Multi-flow passage wellbore fluid cooling system and method

Abstract

The application discloses a multi-flow channel wellbore fluid cooling system and a method thereof. The multi-flow channel wellbore fluid cooling system comprises at least a cooling circulation system and a medium compression system. The cooling circulation system comprises at least a circulation joint, a circulation string and a steering joint. The circulation joint, the circulation string and the steering joint are connected to form a flow channel. The flow channel is connected to the inside of a drill pipe to inject wellbore fluid into a wellbore. The circulation joint, the circulation string and the steering joint form a circulation channel. The medium compression system pressurizes cooling medium. The compressed cooling medium is injected into the circulation channel to cool the wellbore fluid in the flow channel. The cooling medium circulates between the circulation channel and the medium compression system. The application uses the heat absorption principle of the expansion of the compressed cooling medium to exchange heat between the cooling medium and the fluid in the wellbore, thereby effectively reducing the temperature of the wellbore fluid and the bottom of the well.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction, and further to the fields of comprehensive utilization of petroleum, natural gas, geothermal energy and drilling and production of natural gas hydrates, and particularly to a multi-flow-channel wellbore fluid cooling system and method thereof. Background Technology

[0002] With the deterioration of shallow oil and gas development, oil and gas drilling has had to move towards ultra-deep formations. This brings with it increasingly prominent challenges related to high temperatures and high pressures in these ultra-deep formations. However, in some exploration areas, bottom-hole temperatures have reached or exceeded 200°C, pushing existing measuring instruments, downhole drilling tools, and wellbore working fluids to their limits. Tool and additive failures are becoming increasingly frequent, further exacerbating the complexity of exploration operations and continuously increasing drilling difficulty, severely hindering the efficient development of ultra-deep onshore oil and gas. Therefore, in ultra-high temperature drilling environments, conventional technologies face significant technical bottlenecks, necessitating the development of new technologies and methods to support drilling operations and achieve efficient development of ultra-deep oil and gas.

[0003] To address the technical challenge of failures in measuring instruments, downhole drilling tools, and working fluids caused by extremely high bottom-hole temperatures in ultra-deep wells, the temperature of the fluid within the wellbore can be reduced to a suitable range for these instruments and tools. Methods for cooling the fluid within the wellbore include natural cooling, low-temperature medium mixing cooling, forced cooling with cooling devices, temperature control using insulation layers, and the use of phase change material additives. Cooling efficiency can be improved by increasing the length of the circulation path, using axial flow fans, and increasing the heat dissipation area through spraying. However, these methods can only achieve a small reduction in the fluid temperature within the wellbore, and are technically limited by ambient temperature, thermal convection rate, and contact area. They cannot provide the necessary temperature control and adjustment, and therefore cannot meet the requirements for effective bottom-hole temperature reduction in ultra-deep wells.

[0004] The extremely high temperatures in ultra-deep wells render conventional measuring instruments, downhole drilling tools, and working fluids inadequate for demanding applications. During drilling, various technologies and measures have been developed to control drilling fluid temperature, including natural cooling, cryogenic medium mixing cooling, forced cooling with cooling devices, insulation layer temperature control, and phase change material additives. However, for ultra-deep wells with extremely high temperatures, existing technologies are insufficient in terms of cooling reduction and wellbore temperature control. This is because current drilling fluid cooling technologies are primarily affected by climatic conditions, fluid stability, surface equipment, site limitations, and the fluid's own thermal conductivity, resulting in less than ideal cooling effects. Therefore, relying on existing conventional drilling methods is insufficient to achieve significant reductions and control of bottom hole temperatures.

[0005] Therefore, based on years of experience and practice in related industries, the inventor proposes a multi-flow-channel wellbore fluid cooling system and method to overcome the shortcomings of existing technologies. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-flow-channel wellbore fluid cooling system and method, which utilizes the expansion and heat absorption of the compressed medium to exchange and transfer heat between the wellbore wall and the fluid inside the wellbore. By relying on a closed-loop circulation method, the temperature of the fluid inside the wellbore and the bottom of the well can be effectively reduced. The cooling range can be adjusted by adjusting the injection volume of the circulating cooling medium in the circulation channel.

[0007] The objective of this invention can be achieved through the following methods:

[0008] This invention provides a multi-flow-channel wellbore fluid cooling system, comprising:

[0009] A cooling circulation system includes at least a circulation joint, a circulation tubing string, and a diversion joint. The circulation joint and the diversion joint are respectively connected to the top and bottom of the circulation tubing string. The diversion joint is used to connect to the drill pipe. A connecting flow channel is formed between the circulation joint, the circulation tubing string, and the diversion joint. The flow channel is used to communicate with the interior of the drill pipe to inject wellbore fluid into the wellbore. The circulation joint, the circulation tubing string, and the diversion joint form a circulation channel for the circulating flow of cooling medium.

[0010] A medium compression system is provided to pressurize the cooling medium and inject the compressed cooling medium into the circulation channel. The cooling medium in the circulation channel is used to cool the well fluid in the flow channel. The cooling medium can circulate between the circulation channel and the medium compression system.

[0011] In a preferred embodiment of the present invention, the media compression system includes at least a compressor, a booster liquefaction pump set, and a media storage device, wherein the outlet of the compressor is connected to the inlet of the booster liquefaction pump set, and the outlet of the booster liquefaction pump set is connected to the inlet of the media storage device.

[0012] In a preferred embodiment of the present invention, the outlet of the media storage device is connected to the inlet of the circulation channel, and an injection pump is provided between the outlet of the media storage device and the inlet of the circulation channel.

[0013] In a preferred embodiment of the present invention, the multi-flow-channel well fluid cooling system further includes a condensation power generation system, the condensation power generation system including at least a condenser, the inlet of the condenser being connected to the outlet of the circulation channel, and the outlet of the condenser being connected to the inlet of the compressor;

[0014] The condenser includes at least a heat exchange power generation device for converting the kinetic energy of the returned cooling medium into electrical energy.

