Connecting method for parts of rodless pump

Abstract

The invention relates to the technical field of rodless oil extraction, in particular to a connecting method for all parts of a rodless pump. According to the technical scheme, the connecting method for the parts of the rodless pump comprises connecting modes of the parts of the rodless pump; initial positioning and sealing between assemblies are achieved through precisely-machined taper threads, staged hydraulic torque control is combined, it is ensured that a connection interface uniformly and stably reaches the preset tightness, the weight burden and space occupation caused by multi-bolt fastening are fundamentally eliminated, the underground operation time and the labor requirement are greatly reduced, and the construction efficiency is improved. Dependence on complex tools is reduced, and long-term stable operation of the rodless pump under severe working conditions is effectively guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rodless oil production, in particular to a connecting method of components of a rodless pump. BACKGROUND

[0002] The rodless pump is a downhole lifting device applied in the field of oil production, and its core feature is that the long distance sucker rod connecting the ground power and the downhole pump body in the traditional oil pumping system is cancelled, and instead, the driving motor is directly integrated with or closely connected with the downhole pump body, the rotation or linear motion generated by the motor directly drives the plunger or impeller to work, so as to lift the crude oil from the bottom of the well to the ground.

[0003] The connecting method of components of the existing rodless pump generally adopts the flange connection mode, the traditional flange connection relies on multiple bolts for fastening, which not only increases the weight and transverse size of the pump body, but also is inconvenient to install and adjust in the limited space in the downhole, and the bolts are prone to corrosion and creep in the long-term high-pressure and corrosive downhole environment, resulting in failure of the sealing interface and causing leakage risk.

[0004] In view of the above problems, the present application realizes the initial positioning and sealing between components through the taper thread processed with high precision, and combines the phased hydraulic torque control to ensure that the connection interface uniformly and stably reaches the preset tightness, thereby fundamentally eliminating the weight burden and space occupation caused by the multiple bolt fastening, greatly reducing the downhole operation time and manpower demand, reducing the dependence on complex tools, and effectively ensuring the long-term stable operation of the rodless pump in harsh working conditions. SUMMARY

[0005] In order to overcome the problem that the connecting method of components of the existing rodless pump generally adopts the flange connection mode, the traditional flange connection relies on multiple bolts for fastening, which not only increases the weight and transverse size of the pump body, but also is inconvenient to install and adjust in the limited space in the downhole, and the bolts are prone to corrosion and creep in the long-term high-pressure and corrosive downhole environment, resulting in failure of the sealing interface and causing leakage risk.

[0006] The technical scheme of the present application is as follows: a connecting method of components of a rodless pump, comprising the following steps: S11: cleaning, size measurement, defect detection and equipment calibration of the components of the rodless pump, and detecting whether the components meet the assembly conditions; S12: cleaning and checking the threads, spraying sealant, installing the sealing ring, and accurately adjusting the relative positions of the components using a laser centering instrument; S13: manually and low-speed hydraulically driving the threads to be preliminarily screwed, and ensuring the centering and uniform stress through gap measurement and tracer paste inspection; S14: applying incremental torque to the design value in stages, and synchronously monitoring the torque-angle curve and strain; S15: Hydraulic push the locking ring into the installation groove, ensure that the spring buckle is embedded into the positioning groove, and tighten the stop screw to prevent loosening; S16: Install the heat shrink sleeve, wrap the sealing tape, fill the sealing grease, and perform local annealing and corrosion-resistant coating spraying to enhance sealing and durability; S17: Install and cool the tungsten steel bushing, apply axial pre-tightening force to the transmission shaft, and perform stepwise tension and vibration transmission tests; S18: Perform step-by-step pressurization and pressure maintenance tests in the test tank, followed by helium mass spectrometry leak detection and vacuum testing to verify the connection sealing; S19: Laser engrave the logo, install the protective piece, perform three-dimensional scanning and archiving, bind the monitoring module, and complete the final appearance and file inspection.

[0007] As preferred, during the on-site preparation and component pre-inspection, the following steps are included: S21: Transport the main components of the rodless pump to the wellhead operation area, arrange them on the anti-pollution pad according to the assembly sequence, and remove the transportation fixtures; S22: Use an industrial endoscope to inspect the internal flow passages of each component in sections, confirming that there are no metal debris, oil stains, or other foreign matter residues; S23: Measure the outer diameter, inner diameter, and end face flatness of each connection end face using an outer diameter micrometer, record the data and compare it with the design drawings, and mark the components with tolerance deviations separately; S24: Apply fluorescent penetrant to the threaded connection area, and observe under ultraviolet light whether there are fine cracks or material defects, and return unqualified parts for processing; S25: Use compressed air to blow off the thread surfaces and internal oil passages of each part, and detect that there is no dust, oil, or moisture in the thread grooves; S26: Connect the power supply to each installation tool and perform no-load trial operation to calibrate the torque output value; S27: Set up an assembly platform in the operation area, lay a rubber protective layer on the platform surface, and adjust it to a horizontal state.

[0008] As preferred, during the connection component pretreatment and alignment, the following steps are included: S31: Use acetone-soaked non-woven fabric to wipe the outer and inner thread surfaces in sections, remove the oxidation layer and trace amounts of oil stains, and let them stand for five minutes after wiping to evaporate; S32: Use a thread gauge to check the pitch, tooth angle, and taper of the outer thread, and try it on the inner thread to judge the tightness of the fit, and record the initial hand feel torque; S33: Uniformly spray a layer of high-temperature sealing glue with a thickness of about 0.1mm on the outer thread surface, and the sealing glue needs to be preheated to 60℃; S34: Place a fluororubber O-ring in the internal thread bottom groove, the O-ring is previously soaked in silicone grease, to enhance the initial seal and buffer the impact of screwing in; S35: Use a laser centering instrument to emit a cross-shaped light beam, which is projected on the center mark points on the upper end face of the pump body and the lower end face of the motor, respectively. Adjust the position of the assembly to make the light beams coincide; S36: Four temporary positioning pins are evenly distributed circumferentially outside the connecting end face, with an insertion depth of no more than 5 mm. Detect whether the two assemblies are radially offset during initial screwing; S37: Use an infrared temperature measuring instrument to monitor the temperature of the connecting area. The area temperature needs to be kept within the range of 15-30℃. If the temperature is too low, use a hot air gun to preheat the local area to the specified range.

