Intelligent multi-stage cooling system and process for high-temperature slurry in extra-deep well drilling

Abstract

The invention provides an intelligent multi-stage cooling system and process for high-temperature slurry in extra-deep well drilling, and belongs to the technical field of geological drilling. The intelligent multi-stage cooling system comprises a low-temperature slurry tank, a high-temperature slurry tank, a slurry pump, a first heat exchanger, a second heat exchanger, a circulating water tank, a circulating water pump, a first cooling tower, a second cooling tower and a water-cooling forced refrigeration unit; the slurry pump is used for pumping high-temperature slurry into the first heat exchanger and / or the second heat exchanger from the high-temperature slurry tank, the high-temperature slurry after heat exchange flows back to the low-temperature slurry tank, and the circulating water pump is used for pumping circulating water in the circulating water tank into the first heat exchanger and / or the second heat exchanger to conduct heat exchange with the slurry. The circulating water after heat exchange returns to the circulating water tank after being cooled by the first cooling tower and / or the second cooling tower and the water-cooling forced refrigeration unit; the modular heat exchanger and cooling equipment are combined to construct a multi-stage cooling system, a multi-stage cooling mode is intelligently started according to the requirement change of the refrigeration power of the high-temperature slurry in extra-deep well drilling, and high-flow high-temperature slurry is efficiently cooled.

Description

Technical Field

[0001] This invention belongs to the field of geological drilling technology, specifically a smart multi-stage cooling system and process for high-temperature drilling mud in ultra-deep wells. Background Technology

[0002] Deep strata are not only rich in oil and gas resources, but also store ancient climate, biological, and geological information, possessing extremely important scientific value. Ultra-deep well drilling is a key method for obtaining core samples from deep strata. However, with the rapid increase in well depth, the bottom-hole temperature becomes extremely high, reaching 200°C or even above 250°C. This extreme high-temperature environment poses an unprecedented and severe challenge to drilling operations. During ultra-deep well drilling, high temperatures severely damage the rheological properties and borehole stability of the drilling mud, leading not only to complex downhole accidents such as wellbore instability and stuck pipe, but also directly affecting drilling efficiency and safety. Simultaneously, the enormous heat carried by the high-temperature drilling mud after it circulates to the surface can damage surface equipment such as well control equipment and vibrating screen purification equipment, seriously threatening project safety.

[0003] Currently, various patented solutions for mud cooling systems have been proposed in the industry, but they are insufficient to fully meet the stringent requirements of ultra-deep well drilling. Firstly, the heat exchange efficiency is insufficient; existing technologies have minimal overall cooling effect on large-flow mud under ultra-high geothermal conditions, making it difficult to cope with the enormous heat load brought by ultra-deep wells. Secondly, energy consumption is enormous; achieving a limited cooling effect requires the consumption of large amounts of water and electricity resources, resulting in poor economic efficiency and making it difficult to use in water-scarce areas of Northwest my country. Thirdly, intelligent and adaptive control is lacking; the working conditions of ultra-deep well drilling are complex and variable, requiring the cooling system to adaptively adjust and allocate cooling power to achieve multi-level precise temperature control and energy efficiency optimization.

[0004] Therefore, developing a high-efficiency, reliable mud cooling system for ultra-deep well drilling that can adapt to complex working conditions and possesses intelligent and precise temperature control capabilities, and that actively and forcibly cools the circulating mud, has become an urgent technical requirement for overcoming the bottlenecks in ultra-deep well drilling technology and ensuring safe and efficient drilling. This patent proposes a mud cooling system solution for ultra-deep well drilling against this background. Summary of the Invention

[0005] To address the shortcomings of the prior art, the technical problem to be solved by the embodiments of the present invention is to provide an intelligent multi-stage cooling system and process for high-temperature drilling mud in ultra-deep wells.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A smart multi-stage cooling system for high-temperature drilling mud in ultra-deep wells includes a low-temperature mud tank, a high-temperature mud tank, a mud pump, a first heat exchanger, a second heat exchanger, a circulating water tank, a circulating water pump, a cooling water pump, a first cooling tower, a second cooling tower, a water-cooled forced refrigeration unit, and an intelligent control unit.

[0008] The mud pump is used to pump high-temperature mud from the high-temperature mud tank into the first heat exchanger and / or the second heat exchanger. After heat exchange, the high-temperature mud flows back to the low-temperature mud tank. The circulating water pump is used to pump circulating water from the circulating water tank into the first heat exchanger and / or the second heat exchanger to exchange heat with the mud. After heat exchange, the circulating water is cooled by the first cooling tower and / or the second cooling tower before returning to the circulating water tank. Simultaneously, a cooling water pump can be used to force-cool the circulating water in the circulating water tank through a water-cooled forced refrigeration unit. The intelligent control unit is used to calculate the cooling power in real time based on temperature, pressure, and flow monitoring data within the system, and automatically switch between multi-stage cooling operation modes.