[0015] In a preferred embodiment of the present invention, the condensation power generation system further includes at least a power generation device, wherein the power supply terminal of the power generation device is electrically connected to the power supply terminal of the condenser and the power supply terminal of the compressor, respectively.

[0016] In a preferred embodiment of the present invention, the condensation power generation system further includes a power supply system, which is electrically connected to the power supply terminal of the power generation device and the power supply terminal of the heat exchange power generation equipment, respectively, and the power supply terminal of the power supply system is electrically connected to the power supply terminal of the compressor.

[0017] In a preferred embodiment of the present invention, the multi-flow-channel well fluid cooling system further includes a monitoring and control system, wherein the signal receiving end of the monitoring and control system is communicatively connected to the signal output end of the cooling circulation system, the signal output end of the medium compression system, the signal output end of the condensation power generation system, and the signal output end of the power supply system.

[0018] In a preferred embodiment of the present invention, the circulation connector has a first connector inner cavity that extends through the circulation connector, the outer periphery of the first connector inner cavity is provided with a first annular cavity, the outer periphery of the first annular cavity is provided with a second annular cavity, and the circulation connector has an injection port and a return port that communicate with the first annular cavity and the second annular cavity respectively.

[0019] In a preferred embodiment of the present invention, the circulation column has an internal cavity through which the circulation column is connected, a third annular cavity is provided around the outer periphery of the internal cavity of the circulation column, a fourth annular cavity is provided around the outer periphery of the third annular cavity, the top of the third annular cavity is used to communicate with the bottom of the first annular cavity, and the top of the fourth annular cavity is used to communicate with the bottom of the second annular cavity.

[0020] In a preferred embodiment of the present invention, the interior of the steering joint has a second joint inner cavity that extends through the steering joint, the outer periphery of the second joint inner cavity is provided with a fifth annular cavity, the outer periphery of the fifth annular cavity is provided with a sixth annular cavity, the top of the fifth annular cavity is used to communicate with the bottom of the third annular cavity, the top of the sixth annular cavity is used to communicate with the bottom of the fourth annular cavity, and the bottom of the fifth annular cavity and the bottom of the sixth annular cavity are connected by a bending section.

[0021] In a preferred embodiment of the present invention, the inner cavity of the first connector, the inner cavity of the rod body, and the inner cavity of the second connector are sequentially connected along the injection direction of the well fluid to form the flow passage;

[0022] Along the flow direction of the cooling medium, the first annulus, the third annulus, the fifth annulus, the bend section, the sixth annulus, the fourth annulus, and the second annulus are sequentially connected to form the circulation channel.

[0023] In a preferred embodiment of the present invention, the multi-flow-channel wellbore fluid cooling system further includes at least one plug valve and a control switch capable of rotating the plug valve. The plug valve has a multi-layer sleeve structure and is disposed on the circulation channel. The control switch is connected to the plug valve. When the plug valve is rotated to the first position by the control switch, the plug valve is connected to the circulation channel. When the plug valve is rotated to the second position by the control switch, the plug valve cuts off the circulation channel.

[0024] This invention provides a method for cooling wellbore fluids using a multi-flow-channel wellbore fluid cooling system. The method includes the following steps:

[0025] Step S1: The medium compression system pressurizes and compresses the cooling medium;

[0026] Step S2: Inject the compressed cooling medium into the circulation channel of the cooling circulation system so as to cool the well fluid in the flow channel of the cooling circulation system through the cooling medium in the circulation channel;

[0027] Step S3: The cooling medium, after cooling the well fluid, is returned to the medium compression system through the circulation channel of the cooling circulation system;

[0028] Step S4: Repeat steps S1 to S3.

[0029] In a preferred embodiment of the present invention, in step S2, the cooling medium expands and absorbs heat as it enters the circulation channel, and exchanges heat with the well fluid in the flow channel to reduce the temperature of the well fluid.

[0030] In a preferred embodiment of the present invention, in steps S1 to S4, the opening degree of the plug valve is controlled to adjust the on / off state of the flow channel and the circulation channel.

[0031] In a preferred embodiment of the present invention, prior to step S3, the returned cooling medium is cooled by a condenser in the condensation power generation system.

[0032] In a preferred embodiment of the present invention, in steps S1 to S4, the operating parameters of the cooling circulation system, the medium compression system, the condensation power generation system and the power supply system are monitored and recorded in real time by the monitoring and control system, and / or the temperature and / or pressure data at the well outlet.

[0033] As described above, the features and advantages of the multi-flow-channel wellbore fluid cooling system and method of the present invention are as follows: The cooling circulation system includes a circulation joint, a circulation tubing string, and a diversion joint connected sequentially from top to bottom. The bottom of the diversion joint can be connected to the drill pipe. A connected flow channel is formed between the circulation joint, the circulation tubing string, and the diversion joint, and the flow channel is connected to the interior of the drill pipe. This allows wellbore fluid to be injected into the cooling circulation system, and then sequentially pass through the flow channel and the interior of the drill pipe before being injected into the wellbore through the water inlet of the drill bit. Afterward, it returns to the surface through the annulus of the wellbore. In addition, the circulation joint, the circulation tubing string, and the diversion joint form a circulation channel for the cooling medium to circulate. The cooling medium is pressurized by a surface-mounted media compression system and injected into the circulation channel. The cooling medium in the circulation channel cools the well fluid in the flow channel. After cooling the well fluid, the cooling medium circulates between the circulation channel and the media compression system, thus repeatedly participating in the cooling of the well fluid. This invention utilizes the principle of heat absorption due to the expansion of the compressed cooling medium. Through heat exchange and transfer between the cooling medium and the well fluid, the temperature of the well fluid and the bottom of the well can be effectively reduced. During operation, the cooling rate can be adjusted by changing the amount of cooling medium injected into the circulation channel. Attached Figure Description

[0034] The accompanying drawings are intended only to illustrate and explain the present invention and do not limit the scope of the invention.

[0035] in:

[0036] Figure 1 This is a schematic diagram of the structure of the multi-flow-channel wellbore fluid cooling system of the present invention.