[0009] As a preferred, during the initial screwing and axial guidance, the following steps are included: S41: Slowly lower the motor assembly using the lifting equipment, so that the internal thread port lightly contacts the top end of the external thread. The crane automatically hovers at the moment of contact; S42: Manually rotate the motor housing for preliminary engagement. The rotation angle is no more than 90°. Feel whether there is abnormal resistance or jamming, and adjust the centering in time; S43: After the initial screwing of the two buckles, remove the temporary positioning pins and replace them with a three-jaw centering clamp to hold the connecting part from the outside, maintaining radial concentricity; S44: Drive the external thread assembly to rotate uniformly at a low speed of 5-8 revolutions per minute through the hydraulic wrench. At the same time, monitor the change in torque sensor readings; S45: Pause every 180° during screwing. Use a feeler gauge to check the gap between the two connecting end faces. Detect whether the gap around is uniform, with a difference of no more than 0.05 mm; S46: When the screwing length reaches one-third of the designed engagement length, stop screwing and rotate in the opposite direction by 15° to release assembly stress, then continue screwing in the positive direction; S47: Apply tracing paste to the visible segment of the thread. Observe whether the distribution is continuous and uniform to determine whether the thread is under consistent stress, and make fine adjustments.

[0010] As a preferred, during the hydraulic torque precise application and fitting control, the following steps are included: S51: Switch the hydraulic wrench to torque control mode. Set the target torque to 50% of the final torque and load slowly at a speed of 3 revolutions per minute; S52: Collect the torque-angle curve in real time during the loading process. If the curve increases sharply or reaches a plateau, stop immediately and analyze whether it is thread damage or foreign object jamming; S53: After reaching the first stage torque, maintain the pressure for 30 seconds to redistribute the sealant in the thread gap. Then completely release the pressure and record the rotation angle. S54: Reset the target torque to 80% of the final torque, and slowly load again, this time reducing the loading speed to 2 revolutions per minute; S55: Pause when the torque reaches 1800 N·m, use an ultrasonic thickness gauge to measure the thickness change of the outer shell in the connection area, and detect no local excessive deformation; S56: Continue loading to 2000 N·m, and after stabilization, use a high-precision strain gauge to measure the circumferential strain of the connection area. The strain value must be within the elastic range of the material. S57: In the final stage, the load is applied to the designed final torque of 2500 N·m, and the loading speed is controlled within 1 revolution per minute. After reaching this, the voltage is stabilized for one minute.

[0011] Preferably, the following steps are included when installing the locking ring and mechanically preventing loosening: S61: After the thread is fully engaged, clean the sealant and dirt from the exposed section at the end of the thread to expose the locking ring mounting groove, and apply a small amount of molybdenum disulfide grease to the groove; S62: Close the two halves of the split metal locking ring so that its inner conical surface fits against the outer conical surface of the threaded end, and push it by hand until it is flush with the end face; S63: A ring-shaped hydraulic cylinder liner is used on the outside of the locking ring. The hydraulic cylinder piston pushes the locking ring to move inward along the conical surface. The displacement is controlled by a displacement sensor to be 3mm. S64: When the locking ring moves into position, its internal spring clip automatically springs into the annular positioning groove of the drive rod under preload; S65: Use an endoscope to inspect through the side viewing hole to check whether the spring clip is fully embedded in the groove bottom, and confirm that there are no visible gaps between the locking ring and the two end faces; S66: Install two symmetrical locking screws on the outside of the locking ring. Apply thread-locking compound when screwing the screws in, and tighten with a torque wrench to the specified value of 45 N·m; S67: Finally, coat the outer surface of the locking ring with a peelable anti-corrosion wax and install an anti-rotation label. The label is connected to both the locking ring and the pump body at one point.

[0012] Preferably, the secondary sealing and reinforcement of the connection area includes the following steps: S71: A double-layer heat-shrink sleeve is fitted on the outside of the threaded connection area, with the inner layer being a conductive epoxy adhesive layer and the outer layer being a radiation-crosslinked polyolefin material; S72: Use a hot air gun to evenly heat the heat shrink sleeve from the middle to both ends, controlling the temperature at 150℃±10℃, so that it shrinks and adheres tightly to the metal surface and activates the inner layer adhesive; S73: Wrap fluororubber sealing tape around both ends of the heat shrink sleeve, in the opposite direction to the thread direction, with an overlap width of not less than 10mm, and keep the wrapping tension uniform; S74: A 0.5mm deep and 6mm wide annular groove is machined on the outer surface of the middle part of the connection area. The groove is filled with nickel-based high-temperature sealant and compacted and smoothed. S75: The connection area is locally annealed using an induction heating coil, with the heating temperature controlled at 300℃ for 3 minutes to eliminate residual stress from the assembly; S76: Immediately after annealing, wrap the joint with an insulating blanket to allow it to cool slowly to room temperature at a rate not exceeding 20°C / minute, to prevent the generation of new thermal stress; S77: After cooling, spray a ceramic-based anti-corrosion coating with a thickness of about 80μm onto the outer surface of the heat shrink sleeve. The spraying is done in two stages with an interval of 20 minutes. After spraying, cure at room temperature for 24 hours.

[0013] Preferably, the assembly and testing of the axial force transmission structure includes the following steps: S81: A tungsten carbide bushing is installed in the connection section between the motor and the protector. The outer surface of the bushing is machined with a rectangular spline that mates with the inner wall of the connection body. S82: When installing the bushing, immerse it in liquid nitrogen for 10 minutes to cool it, then easily push it into the installation position using the cooling contraction effect. After returning to room temperature, an interference fit is achieved. S83: Apply extreme pressure grease to the inner bore of the bushing, insert the drive shaft, and design a 2° micro-tapered mating surface between the drive shaft and the bushing; S84: Apply an axial preload of 50kN to the drive shaft using a hydraulic puller, hold for 5 minutes, and then release the force; S85: Four piezoelectric accelerometers are installed around the periphery of the section where the drive shaft meets the bushing, with the sensors arranged in a 90° circumferential pattern; S86: Drives the transmission shaft to rotate at low speed via an external driver, while simultaneously acquiring signals from various sensors to analyze the uniformity of the vibration spectrum; S87: Apply a stepped, increasing axial tensile force to the assembly on an axial force test bench, increasing by 25kN at each step until 120% of the design maximum working tensile force is reached, and record the displacement curves at each step.

