface of the displacement body receiving portion, and is used to contain a cooling liquid for cooling the hardware circuit of the downhole measuring instrument; A high-temperature coolant storage cavity disposed in the sleeve, which is located below the cooling cavity; A first control circuit is arranged in the cooling cavity, which is used to notify the ground to drop a coolant carrier module when it is detected that the coolant in the cooling cavity reaches a high temperature state, and when the arrival of the coolant carrier module is detected, control itself to achieve physical connection with the coolant carrier module at the displacement body accommodating part, so as to control the coolant in the cooling cavity to drain into the high-temperature coolant storage cavity, and guide the coolant in the coolant carrier module to the cooling cavity.

2. The central control cooling module according to claim 1, characterized in that: The cooling cavity comprises: A circuit skeleton, the upper end surface of which is formed as the upper end surface of the cooling cavity, and is physically connected to the coolant carrier module through a first valve body, the first control circuit and the hardware circuit of the downhole measuring instrument are arranged inside the circuit skeleton, wherein the lower end surface of the circuit skeleton is connected to the high-temperature coolant storage cavity through a second valve body; The spare coolant storage cavity arranged on the side wall of the circuit skeleton is constructed as a U-shaped structure. The two ends of the spare coolant storage cavity are connected to the circuit skeleton through a third valve body and a fourth valve body respectively to realize the movement of coolant between the inside of the circuit skeleton and the spare coolant storage cavity.

3. The central control cooling module according to claim 2, characterized in that: The first control circuit comprises: A temperature sensor, which is used to measure the coolant temperature in real time; A detector, which is used to emit a detection signal to detect the position of the coolant carrier module in real time, and when it is detected that the coolant carrier module moves to the detection boundary of the central control cooling module, sends an arrival signal to the microcontroller; A magnetizing and demagnetizing device, which is arranged adjacent to the upper end surface of the circuit skeleton and is used to generate or stop generating electromagnetic force under the action of the microcontroller; The microcontroller is used to detect whether the current coolant has reached a high temperature state according to the real-time temperature of the coolant, and to issue a delivery notification when the coolant has reached a high temperature state, and then to control the detector to detect the coolant carrier module, and when the coolant carrier module arrives according to the detected feedback signal, control the magnetization and demagnetization device to magnetize, thereby achieving physical connection with the coolant carrier module.

4. The central control cooling module according to claim 3, characterized in that: The microcontroller is also used to control the connection between the circuit skeleton and the spare coolant storage cavity, and to control the connection between the circuit skeleton and the high-temperature coolant storage cavity after the central control cooling module and the coolant carrier module are physically connected, so that the high-temperature coolant in the cooling cavity can flow into the high-temperature coolant storage cavity, and then control the disconnection between the circuit skeleton and the high-temperature coolant storage cavity after the leakage is completed.

5. The central control cooling module according to claim 3 or 4, characterized in that: The first control circuit further includes: A microcontroller monitoring unit, which is used to monitor the operating state of the microcontroller to control the microcontroller to restart when the operation is abnormal; A crystal oscillator is used to provide a clock signal for the operation of the microcontroller.

6. The central control cooling module according to any one of claims 3 to 5, characterized in that: The detector has an RFID reader and an antenna for periodically transmitting radio frequency signals and detecting the position of the coolant carrier module through the RFID tag carried by the coolant carrier module; The magnetizing and demagnetizing device comprises an iron core and a coil; The microcontroller adopts an MCU device.

7. The central control cooling module according to any one of claims 3 to 6, characterized in that: The microcontroller is also used to detect whether the coolant reaches a high temperature state according to the following process: The first step is to determine whether the current coolant temperature reaches or exceeds a preset temperature threshold in the first stage according to the real-time coolant temperature, so as to realize the movement of the coolant between the circuit skeleton and the standby coolant storage cavity according to the corresponding strategy according to the temperature evaluation result of the first stage, so as to enter the next step when the movement is completed; The second step is to determine whether the current coolant temperature reaches or exceeds the preset temperature threshold in the second stage according to the real-time temperature of the coolant after migration. If yes, it indicates that the current coolant has reached a high temperature state. If not, return to the first step to continue to transfer the coolant to conduct heat for the downhole measuring instrument.

8. The central control cooling module according to claim 7, characterized in that: In the first step, it includes: If the real-time temperature of the coolant reaches or exceeds the preset temperature threshold in the first stage, the third valve body and the fourth valve body are immediately opened to realize the coolant migration, so that when the duration of the migration process reaches the preset migration time, the current migration is ended by controlling the closing of the third valve body and the fourth valve body; If the real-time temperature of the coolant is lower than the preset temperature threshold in the first stage, the coolant migration is achieved by opening the third valve body and the fourth valve body at preset intervals, so that when the duration of the migration process reaches the preset migration time, the current migration is ended by controlling the closing of the third valve body and the fourth valve body.

9. The central control cooling module according to any one of claims 1 to 8, characterized in that: The first control circuit is communicatively connected with the hardware circuit of the downhole measuring instrument, and is also used to send a release instruction to the hardware circuit of the downhole measuring instrument when the coolant reaches a high temperature state, so as to use the hardware circuit of the downhole measuring instrument to notify the ground system to release the coolant carrier module, wherein the downhole measuring instrument is an MWD instrument, an EM-MWD instrument, or an LWD instrument.

10. A downhole instrument cooling control system, characterized in that: include: The central control cooling module according to any one of claims 1 to 9; as well as The coolant carrier module is used to drop the coolant from the wellhead when the coolant inside the central control cooling module reaches a high temperature state, and after achieving physical connection with the central control cooling module, the carried coolant is introduced into the central control cooling module.

Images