Rapid splicing and cold welding method for SAGD lifting operation temperature and pressure monitoring cable

Abstract

The invention relates to the technical field of temperature and pressure monitoring cable splicing, and provides an SAGD lifting operation temperature and pressure monitoring cable rapid splicing cold welding method which comprises the following steps: S1, preparation work; s2, point solidification is carried out; s3, welding is conducted; s4, post-welding treatment is carried out; s5, a welding seam is inspected; according to the method, a stable and uniform welding foundation can be provided for subsequent argon tungsten-arc welding filling and capping through cold welding bottoming, and the overall welding quality can be improved; argon tungsten-arc welding which has the advantages of being concentrated in heat, narrow in weldment heat affected zone, small in welding deformation and high in welding quality is selected for seam filling so as to ensure the sealing performance, and then argon tungsten-arc welding is used for covering so as to ensure the attractiveness and the protection effect of welding seams; the method is suitable for high-temperature underground operation of SAGD, fireflooding, electric heating wells and the like due to simple and convenient operation and good sealing performance and corrosion resistance, and the use requirements in different environments are met.

Description

Technical Field

[0001] The invention relates to the technical field of temperature and pressure monitoring cable splicing, in particular to a cold welding method for quickly splicing temperature and pressure monitoring cables for SAGD lifting and lowering operations. Background Art

[0002] In the development of modern oil and gas fields, SAGD technology reduces the viscosity of crude oil by injecting high-temperature steam into the oil layer. In this process, the downhole temperature of the SAGD well is extremely high, usually maintained above 200°C, and can reach up to 300°C. This extreme high temperature environment poses severe challenges to the temperature and pressure monitoring cable, especially the welding technology of its outer armored 316L stainless steel thin-walled tube. The difficulties of existing welding technology mainly include burn-through and deformation, thermal stress and oxidation problems, which seriously affect the mechanical properties and corrosion resistance of the weld. As an efficient welding method, cold welding machine can effectively solve the above problems. Summary of the invention

[0003] The present invention provides a cold welding method for quickly connecting the temperature and pressure monitoring cable of the SAGD lifting operation. The cold welding primer can provide a stable and uniform welding foundation for the subsequent tungsten inert gas welding filling and covering, which is helpful to improve the overall welding quality. Then, tungsten inert gas welding is used for filling to ensure the sealing, and then the covering is performed to ensure the beauty and protection effect of the weld, so as to solve the problems existing in the background technology.

[0004] The technical solution of the present invention is as follows:

[0005] The SAGD lifting and lowering operation temperature and pressure monitoring cable rapid connection cold welding method includes the following steps:

[0006] S1. Preparation: Make the temperature and pressure monitoring cable and the connecting joint into a socket-type joint to ensure that the assembly is flat and without misalignment; and use alcohol to clean the welded parts at both ends of the weld to remove oil and impurities, and then check the status of the welding equipment. The welding equipment uses a cold welding machine and a tungsten inert gas arc welding machine;

[0007] S2, spot fixation: align the two sections of temperature and pressure monitoring cable socket joints to be welded, fix them with positioning welding points to ensure alignment and no gaps; use the same welding parameters, but a shorter welding time to avoid melting too much material in advance;

[0008] S3. Welding: Using cold welding as the base can effectively reduce the heat input during welding, reduce the thermal impact on the 316L stainless steel thin-walled tube, and prevent material deformation or performance degradation due to excessive temperature. Tungsten inert gas arc welding filling and covering can effectively isolate the air, ensure sealing, and prevent oxidation and contamination during welding, thereby obtaining high-quality welds;

[0009] S4. Post-weld treatment: After welding, the weld is polished with a polishing machine to avoid scratches that affect quality;

[0010] S5. Inspect the weld.

[0011] Furthermore, the welding material used was 316L stainless steel welding wire with a diameter of 1.2 mm.