[0014] Preferably, the overall airtightness and pressure resistance test includes the following steps: S91: The completed rodless pump assembly is hoisted into the horizontal pressure testing tank, which is filled with clean water, and the water temperature is controlled at 50℃, similar to the working conditions underground; S92: Apply internal pressure to the pump cavity through the pressurization port at the top of the pressure test tank. The pressure starts from 0 and slowly rises to the rated working pressure at a rate of 0.5 MPa / min. S93: Maintain pressure at rated pressure for 30 minutes, during which a high-precision pressure sensor is used to monitor pressure fluctuations, and the pressure drop is allowed to not exceed 0.5% of the initial value; S94: After the pressure holding period, continue to increase the pressure to 1.5 times the design pressure, maintain this pressure for 15 minutes, and observe the connection area for any leakage, sweating, or abnormal deformation; S95: After depressurization, open the test tank, dry the connection parts with dry compressed air, then spray white developer, let it stand for 10 minutes and check for any signs of moisture seepage; S96: Use a helium mass spectrometer leak detector to perform a local scan of the connection area, with the probe moving at a speed not exceeding 10 mm / s; S97: Finally, perform a negative pressure test by evacuating the pump's internal cavity to -0.08 MPa and maintaining it for 10 minutes.

[0015] Preferably, the following steps are included when marking completion and preparing for well entry: S101: Use a laser engraving machine to engrave a unique assembly number, date, and operator number 100mm above the connection area, with a depth of 0.1mm, and fill with heat-resistant pigment; S102: Install plastic protective caps on all exposed threaded ends, fill the caps with anti-rust grease, and fix the caps with stainless steel clamps with a clamp torque of 10 N·m; S103: Use a 3D scanner to perform a final shape scan of the connecting area, generate a 3D model, compare it with the design model, and archive it for future reference; S104: A wireless temperature and vibration monitoring module is attached to the connection point. The module's battery life is no less than 5 years, and its data storage capacity supports continuous recording for 30 days. S105: The outer surface of the entire component is coated with a conspicuous downhole guide marking line, which is continuous and uninterrupted; S106: Prepare an assembly process report for this connection, including all key parameter records, test data, problem handling records, and operator signatures; S107: Hoist the components to the wellhead preparation area, perform a final visual inspection while suspended, and remove surface dust.

[0016] The beneficial effects of this invention are: Existing rodless pumps generally use flange connections for connecting various components. Traditional flange connections rely on multiple bolts for fastening, which not only increases the overall weight and lateral dimensions of the pump body, but also makes installation and adjustment in the limited space downhole difficult. Furthermore, bolts are prone to corrosion and creep in the long-term high-pressure and corrosive downhole environment, leading to sealing interface failure and leakage risks. This invention achieves initial positioning and sealing between components through precision-machined tapered threads, combined with staged hydraulic torque control, ensuring that the connection interface uniformly and stably reaches the preset tightness. This fundamentally eliminates the weight burden and space occupation caused by multiple bolt fastenings, significantly reduces downhole operation time and manpower requirements, reduces reliance on complex tools, and effectively ensures the long-term stable operation of the rodless pump under harsh working conditions. Attached Figure Description

[0017] Figure 1 The diagram shown is a framework flow diagram of a method for connecting the components of a rodless pump according to the present invention. Figure 2 The diagram illustrates the on-site preparation and component pre-inspection process for a method of connecting various components of a rodless pump according to the present invention. Figure 3 The diagram shows a pre-processing and alignment flow of the connecting components in a rodless pump according to the present invention. Figure 4 The diagram shown is a schematic diagram of the initial engagement and axial guidance process of the clamping assembly in a method for connecting the components of a rodless pump according to the present invention. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Please see Figures 1-4 The present invention provides an embodiment of a method for connecting the components of a rodless pump, comprising the following steps: S11: Clean, measure dimensions, inspect for defects, and calibrate all components of the rodless pump to ensure they meet assembly requirements; S12: Clean and inspect the threads, apply sealant, install the sealing ring, and use a laser alignment instrument to precisely adjust the relative positions of the components; S13: Manual and low-speed hydraulic drive for initial thread engagement, ensuring alignment and uniform force distribution through clearance measurement and tracer paste inspection; S14: Apply incremental torque to the design value in stages, while simultaneously monitoring the torque-rotation angle curve and strain; S15: Hydraulically push the locking ring into the mounting groove, ensuring its spring clip is embedded in the positioning groove, and tighten the stop screw to prevent loosening; S16: Install heat shrink sleeves, wrap sealing tape, fill with sealant, and perform local annealing and anti-corrosion coating spraying to enhance sealing and durability; S17: Install and cool the assembled tungsten carbide bushing, apply axial preload to the drive shaft, and perform stepped tension and vibration transmission tests; S18: Perform graded pressurization and pressure holding tests in the pressure testing tank, followed by helium mass spectrometry leak detection and vacuum testing to verify the connection sealing performance; S19: Laser engraving of markings, installation of protective components, 3D scanning and archiving, binding of monitoring modules, and completion of final appearance and document inspection.

[0020] Preferably, the on-site preparation and component pre-inspection include the following steps: S21: Transport all major components of the rodless pump to the wellhead operating area, arrange them on the anti-contamination pad according to the assembly sequence, and remove the transport fixtures; S22: Use an industrial endoscope to inspect the internal flow channels of each component section by section to confirm that there are no metal shavings, oil stains or other foreign objects remaining; S23: Use an outside micrometer to measure the outer diameter, inner diameter, and flatness of each connecting end face, record the data, and compare it with the design drawings. Components with tolerances exceeding the tolerance should be marked separately. S24: Apply fluorescent penetrant to the threaded connection area and observe under ultraviolet light for any minor cracks or material defects. Return any non-conforming parts for processing. S25: Use compressed air to blow away the threaded surfaces and internal oil passages of each component, and check that the thread grooves are free of dust, oil, and moisture; S26: Connect all installation tools to the power supply and run them under no-load test to calibrate the torque output value; S27: Set up an assembly platform in the operating area, cover the surface of the platform with a rubber protective layer, and adjust it to a horizontal state.

