Tubing buckle type commonly divided into three are EU, NU and NewVam. These three buckle-type can be found in the tool shop, where the EU and NU separate from the button appearance is difficult to distinguish, it is 1.30 deduction type, but from the entire string can easily distinguish that represents EU external upset NU means no external upset. New Vam actually a trapezoidal buckle (buckle rectangular cross-section), it is not outside the thick band, so it is very easy to distinguish. The following describes three buckle detail type schematically. 1) EU (External upset)  EU external upset tubing is a buckle clasp type. On the shop shelves buckle joint understanding change process and the EU will find three kinds of related biano identity. Wherein EUE (External Upset End) represents external upset end, EUP (External Upset Pin) denotes an outer thickened male buckle, EUB (External Upset Box) indicates external upset female buckle. 2) NU (Non-upset) no external upset NU is showing no external upset tubing connector. Except that no external upset and EU external difference is that in general there is a general NU 10 threads per inch, EU general 8 threads per inch. NUE which represents the non-thickened end or the end of the non-thickened. Similarly E represents End. 3) New VAM This type is characterized buckle buckle substantially rectangular cross section, equally spaced pitch, little taper, no external upset. In the production workshop sleeve sleeve ends seen.

Coiled tubing is a single length of several kilometers and repeated bending, achieve multiple plastic deformation of the new oil pipe. This special tubing on core manufacturing technology is: 1, The chemical elements Due to the harsh environment service, coiled tubing mechanical properties and corrosion resistance have high requirements, to optimize the design of the chemical composition of the material, it must also implement clean control the whole process of smelting, rolling, etc., to minimize inclusions and S, P and other harmful elements. 2, Processing Since dislocation multiplication after other causes hardening and Bauschinger effect together, transform law tubular body strength to control. 3, Heat treatment By tube heat treatment to achieve optimum control of microstructure and properties, especially high strength and high ductility and low residual stress. 4, Welding Technology Low carbon and low alloy steel, currently used mainly HFW welding technology, need to study the optimum welding parameters (such as current, voltage, frequency, welding speed, forming angle, the pressing amount, etc.), research and seam weld heat treatment technology. 5, Butt To achieve continuous production HFW pipe, it must first take a long sheet, the current sheet docking mainly TIG, MAG and plasma welding or the like. The method under study is friction stir welding method. 6, Pipe butt Coiled tubing during use may cause local damage, injury or defect part must be cut away, and the tubes are connected by welding. The traditional method of docking ships by hand TIG welding, the welding quality is difficult to control, so that the current automatic welding technology. 7, New manufacturing technologies As CVR technology, which uses continuous pipe of the same size tube and heated to 940 ℃ through online medium frequency induction by thermomechanical rolling, on the one hand to achieve seamless or HFW weld optimization, on the other hand to achieve variable wall thickness or adjustable. In addition, there are special stainless steel tube continuous laser welding technology.

Actual piping used in the project structure type oil casing , in addition to the introduction, there are a variety of other structural forms of oil casing, to meet a variety of different conditions, in particular the special requirements of working conditions. In the engineering design or selection, the oil casing intensity level is higher, the higher the security, but also the greater cost of the project costs, will result in unnecessary waste. From economic considerations, meet the design requirements while minimizing costs, the result is often easy to form a small selection of the many varieties appear on the whole oil casing, which is not conducive to the construction site materials management, regulation and design changes Replacement and other materials needed. Thus, the oil casing selection, should be integrated security and economy, minimize the oil casing varieties appropriate. In addition, the conditions of the construction site, construction level, oil casing of the procurement cycle and other factors, it may have caused the necessary attention in the selection of the oil casing. Under the circumstances, it should be considered to strengthen the pipe joint, the possibility of miter bend and small caliber tube bending field and the like.

Oil well cementing plug are as follows: 1. The balance safa Cypriot balance is one of the most common methods. The next drill or tubing to the bottom cement plug design depth, playing after the main cement for water mud, cement pipe enough volume to make the cement plug surface height and slowly pulled out of the column so that the cement plug to stay in meta position, generally from Risse the top surface of 20-30m, flush or reverse circulation. Construction should be noted that under the control of its ring, such as drilling fluid column pressure balance. 2. Preferences act First in the lower portion of the lower portion of the wellbore is expected to cement plug Yaru been fixed bridge plug. Use dump a certain amount of bottled water slurry, cementing by a cable to the depth, the depth of the current passing through mechanical means or method tilt cylinder switch is turned on, the lift cylinder dumping slurry was poured out. 3. Double safa The same method as described above is expected to advance into the men under the cement plug bridge plug. And a cementing cementing of two games is similar, but the two games for the drill pipe, the bottom of the column there is a special ring, which can be pulled out from under the stopper inside the drill pipe through the ring, the rubber stopper being plug seat blocked by the Cypriot control slurry reflux. Then put on the drill pipe reverse circulation flushing excess cement and cement tube.

Corrosion of oil casing 1. First, do a good job of water quality standards, strict testing and quality management. Dispensing implement remediation, cleaning work to strengthen the main water pipe, so that the station, the bottom water quality standards, reduce corrosion source into the annular space; 2. Have been put into operation a new water injection wells, mainly taken in dosing sterilizing annulus protection fluid, and institutionalized, regular dosing; 3. In view of the mechanical abrasion on the casing pipe corrosion in acceleration, proposes to add a rubber ring on the pipe coupling or inclination serious parts plus a centralizer, avoid water during operation and during the tubing and casing scratches contacting one side of the casing; 4. In response to severe corrosion and scale down bacteria SRB slow growth and high temperature to kill the case, may be periodically injected into the annulus to 100 degrees Celsius temperature water or steam to kill the dirt under the SRB; 5. Before injection wells within the casing corrosion has not been effectively controlled, is not recommended to promote the use of cathodic protection and coating sleeve.