[0012] Furthermore, in S3, the inclination angle between the welding gun and the weld is always maintained at 85° to 90°, which can make the arc shape more concentrated and stable. The welding wire and the weld are maintained at 20° to 25°, which can make it easier for the welding wire to enter the molten pool at a suitable speed and angle, reduce spatter and welding defects. At the same time, this angle also helps to evenly distribute the welding wire in the molten pool, improve the uniformity and density of the weld, and ensure penetration of the weld root.

[0013] Furthermore, in S3, when using tungsten inert gas welding for filling and covering, the argon arc welding gun is kept stable, the welding gun is swung left and right and moves forward at a predetermined speed to ensure that both sides of the weld are fully fused and formed evenly. Sufficient fusion is the basis of weld strength and durability, and can avoid welding defects caused by poor fusion.

[0014] Furthermore, in the welding process of S3 and S4, the copper sleeve is used to continuously dissipate heat and cool down, and the temperature between welding layers is controlled to be lower than the ambient temperature (<20°C). After welding is completed, the copper sleeve is used for physical cooling and continuous cooling to the ambient temperature, which can effectively control the interlayer temperature at a low level.

[0015] Furthermore, during the inspection process in S5, it is necessary to ensure that the weld is narrow and uniform, has clear edges, is free of pores, cracks, undercuts, and is well formed without obvious defects.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention can provide a stable and uniform welding foundation for subsequent tungsten inert gas arc welding filling and covering through cold welding, which is helpful to improve the overall welding quality; and selects tungsten inert gas arc welding with the advantages of heat concentration, narrow heat affected zone of weldment, small welding deformation and high welding quality for filling to ensure sealing, and then uses tungsten inert gas arc welding for covering to ensure the beauty and protection effect of the weld; simple operation, good sealing and corrosion resistance make this method suitable for high-temperature downhole operations such as SAGD, fire drive and electric heating wells, and meet the use requirements in different environments.

[0018] 2. The present invention makes the arc shape more concentrated and stable through the special inclination angle between the welding gun and the weld. The specific angle between the welding wire and the weld makes it easier for the welding wire to enter the molten pool at a suitable speed and angle, reducing the generation of spatter and welding defects. At the same time, this angle also helps the welding wire to be evenly distributed in the molten pool, improving the uniformity and density of the weld. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0020] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0021] like Figure 1 As shown, the present invention provides a method for quickly connecting and cold welding a temperature and pressure monitoring cable for SAGD lifting and lowering operation, comprising the following steps:

[0022] S1. Preparation: Make the temperature and pressure monitoring cable and the connecting joint into a socket-type joint to ensure that the assembly is flat and without misalignment; and use alcohol to clean the welded parts at both ends of the weld to remove oil and impurities, and then check the status of the welding equipment. The welding equipment uses a cold welding machine and a tungsten inert gas arc welding machine;

[0023] S2. Spot fixation: Align the socket joints of the two sections of temperature and pressure monitoring cables to be welded, and fix them with positioning welds to ensure alignment and no gaps. This can greatly shorten the welding time and improve the welding efficiency. Since the positioning welds have already fixed the position of the cables in advance, the welding operation can be completed quickly during the actual welding process. The same welding parameters are used, but the welding time is shorter to avoid melting too much material in advance.

[0024] S3. Welding: Using cold welding as the base can effectively reduce the heat input during welding, reduce the thermal impact on the 316L stainless steel thin-walled tube, and prevent material deformation or performance degradation due to excessive temperature. Tungsten inert gas arc welding filling and covering can effectively isolate the air, ensure sealing, and prevent oxidation and contamination during welding, thereby obtaining high-quality welds;

[0025] S4. Post-weld treatment: After welding, the weld is polished with a polishing machine to avoid scratches that affect quality;

[0026] S5. Inspect the weld.

[0027] As a technical solution of the present invention, the welding material adopts 1.2 mm diameter 316L stainless steel welding wire, which has excellent corrosion resistance and low temperature performance and is suitable for high-precision welding tasks.