[0009] This invention also provides an intelligent multi-stage cooling process using an intelligent multi-stage cooling system for high-temperature drilling mud in ultra-deep wells, the steps of which include:

[0010] Step 1: Acquire sensor monitoring data and calculate the real-time cooling power required during the ultra-deep well drilling process based on sensor monitoring data;

[0011] Step 2: Pump the high-temperature mud from the high-temperature mud tank into at least one heat exchanger. The cooled mud is then returned to the low-temperature mud tank. The number of heat exchangers required is determined by the real-time cooling power required.

[0012] Step 3: Pump the circulating water in the circulating water tank into the heat exchanger to exchange heat with the high-temperature mud through convection.

[0013] Step 4: The circulating water after heat exchange is cooled by at least one cooling tower. The number of cooling towers required is determined by the real-time cooling power required. When the temperature of the circulating water tank exceeds the set threshold, the water-cooled forced refrigeration unit is started to force-cool the circulating water.

[0014] As a further improvement: the operating mode is determined based on the real-time required cooling power, and the multi-level operating modes include:

[0015] In low-power mode, the first heat exchanger and the first cooling tower are used;

[0016] In medium power mode, a first heat exchanger, a first cooling tower, and a second cooling tower are used;

[0017] In high-power mode, a first heat exchanger, a second heat exchanger, a first cooling tower, and a second cooling tower are used;

[0018] In full-power mode, the system uses a first heat exchanger, a second heat exchanger, a first cooling tower, a second cooling tower, and a water-cooled forced refrigeration unit.

[0019] As a further improvement: the switching of operating modes is automatically executed based on the relationship between the real-time calculated cooling power Q and the preset power threshold, including:

[0020] When Q 低 When this happens, it enters low power mode;

[0021] When Q 低 ≤Q 中 When the power is low, it enters medium power mode;

[0022] When Q 中 ≤Q 高 When this happens, it enters high-power mode;

[0023] When Q≥Q 高 When it is time, it enters full power mode.

[0024] As a further improvement: based on the actual water source conditions at the construction site, the first and second cooling towers can be air-cooled or water-cooled cooling towers.

[0025] Compared with existing technologies, the advantages of this invention are: a multi-stage cooling system is constructed by combining modular heat exchangers and cooling equipment; based on the changing cooling power requirements of high-temperature drilling mud in ultra-deep wells, the multi-stage cooling mode is intelligently activated, achieving efficient cooling of large-flow, high-temperature drilling mud, while meeting the needs of different regions. By monitoring parameters such as temperature, pressure, and flow rate in real time, the required cooling power is automatically calculated and compared with preset thresholds, thereby achieving unmanned operation and adaptive switching of operating modes. Attached Figure Description

[0026] Figure 1 This is a diagram of the low-power operation mode of an intelligent multi-stage cooling system for high-temperature drilling mud in ultra-deep wells.

[0027] Figure 2 A diagram showing the medium-power operation mode of a smart multi-stage cooling system for high-temperature drilling mud in ultra-deep wells.

[0028] Figure 3 This is a diagram illustrating the high-power operation mode of an intelligent multi-stage cooling system for high-temperature drilling mud in ultra-deep wells.

[0029] Figure 4 A diagram showing the full-power operation mode of an intelligent multi-stage cooling system for high-temperature drilling mud in ultra-deep wells.

[0030] Figure 5 An adaptive intelligent control logic diagram for a multi-stage intelligent cooling system for high-temperature drilling mud in ultra-deep wells; ​​​

[0031] In the diagram: 1. Low-temperature mud tank; 2. High-temperature mud tank; 3. Mud pump; 4. First heat exchanger; 5. Second heat exchanger; 6. Circulating water tank; 7. Circulating water pump; 8. Cooling water pump; 9. First cooling tower; 10. Second cooling tower; 11. Water-cooled forced refrigeration unit. Detailed Implementation

[0032] The technical solution of this application will be further described in detail below with reference to specific embodiments.

[0033] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0034] Please see Figures 1 to 4 In one embodiment, a smart multi-stage cooling system for high-temperature drilling mud in ultra-deep wells includes a low-temperature mud tank 1, a high-temperature mud tank 2, a mud pump 3, a first heat exchanger 4, a second heat exchanger 5, a cooling water pump 8, a circulating water tank 6, a circulating water pump 7, a first cooling tower 9, a second cooling tower 10, and a water-cooled forced refrigeration unit 11.

