机械毕业设计英文外文翻译588柱塞式液压缸、起重器和柱塞

附录A译文

(一) 柱塞式液压缸、起重器和柱塞

液压缸、起重器和柱塞的基本术语可以被看作为同义词。通常首先描述的是其基本质特征，“jack”通常用来描述，应用于起重器中的液压缸，而且在大多数应用驱动器的特定工业场合来提供起重装置，“ram”经常被应用于高输出力的大型、重型液压缸，其它一些权威书籍可能将“ram”定义为活塞和杆是相同直径的液压缸，尽管这种液压缸更准确的应该被叫做柱塞式油缸，或置换式液压缸，这些形式的液压缸单一作用式并有其相对的应用局限。

液压缸可为单作用式，在单作用液压缸情况下，运动由弹簧或某种外力或重力使活塞返回到起始位置时释放压力来完成，在这种情况下弹簧返回，再液压条件下可获得的输出力可以被弹簧抗力所减轻。

双作用液压缸再普通应用场合是最常用的，液流上被安装液压缸两端，被选择器交替实现输入口，输出口作用。最大的可获得的输出的仅比单作用液压缸所获得的输出稍小些，因为当液体压力被反向加压时组织泄露，因而增加了摩擦力抵抗运动。

在反向运动时，可获得的力会由于活塞和杆面积的不同而降低了活塞作用面积减少，反向压力也是存在的，这种性能损失也许会很小，但在实际中明显地减少理论性能，而且液压缸的理论性能是有一定规格的，允许的公称公差以适应摩擦损失。

大多数的液压缸是单杆式的，双杆式的液压缸可能被应用在要求特高刚度下。对于双作用式液压缸，冲压力在伸出和缩回是相等的，这里可以估计到相比在相同直径的液压缸由于杆的封闭作用，摩擦力也会两端的密封杆和密封轴承而增大。

液压缸被广泛用于工业液体系统中，这些液压缸也别称为线性原动机或往复原动机。通常液压缸由循环管，活塞和杆运动处两侧的密封组织，活塞杆可被设计在液压缸的一侧或两侧，围绕活塞杆向液压缸外的液体温度可以由正确设计的还有密封垫用途的应用。再这当中我们将学习各种类型的液压缸以及它们是如何应用的液压缸的用途会对工业水利学的学习有很大帮助。

(二) 液压动力钳的发展

近年来，随着我国国民经济的持续快速发展，我国的石油消费量逐年增加。2002年达到2．457亿吨，排名已超过日本，成为继美国之后的第二大石油消费国。相比之下，我国石油机械制造生产增长比较缓慢，供需矛盾日益突出。而现在人类的机械创新的不断进步，使机械代替了人。以前在油田修井时或者下油管时，管与管连接时是用管钳来上扣和卸扣，现在使用这种液压钳，就给人类带来很多方便，使工作效率和安全系数提高，也减少了很多井口的工作人员，因此这是油田经常使用的卸管工具。针对修井作业中人力上卸抽油杆螺纹效率低,劳动强度大,又不能保证不同规格抽油杆所要求的上扣扭矩等问题,研制了液压抽油杆钳,这种抽油杆钳由主钳,手动换向阀,液压马达,底钳,弹簧吊筒和调节弹簧等组成,在设计中省掉了转速换挡机构,同时通过改变制动板上压簧螺栓的结构,解决了制动板减薄时颚板滚子爬坡力量不足这一技术难题，介绍了这种抽油杆钳的工作原理!主要技术参数和室内试验情况，现场应用结果表明,采用液压抽油杆钳可大大减少抽油杆脱扣次数,提高修井质量和修井速度。但液压元件的制造精度和密封性能要求高，加工和安装都比较困难。泄漏难以避免，并且油液有一定的可压缩性，因此，传动比不能恒定，不适用于传动比要求严格的场合。泄漏引起的能量损失（称容积损失），是液压传动中主要的能量损失，此外油液在管道中受到的阻力及机械摩擦等也引起一定的能量损失，致使液压传动的效率较低。油液的黏度随温度而变化，当油温变化时，会直接影响传动机构的工作性能。此外，在低温条件或高温条件下采用液压传动有较大的困难。油液中渗入空气时，会产生噪声，容易引起振动和爬行（运动速度不均匀），影响传动的平稳。维修保养较困难，工作量大。当液压系统产生故障时，故障原因不易查找，排除困难等通过设计优化减少负影响。目前，国外钻杆动力钳的种类很多，而且产品性能及质量都相对稳定，特别是他们产品的体积与输出扭矩不会成比例变化，即使动力钳输出扭矩相当大时，其产品的体积也不会增加多少，因而适用于现场需要。而国内产品还处在研发和改进阶段，产品性能及质量都有待进一步提高，国内产品的体积和重量都随输出扭矩的增大而增大，从而导致无法适用于某些大型钻管。近10年来，中国国内生产动力钳有所增长，但相比国外我国动力钳结构复杂不方便使用与维护，使用期短等缺点，所以我国正大力发展动力钳设计改造，达到世