[0028] As a technical solution of the present invention, the inclination angle of the welding gun and the weld in S3 is always maintained at 85° to 90°, which can make the arc shape more concentrated and stable. The welding wire and the weld are maintained at 20° to 25°, which can make it easier for the welding wire to enter the molten pool at a suitable speed and angle, reduce spatter and welding defects, and at the same time, this angle also helps to evenly distribute the welding wire in the molten pool, improve the uniformity and density of the weld, and ensure penetration of the weld root.

[0029] As a technical solution of the present invention, in S3, when using tungsten inert gas welding for filling and covering, the argon arc welding gun is kept stable, the welding gun is swung left and right and moves forward at a predetermined speed to ensure that both sides of the weld are fully fused and evenly formed. Sufficient fusion is the basis of weld strength and durability, and can avoid welding defects caused by poor fusion; by controlling the swing amplitude and speed of the welding gun, the shape and size of the parent material can be adjusted to obtain uniform weld formation. Uniform weld formation not only improves the appearance quality of the welded part, but also helps to reduce stress concentration and crack risks caused by irregular weld shape.

[0030] As a technical solution of the present invention, in the welding process of S3 and S4, a copper sleeve is used for continuous heat dissipation and cooling, and the temperature between welding layers is controlled to be lower than the ambient temperature (<20°C). After welding is completed, the copper sleeve is used for physical cooling and continuous cooling to the ambient temperature, which can effectively control the interlayer temperature at a low level, thereby avoiding adverse changes in the structure and performance of the heat-affected zone of the weld metal and the base material due to excessively high interlayer temperature, such as grain coarsening and decreased toughness.

[0031] As a technical solution of the present invention, during the inspection process in S5, it is necessary to ensure that the weld is narrow and uniform, has clear edges, is free of pores, cracks, undercuts, and is well formed without obvious defects.

[0032] Working principle:

[0033] Example

[0034] 1. Preparation

[0035] 1. Make the 316L stainless steel thin-walled tube and the connecting joint into a socket-type joint. The length of the connecting joint inserted into the thin-walled tube is 20 mm to ensure that the assembly is flat and without misalignment. The design of the socket-type joint enables the two sections of the cable to be accurately aligned, avoiding the misalignment problem that may occur in traditional welding methods.

[0036] 2. Use alcohol to clean the welded parts at both ends of the weld to remove oil and impurities.

[0037] 3. Check the status of welding equipment to ensure the normal operation of cold welding machine and tungsten inert gas welding machine.

[0038] 2. Point solid

[0039] 1. Align the two thin-walled pipe socket joints to be welded and fix them with positioning welds to ensure alignment and no gaps. This can greatly shorten the welding time and improve the welding efficiency. Since the positioning welds have pre-fixed the position of the cable, the welding operation can be completed quickly during the actual welding process.

[0040] 2. Use the same welding parameters but with a shorter welding time to avoid melting too much material prematurely.

[0041] 3. Welding

[0042] 1. Cold welding primer: The inclination angle between the welding gun and the weld is always maintained at 85°~90°, and the welding wire and the weld are maintained at 20°~25° to ensure that the root of the weld is fully penetrated. Cold welding is easy to operate, improves the welding speed, is suitable for rapid on-site construction, and can maintain the excellent properties of the parent material. The weld has high strength and good corrosion resistance.

[0043] 2. Filling and covering with tungsten inert gas arc welding: Keep the argon arc welding gun stable, swing the welding gun left and right and move forward at a predetermined speed to ensure that both sides of the weld are fully fused and evenly formed. Use a copper sleeve to continuously dissipate heat and cool down during the welding process. The temperature between welding layers is controlled below the ambient temperature (<20℃). The entire welding process is strictly controlled to ensure that the weld has no defects such as pores and cracks and has good sealing.

[0044] Table 1 Cold welding base welding parameters

[0045]

[0046] Table 2 TIG welding parameters

[0047]

[0048] 4. Post-weld treatment

[0049] 1. After welding is completed, use the copper sleeve to cool down the machine to ambient temperature.

