Cooling device for downhole instrument while drilling and control method

Abstract

The invention provides a downhole instrument heat dissipation device while drilling and a control method. A drilling fluid descending channel is formed in a collar body, an instrument cavity is formed in the drilling fluid descending channel, drilling fluid flows through the outer wall of the instrument cavity, a heat insulation layer is arranged on the inner wall of the instrument cavity, a downhole instrument is arranged in the instrument cavity, and the downhole instrument is arranged in the instrument cavity. A first heat conduction part is attached to the underground instrument; the semiconductor module is provided with a semiconductor assembly, the semiconductor assembly comprises multiple stages of semiconductor sheets, and the semiconductor assembly is arranged in the instrument cavity and is connected with the first heat conduction part, so that heat of the first heat conduction part is conducted to the semiconductor assembly; and a second heat conduction part is arranged, the second heat conduction part is connected with the semiconductor assembly, heat of the semiconductor assembly is conducted to the second heat conduction part, the second heat conduction part extends into a drilling fluid descending channel outside the instrument cavity, the output power of the semiconductor assembly is accurately controlled according to the underground temperature, and control is more intelligent.

Description

Technical Field

[0001] The invention relates to the field of petroleum equipment, in particular to a heat dissipation device for downhole drilling instruments and a control method thereof. Background Art

[0002] Logging while drilling is an important key technology in current drilling logging technology. It installs logging instruments in the drill collar behind the drill bit and close to the drill bit to achieve logging while drilling and obtain various formation data in a timely manner. This technology can not only be used for geological guidance and drilling guidance, but also can evaluate the oil and gas content of complex wells and complex formations. With the continuous advancement of technology and the expansion of the scope of application, these instruments will play a more important role in oil and gas exploration and development. However, with the increase in drilling depth, the temperature at the bottom of the well gradually increases, which poses a severe challenge to the heat dissipation of downhole instruments. High temperature environment will cause the internal temperature of the instrument to rise rapidly, affecting the normal operation and measurement accuracy of the instrument. The temperature resistance limit of conventional downhole instruments is 150°C, while the temperature of deep formations may reach 200°C or even higher, which leads to the problem of failure of downhole instruments in high temperature environments. Therefore, in order to overcome this problem, it is necessary to develop heat dissipation for downhole instruments to improve their stability and reliability in high temperature environments, thereby promoting the exploration and development of oil and gas resources in deep formations.

[0003] The invention patent application document with publication number: CN 109788715 A, title: A semiconductor active cooling system and cooling method for downhole circuits while drilling, discloses a cooling device and method for a downhole instrument while drilling. The technical solution uses semiconductor refrigeration sheets for cooling, but in terms of its structure, the heat dissipation is conducted through the shell, and the heat dissipation effect is not good; the control method only controls whether the semiconductor works according to the temperature, and does not achieve precise control of the entire cooling system. The intelligence level is low and energy waste is caused. Summary of the invention

[0004] The purpose of the present invention is to provide a heat dissipation device and control method for downhole instruments while drilling in view of the defects existing in the above-mentioned technology. In terms of structure, the heat of the heat dissipation device is transferred to the drilling fluid through the second heat conduction part to improve the heat dissipation effect; in the control method, the output power of the semiconductor component is accurately controlled according to the downhole temperature, making the control more intelligent.

[0005] The object of the present invention is achieved in that:

[0006] Provided is a heat dissipation device for a downhole tool while drilling, comprising:

[0007] A collar body, wherein a drilling fluid descending channel is provided inside the collar body, an instrument cavity is provided inside the drilling fluid descending channel, so that the descending drilling fluid flows through the outer wall of the instrument cavity, an inner wall of the instrument cavity is provided with a heat insulating layer, a downhole instrument is provided in the instrument cavity, and a first heat conducting part is provided close to the downhole instrument;

[0008] A semiconductor component, the semiconductor component comprising a multi-stage semiconductor sheet, the semiconductor component is arranged in the instrument cavity and connected to the first heat conducting part so that the heat of the first heat conducting part is transferred to the semiconductor component;

[0009] A second heat conducting part, the second heat conducting part is connected to the semiconductor component so that the heat of the semiconductor component is transferred to the second heat conducting part, the second heat conducting part extends into the drilling fluid descending channel outside the instrument cavity, and the heat is carried out by the descending fluid;

[0010] A power supply device, which is arranged in the instrument cavity and supplies power to the semiconductor component;

[0011] A control module is used to control the operation of semiconductor components.