[0035] The mud pump 3 is used to pump high-temperature mud from the high-temperature mud tank 2 into the first heat exchanger 4 and / or the second heat exchanger 5. After heat exchange, the high-temperature mud flows back to the low-temperature mud tank 1. The low-temperature circulating water pump 7 is used to pump the circulating water in the circulating water tank 6 into the first heat exchanger 4 and / or the second heat exchanger 5 to exchange heat with the mud. After heat exchange, the circulating water is cooled by the first cooling tower 9 and / or the second cooling tower 10 and then returned to the circulating water tank 6. The cooling water pump 8 is used to force the circulating water in the circulating water tank 6 to be cooled by the water-cooled forced refrigeration unit 11.

[0036] In this embodiment, the system also includes the necessary piping and valves for cooling. During cooling: the high-temperature mud tank 2 collects the high-temperature mud circulating from the ultra-deep well. Under the action of the mud pump 3, the high-temperature mud flows at high speed in the first heat exchanger 4 and / or the second heat exchanger 5, and after cooling, flows back to the low-temperature mud tank 1 for reuse in drilling. The circulating water tank 6 stores low-temperature circulating water. Under the action of the circulating water pump 7, the low-temperature circulating water flows at high speed in the first heat exchanger 4 and / or the second heat exchanger 5, exchanging heat with the high-temperature mud via convection. The circulated high-temperature circulating water can then flow through the first cooling tower 9 and / or the second cooling tower 10 for cooling, and finally flows back to the circulating water tank 6. When the temperature of the circulating water tank 6 is too high, the circulating water in the circulating water tank 6 can be forcibly cooled by a water-cooled forced refrigeration unit 11 under the action of the cooling water pump 8.

[0037] When the mud temperature is high and the current cooling system is insufficient, the circulating water in the circulating water tank 6 is forcibly cooled by the water-cooled forced refrigeration unit 11 under the action of the cooling water pump 8.

[0038] Please see Figure 5 In one embodiment, the system further includes an intelligent control unit, which is used to calculate the cooling power in real time based on temperature, pressure, and flow monitoring data within the system, and to automatically switch operating modes.

[0039] In this embodiment, the intelligent control program calculates the cooling power Q and the mud inlet temperature in real time using the temperature, pressure and flow monitoring data at different points in the mud cooling system, and intelligently starts the operation process and adjusts the equipment status.

[0040] Please see Figures 1 to 5 The present invention also provides an intelligent multi-stage cooling process using the aforementioned intelligent multi-stage cooling system for high-temperature drilling mud in ultra-deep wells, specifically including:

[0041] Step 1: Acquire sensor monitoring data and calculate the real-time required cooling power based on sensor monitoring data;

[0042] Step 2: Pump the high-temperature mud from the high-temperature mud tank 2 into at least one heat exchanger. The number of heat exchangers required is determined by the real-time required cooling power.

[0043] Step 3: Pump the circulating water from the circulating water tank 6 into the heat exchanger to exchange heat with the high-temperature mud via convection.

[0044] Step 4: The circulating water after heat exchange is cooled by at least one cooling tower. The number of cooling towers required is determined by the real-time cooling power required. When the temperature of the circulating water tank 6 exceeds the set threshold, the water-cooled forced refrigeration unit 11 is started to force-cool the circulating water. The cooled mud is returned to the low-temperature mud tank 1.

[0045] In this embodiment, the system continuously collects real-time operational data through sensors (such as temperature sensors, pressure sensors, and flow meters) deployed at various key nodes. This data primarily includes: the inlet and outlet temperatures and flow rates of the mud, the inlet and outlet temperatures and flow rates of the circulating water, the temperature of the circulating water tank 6, and the pressure of related pipelines.

[0046] Based on the acquired real-time data, the control unit (such as a PLC or industrial computer) calculates two key control parameters using a built-in algorithm model:

[0047] Real-time required cooling power (Q): Based on the flow rate, specific heat capacity, and temperature difference to be reduced of the mud, calculate the heat that needs to be removed from the mud, which is the total cooling power that the system needs to provide.

[0048] Mud inlet temperature: Calculate or directly monitor the temperature of the mud returning to the wellhead after cooling. Compare the calculated real-time cooling power Q with the preset multi-level power thresholds in the system. Simultaneously, determine if the mud inlet temperature meets engineering requirements. Based on the comparison results, the control system automatically selects and switches to the optimal operating mode and controls the start and stop of corresponding equipment (such as valves, pumps, and chiller units).