[0050] 2. Use a polishing machine to grind and polish the weld to avoid scratches and damage that affect quality.

[0051] It should be noted that: since the 316L stainless steel thin-walled tube of the temperature and pressure monitoring cable outer armor has a thin wall and a small heat capacity, burn-through and deformation problems are prone to occur during welding, and high temperature will cause local overheating of the thin-walled tube, resulting in greater thermal stress, leading to deformation or burn-through, and the weld area is prone to react with oxygen in the air to form oxides during high-temperature welding, reducing the mechanical properties and corrosion resistance of the weld; therefore, the present invention adopts 1.2 mm diameter 316L stainless steel welding wire, which has excellent corrosion resistance and low temperature performance, is suitable for high-precision welding tasks, and is selected with excellent heat output fine control performance, suitable for A cold welding machine for fine welding operations is used for primer laying, and cold welding primer laying can provide a stable and uniform welding foundation for subsequent tungsten inert gas welding filling and covering, which helps to improve the overall welding quality; and tungsten inert gas welding (TIG welding) with the advantages of concentrated heat, narrow heat affected zone of weldment, small welding deformation and high welding quality is used for filling to ensure sealing, and then tungsten inert gas welding is used for covering to ensure the beauty and protection of the weld; simple operation, good sealing and corrosion resistance make this method suitable for high-temperature downhole operations such as SAGD, fire drive and electric heating wells, and meet the use requirements in different environments.

[0052] The embodiments of the present invention are provided for the purpose of illustration and description. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A cold welding method for rapid connection of temperature and pressure monitoring cables for SAGD lifting and lowering operations, characterized in that: The steps include: S1. Preparation: Make the temperature and pressure monitoring cable and the connecting joint into a socket-type joint to ensure that the assembly is flat and without misalignment; and use alcohol to clean the welded parts at both ends of the weld to remove oil and impurities, and then check the status of the welding equipment. The welding equipment uses a cold welding machine and a tungsten inert gas arc welding machine; S2, spot fixation: align the two sections of temperature and pressure monitoring cable socket joints to be welded, fix them with positioning welding points to ensure alignment and no gaps; use the same welding parameters, but short welding time to avoid melting too much material in advance; S3. Welding: Use cold welding for base, tungsten inert gas welding for filling and covering; S4. Post-weld treatment: After welding, the weld is polished with a polishing machine to avoid scratches that affect quality; S5. Inspect the weld.

2. The SAGD lifting and lowering operation temperature and pressure monitoring cable rapid connection cold welding method as claimed in claim 1, characterized in that: The welding material is 316L stainless steel welding wire.

3. The SAGD lifting and lowering operation temperature and pressure monitoring cable rapid connection cold welding method as claimed in claim 1, characterized in that: In S3, the inclination angle between the welding gun and the weld is always maintained at 85° to 90°, and the inclination angle between the welding wire and the weld is maintained at 20° to 25°, so as to ensure penetration of the weld root.

4. The SAGD lifting and lowering operation temperature and pressure monitoring cable rapid connection cold welding method as claimed in claim 1, characterized in that: In the S3, when using tungsten inert gas welding for filling and covering, the argon arc welding gun is kept stable, and the welding gun is swung left and right and moves forward according to a predetermined speed to ensure that both sides of the weld are fully fused and evenly formed.

5. The SAGD lifting and lowering operation temperature and pressure monitoring cable rapid connection cold welding method as claimed in claim 1, characterized in that: In the welding process of S3 and S4, the copper sleeve is used to continuously dissipate heat and cool down, and the temperature between welding layers is controlled to be lower than the ambient temperature (<20° C.). After welding is completed, the copper sleeve is used for physical cooling to continuously cool down to the ambient temperature.

6. The SAGD lifting and lowering operation temperature and pressure monitoring cable rapid connection cold welding method as claimed in claim 1, characterized in that: During the inspection in S5, it is necessary to ensure that the weld is narrow and uniform, has clear edges, is free of pores, cracks, undercuts, and is well formed without obvious defects.

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