[0012] In the above structure, the first heat conducting part includes a horizontal plate and a vertical plate, the vertical plate is close to the surface of the downhole instrument, and the surface of the horizontal plate facing the downhole instrument is provided with a plurality of fins.

[0013] In the above structure, the method for determining the number of semiconductor wafers in the semiconductor assembly comprises the following steps: S11: determining the target temperature and the ambient temperature;

[0014] S12: Calculate the cooling power requirement of each semiconductor chip:

[0015] Q i =P i +kΔT i

[0016] Among them, Q i is the power requirement of each semiconductor chip, P i is the heat input power, ΔT i is the temperature difference of the semiconductor chip at this level, and k is the thermal conductivity;

[0017] S13: Calculate the total power demand of the system:

[0018]

[0019] Among them, Q t is the total power, N is the total number of semiconductors;

[0020] S14: Calculate the total number of semiconductor wafer stages required based on the total power requirement and the capacity of each semiconductor wafer stage:

[0021]

[0022] S14: Based on the total number of levels, design a certain proportion of redundant levels and calculate the actual number of levels:

[0023] N r =N·(1+C)

[0024] Among them, N r is the actual number of levels, and C is the redundancy ratio.

[0025] A control method is provided, the method comprising:

[0026] S21: monitor the instrument temperature in real time through the temperature sensor and feed the data back to the control module;

[0027] S22: The control module dynamically adjusts the operating parameters of each level of semiconductor chips according to the temperature monitoring data;

[0028] S23: Reduce energy consumption and improve heat dissipation efficiency by optimizing control algorithms.

[0029] In the above method, the adjustment method in step S22 is:

[0030] The control module adjusts the operating current and voltage of each level of semiconductor chips according to the temperature monitoring data to meet the requirements under different temperatures, including:

[0031] The heat dissipation capacity of a semiconductor chip is determined by its operating current and applied voltage, and its cooling power is:

[0032]

[0033] Where Q is the cooling power of each semiconductor chip, n is the number of thermocouples, α is the Seebeck coefficient, T C and T h are the cold end and hot end temperatures respectively, R is the resistance of each semiconductor chip, and k is the thermal conductivity of each semiconductor chip;

[0034] Calculate the temperature difference of each semiconductor chip:

[0035] ΔT i =T hi -T ci

[0036] Where, ΔT i is the temperature difference of each semiconductor chip; T hi is the hot end temperature of the semiconductor chip, T ci is the cold end temperature of the semiconductor chip, i is the semiconductor chip level;

[0037] Calculate the current required cooling power:

[0038] Q i =f(ΔT i , P i )

[0039] Among them, Q i is the current required cooling power, P i is the heat flow input power of the i-th semiconductor chip; calculate the current optimal working current and voltage:

[0040]

[0041] V i =I i ·R;

[0042] Dynamic adjustment: The control module periodically collects new temperature data T ci and T hi , recalculate the temperature difference ΔT i and the required cooling power Q i Based on these data, the operating current and voltage of each level of semiconductor wafer are dynamically adjusted.

[0043] In the above method, step S23 specifically includes:

[0044] S23.1: Initialize the working state of each TEC and set the initial current and voltage V i (0) ;

[0045] S23.2: Calculate the current total energy consumption E (0) ;

[0046] S23.3: Computing Gradients and update and V i (k) :

[0047]

[0048] Optimal power distribution is achieved by adjusting the current and voltage of each semiconductor chip to minimize total energy consumption.

[0049] The beneficial effects of the present invention are as follows: in terms of structure, the second heat-conducting part extends into the drilling fluid channel outside the instrument cavity, and the heat of the heat sink is taken away by the drilling fluid, thereby optimizing the heat dissipation effect; in addition, according to the conditions of different oil wells, the required number of semiconductor chips is specifically calculated, and the design is precise to prevent waste of resources. On the basis of the calculated number of semiconductor chips, a certain proportion of redundant levels is set. When the main channel fails or cannot meet the heat dissipation requirements, the control system automatically switches to the backup channel and enables the semiconductor chips in the redundant levels to ensure the heat dissipation effect.