界水平。

(三) 钻井设备与技术

钻井设备第一需要是配备扭矩为三十万ft/lbs的电力装置，安装在直径21米的海上平台上，是两年前印尼研制的项目。这个安装交叉生产线项目范围其中包括建筑连接10万多FT配对扭矩和20多万配对液压扭矩。这些新型的螺纹连接是专为生产海上平台和输出扭矩建设的。新型螺纹的生产极力用于海上浮动平台管道连接，当面临巨大的海浪的力量，并夹杂着水流不断的冲击，可起着稳固平台的艰巨任务。这些参数是完全按照设计要求和建设需求去做的。21-300型钳子也是为设计而生产的配套产品。以上产品在不到12个月里，完成设计、建造、测试实验室，可迅速完成建设投入使用。在新产品中包括新概念的液压马达系统，以液压马达启动和组合泵、工程液压系统内都具有独立转子堂.这些都成功用在海上平台。这种新概念马达的体积和重量是以前没有过的可带动旋转。在其它一些项目中也应用了包括专门设计框架伺服支持的框架。而且装置都提供了遥控和完全的电子计算机操作。

技术要求

扭矩输出力所需螺纹生产建筑连接的技术要求包括大型辐射干扰，并且之间有内在联系。大扭矩要求"预先装载"的扭矩后线干扰,能顶住了动力海洋和抗压力。这种事先装配的装置叫做三角扭矩，它有着全功能的重要通道,是决定性的机械方面的机械摩擦装置，缓冲、解压等功能，可使几何扭矩高达输出扭矩的2至3倍。而且有其共同点就是扭矩输出最小15万余FT/，最大高达30万FT。这些典型参数都是技术上所必须的，很好的利用在建筑上是很容易解决综合技术所需的理论。综合扭矩抗压反应则需重新设计新概念，找住典型的生产建筑技术是必要的，设计不可缺少的因素。

发展构想

对这些概念进行讨论,以便找出最佳设计方案. 常规力量经常用动力钳凸轮曲线的形状进行系统内容的分析. 优点是依靠着力量直接应用输出的扭矩上,这是特别重要的，而且外壳和管道连接所需最大扭矩值三十万FT/配对,但需要相当高的输出扭矩系统提供比凸轮曲线，以便解决利用液压系统带动动力钳夹紧管

箍，并按标准规定设计。

这些技术可用在有<系统启动水压调节式独立液压驱动的汽车电路上，还可以用在液压钳弹簧转子上。然后是马达、泵股(在备份和堂)由水压驱动的汽车上,塘房的活塞泵装上塘生产转子液压筒的冲击，活塞泵的活塞上装有6门的装置运动，两个活塞泵供应压力增大每个液压缸.这可确保每个铣镗得到同样数量的油量,确保完成整个工作过程。

动力安排

它把两种不同的装备系统,可以把行星减速器装置的运行模式两个(外壳和建筑模式)和液压装置,总共将包括轮换速度从0.2-16分钟.三个平行驱动液压汽车外壳堂位于轮换分起床,从西三面部队驾驶系统.大型工具扶轮成绩封闭和轮换的建筑-听着. 机械动力传递的液压马达将加强扶轮来往.扶轮是一具大直径装置已分三节,关键在于构件和机制. 小扶轮起开放部分渔具建筑包围,然后设法接近工作的同时,门闩建筑国内直径的地面装备有加的打击部队,这是一个单独的驱动马达/泵股之上的情况下,确保液压堂在轮换.该装置由三个液压汽车列车装在一个单独的行星变速器堂扶轮社的房屋. 每个液压马达直接带动了鸟羽,进而扶轮驱动装置.