[0049] After selecting the operating mode, the system does not stop but immediately returns to the real-time data monitoring process, starting a new cycle of data acquisition, calculation, judgment, and adjustment. This allows the system to continuously respond to changes in drilling conditions (such as increased well depth, changes in formation temperature, and adjustments in mud flow rate), achieving truly adaptive, intelligent, and precise temperature control.

[0050] Please see Figures 1 to 4 In one embodiment, the operating mode is determined based on the real-time required cooling power, the operating mode including:

[0051] In low-power mode, the first heat exchanger 4 and the first cooling tower 9 are used;

[0052] In medium power mode, the first heat exchanger 4, the first cooling tower 9, and the second cooling tower 10 are used;

[0053] In high-power mode, the first heat exchanger 4, the second heat exchanger 5, the first cooling tower 9, and the second cooling tower 10 are used;

[0054] In full-power mode, the system uses a first heat exchanger 4, a second heat exchanger 5, a first cooling tower 9, a second cooling tower 10, and a water-cooled forced refrigeration unit 11.

[0055] In this embodiment, the low-power operation mode is activated when the mud circulation flow rate is low or the mud temperature is low. The operation process is as follows: the mud pump 3 pumps the mud from the high-temperature mud tank 2 into the first heat exchanger 4, and the circulating water pump 7 pumps the low-temperature circulating water from the circulating water tank 6 into the other end of the first heat exchanger 4. After absorbing the heat of the high-temperature mud, the low-temperature circulating water flows through the first cooling tower 9 and is cooled by air or water before flowing back to the circulating water tank 6. The above process uses a set of heat exchangers and a set of cooling towers to achieve low-power operation.

[0056] The medium-power operation mode is automatically activated when the low-power operation mode is insufficient. Its operation process is as follows: the mud pump 3 pumps the mud pump 3 in the high-temperature mud tank 2 into the first heat exchanger 4, and the circulating water pump 7 pumps the low-temperature circulating water 7 in the circulating water tank 6 into the other end of the first heat exchanger 4. After absorbing the heat of the high-temperature mud, the low-temperature circulating water flows through the first cooling tower 9 and the second cooling tower 10 respectively. After being cooled by air cooling or water cooling, it flows back to the circulating water tank 6. The above process uses one set of heat exchangers and two sets of cooling towers to achieve medium-power operation.

[0057] The high-power operation mode is activated when the medium-power operation mode cannot meet the demand. The operation process is as follows: the mud pump 3 pumps the mud in the high-temperature mud tank 2 into the first heat exchanger 4 and the second heat exchanger 5 respectively. The circulating water pump 7 pumps the low-temperature circulating water in the circulating water tank 6 into the other end of the first heat exchanger 4 and the second heat exchanger 5 respectively. After absorbing the heat of the high-temperature mud, the low-temperature circulating water flows through the first cooling tower 9 and the second cooling tower 10 respectively. After being cooled by air cooling or water cooling, it flows back to the circulating water tank 6. The above process uses two sets of heat exchangers and two sets of cooling towers to achieve high-power operation.

[0058] The full-power operation mode is activated when the high-power operation mode cannot meet the demand. The operation process is as follows: the mud pump 3 pumps the mud in the high-temperature mud tank 2 into the first heat exchanger 4 and the second heat exchanger 5 respectively. The circulating water pump 7 pumps the low-temperature circulating water in the circulating water tank 6 into the other end of the first heat exchanger 4 and the second heat exchanger 5 respectively. After absorbing the heat of the high-temperature mud, the low-temperature circulating water flows through the first cooling tower 9 and the second cooling tower 10 respectively. After being cooled by air cooling or water cooling, it flows back to the circulating water tank 6. At the same time, under the action of the cooling water pump 8, the circulating water in the circulating water tank 6 is forcibly cooled by the water-cooled forced refrigeration unit 11. The above process uses two sets of heat exchangers, two sets of cooling towers and water-cooled forced refrigeration unit 11 to achieve full-power operation.

[0059] By setting four power operation modes—low, medium, high, and full power—the system can intelligently activate the minimum necessary number of devices based on real-time calculated cooling demand. When the heat load is low, only some devices operate, avoiding energy waste caused by over-powering equipment; all devices (including energy-intensive forced-air chillers) are only activated under extreme conditions. This on-demand cooling strategy significantly reduces the system's water and electricity consumption, making it particularly suitable for drilling areas in water-scarce regions like Northwest my country, resulting in a significant improvement in economic efficiency.