[0050] In terms of control methods, the output power of semiconductor components is dynamically controlled in real time according to the underground temperature to achieve precise and intelligent control and save energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic diagram of the cross-sectional structure of the heat dissipation device of the present invention;

[0052] Figure 2 yes Figure 1 AA-direction cross-sectional structural diagram;

[0053] Figure 3 It is a flow chart of the control method of the present invention. DETAILED DESCRIPTION

[0054] The present application provides a heat dissipation device and control method for downhole instruments while drilling. In terms of structure, the second heat-conducting part extends into the downward channel of the drilling fluid outside the instrument cavity, and the heat of the heat dissipation device is taken away by the downward drilling fluid, thereby optimizing the heat dissipation effect. In addition, according to the conditions of different oil wells, the required number of semiconductor chips is specifically calculated, and the design is precise to prevent waste of resources. On the basis of the calculated number of semiconductor chips, a certain proportion of redundant chips is set. When the main channel fails or cannot meet the heat dissipation requirements, the control system automatically switches to the backup channel and enables the semiconductor chips in the redundant chips to ensure the heat dissipation effect, thereby solving the problem that the heat dissipation effect cannot be guaranteed in the prior art. In terms of control method, the output power of the semiconductor component is dynamically controlled in real time according to the downhole temperature, so as to realize precise and intelligent control and save energy. This solves the problem that the existing control method cannot achieve precise control.

[0055] The following is a further description of this implementation case:

[0056] The present application provides a heat dissipation device for a downhole instrument while drilling, referring to Figure 1-Figure 2, including a collar 1, wherein a drilling fluid downward channel 110 is provided inside the collar 1, wherein an instrument cavity 120 is provided inside the drilling fluid downward channel 110, so that the downward drilling fluid flows through the outer wall of the instrument cavity 120, and an insulation layer 2 is provided on the inner wall of the instrument cavity 120. After the insulation layer 2 is provided, the heat of the collar 1 can be effectively reduced from being transferred into the instrument cavity, so as to prevent the downhole instrument 3 from being overheated. In this embodiment, the material of the insulation layer 2 is preferably aerogel. A downhole instrument 3 is provided in the instrument cavity 120, and a first heat conducting part 4 is provided close to the downhole instrument 3. A semiconductor component 5 is provided, and the semiconductor component 5 includes a multi-stage semiconductor sheet 510. The semiconductor component 5 is provided in the instrument cavity 120 and connected to the first heat conducting part 4, so that the heat of the first heat conducting part 4 is transferred to the semiconductor component 5. A second heat conducting part 6 is also provided, and the second heat conducting part 6 is connected to the semiconductor component 5, so that the heat of the semiconductor component 5 is transferred to the second heat conducting part 6, and the second heat conducting part 6 extends to the drilling fluid downward channel 110 outside the instrument cavity 120. Among them, the cold surface of the semiconductor component 5 is against the first heat conducting part 4, and the hot surface of the semiconductor component 5 is against the second heat conducting part 6, and the second heat conducting part 6 extends to the drilling fluid downward channel 110. When the drilling fluid flows through the second heat conducting part 6, it will take away the temperature of the second heat conducting part 6, thereby improving the heat dissipation effect. In addition, a power supply device 7 is provided, and the power supply device 7 is arranged in the instrument cavity 120 to supply power to the semiconductor component 5. A control module 8 is provided, and the operation of the semiconductor component 5 is controlled by the control module 8.

[0057] In this embodiment, the instrument cavity 120 is convex toward the drilling fluid downward channel 110 , and a cover plate 130 is provided outside the instrument cavity 120 . The connection between the cover plate 130 and the instrument cavity 120 is sealed, and the second heat conducting part 6 and the collar body 1 are also sealed to prevent the drilling fluid from flowing into the instrument cavity 120 .