自由浮动

自由浮动的备份在钳子之下克制它从行动在管道附近当扭矩是应用的。会导致可能的安全危险在高扭矩值钳子可能提供的备用线路不必需。它并且包含三个水力夹紧的磁道提供肯定的字符串夹子以最大扣人心弦的强制。自由浮动的类型回应系统消灭所有剪和弯曲的负荷横跨工具联接, 服从联接只对扭力负荷和因此使残损的线程数侧面或肩膀减到最小风险由擦伤。可分开的自由浮动的备份(通过水喉) 与钳子机械上和水力被链接和对连接数线程数差旅自已补偿在构成和包围突破方向。

压电池(扭矩磁道) 适合在钳子和备份之间和, 由选择, 可能被使用记录构成或包围突破扭矩。三个下颌提供夹住的平均值。一个扣人心弦的系统相似和在钳子(还以分开的水力电路) 保证水力夹紧的磁道的一个中心夹紧的活动。备用夹紧的范围被设计容纳在衣领直径上所有变化在他们有名无实的范围范围之内从通过最大24米直径。

扭矩评定

弯曲的和剪切力被自由浮动的备用系统消灭当这些强制对称地被分配入扭矩过帐, 允许应用的扭矩的评定非常准确地被做。扭矩评定的系统与力量钳子被结合以自由浮动的备份消灭动摆和额外干涉的强制。结果, 构成和包围突破扭矩可能被评定以同样准确性。扭矩负荷被评定以一个有效的压缩类型压电池。强制直接地被评定在自由浮动的备份的扭矩回应系统之内。如果需要, 构成或包围突破与造反者钳子21-300 可能是受控的使用记录扭矩轮图形当化妆的torque/turn 系统(或中断) 连接数。那止步不前构成进程当被预先选定的最佳扭矩值被到达。许多生产造反者连接今天被使用外部被担负和要求"预先输入" 那些肩膀保证他们将承受弯曲的重音由环境造成当不取消。这由申请达到"三角洲扭矩" 向连接数在连接数担负了之后。制造商要求, 这三角洲扭矩是应用和受控的在非常紧的容差之内。新建私有的软件被设计分析连接数torque/turn 数据在实时, 然后运用被预先决定的相当数量三角洲扭矩或三角洲轮向连接数为最终构成。

钳子操纵

造液压钳子21-300型被设计了以各种各样的类型船具在头脑里。钳子可能或者被暂停从推力磁道和被操作到/从好的中心以Weatherford 力量范围, 或另一选项将集成造反者钳子21-300 Weatherford 轨行力量框架和伺服框架系统。取决于申请, 所有钳子的功能可能被控制或直接地从水力控制面板在钳子的边或通过一个遥控盘区。遥控可能是成功的通过航空在水力控制或电子与钳子是电子控制系统的整体部分。在这种情况下, 钳子和钳子承运人设备可能被连接到船的区域管理系统防止碰撞在不同的设备譬如力量框架, 顶层驱动器, 或管道操作系统之间。

案件历史记录

一、21-300型钳子被传送了为西方Seno 紧张行程平台(TLP) 由管理在海峡

在印度尼西亚。挑战被存在对Weatherford 将运行大3,000 ft 13 3/8钢框(在泥线路之下), 钛逐渐变细的重音联接(天桥联接), 和大约3,000 ft 生产造反者(在泥线路之上) 如同一个字符串在一个严重地偏离的未结漏洞。生产者包括了联接以焊接在连接在要求得超过的高重音面积100,000 ft/lbs 做输出扭矩, 并且专门研究穿线的和耦合的连接为字符串的余数在泥之上排行。由于疲劳关心, 处理生产造反者的需求是最小的标号对造反者的OD 。结果, 微夹子滑动被开发了为项目和被使用了在一只500 吨输出与一块远程地被管理的可撤回的基本的板材。滑动没有击穿入管道机体并且蜘蛛远程地和安全地被缩回从好的中心容纳所有大OD 制造者字符串要素。二把钳子被装配同时在彼此对面在船具楼层上处理穿线的和耦合的造反者的非标号需求和高扭矩需求焊接在造反者连接数。由于未结漏洞适应, 它是必要减少时刻在滑动为管道字符串避免陷进的管道。一把24-80钳子与pneumatic/hydraulic扣人心弦的设备和铝插入未被使用组成穿线的和耦合的，离开渗透成管道机体墙壁。这把钳子断断续续被安置了管道远程地与水力推进重要资料, 并且钳子门是远程地开动。

