Oil casing is the lifeline to maintain the normal operation of oil wells. Because of the different geological conditions, the stress state of the underground is complex, and the tensile, compressive, bending and torsional stresses act on the pipe body together, and the crude oil contains a lot of corrosive substances, and the oil casing is very easy to produce the corrosion. There are some anti-corrosion measures of oil casing following below: 1, Do a good job of water quality standards, strict water quality testing and management. The implementation of clean-up sub-injection, strengthening the main water pipe cleaning work, so that the station, the bottom of water quality standards, to reduce the introduction of corrosion space annular space. 2. Put into operation for the new injection wells, to take the main sterilization to vote for the ring to protect the liquid, and the formation of regular investment dosing. 3. In view of the mechanical abrasion to accelerate the role of corrosion of oil casing, it is recommended in the tubing coupling with a rubber ring or a serious deviation in the well plus a centralizer, to avoid the process and the process of water injection pipe casing and One side contact sleeve. 4. For serious bacteria corrosion and high temperature SRB slow growth and kill the situation, can be periodically injected into the annulus of 100 degrees Celsius high temperature water or water vapor to kill the SRB under the scale. Share from the Hebei Xin joint oil tube. 5. It is not recommended to promote cathodic protection and catalog casing before corrosion in the casing of injection wells is not effectively controlled. 6. You can brush the oil inside and outside the casing wall layer of anti-corrosion coating.

Stainless steel welded pipe in the same size specifications, the smaller the dimensional tolerance, processing, the higher the dimensional accuracy. Therefore, in order to ensure the cutting effect of stainless steel pipe, the actual size should be controlled to allow changes in the range, that is, design a reasonable amount of dimensional tolerance. In the stainless steel pipe cutting process, some operators always reach the expected cutting effect, but can not find the specific reasons, spring that it may be because it does not take into account the size of stainless steel pipe cutting tolerance. In the actual processing, due to processing measurement and other factors, the actual situation after cutting and expected there may be some error. Stainless steel pipe in the cutting before the first analysis of its hardness, thickness, (does not rule out the ductility of the analysis and testing), and then machine cutting accuracy, stability and blade flatness, stability and other comprehensive assessment, and then through the test method , To obtain the finished size sample data, and its CPK calculation, the final production capacity index, and finally a reasonable size tolerance design. This process, relatively speaking, is a little more complicated, because it is to ensure product quality more reliable approach.

Corrosion of steel pipes is inevitable, as the main use of steel pipe underground pipe thermal pipe corrosion is inevitable, so it is necessary to introduce the impact of its corrosion of the various Factors, in order to be treated with caution in future projects. Briefly, the causes of corrosion are the following. Temperature Effects: Temperature will increase the rate of corrosion. In general, in the atmospheric environment, the speed increased by 10 ℃, the corrosion rate doubled. Potential difference: two metals in the same medium environment, the higher potential of the metal will be corrosion, the lower potential of the metal is protected. Heat treatment: Heat treatment will alter the corrosion behavior of the metal. Surface state: surface cleanliness, with or without the surface membrane and the surface with or without other substances, the incidence of corrosion and the development of a great impact. Impurities: Impurities are an extremely important factor in corrosion. Radiation: Radiation can accelerate corrosion. Effect of abrasion: Even very light abrasion can damage the protective film formed on the surface of the substrate by corrosion, and the exposed fresh metal is subject to corrosion, thus accelerating the damage. Stress: usually under the action of tensile stress in the metal under the action of stress in the corrosion occurred earlier, the speed is faster. At the same time, the stress of the material under stress than the material to be faster corrosion, especially when the applied load close to or exceed the yield limit, especially. Time: As the time lengthens, the degree of corrosion increases. The rate of corrosion increases with time, under different conditions, or increases or decreases. Pressure: the pressure of the chemical reaction of the material oxidation, must also be considered factors. Other factors: process, process conditions, oxygen, concentration, the surrounding environment, biological factors such as corrosion will have an impact.

Raw material characteristics: * The steel is pure, the chemical composition is stable, the steel performance is stable; * High precision coil size, shape control, coil surface quality. Online detection technology: * Ultrasonic plate exploration: detection of defects and defects in the longitudinal long, defective configuration tracking device can guarantee 100% defect detection, tracking and removal. *  Ultrasonic inspection of welds in line: weld longitudinal and transverse defect detection, heat affected zone delamination detection and burr height control, mainly used in the production process control. In-line flattening test: Samples are made to weld and pressure direction into 0 ° and 90 ° flattening test to ensure the basic performance requirements of the weld. * Water pressure test: The base material and the weld seam of each pipe are provided with the solidity guarantee. * Off-line weld ultrasonic flaw detection: the end of the pipe and the bevel surface of the magnetic particle inspection and manual ultrasonic inspection of the pipe end and finished size inspection. Product manufacturing process: Converter steelmaking → furnace refining → continuous casting → hot rolling → uncoiling → strip Jiao Ping → cutting → butt welding → spiral band looper → washing edge → strip ultrasonic testing → forming → high frequency welding → online weld Ultrasonic flaw detection → online weld heat treatment → air cooling, water cooling → sizing → flying saw segment (flattening test) → pipe end chamfering → water pressure test → weld ultrasonic flaw detection → pipe end flaw detection → appearance dimension inspection → length measurement Re-mark → coating → packaging → factory

Because of the long distance and long-distance natural gas pipeline, the geographical environment is complex. Therefore, there are many factors influencing the normal service of the pipeline, but the main factors can be divided into the external environment and the quality of the pipeline itself. The quality of steel pipe is an important factor affecting the quality of the pipe, and the main factors affecting the quality of the steel pipe, including the quality of steel used in steel and steel pipe manufacturing process. Quality of steel plate The characterization parameters related to steel quality include steel grade, chemical composition, metallographic structure and mechanical properties. Forming method The quality of forming the ultimate impact of the final pipe residual stress distribution, springback and cross-section size accuracy. Welding process Key Process of Welding Submerged Arc Welding Straight - seam Steel Tube Production. Welding parameters, such as welding material, welding speed, welding current, welding voltage, welding wire arrangement, pitch and inclination, affect the performance of the weld. Expansion Expansion is the use of hydraulic pressure or mechanical force from the inner wall of the steel pipe to expand the steel radial outward a process that can eliminate the formation of steel pipe and welding residual stress generated during the process to improve the accuracy of steel pipe geometry and strength. The expanding diameter, the pressure of hydraulic expansion, the number of fan-shaped blocks in mechanical expanding, the speed of expanding and the conditions of lubricating have influence on the quality of expanding diameter. Inspection during production In the steel pipe production process, the need for material physical and chemical properties of the test, ultrasonic testing, X-ray detection, magnetic particle testing and other tests. The strict implementation of these test items can be monitored at any time pipe production, quality problems and timely feedback and treatment to ensure the quality of steel production.