[0058] In the above embodiment, preferably, the first heat conducting part 4 includes a horizontal plate 410 and a vertical plate 420, the vertical plate 420 is close to the surface of the downhole instrument 3, and the surface of the horizontal plate 410 facing the downhole instrument 3 is provided with a plurality of fins 430. The cold energy of the semiconductor component 5 is conducted to the downhole instrument 3 through the vertical plate 420, and the fins 430 are provided to conduct the cold energy into the instrument cavity 120 and dissipate it better.

[0059] In the above structure, the method for determining the number of semiconductor chips 510 in the semiconductor component 5 comprises the following steps:

[0060] S11: Determine the target temperature and the ambient temperature;

[0061] S12: Calculate the cooling power requirement of each semiconductor chip:

[0062] Q i =P i +kΔT i

[0063] Among them, Q i is the power requirement of each semiconductor chip, P i is the heat input power, ΔT i is the temperature difference of the semiconductor chip at this level, and k is the thermal conductivity;

[0064] S13: Calculate the total power demand of the system:

[0065]

[0066] Among them, Q t is the total power, N is the total number of semiconductors;

[0067] S14: Calculate the total number of semiconductor wafer stages required based on the total power requirement and the capacity of each semiconductor wafer stage:

[0068]

[0069] S14: Based on the total number of levels, design a certain proportion of redundant levels and calculate the actual number of levels:

[0070] N r =N·(1+C)

[0071] Among them, N r is the actual number of levels, and c is the redundancy ratio.

[0072] A specific example calculation for calculating the number of semiconductor wafers is given below:

[0073] Set the target temperature and environmental conditions, determine the target temperature and ambient temperature, assuming that the underground ambient temperature is 160℃ (433K), and the set target temperature is 100℃ (373K). The cold end temperature needs to be lowered to this value through semiconductor components.

[0074] Assume that the temperature difference of each semiconductor refrigeration module is (6K);

[0075] The power requirement of each semiconductor refrigeration module is determined by the input power P i and thermal conductivity k. Assume that the thermal conductivity k is 1W / K and the input power P of each semiconductor chip i If the power requirement is 5W, the power requirement for each stage can be calculated as follows:

[0076] Q i =5W+1W / K×6K=5W+6W=11W;

[0077] The total power demand of the system can be calculated by power recursion. The calculation example is as follows:

[0078] First-stage power requirement: Q1=11W;

[0079] Second stage power requirement (including first stage heat): Q2 = 11 + 11 = 22W;

[0080] The third-stage power requirement (including the heat from the first two stages): Q3 = 11 + 11 + 11 = 33W;

[0081] And so on, until the power demand meets the total system demand.

[0082] Assuming the total power requirement of the system is 60W, we need to determine the total number of stages based on the semiconductor chip capacity. Calculate the total number of modules based on the capacity of each semiconductor chip:

[0083] N = 60W / 11W≈5.45, take the integer 6;

[0084] Assuming the redundancy ratio C is 0.3, the actual total number of levels is:

[0085] 6*(1+0.3)=7.8, the integer is level 8.

[0086] A control method is provided, the method comprising:

[0087] S21: monitor the instrument temperature in real time through the temperature sensor and feed the data back to the control module;

[0088] S22: The control module dynamically adjusts the operating parameters of each level of semiconductor chips according to the temperature monitoring data;

[0089] S23: Reduce energy consumption and improve heat dissipation efficiency by optimizing control algorithms.

[0090] In the above method, the adjustment method in step S22 is:

[0091] The control module adjusts the operating current and voltage of each level of semiconductor chips according to the temperature monitoring data to meet the requirements under different temperatures, including:

[0092] The heat dissipation capacity of a semiconductor chip is determined by its operating current and applied voltage, and its cooling power is:

[0093]

[0094] Where Q is the cooling power of each semiconductor chip, n is the number of thermocouples, α is the Seebeck coefficient, T C and T h are the cold end and hot end temperatures respectively, R is the resistance of each semiconductor chip, and k is the thermal conductivity of each semiconductor chip;

[0095] Calculate the temperature difference of each semiconductor chip:

[0096] ΔTi =T hi -T ci

[0097] Where, ΔT i is the temperature difference of each semiconductor chip; T hi is the hot end temperature of the semiconductor chip, T ci is the cold end temperature of the semiconductor chip, i is the semiconductor chip level;

[0098] Calculate the current required cooling power:

[0099] Q i =f(ΔT i , P i )

[0100] Among them, Q i is the current required cooling power, P i is the heat flow input power of the i-th semiconductor chip; calculate the current optimal working current and voltage:

[0101]

[0102] V i =I i ·R;

[0103] Dynamic adjustment: The control module periodically collects new temperature data T ci and T hi , recalculate the temperature difference ΔT i and the required cooling power Q i Based on these data, the operating current and voltage of each level of semiconductor wafer are dynamically adjusted.

[0104] A computational example of this control method is provided below:

[0105] Known conditions: underground temperature 160℃; semiconductor component refrigeration level 10, assumed semiconductor refrigeration module parameters:

[0106] 1. Heat flow input power (Pi): Assume that the heat flow input power of each module is P (the specific value can be set according to actual conditions);

[0107] 2. Thermal conductivity (k): 0.3W / K;

[0108] 3. Seebeck coefficient (α): 0.04V / K;

[0109] 4. Resistance (R): 0.5Ω;

[0110] 5. Cold junction temperature (T ci ): needs to be calculated;

[0111] 6. Hot end temperature (T hi ): Ambient temperature (160°C);

[0112] Calculate the cold junction temperature of each semiconductor:

[0113] Since the temperature difference can affect the cooling effect of the semiconductor, set a reasonable cold end temperature range.

[0114] For example, assuming the cold junction temperature T ci 100℃ (can be adjusted according to actual needs);

[0115] Calculate the temperature difference of each semiconductor stage:

[0116] Temperature difference ΔT i It can be calculated as:

[0117] ΔT i =160℃-100℃=60K;

[0118] Calculate the cooling power requirement for each semiconductor stage:

[0119] Use the formula:

[0120] Q i =P i +k·ΔT i ;

[0121] Among them, P i is the heat input power, we need to calculate the required power. Assume that the heat input power P of each stage i For P:

[0122] Q i =P+0.3W / K×60K;

[0123] Q i =P+18W;

[0124] Calculate the current and voltage:

[0125] For each level of TEC, if we have a specific P value, we can further calculate the current and voltage. Here we take P = 20W as an example:

[0126] Q i =20W+18W=38W;

[0127] Current I i It can be calculated by solving the following equation (note that this is an approximation and actual current calculation requires iteration):

[0128]

[0129] Make an estimate:

[0130] Approximate value I i ≈2.5A (accurate value obtained by iteration or solving equations)

[0131] Voltage V i :

[0132] V i =I i R = 2.5A × 0.5Ω = 1.25V.

[0133] Based on the above calculation, under this condition, controlling the semiconductor chip current to 2.5A and the voltage to 1.25V can meet the working requirements and avoid energy waste.

[0134] In the above method, step S23 specifically includes:

[0135] S23.1: Initialize the working state of each TEC and set the initial current and voltage V i (0) ;

[0136] S23.2: Calculate the current total energy consumption E (0) ;

[0137] S23.3: Computing Gradients and update and V i (k) :

[0138]

[0139] The optimal power distribution is achieved by adjusting the current and voltage of each semiconductor chip to minimize the total energy consumption. An exemplary calculation process is given below:

[0140] Assume that there are 10 semiconductor chips in the system and the target total power demand is Q t =50W. We will optimize and set it through the following steps:

[0141] 1. Initial current of each semiconductor chip

[0142] 2. Initial voltage V of each semiconductor chip i (0) =5V;

[0143] 3. Initial total energy consumption E (0) =100W;

[0144] Select the learning rate η = 0.01, and use the gradient descent method to update the current and voltage of each semiconductor chip:

[0145] 1. First iteration:

[0146]

[0147] Update current and voltage:

[0148] I i (1) =2-0.01×5=2-0.05=1.95A;

[0149] V i (1) =5-0.01×2=5-0.02=4.98V;

[0150] Calculate the new total energy consumption after updating:

[0151] E (1) =10×(1.95×4.98)=97.11W;

[0152] 2. Second iteration:

[0153] Compute the new gradient:

[0154]

[0155] Update current and voltage:

[0156] I i (2) =1.95-0.01×4.98=1.95-0.0498=1.9002A;

[0157] V i (2) =4.98-0.01×2=5-0.02=4.9605V;

[0158] Calculate the new total energy consumption after updating: E (2) =10×(1.9002×4.9605)=94.3W;

[0159] 3. Continue to use the same gradient descent update method, and the current and voltage will gradually decrease. After many iterations, the total energy consumption of the system gradually approaches 50W.