[0021] Preferably, the pre-processing and alignment of the connecting components includes the following steps: S31: Wipe the surface of the external and internal threads section by section with a non-woven cloth soaked in acetone to remove the oxide layer and trace amounts of oil stains. After wiping, let it stand for five minutes to evaporate. S32: Use a thread gauge to check the pitch, tooth angle, and taper of the external thread, and perform a test fitting with the internal thread to determine the tightness of the fit, and record the initial feel torque; S33: Apply a uniform layer of high-temperature sealant with a thickness of approximately 0.1 mm to the surface of the external thread. The sealant needs to be preheated to 60°C. S34: A fluororubber O-ring is placed in the groove at the bottom of the internal thread. The O-ring is pre-impregnated with silicone grease to enhance the initial seal and buffer the impact of screwing in. S35: A laser alignment instrument emits a cross beam, which is projected onto the center marks on the upper end face of the pump body and the lower end face of the motor, respectively. The position of the components is adjusted to make the beams coincide. S36: Four temporary locating pins are evenly distributed circumferentially on the outer side of the connecting end face, with an insertion depth not exceeding 5mm, to check that no radial displacement occurs when the two components are initially screwed together; S37: Use an infrared thermometer to monitor the temperature of the connection area. The temperature of the area must be maintained within the range of 15℃-30℃. If the temperature is too low, use a hot air gun to preheat the area to the specified range.

[0022] Preferably, the initial engagement and axial guidance include the following steps: S41: Operate the hoisting equipment to slowly lower the discharge motor assembly, so that the internal thread port gently contacts the tip of the external thread. The hoist will automatically remain suspended at the moment of contact. S42: Manually rotate the motor housing for initial engagement, rotating no more than 90°, and check for any abnormal resistance or jamming, adjusting the alignment as needed. S43: After initially screwing in two turns, remove the temporary positioning pin and use a three-jaw centering clamp to hold the connection part from the outside to maintain radial concentricity; S44: The external thread assembly is driven to rotate at a constant speed using a hydraulic wrench in low speed mode, with the speed controlled at 5-8 rpm, while monitoring the changes in the torque sensor reading; S45: During the engagement process, pause every 180° and use a feeler gauge to check the gap between the two connecting end faces. The gap should be uniform around the perimeter, with a difference not exceeding 0.05mm. S46: When the screw-in length reaches one-third of the designed engagement length, stop screwing in, rotate 15° in the opposite direction to release assembly stress, and then continue screwing in in the forward direction; S47: Apply tracer paste to the visible section of the thread and observe whether its distribution is continuous and uniform to determine whether the thread is under consistent stress and make fine adjustments.

[0023] Preferably, when performing precise application and fit control of hydraulic torque, the following steps are included: S51: Switch the hydraulic wrench to torque control mode, set the target torque to 50% of the final torque, and slowly apply load at a speed of 3 revolutions per minute; S52: During loading, the torque-angle curve is collected in real time. If the curve shows a sharp increase or plateau, the process is stopped immediately to analyze whether it is due to thread damage or foreign object obstruction. S53: After reaching the first stage torque, maintain pressure for 30 seconds to allow the sealant to redistribute within the thread gap, then completely release pressure and record the rotation angle; S54: Reset the target torque to 80% of the final torque, and slowly load again, this time reducing the loading speed to 2 revolutions per minute; S55: Pause when the torque reaches 1800 N·m, use an ultrasonic thickness gauge to measure the thickness change of the outer shell in the connection area, and detect no local excessive deformation; S56: Continue loading to 2000 N·m, and after stabilization, use a high-precision strain gauge to measure the circumferential strain of the connection area. The strain value must be within the elastic range of the material. S57: In the final stage, the load is applied to the designed final torque of 2500 N·m, and the loading speed is controlled within 1 revolution per minute. After reaching this, the voltage is stabilized for one minute.

[0024] Preferably, the following steps are included when installing the locking ring and mechanically preventing loosening: S61: After the thread is fully engaged, clean the sealant and dirt from the exposed section at the end of the thread to expose the locking ring mounting groove, and apply a small amount of molybdenum disulfide grease to the groove; S62: Close the two halves of the split metal locking ring so that its inner conical surface fits against the outer conical surface of the threaded end, and push it by hand until it is flush with the end face; S63: A ring-shaped hydraulic cylinder liner is used on the outside of the locking ring. The hydraulic cylinder piston pushes the locking ring to move inward along the conical surface. The displacement is controlled by a displacement sensor to be 3mm. S64: When the locking ring moves into position, its internal spring clip automatically springs into the annular positioning groove of the drive rod under preload; S65: Use an endoscope to inspect through the side viewing hole to check whether the spring clip is fully embedded in the groove bottom, and confirm that there are no visible gaps between the locking ring and the two end faces; S66: Install two symmetrical locking screws on the outside of the locking ring. Apply thread-locking compound when screwing the screws in, and tighten with a torque wrench to the specified value of 45 N·m; S67: Finally, coat the outer surface of the locking ring with a peelable anti-corrosion wax and install an anti-rotation label. The label is connected to both the locking ring and the pump body at one point.

[0025] Preferably, the secondary sealing and reinforcement of the connection area includes the following steps: S71: A double-layer heat-shrink sleeve is fitted on the outside of the threaded connection area, with the inner layer being a conductive epoxy adhesive layer and the outer layer being a radiation-crosslinked polyolefin material; S72: Use a hot air gun to evenly heat the heat shrink sleeve from the middle to both ends, controlling the temperature at 150℃±10℃, so that it shrinks and adheres tightly to the metal surface and activates the inner layer adhesive; S73: Wrap fluororubber sealing tape around both ends of the heat shrink sleeve, in the opposite direction to the thread direction, with an overlap width of not less than 10mm, and keep the wrapping tension uniform; S74: A 0.5mm deep and 6mm wide annular groove is machined on the outer surface of the middle part of the connection area. The groove is filled with nickel-based high-temperature sealant and compacted and smoothed. S75: The connection area is locally annealed using an induction heating coil, with the heating temperature controlled at 300℃ for 3 minutes to eliminate residual stress from the assembly; S76: Immediately after annealing, wrap the joint with an insulating blanket to allow it to cool slowly to room temperature at a rate not exceeding 20°C / minute, to prevent the generation of new thermal stress; S77: After cooling, spray a ceramic-based anti-corrosion coating with a thickness of about 80μm onto the outer surface of the heat shrink sleeve. The spraying is done in two stages with an interval of 20 minutes. After spraying, cure at room temperature for 24 hours.