21-300型钳子被使用组成所有焊接在专业连接数和断断续续被安置了管道以力量范围。钳子门是远程地并且开动。总产量造反者和框被安装了没有人的井架。井架登上的刺重要资料被使用垂直排列所有联接在构成期间。所有设备由Weatherford 制造了; 实验室测试了和传送了对印度尼西亚在12 个月内从设计开球会议对最终验收试验, 和成功执行了第一批套生产造反者。当Weatherford 被授予了工作, 同时设计、制造、培训。由于成功的21-300型钳子在印度尼西亚, 2004 年两个项目在墨西哥湾被授予安装生产者。这些项目要求四把额外21-300 把钳子被编译。领先者发展项目为墨菲探险并且要求了能生产很好200,000 ft/lbs 的一把钳子。西部项目中的这个项目并且有生产者与焊接在和穿线的和耦合的连接数一个混杂的字符串。以这个项目, 只一把钳子必需运行所有13 个3/8外面造反者和9 个7/8 in. 内在造反者没有渗透入管道机体墙壁。21- 300 成功被使用了为所有申请。机械化的钳子和力量范围远程地运行了从控制面板。21-300型钳子获得成功。

附录B英文文献

(One) Cylinders, Jacks and Rams

The terms cylinder, jack and ram can be considered synonymous, the first being the general description. The description “jack” is commonly used for cylinders employed as lifting devices, and also on specific industries where the most common application of a linear actuator is to provide a “jacking” action. The description “ram” is often applied to large, heavy-duty cylinder with high output forces. Other authorities may designate a “ram” as a cylinder in which the piston and rod are of the same diameter, although this is more correctly called a plunger-type cylinder, or displacement cylinder. Such types are usually single-acting and have relatively limited application.

Cylinders may be single-acting or double-acting. In the case of single-acting cylinders, motion is accomplished by the pressure when the piston as moved back to its original position by a spring or some external force, or gravity. In the case or spring return, the output force available hydraulic pressure is modified by the resistance of the spring.

Double-acting cylinders are by far the more common choice for general application. Fluid ports are fitted to each end, to function alternately as inlet and outlet ports, switched by a selector. The maximum outup available is slightly less than that obtainable from a single-acting cylinder, since, when the fluid pressure is applied to the full piston area, some back pressure will be generated on the outlet side, also a rod seal will be required to prevent leakage when the piston is proess in the reverse direction, with consequently increased frictional resistance to motion.

In the reverse direction of motion, the force available will be lower since the effective piston area is reduced to that of the difference between the piston and rod areas. Back pressure effects will, of vours, also be present. Such performance losses may be small, but can appreciably modify the theoretical

performance in practive and it is usually on theoretical performance that cylinders are sized, with a nominal allowance for frictional losses.

Most cylinders are of single-rod type. A through rod may be see where extra rigidity is required. In the case of a double-acting cylinder, thrust will then be the same when extending and retracting. There will be an appreciable loss of extending thrust compared with a single-rid cylinder of the same diameter due to the blanking effect of the rod. Frictional forces will also be higher since a rod seal and bearing seal are required at each end.

Hydraulic cylinders are widely used in industrial hydraulic systems. These cylinders are called linear motors and reciprocating motors. The usual hydraulic cylinder cost of tube, sealed at both ends, in which a piston and its rod move. The piston rod projects through either or both ends of the cylinder. Leakage of the cylinder around the piston rod is controlled by suitably designed seal usually containing packing. A hydraulic cylinder transforms the flow of pressurized fluid into a push or pull of the piston rod. Hydraulic cylinders are designed for a variety of services. In this chapter we shall study types of cylinders and how they are used. A knowledge of cylinder is a great help in your study of the uses of industrial hydraulics.

(Tow) Hydraulic pressure power pliers development

In recent years, continued along with our country national economy fast to develop, our country petroleum consumption quantity added year by year. In 2002 achieved 245.7 million tons, the place have surpassed Japan, after becomes continues American second big petroleum expense country. In comparison, our country petroleum machine manufacture produces grows quite slowly, the supply and demand contradictory is day by day prominent. But the present humanity's machinery innovation unceasing progress, caused the machinery to replace the person. Before when oil field repair of wells now