[0160] Continue to repeat the above process, by gradually adjusting the current and voltage until the convergence condition is met. Each iteration adjusts the current and voltage in the direction of reducing the total energy consumption until the energy consumption of the system reaches the minimum or the change is very small. Specifically, set a stop condition, such as the change in total energy consumption is less than a certain threshold such as 0.01W, or the change in current and voltage is very small such as 0.001A and 0.001V. When these conditions are met, it can be considered that the optimal current and voltage distribution has been found.

[0161] The following provides the thermal analysis process of the downhole instrument while drilling:

[0162] 1. Heat production calculation:

[0163] 1. Calculate the heat output per minute Q1 of the instrument.

[0164] Q1=P·t·θ;

[0165] Where: P—equipment working power, 15W;

[0166] T is working time, 60s;

[0167] θ is the efficiency factor, 0.8.

[0168] Q1=P·t·θ=15×60×0.8=720J

[0169] Therefore, the heat generated by the instrument in 1 minute is about 720 joules.

[0170] When the temperature of the instrument changes, the heat released can be calculated by the following formula:

[0171] Q1=mCΔT1;

[0172] Where: Q1 is heat, J;

[0173] m is the mass of the instrument, 0.5 kg;

[0174] c is the specific heat capacity of the instrument, about 1200 J / (kg·℃);

[0175] ΔT1 is the temperature rise of the instrument per minute, °C.

[0176]

[0177] The temperature of the instrument rises by 1.2°C per minute.

[0178] 2. Calculation of heat transfer per minute of collar body Q2:

[0179] The heat conduction formula is:

[0180]

[0181] Where: P z is the heat flux, W;

[0182] λ is thermal conductivity, 18.5W / (m·K);

[0183] A is the heat transfer area, 0.2635m 2 ;

[0184] ΔT is the temperature difference between the high temperature environment and the instrument cavity, which is set to 160°C;

[0185] δ is the heat transfer distance, 0.04m.

[0186]

[0187] Heat transferred to the insulation layer per minute Q2:

[0188] Q2=P z ·t·θ;

[0189] Where: P z is the heat flux, 19499W;

[0190] t is the working time, 60s;

[0191] θ is the efficiency factor, 0.8.

[0192] Q2=P z ·t·θ=19499×60×0.8=935952J.

[0193] When the temperature of the instrument changes, the amount of heat absorbed or released can be calculated using the following formula:

[0194] Q2 = mcΔT2;

[0195] m=Vρ;

[0196] Where: Q2 is heat, J;

[0197] m is the mass of the drill collar, kg;

[0198] V is the heat transfer volume of the drill collar, 0.01054m3;

[0199] ρ is the density of drill collar, 8.05×103kg / m3;

[0200] c is the specific heat capacity of the drill collar, about 500 J / (kg·℃);

[0201] ΔT2—The external temperature is transferred to the insulation layer temperature through the drill collar, ℃.

[0202] m=Vρ=0.01054×8.05×10 3 =84.847kg;

[0203]

[0204] Based on the above calculation, the external temperature is transferred to the insulation layer through the drill collar every minute at a temperature of 22.06°C. 3. The heat Q3 transferred from the insulation layer to the instrument every minute:

[0205] The heat conduction formula is:

[0206]

[0207] Where: P g is the heat flux, W;

[0208] λ is thermal conductivity, 0.02W / (m·K);

[0209] A is the heat transfer area, 0.2635m 2 ;

[0210] ΔT is the temperature difference between the cold end and the hot end, 22.06°C;

[0211] δ is the thickness of the insulation layer, 0.01m.