[0026] Preferably, the assembly and testing of the axial force transmission structure includes the following steps: S81: A tungsten carbide bushing is installed in the connection section between the motor and the protector. The outer surface of the bushing is machined with a rectangular spline that mates with the inner wall of the connection body. S82: When installing the bushing, immerse it in liquid nitrogen for 10 minutes to cool it, then easily push it into the installation position using the cooling contraction effect. After returning to room temperature, an interference fit is achieved. S83: Apply extreme pressure grease to the inner bore of the bushing, insert the drive shaft, and design a 2° micro-tapered mating surface between the drive shaft and the bushing; S84: Apply an axial preload of 50kN to the drive shaft using a hydraulic puller, hold for 5 minutes, and then release the force; S85: Four piezoelectric accelerometers are installed around the periphery of the section where the drive shaft meets the bushing, with the sensors arranged in a 90° circumferential pattern; S86: Drives the transmission shaft to rotate at low speed via an external driver, while simultaneously acquiring signals from various sensors to analyze the uniformity of the vibration spectrum; S87: Apply a stepped, increasing axial tensile force to the assembly on an axial force test bench, increasing by 25kN at each step until 120% of the design maximum working tensile force is reached, and record the displacement curves at each step.

[0027] Preferably, the overall airtightness and pressure resistance test includes the following steps: S91: The completed rodless pump assembly is hoisted into the horizontal pressure testing tank, which is filled with clean water, and the water temperature is controlled at 50℃, similar to the working conditions underground; S92: Apply internal pressure to the pump cavity through the pressurization port at the top of the pressure test tank. The pressure starts from 0 and slowly rises to the rated working pressure at a rate of 0.5 MPa / min. S93: Maintain pressure at rated pressure for 30 minutes, during which a high-precision pressure sensor is used to monitor pressure fluctuations, and the pressure drop is allowed to not exceed 0.5% of the initial value; S94: After the pressure holding period, continue to increase the pressure to 1.5 times the design pressure, maintain this pressure for 15 minutes, and observe the connection area for any leakage, sweating, or abnormal deformation; S95: After depressurization, open the test tank, dry the connection parts with dry compressed air, then spray white developer, let it stand for 10 minutes and check for any signs of moisture seepage; S96: Use a helium mass spectrometer leak detector to perform a local scan of the connection area, with the probe moving at a speed not exceeding 10 mm / s; S97: Finally, perform a negative pressure test by evacuating the pump's internal cavity to -0.08 MPa and maintaining it for 10 minutes.

[0028] Preferably, the following steps are included when marking completion and preparing for well entry: S101: Use a laser engraving machine to engrave a unique assembly number, date, and operator number 100mm above the connection area, with a depth of 0.1mm, and fill with heat-resistant pigment; S102: Install plastic protective caps on all exposed threaded ends, fill the caps with anti-rust grease, and fix the caps with stainless steel clamps with a clamp torque of 10 N·m; S103: Use a 3D scanner to perform a final shape scan of the connecting area, generate a 3D model, compare it with the design model, and archive it for future reference; S104: A wireless temperature and vibration monitoring module is attached to the connection point. The module's battery life is no less than 5 years, and its data storage capacity supports continuous recording for 30 days. S105: The outer surface of the entire component is coated with a conspicuous downhole guide marking line, which is continuous and uninterrupted; S106: Prepare an assembly process report for this connection, including all key parameter records, test data, problem handling records, and operator signatures; S107: Hoist the components to the wellhead preparation area, perform a final visual inspection while suspended, and remove surface dust.

[0029] Example 1 At a well site in an oilfield, technicians transported the rodless pump body, permanent magnet synchronous motor, and protector assembly to the wellhead work area, neatly arranging them on a prepared anti-contamination mat. First, all transport fixtures were removed. Then, an industrial endoscope was used to inspect the pump body flow channel, motor cavity, and protector channel section by section to confirm the absence of any metal debris, sludge, or foreign matter. Next, an outside micrometer was used to precisely measure the outer diameter, inner diameter, and flatness of each connecting end face. The measured data were compared one by one with the design drawings, and one end face flatness deviation was found to be 0. The 0.02mm pump body was marked and isolated. Fluorescent penetrant was applied to the threaded connection area and observed under ultraviolet light for 5 minutes. No cracks or defects were found. Then, compressed air was used to blow away all thread surfaces and internal oil passages at a pressure of 0.6MPa until no dust was visible. Special equipment such as hydraulic wrenches and torque sensors were powered on and tested under no-load conditions. The output torque of the hydraulic wrench was calibrated to within ±1% of the error. Finally, with the assistance of a level, the assembly platform was adjusted to be absolutely level and a rubber protective layer was laid, completing all preparations before the operation.

[0030] The operator carefully wiped each tooth groove of the external thread on the upper end of the pump body and the internal thread on the lower end of the motor with acetone-soaked non-woven cloth to remove the surface oxide film and trace amounts of grease. After standing for 5 minutes to ensure complete solvent evaporation, the pitch and tooth profile angle of the external thread were checked with an API standard thread gauge and a trial fit was performed with the internal thread. The initial torque felt by hand was about 15 N·m, which was recorded. The heat-resistant sealant was preheated to 60°C and then evenly sprayed onto the surface of the external thread to form a layer of about 0.1 mm thick. At the same time, the fluororubber O-ring was soaked in silicone grease and accurately embedded into the sealing groove at the bottom of the internal thread. Using a laser alignment instrument, the cross beam was aligned with the center mark on the upper end face of the pump body and the lower end face of the motor. The position of the crane was finely adjusted to make the two beams completely overlap. Four temporary positioning pins were inserted at equal angles on the outer side of the connection end face to ensure alignment. After ensuring alignment, the temperature of the connection area was measured to be 18°C ​​using an infrared thermometer, which meets the operating requirements of 15-30°C.

[0031] Start the hoisting equipment and slowly lower the motor assembly until the internal thread of the motor makes light contact with the top of the external thread of the pump body. The crane then remains suspended. The operator manually rotates the motor housing clockwise by about 60° to ensure a smooth and unobstructed screwing process. After screwing in two turns, remove the four temporary locating pins and use a three-jaw centering clamp to externally grip the connection to maintain radial concentricity. Then, start the hydraulic wrench on low speed to drive the pump body to rotate at a constant speed for engagement. Observe the torque sensor reading rise steadily. Pause after every 180° of engagement and use a feeler gauge to measure the clearance around the end face. The maximum deviation is 0.03mm, which meets the requirement of ≤0.05mm. When the engagement length reaches 1 / 3 of the total engagement length, reverse the rotation by 15° counterclockwise to release stress, and then continue screwing in forward. Finally, apply blue tracer paste evenly to the exposed thread section and observe its continuous distribution after compression, indicating that the thread engagement is uniformly stressed.