[0060] Please see Figure 5 In one embodiment, the switching of operating modes is automatically performed based on the relationship between the real-time calculated cooling power Q and a preset power threshold, including:

[0061] When Q 低 When this happens, it enters low power mode;

[0062] When Q 低 ≤Q 中 When the power is medium, enter medium power mode;

[0063] When Q 中 ≤Q 高 When this happens, it enters high-power mode;

[0064] When Q≥Q 高 When it is time, it enters full power mode.​​​

[0065] In this embodiment, the ground intelligent control program calculates the cooling power Q and the mud inlet temperature in real time using the temperature, pressure and flow monitoring data at different points in the mud cooling system.

[0066] Taking the drilling of a 13,000m ultra-deep well in a certain area as an example, the project requires that the mud circulation flow rate not exceed 80L / s and the mud temperature entering the well not exceed 60℃.

[0067] The first heat exchanger 4 and the second heat exchanger 5 each have a cooling capacity of 6000kW, the first cooling tower 9 and the second cooling tower 10 each have a cooling capacity of 75kW, and the water-cooled forced refrigeration unit 11 has a cooling capacity of 150kW. The equipment required for this implementation also includes electrically controlled valves, temperature sensors, pressure sensors, etc.

[0068] Power threshold Q 低 Q 中 Q 高 The capacities are 4000kW, 6000kW, and 8000kW respectively.

[0069] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.

[0070] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A smart multi-stage cooling system for high-temperature drilling mud in ultra-deep wells, characterized in that, It includes a low-temperature mud tank, a high-temperature mud tank, a mud pump, a first heat exchanger, a second heat exchanger, a circulating water tank, a circulating water pump, a cooling water pump, a first cooling tower, a second cooling tower, and a water-cooled forced refrigeration unit; The mud pump is used to pump high-temperature mud from the high-temperature mud tank into the first heat exchanger and / or the second heat exchanger. After heat exchange, the high-temperature mud flows back to the low-temperature mud tank. The low-temperature circulating water pump is used to pump the circulating water in the circulating water tank into the first heat exchanger and / or the second heat exchanger to exchange heat with the mud. After heat exchange, the circulating water is cooled by the first cooling tower and / or the second cooling tower and then returned to the circulating water tank. The cooling water pump is used to force the circulating water in the circulating water tank to be cooled by a water-cooled forced refrigeration unit.

2. The intelligent multi-stage cooling system for high-temperature drilling mud in ultra-deep wells according to claim 1, characterized in that, It also includes an intelligent control unit, which is used to calculate the cooling power in real time based on the temperature, pressure and flow monitoring data in the system, and automatically switch between multiple operating modes.

3. An intelligent multi-stage cooling process using an intelligent multi-stage cooling system for high-temperature drilling mud in ultra-deep wells as described in claim 1 or 2, characterized in that, include Step 1: Acquire sensor monitoring data and calculate the real-time required cooling power based on sensor monitoring data; Step 2: Pump the high-temperature mud from the high-temperature mud tank into at least one heat exchanger. The number of heat exchangers required is determined by the real-time required cooling power. Step 3: Pump the circulating water in the circulating water tank into the heat exchanger to exchange heat with the high-temperature mud through convection. Step 4: The circulating water after heat exchange is cooled by at least one cooling tower. The number of cooling towers required is determined by the real-time cooling power required. When the temperature of the circulating water tank exceeds the set threshold, the water-cooled forced refrigeration unit is started to force-cool the circulating water.

4. The intelligent multi-stage cooling system for high-temperature drilling mud in ultra-deep wells according to claim 3, characterized in that, The operating mode is determined based on the real-time required cooling power. The multi-level operating modes include: In low-power mode, the first heat exchanger and the first cooling tower are used; In medium power mode, a first heat exchanger, a first cooling tower, and a second cooling tower are used; In high-power mode, a first heat exchanger, a second heat exchanger, a first cooling tower, and a second cooling tower are used; In full-power mode, the system uses a first heat exchanger, a second heat exchanger, a first cooling tower, a second cooling tower, and a water-cooled forced refrigeration unit.

5. The intelligent multi-stage cooling system for high-temperature drilling mud in ultra-deep wells according to claim 4, characterized in that, The switching of operating modes is automatically executed based on the relationship between the real-time calculated cooling power Q and the preset power threshold, including: When Q 低 When this happens, it enters low power mode;​ When Q 低 ≤Q 中 When the power is low, it enters medium power mode;​ When Q 中 ≤Q 高 When this happens, it enters high-power mode;​ When Q≥Q 高 When it is time, it enters full power mode.

6. The intelligent multi-stage cooling system for high-temperature drilling mud in ultra-deep wells according to claim 3, characterized in that, The first and second cooling towers are either air-cooled or water-cooled cooling towers.

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