[0212]

[0213] Heat transferred to the insulation layer per minute Q3:

[0214] Q3=P g ·t·θ;

[0215] Where: P g is the heat flux, 11.626W;

[0216] t is the working time, 60s;

[0217] θ is the efficiency factor, 0.8;

[0218] Q3=P g ·t·θ=11.626×60×0.8=558.03J.

[0219] The amount of heat absorbed or released can be calculated using the following formula:

[0220] Q3=mcΔT3

[0221] Where: Q3 is heat, J;

[0222] m is the mass of the instrument, 0.5 kg;

[0223] c is the specific heat capacity of the instrument, about 1200 J / (kg·℃);

[0224] ΔT3 is the temperature rise of the instrument per minute, °C;

[0225]

[0226] Therefore, the temperature of the outside world transmitted to the instrument through the insulation layer rises by 0.93℃ per minute.

[0227] 2. Heat Dissipation Calculation

[0228] 1. The semiconductor absorbs heat from the instrument Q4:

[0229] The mathematical model of heat absorption power at the semiconductor cold end is:

[0230] P c =α·I·ΔT-R·I 2 ,

[0231] Where: P c is the cooling capacity, which means the heat absorbed by the semiconductor from the environment, W;

[0232] α is the Seebeck coefficient, 0.07435 V / K;

[0233] I is the operating current, 2.5A;

[0234] ΔT is the temperature difference between the cold end and the hot end, 160°C;

[0235] R is the internal resistance of the semiconductor, 0.5Ω;

[0236] P c =α·I·ΔT-R·I 2 =0.07435×2.5×160-0.5×2.5 2 =26.615W.

[0237] Calculate the heat absorbed per minute Q4:

[0238] Q4=P c ·t·θ

[0239] Where: P c is the cooling capacity, 26.615W;

[0240] t is the working time, 60s;

[0241] θ is the efficiency factor, 0.8;

[0242] Q4=P c ·t·θ=26.615×60×0.774=1277.52J,

[0243] Therefore, the semiconductor can absorb 1277.52J of heat per minute.

[0244] When the temperature of the instrument changes, the amount of heat absorbed by the semiconductor can be calculated using the following formula:

[0245] Q4 = mcΔT4;

[0246] Where: Q4 is heat, J;

[0247] m is the mass of the instrument, 0.5 kg;

[0248] c is the specific heat capacity of the instrument, about 1200 J / (kg·℃);

[0249] ΔT4 is the temperature change per minute, °C;

[0250]

[0251] The semiconductor absorbs temperature 2.1292°C per minute.

[0252] 3. Calculation of working hours

[0253] (1) The total working hours of the instrument are 200 hours, and the total heat generated by the equipment is:

[0254] Q 1总 =P·t·θ=15×200×60×60×0.8=8.64×10 6 J;

[0255] (2) The total heat transferred from the outside into the instrument through the drill collar and the insulation layer for 200 hours is:

[0256] Q 3总 =P g ·t·θ=11.626×200×60×60×0.8=6.7×10 6 J;

[0257] (3) The total heat absorbed by the semiconductor from the instrument for 200 hours is:

[0258] Q 4总 =P c ·t·θ=26.615×200×60×60×0.8=15.33×10 6 J;

[0259] When the temperature of the instrument changes, the amount of heat absorbed or released, ΔQ, can be calculated using the following formula:

[0260] ΔQ = mcΔT;

[0261] Where: ΔQ is heat, J;

[0262] m is the mass of the instrument, 0.5 kg;

[0263] c is the specific heat capacity of the instrument, about 1200 J / (kg·℃);

[0264] ΔT is the temperature change after 200 hours of operation, °C;

[0265]

[0266] Assuming the initial operating temperature of the instrument is 20°C, the total temperature rises by 16.67°C after 200 hours, meeting the requirement that the instrument should not exceed 40°C.