[0037] Figure 2 : This is a top cross-sectional view of the circulation joint in the multi-flow-channel wellbore fluid cooling system of the present invention.

[0038] Figure 3 This is one of the partial cross-sectional views of the circulation joint in the multi-flow-channel wellbore fluid cooling system of the present invention.

[0039] Figure 4This is the second partial cross-sectional view of the circulation joint in the multi-flow-channel wellbore fluid cooling system of the present invention.

[0040] Figure 5 This is a partial cross-sectional view of the circulating tubing in the multi-flow-channel wellbore fluid cooling system of the present invention.

[0041] Figure 6 : This is a top cross-sectional view of the steering joint in the multi-flow-channel wellbore fluid cooling system of the present invention.

[0042] Figure 7 This is a partial cross-sectional view of the steering joint in the multi-flow-channel wellbore fluid cooling system of the present invention.

[0043] Figure 8 This is a schematic diagram of the connection structure between the multi-flow-channel wellbore fluid cooling system of the present invention and the drill pipe.

[0044] Figure 9 : This is a partial cross-sectional view of the plug valve in the multi-flow-channel well fluid cooling system of the present invention.

[0045] Figure 10 This is a schematic diagram of the plug valve in the closed state of the multi-flow-channel well fluid cooling system of the present invention.

[0046] Figure 11 This is a schematic diagram of the plug valve in the conducting state of the multi-flow-channel well fluid cooling system of the present invention.

[0047] The reference numerals in the accompanying drawings of this invention are:

[0048] 1. Cooling circulation system; 101. Circulation connector; 1011. First connector inner cavity; 1012. First annulus; 1013. Second annulus; 1014. Inlet; 1015. Outlet; 1016. First thread; 1017. Second thread; 1018. First support block; 1019. Second support block; 102. Circulation tubing; 1021. Rod inner cavity; 1022. Third annulus; 1023. Fourth annulus; 1024. Third support block; 1025. Fourth support block; 103. Diverting connector; 1031. Second connector inner cavity; 1032. Fifth annulus; 1033. Sixth annulus; 034, Fifth support block; 1035, Sixth support block; 1036, Bend section; 1037, Third thread; 1038, Fourth thread; 104, Plug valve; 1041, First channel; 1042, Second channel; 1043, Third channel; 105, Control switch; 106, First sealing ring; 107, Second sealing ring; 2. Medium compression system; 201, Compressor; 202, Booster liquefaction pump set; 203, Medium storage device; 204, Injection pump; 3. Power supply system; 4. Condensation power generation system; 401, Power generation device; 402, Condenser; 5. Monitoring and control system; 6. Drill pipe; 7. Wellbore. Detailed Implementation

[0049] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0050] In this invention, terms such as "top" and "bottom," which indicate direction, are all used in this way. Figure 8 The top and bottom directions are used as a reference, and will be explained here as well.

[0051] Implementation Method 1

[0052] like Figures 1 to 11As shown, the present invention provides a multi-flow-channel wellbore fluid cooling system, which includes a cooling circulation system 1 and a medium compression system 2. The cooling circulation system 1 includes at least a circulation connector 101, a circulation tubing string 102, and a diversion connector 103. The circulation connector 101 is connected to the top of the circulation tubing string 102, and the diversion connector 103 is connected to the bottom of the circulation tubing string 102. The diversion connector 103 is used to connect a drill pipe 6 (i.e., a regular drill pipe 6 can be connected to the bottom of the diversion connector 103). The circulation connector 101, the circulation tubing string 102, and the diversion connector 103... A flow passage is formed between 03, which is used to connect with the interior of drill pipe 6 to inject wellbore fluid into wellbore 7; circulation joint 101, circulation tubing 102 and diversion joint 103 form a circulation passage for circulating flow of cooling medium; medium compression system 2 is used to pressurize the cooling medium, and the compressed cooling medium is in a high-pressure gaseous or liquid state. The compressed cooling medium is injected into the circulation passage, and the cooling medium in the circulation passage is used to cool the wellbore fluid in the flow passage. The cooling medium can circulate between the circulation passage and medium compression system 2.

[0053] Furthermore, the cooling medium may be, but is not limited to, liquid carbon dioxide or liquid nitrogen.

[0054] In this invention, the cooling circulation system 1 includes a circulation connector 101, a circulation tubing string 102, and a diversion connector 103 connected sequentially from top to bottom. The bottom of the diversion connector 103 can be connected to the drill pipe 6. A connected flow channel is formed between the circulation connector 101, the circulation tubing string 102, and the diversion connector 103, and the flow channel is connected to the interior of the drill pipe 6. This allows wellbore fluid to be injected into the cooling circulation system 1, and then sequentially through the flow channel and the interior of the drill pipe 6 before being injected into the wellbore 7 through the water inlet of the drill bit. Afterward, it returns to the surface through the annulus of the wellbore 7. In addition, the circulation connector 101, the circulation tubing string 102, and the diversion connector 103 form a system for the circulation of cooling medium. The circulating channel is pressurized by the medium compression system 2 on the ground and injected into the circulating channel. The cooling medium in the circulating channel cools the well fluid in the flow channel. The cooled medium can circulate between the circulating channel and the medium compression system 2, thus repeatedly participating in the cooling of the well fluid. This invention utilizes the principle of heat absorption by the expansion of the compressed cooling medium. Through heat exchange and transfer between the cooling medium and the well fluid, the temperature of the well fluid and the bottom of the well can be effectively reduced. During operation, the cooling rate can be adjusted by adjusting the amount of cooling medium injected into the circulating channel.

[0055] In an optional embodiment of the present invention, such as Figure 1As shown, the medium compression system 2 includes at least a compressor 201, a booster liquefaction pump set 202, and a medium storage device 203. The outlet of the compressor 201 is connected to the inlet of the booster liquefaction pump set 202, and the outlet of the booster liquefaction pump set 202 is connected to the inlet of the medium storage device 203. Multiple compressors 201 can be connected in parallel, and the medium storage device 203 can be, but is not limited to, a high-pressure storage tank. The function of the medium compression system 2 is to provide high-pressure gaseous or liquid cryogenic cooling medium to the cooling circulation system 1. The compressor 201, the booster liquefaction pump set 202, and the medium storage device 203 can respectively realize the functions of pressurizing, secondary pressurizing and liquefying, and storing cryogenic medium, ensuring a continuous supply of cooling medium to the cooling circulation system 1.

