The safe production and transport of oil and gas is highly dependent on reliable pipelines. Jurgen Kruger for Polysoude, France, discusses weld overlay cladding of advanced metallurgical quality.
油气安全生产与运输很大程度上依赖于可靠的管路设施.以下我们将讨论的是POLYSOUDE高质量的堆焊技术.
Production lines are used to transport production fluids from subsea wells and manifolds to offshore processing facilities, loading buoys and subsea to beach. These production fluids are still unprocessed and are usually composed of hydrocarbons from gas and condensates, crude oil, water and solid impurities in varying proportions. Where the pipes close to connect with the subsea wells, the pipes often have to carry crude oil, which is of a very high pressure and temperature.
生产管道将生产流体从水下油井和管汇输送至海上采油平台或岸上基地.这些生产流体均未经加工,通常由碳氢化合物,原油,水,固态杂质构成.生产管道连接海底油井,靠近采油树出口,所输送原油具有高压高温的特性.
Export lines (or pipelines) are used to convey gas or oil after its separation from the other products found in production fluids. The operating environment of pipelines is moderate when compared to the environment within which production lines have to work. The conveyed fluid is the same temperature as the surrounding water and the pressure is low to medium. Therefore, it is essential that the basic material chosen for an offshore pipeline is collapse resistant.
外输管道用来输送生产流体经过分离后所产生的油气产品.该管路的作业环境相对温和,输送流体温度与周围水温相同,压力也降为中低压.但是管路母材具有高抗挤毁性是一基本原则.
Whilst design regulations for pipelines are less stringent than those for production lines, there is a growing demand for higher quality pipelines du immense environmental damage that leaks or failures of tubular structures can cause.
尽管外输管道的设计要求低于生产管道,管道泄漏或损坏将导致的严重环境破坏问题给管道质量提出了更高的要求.
Due to the declining productivity of existing wells, operators are forced to extend their exploration activities into deeper offshore waters. Consequently, an increase of production lines with improved mechanical strength will be necessary.
由于现有油井产油量下降,采油作业不得不往更深水域拓展.而这将需要更多的具有更佳机械强度的生产管道.
The subsea tieback system is the preferred solution, where possible. This involves the production lines of recently completed wells being connected to existing installations. This is a good way to overcome the ever more significant offset between production facilities and related wells. It can help to reduce costs considerably. Reel-laying of pipes is a fast and cost-effective way to establish the necessary connections. Pipes of and adequate quality can only absorb the additional strain caused by the laying procedure.
海底管道回接是最佳的解决方案,它可将新油井的生产管道连接至现有钻井平台,节约可观成本.卷管式管道铺设是建立必要连接的一种快速,经济的铺管法.高质量的管件可以吸收铺设过程中产生的额外应变.
Another major concern is making sure that production lines are corrosion resistant. If the concentration of chloride, carbon dioxide or sulphur ions exceeds a certain level, the high streigth low alloy C-Mn steel can corrode at a rate of approximately 0.2mm/yr. Corrosion resistant alloys (CRA), such as austenitic and martensitic stainless steel and nickel-base and titanium-base alloys, can withstand the strain of the corrosive chemicals.
另一关键点是确保生产管道的耐腐蚀性能.一旦氯化物,二氧化碳或硫离子的浓度超过一定比例,低合金高强度碳锰钢将按照大约0.2mm/年的腐蚀率腐蚀.耐腐蚀合金,例如奥氏体马氏体不锈钢,镍基合金,钛基合金,可以抵抗腐蚀性化学物质导致的应变.
Corrosion resistant alloy clad pipe
耐腐蚀合金堆焊管件
To combine the strength of low-alloyed carbon steel with the corrosion resistance of CRAs, the inside of C-Mn steel pipes is covered with a layer of a suitable corrosion resistant alloy. Excellent bonding between the parent metal of the outer pipe and the deposited layer inside can be achieved if overlay cladding is applied. CRA clad steel pipes are characterized by the firm metallurgical bond between the host pipe and the inner CRA layer. It meets the highest quality standards.