[0032] Switch the hydraulic wrench to torque control mode. Set the target torque to 1250 N·m for the first stage and apply it at 3 rpm. The torque-rotation angle curve plotted in real time rises smoothly. After reaching 1250 N·m, hold the pressure for 30 seconds to allow the sealant to fully fill the thread gap. After depressurization, the rotation angle is measured to be 2°. Set the target torque to 2000 N·m for the second stage and reduce the loading speed to 2 rpm. Pause when the torque reaches 1800 N·m and use an ultrasonic thickness gauge to check the wall thickness of the connection area. No local thinning was found. Continue loading to 2000 N·m. After stabilization, the attached high-precision strain gauge shows a circumferential strain of 0.12%, which is within the material's elastic range. The final stage applies the final designed torque of 2500 N·m at 1 rpm and holds the pressure for 60 seconds to allow the material to adhere further under continuous pressure, completing the entire torque application process.

[0033] After the threads are screwed in place, clean the residual sealant from the exposed end section to expose the specially designed locking ring mounting conical groove. Apply a small amount of molybdenum disulfide grease evenly to the groove. Snap the two halves of the split high-strength alloy locking ring together, ensuring the inner conical surface aligns with the threaded end conical surface. Manually pre-push it until it is flush with the end face. Then, mount the annular hydraulic cylinder around the locking ring and start the hydraulic pump. The piston pushes the locking ring inward along the conical surface, precisely moving it 3mm. At the moment of final engagement, the spring clip inside the locking ring snaps into the annular positioning groove of the drive rod under the pre-compression force. Insert an endoscope through the side observation hole to confirm that the clip is fully embedded in the bottom of the groove and that there are no visible gaps on either side of the locking ring's end face. Then, symmetrically screw in two locking screws coated with thread-locking agent on the outside of the locking ring and tighten them to 45 N·m with a torque wrench. Finally, coat the outer surface of the locking ring with a peelable anti-corrosion wax and install an anti-rotation marker, which connects to both the locking ring and the pump housing.

[0034] A double-layer heat shrink sleeve is fitted around the threaded connection. Using a heat gun, the sleeve is heated evenly from the middle to both ends at 150°C, causing it to shrink uniformly and adhere tightly to the metal surface. This activates the inner adhesive layer, forming a bond. Fluororubber sealing tape is wrapped around both ends of the heat shrink sleeve against the direction of the threads, maintaining consistent tension and overlapping with a width of 12mm. Subsequently, a 0.5mm deep and 6mm wide annular groove is machined into the outer surface of the connection area. Nickel-based high-temperature sealant is pressed into the groove and smoothed. The connection area is then locally annealed using an induction heating coil at 300°C for 3 minutes. Immediately afterward, it is wrapped with an insulating blanket and allowed to cool slowly to room temperature at a rate of less than 20°C / minute. After cooling, a ceramic-based anti-corrosion coating is sprayed twice onto the outer surface of the heat shrink sleeve, with a 20-minute interval between applications, until the total dry film thickness reaches 80μm. The coating is then cured at room temperature for 24 hours.

[0035] A tungsten carbide bushing pre-machined with rectangular splines was immersed in liquid nitrogen for 10 minutes to cool it. Utilizing the shrinkage effect, it was smoothly pushed into the predetermined position of the connection between the motor and the protector. After returning to room temperature, an interference fit was achieved. Extreme pressure grease was evenly applied to the inner bore of the bushing. Then, a drive shaft with a 2° micro-tapered mating surface was inserted. A hydraulic puller was used to apply an axial preload of 50 kN to the drive shaft. After holding the load for 5 minutes, the load was removed. The springback at the shaft end was measured to be 0.015 mm, meeting the requirements. An isometric groove was then applied to the outer periphery of the drive shaft and bushing connection section. Four piezoelectric accelerometers were installed and connected to an external test driver, causing the drive shaft to rotate at a low speed of 20 rpm. The vibration signals collected synchronously were analyzed by spectrum, showing that the amplitude was uniform in all directions and there were no abnormal peaks. Finally, the component was placed on an axial force test bench, and a stepped axial tensile force was applied, starting from 25 kN and increasing by 25 kN in each step, until it reached 120% of the maximum working tensile force of 150 kN. The displacement curve recorded throughout the process showed a linear change without abrupt changes, verifying the reliability of the axial force transmission structure.

[0036] The assembled rodless pump assembly was hoisted into a horizontal pressure testing tank, which was filled with 50°C water to simulate the downhole temperature environment. Pressure was applied to the pump's internal cavity through the top interface of the tank, slowly increasing the pressure from 0 to the rated operating pressure of 25MPa at a rate of 0.5MPa / minute. This pressure was maintained for 30 minutes. During this period, high-precision pressure sensors monitored minimal pressure fluctuations, with a pressure drop of only 0.08MPa, below the allowable value. After the pressure holding period, the pressure was further increased to 37.5MPa and maintained. After 15 minutes, the connection area was observed to show no leakage, sweating, or visible deformation. After depressurization, the component was lifted out, and the connection area was dried with dry compressed air. White developer was sprayed on, and after standing for 10 minutes, no traces of moisture were found. Subsequently, a helium mass spectrometer was used to scan the critical connection area at a speed of 8 mm / s. Finally, a negative pressure test was performed, and the pump cavity was evacuated to -0.08 MPa and maintained for 10 minutes. The vacuum drop was only 0.003 MPa, which met the sealing requirements.

[0037] At a prominent location 100mm above the connection area, a unique assembly number, date, and operator's number are laser-engraved to a depth of 0.1mm and filled with red heat-resistant pigment. Plastic protective caps are installed on all exposed threaded ends, filled with anti-rust grease, and then secured with stainless steel clamps. The clamps are tightened to a torque of 10 N·m. A 3D scanner is used to perform a final shape scan of the connection area. The generated 3D point cloud model is compared with the original design model, and the maximum deviation is 0.2mm, which meets the tolerance requirements. The data is archived. A wireless temperature-vibration monitoring module is securely tied to the connection point. The module's battery has a design life of 5 years and can continuously store 30 days of data. A bright yellow well guide marking line is sprayed on the entire outer surface of the component, ensuring that the line is continuous and uninterrupted. A complete assembly process report is compiled, recording all key parameters, test data, and operator signatures from S11 to S107. Finally, the component is hoisted to the wellhead preparation area and a final visual inspection is performed while suspended. Surface dust is removed, and all accompanying documents are verified to be complete and correct before the component is lowered into the well.