[0267] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0268] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

Claims

1. A heat dissipation device for downhole tools while drilling, characterized in that: include: A collar body, wherein a drilling fluid descending channel is provided inside the collar body, an instrument cavity is provided inside the drilling fluid descending channel, so that the descending drilling fluid flows through the outer wall of the instrument cavity, an inner wall of the instrument cavity is provided with a heat insulating layer, a downhole instrument is provided in the instrument cavity, and a first heat conducting part is provided close to the downhole instrument; A semiconductor component, the semiconductor component comprising a multi-stage semiconductor sheet, the semiconductor component is arranged in the instrument cavity and connected to the first heat conducting part so that the heat of the first heat conducting part is transferred to the semiconductor component; a second heat conducting portion, the second heat conducting portion being connected to the semiconductor component so that the heat of the semiconductor component is conducted to the second heat conducting portion, and the second heat conducting portion extending into a drilling fluid descending channel outside the instrument cavity; A power supply device, which is arranged in the instrument cavity and supplies power to the semiconductor component; A control module is used to control the operation of semiconductor components.

2. The heat dissipation device for downhole tools while drilling according to claim 1, characterized in that: The first heat conducting part comprises a horizontal plate and a vertical plate. The vertical plate is attached to the surface of the downhole instrument. The surface of the horizontal plate facing the downhole instrument is provided with a plurality of fins.

3. The heat dissipation device for downhole drilling tools according to claim 1, characterized in that: The method for determining the number of semiconductor wafers in the semiconductor component comprises the following steps: S11: Determine the target temperature and the ambient temperature; S12: Calculate the cooling power requirement of each semiconductor chip: Q q =P i +kΔT i Among them, Q i is the power requirement of each semiconductor chip, P i is the heat input power, ΔT i is the temperature difference of the semiconductor chip at this level, and k is the thermal conductivity; S13: Calculate the total power demand of the system: Among them, Q t is the total power, N is the total number of semiconductors; S14: Calculate the total number of semiconductor wafer stages required based on the total power requirement and the capacity of each semiconductor wafer stage: S14: Based on the total number of levels, design a certain proportion of redundant levels and calculate the actual number of levels: N r =N·(1+C) Among them, N r is the actual number of levels, and C is the redundancy ratio.

4. A control method, characterized in that: The method is applicable to the heat dissipation device for downhole tools while drilling according to any one of claims 1 to 3, and comprises: S21: monitor the instrument temperature in real time through the temperature sensor and feed the data back to the control module; S22: The control module dynamically adjusts the operating parameters of each level of semiconductor chips according to the temperature monitoring data; S23: Reduce energy consumption and improve heat dissipation efficiency by optimizing control algorithms.

5. The control method according to claim 4, characterized in that: The adjustment method in step S22 is: the control module adjusts the operating current and voltage of each level of semiconductor chips according to the temperature monitoring data to adapt to the requirements under different temperatures, specifically including: The heat dissipation capacity of a semiconductor chip is determined by its operating current and applied voltage, and its cooling power is: Among them, Q is the cooling power of each semiconductor chip, n is the number of thermocouples, α is the Seebeck coefficient, Tc and T h are the cold end and hot end temperatures respectively, R is the resistance of each semiconductor chip, and k is the thermal conductivity of each semiconductor chip; Calculate the temperature difference of each semiconductor chip: △T i =T hi -T ci Among them, △T i is the temperature difference of each semiconductor chip; T hi is the hot end temperature of the semiconductor chip, T ci is the cold end temperature of the semiconductor chip, i is the semiconductor chip level; Calculate the current required cooling power: Q i =f(△T i ,P i ) Among them, Q i is the current required cooling power, P i is the heat flux input power of the i-th semiconductor chip; Calculate the current optimal working current and voltage: V i =I i ·R; Dynamic adjustment: The control module periodically collects new temperature data T ci and T hi , recalculate the temperature difference ΔT i and the required cooling power Q i Based on these data, the operating current and voltage of each level of semiconductor wafer are dynamically adjusted.

6. The control method according to claim 4, characterized in that: The step S23 specifically includes: S23.1: Initialize the working state of each TEC and set the initial current and voltage V i (0) ; S23.2: Calculate the current total energy consumption E (0) ; S23.3: Computing Gradients and update and V i (k) : Optimal power distribution is achieved by adjusting the current and voltage of each semiconductor chip to minimize total energy consumption.

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