为了结合低合金碳钢管的强度性能和耐腐蚀合金的耐腐蚀性能,可以在碳锰钢的内壁覆以耐腐蚀合金层.堆焊技术的采用可以确保获得外管基材和内部熔敷层的完美结合.耐腐蚀合金堆焊钢管具有主管和内部耐腐蚀层间牢固的冶金结合的特性,达到了最高的质量标准.
The tungsten inert gas (TIG) weld overlay cladding process is becoming ever more popular for the manufacturing of CRA clad steel pipes. It is known for providing a smooth and regular surface with only small variations in thickness. The layer has “zero defects”, no pores, no lack of fusion and particularly low dilution rates.
TIG钨极氩弧堆焊技术,因其堆焊表面光滑一致,厚度差异小,“零缺陷”,无气孔,无未熔合,稀释率尤其低的特性,越来越广泛地被应用于耐腐蚀合金堆焊钢管的生产制造中.
Conventional GTAW/TIG welding is characterized by the creation of an electric arc between a refractory metal (alloyed tungsten) electrode and the work piece in an atmosphere filled with inert gas. The electrode withstands the high temperature of the arc and directs it towards the fusion zone. The impact of the electrons causes the fusion of the parent metal, forming the weld pool, which is shielded by the inert gas flow. In the case of cold-wire TIG cladding, the energy required to melt the added wire comes from the electric arc, so the melting rates that can be achieved are quite limited. In case of the Hot Wire TIG process, the wire is preheated by the Joule effect of a separate current that is provided by an additional power source. Hot Wire TIG cladding allows increased melting rates and advanced productivity without compromising the reliability of the process or the quality of the deposited layers.
传统TIG焊接技术是在惰性气体环境中在难熔金属(合金钨)电极与工件间建立电弧.电极将电弧的高温传导至需熔化区域,在惰性气体的保护下熔化母材,形成熔池.冷丝TIG堆焊中,熔化填充焊丝所需的热量来自电弧,可获得的熔化率相对有限.而热丝TIG堆焊则是通过额外电源提供单独电流预热焊丝,从而获得高熔化率和高生产率,同时又确保了TIG工艺的可靠性以及熔敷层的质量.
Using the technology to clad pipes
将该技术使用至管件堆焊
The process of TIG welding (particularly TIG Hot Wire cladding applications) has been made more efficient thanks to a recent development, known as TIGer technology. It is based on a new torch design. Whilst a common TIG torch has one single tungsten electrode, the distinct TIGer torch is equipped with two electrodes. Each electrode is supplied with current by its own power source. The position of the electrodes (with the tips next to each other) means that a single bi-cathodic arc is generated.
POLYSOUDE近年最新技术开发成果,TIGer双钨极技术,大大提高了TIG焊(尤其是TIG热丝堆焊)的工作效率.普通的TIG焊枪使用一根钨极,而独特的TIGer焊枪装备有两根钨电极.每一电极由独立电源提供电流.电极的位置(电极尖部相邻)意味着复合双阴极电弧的形成.
The low arc pressure of the TIGer arc, combined with high welding intensity, allows extremely fast welding speeds to be reached (over 1000 mm/min). Furthermore, high deposition rates of 6 kg/hr or more per TIGer torch can be achieved, with only a low dilution rate between the deposited alloy and the substrate material. The dilution rates are less than 10% for the first layer and 2% for each of the following layers. If only one layer is deposited, it is possible to adjust the welding parameters to limit the dilution at 6%.
TIGer电弧的低电弧压力特性与高电流强度相配合,可确保获得极快的焊接速度(超过1000mm/min).每一双钨极焊枪的熔敷率可高达6 kg/hr或更高,而熔敷金属与基材的稀释率却能保证在第一层10%以下,以后每层2%以下.如果仅堆焊一层,可以通过调节焊接参数将稀释率控制在6%.
It is possible to optimize the thickness of each layer to within a range of 1-3mm, this meets all known codes and standards. Consequently, only the exact quantity of corrosion resistant alloy material need be added, which creates significant cost savings, considering the cost of CRA filler products.
堆焊层单层厚度可在1-3mm间优化,这满足所有已知准则和标准.按此方法,可以将耐腐蚀合金材料的添加量精确控制在需求范围,大大节约成本.
Suitable cladding equipment for the technology
该技术所需合适堆焊设备
Optimised industrial TWIN TIGer (double torch) solutions are available for the internal cladding of C-Mn steel pipes with an inner diameter of minimum 5 in. and standard lengths of 6m or 12m.