[0056] Furthermore, such as Figure 1 As shown, the outlet of the media storage device 203 is connected to the inlet of the circulation channel. An injection pump 204 is installed on the pipeline between the outlet of the media storage device 203 and the inlet of the circulation channel. The injection pump 204 pumps the cooling medium into the cooling circulation system 1.

[0057] In an optional embodiment of the present invention, such as Figure 1 As shown, the multi-flow-channel well fluid cooling system also includes a condensation power generation system 4. The condensation power generation system 4 includes at least a condenser 402 and a power generation device 401. The inlet of the condenser 402 is connected to the outlet of the circulation channel, and the outlet of the condenser 402 is connected to the inlet of the compressor 201. The power supply terminal of the power generation device 401 is electrically connected to the power supply terminal of the condenser 402 and the power supply terminal of the compressor 201, respectively.

[0058] Furthermore, the condenser 402 includes at least a heat exchange power generation device (not shown). Since the returning cooling medium has a high flow rate, the flow rate of the cooling medium can be reduced by the heat exchange power generation device, thereby converting the kinetic energy of the returning cooling medium into electrical energy.

[0059] Furthermore, the power generation device 401 is a pneumatic motor power generation device. The function of the condensation power generation system 4 is to realize the condensation and cooling of the cooling medium after it is circulated to the wellhead and the multi-gradient deceleration. The pneumatic motor power generation device uses the high-speed flowing cooling medium after the temperature rise to carry energy for energy conversion and power generation, which has the function of compensating for energy dissipation.

[0060] In an optional embodiment of the present invention, such as Figure 1As shown, the condensing power generation system 4 also includes a power supply system 3. The power supply system 3 is electrically connected to the power supply terminal of the heat exchange power generation equipment at the power supply terminal of the power generation device 401, and the power supply terminal of the power supply system 3 is electrically connected to the power supply terminal of the compressor 201. The power supply system 3 can supply power to the compressor 201. Of course, according to actual power demand, the power supply system 3 can also supply power to other electrical equipment (such as the condenser 402).

[0061] The power supply system 3 can be powered by the power generation device 401, or it can use other external generator sets or power grids to provide the electrical energy required for system operation. The power output is compensated by the electrical energy generated by the condensing power generation system 4.

[0062] Furthermore, the power supply system 3 is an energy storage device capable of storing electrical energy, thereby realizing the storage and stable output of electrical energy.

[0063] In an optional embodiment of the present invention, such as Figure 1 As shown, the multi-channel wellbore fluid cooling system also includes a monitoring and control system 5. The signal receiving end of the monitoring and control system 5 is communicatively connected to the signal output ends of the cooling circulation system 1, the medium compression system 2, the condensation power generation system 4, and the power supply system 3, respectively. The monitoring and control system 5 monitors and records in real time the operating parameters of the cooling circulation system 1, the medium compression system 2, the condensation power generation system 4, and the power supply system 3, and / or the temperature difference data between the wellbore fluid and the cooling medium at the wellbore outlet (i.e., the wellhead).

[0064] Specifically, the main functions of the monitoring and control system 5 include: monitoring and recording the operating parameters of ground equipment (such as the cooling circulation system 1, the medium compression system 2, the condensation power generation system 4, and / or the power supply system 3), providing a basis for software module calculations, real-time data optimization, and operational condition analysis; in addition, it can also monitor and record the temperature and / or pressure data at the outlet of the wellbore 7, providing relevant parameters for automatically adjusting the cooling range by adjusting the flow rate of the cooling medium, providing evaluation of the construction operation effect, and guiding the adjustment of ground construction parameters. The monitoring and control system 5 may include components such as pressure sensors, flow meters, temperature sensors, and a control computer. The main ground construction parameters monitored and recorded by the monitoring and control system 5 include the high-pressure storage capacity of the cooling medium, injection flow rate, injection pressure, wellhead temperature, outlet flow rate, outlet pressure, and outlet temperature; the monitoring and control system 5 can interact with the control computer to transmit the monitored and recorded data to the computer for storage and data processing.

[0065] In an optional embodiment of the present invention, the multi-flow-channel wellbore fluid cooling system further includes a return medium treatment system (not shown in the figure), which is located at the wellhead. The return medium treatment system includes one or more of a vibrating screen, a desander, a desilter, and a degasser. The vibrating screen separates particulate rock cuttings from the returned wellbore fluid; the desander and desilter filter out fine sand, mud, and other impurities from the returned wellbore fluid; and the degasser eliminates air bubbles in the wellbore fluid. The treated wellbore fluid can then be reused.

[0066] In an optional embodiment of the present invention, such as Figures 1 to 4 , Figure 8 As shown, the circulation connector 101 has a first connector inner cavity 1011 that runs vertically through the circulation connector 101. A first annular space 1012 is provided around the outer periphery of the first connector inner cavity 1011, and a second annular space 1013 is provided around the outer periphery of the first annular space 1012. The circulation connector 101 has an injection port 1014 communicating with the first annular space 1012, and a return outlet 1015 communicating with the second annular space 1013. Cooling medium can be injected into the first annular space 1012 through the injection port 1014. After cooling the wellbore fluid, the cooling medium can return to the cooling circulation system 1 through the return outlet 1015. The first annular space 1012 and the second annular space 1013 are both annular channels, and both the first annular space 1012 and the second annular space 1013 run vertically through the circulation connector 101.