[0038] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for connecting the components of a rodless pump; characterized in that: It includes the following steps: S11: Clean, measure dimensions, inspect for defects, and calibrate all components of the rodless pump to ensure they meet assembly requirements; S12: Clean and inspect the threads, apply sealant, install the sealing ring, and use a laser alignment instrument to precisely adjust the relative positions of the components; S13: Manual and low-speed hydraulic drive for initial thread engagement, ensuring alignment and uniform force distribution through clearance measurement and tracer paste inspection; S14: Apply incremental torque to the design value in stages, while simultaneously monitoring the torque-rotation angle curve and strain; S15: Hydraulically push the locking ring into the mounting groove, ensuring its spring clip is embedded in the positioning groove, and tighten the stop screw to prevent loosening; S16: Install heat shrink sleeves, wrap sealing tape, fill with sealant, and perform local annealing and anti-corrosion coating spraying to enhance sealing and durability; S17: Install and cool the assembled tungsten carbide bushing, apply axial preload to the drive shaft, and perform stepped tension and vibration transmission tests; S18: Perform graded pressurization and pressure holding tests in the pressure testing tank, followed by helium mass spectrometry leak detection and vacuum testing to verify the connection sealing performance; S19: Laser engraving of markings, installation of protective components, 3D scanning and archiving, binding of monitoring modules, and completion of final appearance and document inspection.

2. The method for connecting the components of a rodless pump according to claim 1, characterized in that: The on-site preparation and component pre-inspection include the following steps: S21: Transport all major components of the rodless pump to the wellhead operating area, arrange them on the anti-contamination pad according to the assembly sequence, and remove the transport fixtures; S22: Use an industrial endoscope to inspect the internal flow channels of each component section by section to confirm that there are no metal shavings, oil stains or other foreign objects remaining; S23: Use an outside micrometer to measure the outer diameter, inner diameter, and flatness of each connecting end face, record the data, and compare it with the design drawings. Components with tolerances exceeding the tolerance should be marked separately. S24: Apply fluorescent penetrant to the threaded connection area and observe under ultraviolet light for any minor cracks or material defects. Return any non-conforming parts for processing. S25: Use compressed air to blow away the threaded surfaces and internal oil passages of each component, and check that the thread grooves are free of dust, oil, and moisture; S26: Connect all installation tools to the power supply and run them under no-load test to calibrate the torque output value; S27: Set up an assembly platform in the operating area, cover the surface of the platform with a rubber protective layer, and adjust it to a horizontal state.

3. The method for connecting the components of a rodless pump according to claim 1, characterized in that: The pre-processing and alignment of connecting components includes the following steps: S31: Wipe the surface of the external and internal threads section by section with a non-woven cloth soaked in acetone to remove the oxide layer and trace amounts of oil stains. After wiping, let it stand for five minutes to evaporate. S32: Use a thread gauge to check the pitch, tooth angle, and taper of the external thread, and perform a test fitting with the internal thread to determine the tightness of the fit, and record the initial feel torque; S33: Apply a uniform layer of high-temperature sealant with a thickness of approximately 0.1 mm to the surface of the external thread. The sealant needs to be preheated to 60°C. S34: A fluororubber O-ring is placed in the groove at the bottom of the internal thread. The O-ring is pre-impregnated with silicone grease to enhance the initial seal and buffer the impact of screwing in. S35: A laser alignment instrument emits a cross beam, which is projected onto the center marks on the upper end face of the pump body and the lower end face of the motor, respectively. The position of the components is adjusted to make the beams coincide. S36: Four temporary locating pins are evenly distributed circumferentially on the outer side of the connecting end face, with an insertion depth not exceeding 5mm, to check that no radial displacement occurs when the two components are initially screwed together; S37: Use an infrared thermometer to monitor the temperature of the connection area. The temperature of the area must be maintained within the range of 15℃-30℃. If the temperature is too low, use a hot air gun to preheat the area to the specified range.

4. The method for connecting the components of a rodless pump according to claim 1, characterized in that: The initial engagement and axial guidance process includes the following steps: S41: Operate the hoisting equipment to slowly lower the discharge motor assembly, so that the internal thread port gently contacts the tip of the external thread. The hoist will automatically remain suspended at the moment of contact. S42: Manually rotate the motor housing for initial engagement, rotating no more than 90°, and check for any abnormal resistance or jamming, adjusting the alignment as needed. S43: After initially screwing in two turns, remove the temporary positioning pin and use a three-jaw centering clamp to hold the connection part from the outside to maintain radial concentricity; S44: The external thread assembly is driven to rotate at a constant speed using a hydraulic wrench in low speed mode, with the speed controlled at 5-8 rpm, while monitoring the changes in the torque sensor reading; S45: During the engagement process, pause every 180° and use a feeler gauge to check the gap between the two connecting end faces. The gap should be uniform around the perimeter, with a difference not exceeding 0.05mm. S46: When the screw-in length reaches one-third of the designed engagement length, stop screwing in, rotate 15° in the opposite direction to release assembly stress, and then continue screwing in in the forward direction; S47: Apply tracer paste to the visible section of the thread and observe whether its distribution is continuous and uniform to determine whether the thread is under consistent stress and make fine adjustments.

5. The method for connecting the components of a rodless pump according to claim 1, characterized in that: When performing precise application and fit control of hydraulic torque, the following steps are included: S51: Switch the hydraulic wrench to torque control mode, set the target torque to 50% of the final torque, and slowly apply load at a speed of 3 revolutions per minute; S52: During loading, the torque-angle curve is collected in real time. If the curve shows a sharp increase or plateau, the process is stopped immediately to analyze whether it is due to thread damage or foreign object obstruction. S53: After reaching the first stage torque, maintain pressure for 30 seconds to allow the sealant to redistribute within the thread gap, then completely release pressure and record the rotation angle; S54: Reset the target torque to 80% of the final torque, and slowly load again, this time reducing the loading speed to 2 revolutions per minute; S55: Pause when the torque reaches 1800 N·m, use an ultrasonic thickness gauge to measure the thickness change of the outer shell in the connection area, and detect no local excessive deformation; S56: Continue loading to 2000 N·m, and after stabilization, use a high-precision strain gauge to measure the circumferential strain of the connection area. The strain value must be within the elastic range of the material. S57: In the final stage, the load is applied to the designed final torque of 2500 N·m, and the loading speed is controlled within 1 revolution per minute. After reaching this, the voltage is stabilized for one minute.