经过优化的TWIN TIGer(两把双钨极焊枪)解决方案,可用于标准6米或12米碳锰钢管的内壁堆焊,堆焊后内径最小可至5英寸.
The pipe that is going to be cladded in a horizontal position (1G) is carried by several pipe supports. The rotary motion of the pipe is generated by a hollow shaft rotator, which is mounted in the vertical position and is adjustable to the appropriate work piece diameter.
需要堆焊的管件由若干滚轮架支撑置于1G水平位置,由端部中空卡盘驱动旋转.卡盘垂直安装,根据工件外径可调.
The technical challenge for such equipment is to guide the torches precisely and reliably through the inside of the pipe (despite its small ID and the high temperatures, which is the result of the cladding operation itself).
该设备的技术挑战在于:如何精确可靠地引导焊枪在管子内部运行并完成堆焊动作(工件内径小,堆焊本身将导致内部高温).
The system is based on a 12m long frame with two horizontally aligned steel ropes, carrying the welding lance, the two ropes are passed through the pipe to be cladded and tightened with strong forces.
系统配有12米钢丝绳牵引和导向装置,两根钢丝绳通过需堆焊管件内部并强力拉紧,携带焊枪完成定位和堆焊进道.
Two TIGer torches with Hot Wire supply are mounted, one behind the other on the welding lance. The lance itself slides along the ropes. The cladding sequence starts at the rear end of the pipe.
两把双钨极焊枪一前一后安装在焊接枪杆上,枪杆自身在钢丝绳上滑动.堆焊由管子后部开始.
During the cladding operation, the lance is pulled through the pipe, thus creating the longitudinal movement of the torches. The two torches rotate in the shape of a helix along the inside and are able to cover the whole internal surface area. The requested deposition of two weld layers can be created by one single movement along the pipe (TWIN TIGer torch).
堆焊过程中,枪杆沿着管子内部被拉动,从而形成了焊枪的水平移动.两把焊枪在工件内部呈螺旋形旋转,覆盖所有内壁区域.沿着管子内部的一次单一运动(两把双钨极焊枪)可完成两层堆焊层的熔敷量.
Two synchronized Polysoude PC600-3 Hot Wire TIGer power sources automatically control the longitudinal movement of the lance, the rotation of the pipe and the intrinsic displacement of the torches each with intendant arc voltage control. Except for the welding speed, all welding parameters of each TIGer torch can be adjusted independently, so the dilution of each CRA layer can be minimized and the specified thickness of the deposition will be followed exactly.
两套同步化的POLYSOUDE PC600-3热丝双钨极电源自动控制着枪杆水平移动和管件旋转,通过AVC控制着每一焊枪的自身位移.除了焊接速度,每一双钨极焊枪的所有焊接参数均可独立调节,因此每堆焊层的稀释率均可实现最小化,特定的熔敷厚度亦可准确控制.
As the sequence of a cladding operation is entirely controlled by the equipment, there is no need for an operator to intervene. The TIGer torches are fitted with integrated high resolution colour cameras, so the process can be followed on video monitors. For quality assurance, all important cladding parameters are continuously monitored and recorded by the data acquisition system.
堆焊顺序由设备完成控制,操作者无需干预.双钨极焊枪配有一体式高分辨率摄像头,整个过程可以在视频监控器前观察.为了确保质量,所有重要堆焊参数都由数据采集系统监控并记录.
Conclusion
结论
TIGer overlay cladding technology is an advantageous way to satisfy the increasing demand for metallurgical bond CRA clad steel pipe. It is of a suitable quality for production lines and the crude oil exploration. 100% defect-free CRA depositions, reasonable investments, increased efficiency and high flexibility are the reasons why companies have chosen and are successfully using Polysoude’s unique cladding technology in their production processes.
面对冶金结合耐腐蚀合金堆焊钢管需求的日益增长,TIGer堆焊技术因其优势明显,大有用武之地.它可确保生产管道和原油开采的质量.100%无缺陷耐腐蚀合金熔敷,投资合理,效率提高,灵活度高,这些都是若干企业选择并成功使用POLYSOUDE独特堆焊技术的原因.