[0067] Furthermore, such as Figure 2 As shown, a plurality of first support blocks 1018 are disposed within the first annular space 1012, and the plurality of first support blocks 1018 are distributed at intervals along the circumference of the first annular space 1012. The two opposite outer walls of the plurality of first support blocks 1018 are respectively connected to the two side walls of the first annular space 1012. A plurality of second support blocks 1019 are disposed within the second annular space 1013, and the plurality of second support blocks 1019 are distributed at intervals along the circumference of the second annular space 1013. The two opposite outer walls of the plurality of second support blocks 1019 are respectively connected to the two side walls of the second annular space 1013. The plurality of first support blocks 1018 and the plurality of second support blocks 1019 provide support for the first annular space 1012 and the second annular space 1013, respectively, thereby improving the stability of the first annular space 1012 and the second annular space 1013.

[0068] Furthermore, such as Figure 3 , Figure 4 As shown, the top of the circulation connector 101 is provided with a first thread 1016 (female thread), and the bottom of the circulation connector 101 is provided with a second thread 1017 (male thread), which facilitates the assembly and disassembly of the circulation connector 101.

[0069] In an optional embodiment of the present invention, such as Figure 1 , Figure 5 , Figure 8 As shown, the circulation column 102 has a vertically penetrating internal cavity 1021. A third annular cavity 1022 surrounds the outer periphery of the internal cavity 1021, and a fourth annular cavity 1023 surrounds the outer periphery of the third annular cavity 1022. The top of the third annular cavity 1022 communicates with the bottom of the first annular cavity 1012, and the top of the fourth annular cavity 1023 communicates with the bottom of the second annular cavity 1013. The third annular cavity 1022 and the fourth annular cavity 1023 are both annular channels, vertically penetrating the circulation column 102, thus providing a path for the circulating flow of the cooling medium within the cooling circulation system 1.

[0070] Furthermore, such as Figure 5 As shown, multiple third support blocks 1024 are arranged within the third annular cavity 1022, and the multiple third support blocks 1024 are distributed at intervals along the circumference of the third annular cavity 1022. The two opposite outer walls of the multiple third support blocks 1024 are connected to the two side walls of the third annular cavity 1022, respectively. Multiple fourth support blocks 1025 are arranged within the fourth annular cavity 1023, and the multiple fourth support blocks 1025 are distributed at intervals along the circumference of the fourth annular cavity 1023. The two opposite outer walls of the multiple fourth support blocks 1025 are connected to the two side walls of the fourth annular cavity 1023, respectively. The multiple third support blocks 1024 and multiple fourth support blocks 1025 provide support for the third annular cavity 1022 and the fourth annular cavity 1023, respectively, thereby improving the stability of the third annular cavity 1022 and the fourth annular cavity 1023.

[0071] In an optional embodiment of the present invention, such as Figure 1 , Figures 6 to 8 As shown, the interior of the diverter 103 has a second internal cavity 1031 that runs vertically through the diverter 103. A fifth annular cavity 1032 is arranged around the outer periphery of the second internal cavity 1031, and a sixth annular cavity 1033 is arranged around the outer periphery of the fifth annular cavity 1032. The top of the fifth annular cavity 1032 communicates with the bottom of the third annular cavity 1022, and the top of the sixth annular cavity 1033 communicates with the bottom of the fourth annular cavity 1023. The bottoms of the fifth annular cavity 1032 and the bottom of the sixth annular cavity 1033 are connected by a bending section 1036. The fifth annular cavity 1032 and the sixth annular cavity 1033 are both annular channels that run vertically through the diverter 103.

[0072] In this embodiment, as Figure 1 , Figure 8As shown, along the injection direction of the wellbore fluid, the inner cavity 1011 of the first connector, the inner cavity 1021 of the rod body, and the inner cavity 1031 of the second connector are sequentially connected to form a flow channel; along the flow direction of the cooling medium, the first annulus 1012, the third annulus 1022, the fifth annulus 1032, the bend section 1036, the sixth annulus 1033, the fourth annulus 1023, and the second annulus 1013 are sequentially connected to form a circulation channel. The bend section 1036 connects the flow channel and the circulation channel, thereby enabling the circulation of the cooling medium.

[0073] Furthermore, such as Figure 6 As shown, multiple fifth support blocks 1034 are arranged within the fifth annular cavity 1032, and the multiple fifth support blocks 1034 are distributed at intervals along the circumference of the fifth annular cavity 1032. The two opposite outer walls of the multiple fifth support blocks 1034 are connected to the two side walls of the fifth annular cavity 1032, respectively. Multiple sixth support blocks 1035 are arranged within the sixth annular cavity 1033, and the multiple sixth support blocks 1035 are distributed at intervals along the circumference of the sixth annular cavity 1033. The two opposite outer walls of the multiple sixth support blocks 1035 are connected to the two side walls of the sixth annular cavity 1033, respectively. The multiple fifth support blocks 1034 and multiple sixth support blocks 1035 provide support for the fifth annular cavity 1032 and the sixth annular cavity 1033, respectively, thereby improving the stability of the fifth annular cavity 1032 and the sixth annular cavity 1033.

[0074] Furthermore, such as Figure 7 As shown, the top of the swivel joint 103 is provided with a third thread 1037 (female thread), and the bottom of the swivel joint 103 is provided with a fourth thread 1038 (male thread), which facilitates the disassembly and assembly of the swivel joint 103.

[0075] In one alternative embodiment of this method, such as Figures 9 to 11 As shown, the multi-flow-channel wellbore fluid cooling system also includes at least one plug valve 104 and a control switch 105 that can drive the plug valve 104 to rotate. The plug valve 104 has a multi-layer sleeve structure and is located on the circulation channel. The control switch 105 is connected to the plug valve 104. By rotating the plug valve 104 to the first position through the control switch 105, the plug valve 104 is connected to the flow channel and the circulation channel. By rotating the plug valve 104 to the second position through the control switch 105, the plug valve 104 cuts off the flow channel and the circulation channel. Thus, the on / off state of the flow channel and the circulation channel can be controlled through the plug valve 104 to facilitate the replacement of the tubing string.