6. The method for connecting the components of a rodless pump according to claim 1, characterized in that: The following steps are included when installing locking rings and mechanically preventing loosening: S61: After the thread is fully engaged, clean the sealant and dirt from the exposed section at the end of the thread to expose the locking ring mounting groove, and apply a small amount of molybdenum disulfide grease to the groove; S62: Close the two halves of the split metal locking ring so that its inner conical surface fits against the outer conical surface of the threaded end, and push it by hand until it is flush with the end face; S63: A ring-shaped hydraulic cylinder liner is used on the outside of the locking ring. The hydraulic cylinder piston pushes the locking ring to move inward along the conical surface. The displacement is controlled by a displacement sensor to be 3mm. S64: When the locking ring moves into position, its internal spring clip automatically springs into the annular positioning groove of the drive rod under preload; S65: Use an endoscope to inspect through the side viewing hole to check whether the spring clip is fully embedded in the groove bottom, and confirm that there are no visible gaps between the locking ring and the two end faces; S66: Install two symmetrical locking screws on the outside of the locking ring. Apply thread-locking compound when screwing the screws in, and tighten with a torque wrench to the specified value of 45 N·m; S67: Finally, coat the outer surface of the locking ring with a peelable anti-corrosion wax and install an anti-rotation label. The label is connected to both the locking ring and the pump body at one point.

7. The method for connecting the components of a rodless pump according to claim 1, characterized in that: The secondary sealing and reinforcement of the connection area includes the following steps: S71: A double-layer heat-shrink sleeve is fitted on the outside of the threaded connection area, with the inner layer being a conductive epoxy adhesive layer and the outer layer being a radiation-crosslinked polyolefin material; S72: Use a hot air gun to evenly heat the heat shrink sleeve from the middle to both ends, controlling the temperature at 150℃±10℃, so that it shrinks and adheres tightly to the metal surface and activates the inner layer adhesive; S73: Wrap fluororubber sealing tape around both ends of the heat shrink sleeve, in the opposite direction to the thread direction, with an overlap width of not less than 10mm, and keep the wrapping tension uniform; S74: A 0.5mm deep and 6mm wide annular groove is machined on the outer surface of the middle part of the connection area. The groove is filled with nickel-based high-temperature sealant and compacted and smoothed. S75: The connection area is locally annealed using an induction heating coil, with the heating temperature controlled at 300℃ for 3 minutes to eliminate residual stress from the assembly; S76: Immediately after annealing, wrap the joint with an insulating blanket to allow it to cool slowly to room temperature at a rate not exceeding 20°C / minute, to prevent the generation of new thermal stress; S77: After cooling, spray a ceramic-based anti-corrosion coating with a thickness of about 80μm onto the outer surface of the heat shrink sleeve. The spraying is done in two stages with an interval of 20 minutes. After spraying, cure at room temperature for 24 hours.

8. The method for connecting the components of a rodless pump according to claim 1, characterized in that: The following steps are included in the assembly and testing of the axial force transmission structure: S81: A tungsten carbide bushing is installed in the connection section between the motor and the protector. The outer surface of the bushing is machined with a rectangular spline that mates with the inner wall of the connection body. S82: When installing the bushing, immerse it in liquid nitrogen for 10 minutes to cool it, then easily push it into the installation position using the cooling contraction effect. After returning to room temperature, an interference fit is achieved. S83: Apply extreme pressure grease to the inner bore of the bushing, insert the drive shaft, and design a 2° micro-tapered mating surface between the drive shaft and the bushing; S84: Apply an axial preload of 50kN to the drive shaft using a hydraulic puller, hold for 5 minutes, and then release the force; S85: Four piezoelectric accelerometers are installed around the periphery of the section where the drive shaft meets the bushing, with the sensors arranged in a 90° circumferential pattern; S86: Drives the transmission shaft to rotate at low speed via an external driver, while simultaneously acquiring signals from various sensors to analyze the uniformity of the vibration spectrum; S87: Apply a stepped, increasing axial tensile force to the assembly on an axial force test bench, increasing by 25kN at each step until 120% of the design maximum working tensile force is reached, and record the displacement curves at each step.

9. The method for connecting the components of a rodless pump according to claim 1, characterized in that: The overall airtightness and pressure resistance test includes the following steps: S91: The completed rodless pump assembly is hoisted into the horizontal pressure testing tank, which is filled with clean water, and the water temperature is controlled at 50℃, similar to the working conditions underground; S92: Apply internal pressure to the pump cavity through the pressurization port at the top of the pressure test tank. The pressure starts from 0 and slowly rises to the rated working pressure at a rate of 0.5 MPa / min. S93: Maintain pressure at rated pressure for 30 minutes, during which a high-precision pressure sensor is used to monitor pressure fluctuations, and the pressure drop is allowed to not exceed 0.5% of the initial value; S94: After the pressure holding period, continue to increase the pressure to 1.5 times the design pressure, maintain this pressure for 15 minutes, and observe the connection area for any leakage, sweating, or abnormal deformation; S95: After depressurization, open the test tank, dry the connection parts with dry compressed air, then spray white developer, let it stand for 10 minutes and check for any signs of moisture seepage; S96: Use a helium mass spectrometer leak detector to perform a local scan of the connection area, with the probe moving at a speed not exceeding 10 mm / s; S97: Finally, perform a negative pressure test by evacuating the pump's internal cavity to -0.08 MPa and maintaining it for 10 minutes.

10. The method for connecting the components of a rodless pump according to claim 1, characterized in that: The following steps are included when marking completion and preparing for well entry: S101: Use a laser engraving machine to engrave a unique assembly number, date, and operator number 100mm above the connection area, with a depth of 0.1mm, and fill with heat-resistant pigment; S102: Install plastic protective caps on all exposed threaded ends, fill the caps with anti-rust grease, and fix the caps with stainless steel clamps with a clamp torque of 10 N·m; S103: Use a 3D scanner to perform a final shape scan of the connecting area, generate a 3D model, compare it with the design model, and archive it for future reference; S104: A wireless temperature and vibration monitoring module is attached to the connection point. The module's battery life is no less than 5 years, and its data storage capacity supports continuous recording for 30 days. S105: The outer surface of the entire component is coated with a conspicuous downhole guide marking line, which is continuous and uninterrupted; S106: Prepare an assembly process report for this connection, including all key parameter records, test data, problem handling records, and operator signatures; S107: Hoist the components to the wellhead preparation area, perform a final visual inspection while suspended, and remove surface dust.

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