[0076] In this embodiment, as Figure 9As shown, the plug valve 104 has a multi-layer sleeve structure, namely: a first channel 1041 is formed inside the plug valve 104, a second channel 1042 is provided around the outer periphery of the first channel 1041, and a third channel 1043 is provided around the outer periphery of the second channel 1042. Both the second channel 1042 and the third channel 1043 pass through the plug valve 104. The plug valve 104 can be disposed inside the circulation joint 101, the circulation tubing 102, and / or the diversion joint 103.

[0077] Specifically, a stopcock valve 104 is disposed inside the circulation connector 101, and a control switch 105 is disposed on the circulation connector 101 and connected to the stopcock valve 104. When the stopcock valve 104 is rotated to the open position by the control switch 105, the first channel 1041, the second channel 1042, and the third channel 1043 are respectively connected to the inner cavity 1011 of the first connector, the first annulus 1012, and the second annulus 1013, allowing the cooling medium to pass through. When the stopcock valve 104 is rotated to the closed position by the control switch 105, the outer wall of the stopcock valve 104 blocks the inner cavity 1011 of the first connector, the first annulus 1012, and the second annulus 1013, stopping the circulation of the cooling medium.

[0078] And / or, a stopcock valve 104 is disposed inside the circulation tubing 102, and a control switch 105 is disposed on the circulation tubing 102 and connected to the stopcock valve 104. When the stopcock valve 104 is rotated to the open position by the control switch 105, the first channel 1041, the second channel 1042, and the third channel 1043 are respectively connected to the internal cavity 1021, the third annulus 1022, and the fourth annulus 1023 of the rod body, and the cooling medium can pass through. When the stopcock valve 104 is rotated to the closed position by the control switch 105, the outer wall of the stopcock valve 104 blocks the internal cavity 1021, the third annulus 1022, and the fourth annulus 1023 of the rod body, and the cooling medium stops circulating.

[0079] And / or, a stopcock valve 104 is disposed inside a diverter joint 103, and a control switch 105 is disposed on the diverter joint 103 and connected to the stopcock valve 104. When the stopcock valve 104 is rotated to the open position by the control switch 105, the first channel 1041, the second channel 1042, and the third channel 1043 are respectively connected to the inner cavity 1031 of the second connector, the fifth annulus 1032, and the sixth annulus 1033, and the cooling medium can pass through. When the stopcock valve 104 is rotated to the closed position by the control switch 105, the outer wall of the stopcock valve 104 blocks the inner cavity 1031, the fifth annulus 1032, and the sixth annulus 1033 of the second connector, and the cooling medium stops circulating.

[0080] Furthermore, such as Figure 9As shown, a first sealing ring 106 is provided above the plug valve 104, and a second sealing ring 107 is provided below the plug valve 104. When the plug valve 104 is in the open state, the top of the first channel 1041, the top of the second channel 1042, and the top of the third channel 1043 are sealed with the first sealing ring 106, and the bottom of the first channel 1041, the second channel 1042, and the bottom of the third channel 1043 are sealed with the second sealing ring 107. This ensures that the plug valve 104 is in the open state, and the cooling medium can pass smoothly through the plug valve 104 to achieve the circulation of the cooling medium.

[0081] In this invention, the wellbore fluid cooling system also includes a surface manifold system (i.e., pipelines connecting the cooling circulation system 1, the medium compression system 2, the power supply system 3, and the condensation power generation system 4, as well as valves and other structures for controlling the flow of these pipelines). The main function of the surface manifold system is to transport the cooling medium and provide a fluid channel between the cooling circulation system 1, the medium compression system 2, the power supply system 3, and the condensation power generation system 4. The surface manifold system mainly includes rigid and flexible pipelines, manifold joints, manifold connectors, and control valves. The surface manifold system can withstand a certain fluid pressure and has good connection sealing under pressurized fluid flow conditions. The main body of the surface manifold system is composed of multiple sections of rigid and flexible pipelines connected together, with manifold joints and connectors at the manifold connection points, facilitating easy disassembly and installation. In addition, the surface manifold system is equipped with multiple control valves, enabling operations such as opening and closing the pipelines, controlling fluid flow, and emergency pressure relief under high pressure conditions.

[0082] The working process of the well fluid cooling system of the flow channel of the present invention is as follows:

[0083] The wellbore fluid used in drilling is injected into the flow channel of the cooling circulation system 1 through the surface circulation system. It then circulates sequentially through the flow channel and the inner cavity of the drill pipe 6 to the drill bit position, and through the drill bit's water hole to the wellbore annulus between the drill pipe 6 and the well wall or casing. Finally, it circulates back to the surface. During normal wellbore fluid circulation, the working gas is compressed by the surface-mounted medium compression system 2 to form a high-pressure gaseous or liquid cooling medium, which is stored in the storage tank of the medium compression system 2. This medium is then injected through the injection pump 204 to the circulation connector 101 of the cooling circulation system 1. The compressed high-pressure gaseous or liquid low-temperature cooling medium enters the circulation channel through the injection port 1014 on the circulation connector 101 and flows downwards along the innermost circulation channel (i.e., from top to bottom, the first annulus 1012, the third annulus 1022, and the fifth annulus 1032). During this process, the cooling medium vaporizes, its volume expands, and it absorbs heat from the flow channel. The wellbore fluid is cooled through heat convection, heat conduction, and heat radiation. During this process, the cooling medium heats up, gradually vaporizes, and continues to flow downwards. After passing through the bottom bend section 1036, the cooling medium flows upwards along the outer circulation channel (i.e., from bottom to top, the sixth annulus 1033, the fourth annulus 1023, and the second annulus 1013). During the upward flow, the circulating medium cools the wellbore fluid that has been heated at the bottom of the well through heat convection, heat conduction, and heat radiation. In the above process, the temperature regulation range of the wellbore fluid can be controlled by adjusting the flow rate of the cooling medium to ensure that the wellbore fluid can be cooled to the preset temperature range. During the circulation process, the cooling medium expands in volume and increases in flow velocity. After heat exchange between the cooling medium and the well fluid, the temperature rises. The high-speed flowing cooling medium circulates to the ground and first needs to be cooled by the condenser 402. After cooling, the cooling medium passes through the condensation power generation system 4 to reduce its flow velocity and continues to circulate to the medium compression system 2 for compression, thus realizing the recycling of the cooling medium. The electricity generated during the ground circulation process is transmitted to the power supply system 3 for storage, serving as a supplementary power supply system and reducing the energy loss of the entire system.

[0084] The following is a specific embodiment of the present invention:

[0085] like Figures 2 to 4As shown, the circulation connector 101 can be a circulation auxiliary device with good sealing performance installed at the wellhead, positioned above the drill platform. The top of the circulation connector 101 has a wellbore fluid inlet communicating with the inner cavity. Wellbore fluid can flow through the top drive or angular drill pipe into the flow passage via the wellbore fluid inlet, and then sequentially flow into the wellbore through the flow passage and the inner cavity of the drill pipe. The cooling medium injection port 1014 and return port 1015 are respectively located on the side wall of the circulation connector 101. The injection port 1014 and return port 1015 can be arranged opposite to each other, with the injection port 1014 serving as the inflow point for the cooling medium and the return port 1015 serving as the outflow point. The injection port 1014 and return port 1015 extend inwards towards the circulation connector 101 to communicate with the corresponding circulation channels. The injection port 1014 and return port 1015 can connect to the surface manifold system on the outside of the circulation connector 101 to realize the injection and discharge of the cooling medium. The circulation joint 101 and the circulation tubing 102 can be connected by a rotary seal (using a sealed bearing) to maintain the normal rotation of the drill pipe 6 during drilling. Figure 6 As shown, a stopcock valve 104 is installed in the cooling circulation system 1. The stopcock valve 104 is rotated by the control switch 105 to realize the on / off control of the flow channel and the circulation channel.

[0086] The features and advantages of the multi-flow-channel wellbore fluid cooling system of the present invention are as follows:

[0087] This multi-channel wellbore fluid cooling system utilizes the principle of heat absorption through the expansion of the compressed cooling medium. By exchanging and transferring heat between the cooling medium and the wellbore fluid, the temperature of the wellbore fluid and the bottom of the well can be effectively reduced. During operation, the cooling rate can be adjusted by regulating the amount of cooling medium injected into the circulation channel.

[0088] Implementation Method 2

[0089] This invention provides a method for cooling fluid in a wellbore with multiple flow channels, comprising the following steps:

[0090] Step S1: The medium compression system 2 pressurizes and compresses the cooling medium;

[0091] Step S2: Inject the compressed cooling medium into the circulation channel of the cooling circulation system 1 so as to cool the well fluid in the flow channel of the cooling circulation system 1 through the cooling medium in the circulation channel.

[0092] Step S3: The cooling medium after cooling the well fluid is returned to the medium compression system 2 through the circulation channel of the cooling circulation system 1;

[0093] Step S4: Repeat step S1 to step S3.

[0094] In an optional embodiment of the present invention, in step S2, the cooling medium expands and absorbs heat in the circulation channel and exchanges heat with the well fluid in the flow channel to reduce the temperature of the well fluid.

[0095] In an optional embodiment of the present invention, in steps S1 to S4, the opening degree of the plug valve 104 can be controlled to adjust the on / off state of the flow channel and the circulation channel so as to replace the tubing.

[0096] In an optional embodiment of the present invention, before performing step S3, the returned cooling medium can be cooled by the condenser 402 in the condensation power generation system 4 to compress the cooling medium, thereby making the cooling medium recyclable.

[0097] In an optional embodiment of the present invention, in steps S1 to S4, the operating parameters of the cooling circulation system 1, the medium compression system 2, the condensation power generation system 4 and the power supply system 3, and / or the temperature and / or pressure data at the outlet of the well 7 can be monitored and recorded in real time by the monitoring and control system 5.

[0098] The features and advantages of the multi-flow-channel wellbore fluid cooling method of the present invention are as follows:

[0099] I. This multi-channel wellbore fluid cooling method can achieve wellbore fluid cooling and cooling range adjustment. At the same time, it can comprehensively utilize the energy carried by the cooling medium (i.e., the flow rate of the cooling medium) to generate electricity and perform energy compensation. It provides a high-quality environment for the normal use of downhole tools, instruments, downhole power drilling tools, and wellbore working fluids in high-temperature environments in ultra-deep and extra-deep wells, creating a brand-new system and method for efficient wellbore fluid cooling operations.

[0100] II. This multi-channel wellbore fluid cooling method provides a creative new environment for the normal use of downhole tools, downhole power drills, and wellbore working fluids in complex formations with high well temperatures. It offers a more flexible wellbore fluid cooling technology concept, allowing for the development of efficient cooling methods tailored to specific field conditions during real-time operation. This ensures the normal operation of downhole tools, downhole power drills, and wellbore working fluids, extends equipment lifespan, and improves drilling efficiency. It provides technical support for efficient drilling and completion in high-temperature environments such as terrestrial and marine formations, and offers a new technical direction for the safe use of instruments, downhole power drills, and wellbore working fluids under ultra-high temperature conditions.

[0101] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A multi-flow-channel wellbore fluid cooling system, characterized in that, include: A cooling circulation system includes at least a circulation joint, a circulation tubing string, and a diversion joint. The circulation joint and the diversion joint are respectively connected to the top and bottom of the circulation tubing string. The diversion joint is used to connect to the drill pipe. A connecting flow channel is formed between the circulation joint, the circulation tubing string, and the diversion joint. The flow channel is used to communicate with the interior of the drill pipe to inject wellbore fluid into the wellbore. The circulation joint, the circulation tubing string, and the diversion joint form a circulation channel for the circulating flow of cooling medium. A medium compression system is provided to pressurize the cooling medium and inject the compressed cooling medium into the circulation channel. The cooling medium in the circulation channel is used to cool the well fluid in the flow channel. The cooling medium can circulate between the circulation channel and the medium compression system. At least one plug valve and a control switch capable of rotating the plug valve. The plug valve has a multi-layer sleeve structure, with a first channel forming inside the plug valve, a second channel surrounding the outer periphery of the first channel, and a third channel surrounding the outer periphery of the second channel. Both the second and third channels pass through the plug valve. The plug valve is located inside the circulation joint, the circulation tubing, or the diverting joint, and is situated on the circulation channel. The control switch is connected to the plug valve. Rotating the plug valve to the first position via the control switch connects the plug valve to the circulation channel; rotating the plug valve to the second position via the control switch disconnects the circulation channel. A first sealing ring is provided above the plug valve, and a second sealing ring is provided below the plug valve. When the plug valve is in the open state, the top of the first channel, the top of the second channel, and the top of the third channel are sealed with the first sealing ring, and the bottom of the first channel, the second channel, and the third channel are sealed with the second sealing ring.

2. The multi-flow-channel wellbore fluid cooling system as described in claim 1, characterized in that, The media compression system includes at least a compressor, a booster liquefaction pump set, and a media storage device. The outlet of the compressor is connected to the inlet of the booster liquefaction pump set, and the outlet of the booster liquefaction pump set is connected to the inlet of the media storage device.

3. The multi-flow-channel wellbore fluid cooling system as described in claim 2, characterized in that, The outlet of the media storage device is connected to the inlet of the circulation channel, and an injection pump is provided between the outlet of the media storage device and the inlet of the circulation channel.

4. The multi-flow-channel wellbore fluid cooling system as described in claim 2, characterized in that, The multi-flow-channel wellbore fluid cooling system also includes a condensation power generation system, which includes at least a condenser. The inlet of the condenser is connected to the outlet of the circulation channel, and the outlet of the condenser is connected to the inlet of the compressor. The condenser includes at least a heat exchange power generation device for converting the kinetic energy of the returned cooling medium into electrical energy.

5. The multi-flow-channel wellbore fluid cooling system as described in claim 4, characterized in that, The condensation power generation system further includes at least a power generation device, the power supply terminal of which is electrically connected to the power supply terminal of the condenser and the power supply terminal of the compressor, respectively.

6. The multi-flow-channel wellbore fluid cooling system as described in claim 5, characterized in that, The condensation power generation system also includes a power supply system, which is electrically connected to the power supply terminal of the power generation device and the power supply terminal of the heat exchange power generation equipment, respectively. The power supply terminal of the power supply system is electrically connected to the power supply terminal of the compressor.

7. The multi-flow-channel wellbore fluid cooling system as described in claim 6, characterized in that, The multi-flow-channel well fluid cooling system also includes a monitoring and control system. The signal receiving end of the monitoring and control system is communicatively connected to the signal output end of the cooling circulation system, the signal output end of the medium compression system, the signal output end of the condensation power generation system, and the signal output end of the power supply system.

8. The multi-flow-channel wellbore fluid cooling system as described in claim 1, characterized in that, The circulation connector has a first connector inner cavity that runs through it. The outer periphery of the first connector inner cavity is provided with a first annular cavity, and the outer periphery of the first annular cavity is provided with a second annular cavity. The circulation connector has an injection port and a return port that communicate with the first annular cavity and the second annular cavity, respectively.

9. The multi-flow-channel wellbore fluid cooling system as described in claim 8, characterized in that, The circulation tube has an internal cavity that runs through it. The outer periphery of the internal cavity is provided with a third annular cavity, and the outer periphery of the third annular cavity is provided with a fourth annular cavity. The top of the third annular cavity is used to communicate with the bottom of the first annular cavity, and the top of the fourth annular cavity is used to communicate with the bottom of the second annular cavity.

10. The multi-flow-channel wellbore fluid cooling system as described in claim 9, characterized in that, The inside of the steering joint has a second joint inner cavity that runs through the steering joint. The outer periphery of the second joint inner cavity is provided with a fifth annular cavity. The outer periphery of the fifth annular cavity is provided with a sixth annular cavity. The top of the fifth annular cavity is used to communicate with the bottom of the third annular cavity. The top of the sixth annular cavity is used to communicate with the bottom of the fourth annular cavity. The bottom of the fifth annular cavity and the bottom of the sixth annular cavity are connected by a bending section.

11. The multi-flow-channel wellbore fluid cooling system as described in claim 10, characterized in that, Along the injection direction of the well fluid, the inner cavity of the first connector, the inner cavity of the rod, and the inner cavity of the second connector are sequentially connected to form the flow passage; Along the flow direction of the cooling medium, the first annulus, the third annulus, the fifth annulus, the bend section, the sixth annulus, the fourth annulus, and the second annulus are sequentially connected to form the circulation channel.

12. A method for cooling wellbore fluid with multiple flow channels, comprising using the multi-flow channel wellbore fluid cooling system according to any one of claims 1 to 11 to cool the wellbore fluid, characterized in that, The method includes the following steps: Step S1: The medium compression system pressurizes and compresses the cooling medium; Step S2: Inject the compressed cooling medium into the circulation channel of the cooling circulation system so as to cool the well fluid in the flow channel of the cooling circulation system through the cooling medium in the circulation channel; Step S3: The cooling medium, after cooling the well fluid, is returned to the medium compression system through the circulation channel of the cooling circulation system; Step S4: Repeat steps S1 to S3.

13. The multi-flow-channel wellbore fluid cooling method as described in claim 12, characterized in that, In step S2, the cooling medium expands and absorbs heat as it enters the circulation channel, and exchanges heat with the well fluid in the flow channel to reduce the temperature of the well fluid.

14. The multi-flow-channel wellbore fluid cooling method as described in claim 12, characterized in that, In steps S1 to S4, the opening degree of the plug valve is controlled to adjust the on / off state of the flow channel and the circulation channel.

15. The multi-flow-channel wellbore fluid cooling method as described in claim 12, characterized in that, Before step S3, the returned cooling medium is cooled by the condenser in the condensation power generation system.

16. The multi-flow-channel wellbore fluid cooling method as described in claim 12, characterized in that, In steps S1 to S4, the operating parameters of the cooling circulation system, the medium compression system, the condensation power generation system, and the power supply system are monitored and recorded in real time by the monitoring and control system, and / or the temperature and / or pressure data at the well outlet.

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