and then under drill tubing, tube with me when is comes with the pipe spanner , now uses this kind of hydraulic pressure pliers, brings very many convenient to the humanity, causes the working efficiency and the safety coefficient enhances, also reduced the very many well heads staff, therefore this is the oil field frequently uses unloads the tube tool. In the manpower unloads the oil extraction rod thread efficiency in view of the rework operation in lowly, the labor intensity is big, also cannot guarantee the different specification oil extraction rod requires and so on the question, has developed the hydraulic pressure oil extraction rod pliers, this kind of oil extraction rod pliers by the host pliers, the manual cross valve, the oil motor, the bottom pliers, the spring hang the tube and the adjusting spring and so on are composed, saved the rotational speed in the design to shift gears the organization, simultaneously on pressed the spring bolt through the change the structure, has solved attenuated when the roller hill climbing lack of strength this technology difficult problem, introduced this kind of oil extraction rod pliers principle of work! In the main technical parameter and the room the experimental situation, the field application result indicated that, uses the hydraulic pressure oil extraction rod pliers to be possible greatly to reduce the oil extraction rod number of times, improves the repair of wells quality and the repair of wells speed. But the hydraulic pressure part manufacture precision harmoniously seals the performance requirement high, the processing and the installment quite is all difficult. Divulges avoids with difficulty, and the fat liquor has certainly certain may the compression, therefore, the velocity ratio cannot be constant, ill uses in the velocity ratio requirement strict situation. Divulges the energy which causes to lose (called volume loss), is in the hydraulic transmission the main energy loss, in addition the fat liquor the resistance and the mechanical friction which receives in the pipeline and so on also causes the certain energy loss, causes the hydraulic transmission the efficiency to be lower. The fat liquor viscosity changes along with the temperature, when oil temperature change, can directly affect the transmission system the operating performance. In

addition, uses the hydraulic transmission under the low temperature condition or the hot conditions to have the comparatively major difficulty. In when the fat liquor permeates the air, can have the noise, is easy to cause the vibration and crawling (velocity of movement non-uniformity), affect the transmission steadiness. Service maintenance more difficult, the work load is big. When the hydraulic system has the breakdown, the breakdown reason is not easy to search, breaks a way and so on to reduce the negative influence through the design optimization. At present, overseas drill rod power pliers type very many, moreover product performance and quality all relatively stable, specially their product volume AND output torque cannot become the proportion change, even if the power pliers output torque is quite big time, its product volume cannot add how many, thus is suitable for the scene need. But the domestic product also occupies the research and development and the improvement phase, the product performance and the quality all waits for further enhances, the domestic product volume and the weight all increase along with the output torque increases, thus causes to be unable to be suitable for certain large-scale drill pipes. In the recent 10 years, the China home production power pliers have the growth, but compares the overseas our country power pliers structure complex not conveniently to use and to safeguard, the lifetime is short and so on the flaw, therefore our country vigorously is developing the power pliers design transformation, achieves the world level.

(Three) DRILLING EQUIPMENT AND TECHNOLOGY

The first demand for a power tong that can deliver a torque value of 300,000 ft/lbs at 21 in diameter came from the Unocal West Seno tension-leg platform (TLP) deepwater development project in Indonesia two years ago. The scope of this project was to install 24 “hybrid” pr oduction riser strings which included production riser connections that required more than 100,000

ft/lbs make-up torque and more than 200,000 ft/lbs break-out torque. These new types of threaded production riser connections were designed especially for spars, TLP, and semi submersible production platforms that require torque values never before seen. Threaded production risers are used to extend the sub sea wellhead from the seabed to the floating platform and are exposed to tremendous forces and stresses caused by water currents and the motion of the vessel due to the waves. These parameters required Weatherford to design and build a completely new tong concept within a very short time window. The new tong was called the

Riser Tong 21-300, and is the first fully rotational tong with integral backups able to generate 300,000 ft/lbs of torque. In less than 12 months, two units were designed, built, lab tested, and delivered to Indonesia in 2002/2003 for the West

Seno Project. The new concept includes a hydraulic gripping system that is activated by a hydraulic motor/pump combination and works with an independent hydraulic system inside the tong rotor. With the successful application of the tong on the West Seno Project, 2004 brought a new challenge. Four of the 21-300 tongs were required in a mechanized version in a “hands-free” environment to be operated on offshore floating platforms in the Gulf of Mexico. Never before has a power tong the size and weight of the 21-300 been operated under these conditions. A rail-mounted system consisting of a hydraulically driven frame and a specially designed supporting servo-frame were developed to safely handle the large weight of the tong. Two versions of remote control were delivered, a fully electronic computer- based remote control system and a simpler pneumatic version.

TECH REQUIRE MENTS

Characteristics that influence the required torque values in threaded production riser connections include large radial interference between the threads that increases the initial make-up of the connection, and large torque shoulders that require “pre-loading” of the shoulders after thread interference

to withstand the dynamic forces of the ocean and to resist backing out under stress. This pre-loading is called Delta-Torque and is important to the functionality of the connector and is decisive for the mechanical integrity of the connection. Due to the mechanical friction within the thread and the torque shoulder as well as to the geometry of the thread, the break-out torque values can be as high as 2 to 3 times the make-up torque. These characteristics together lead to required potential make-up torque values of over 150,000 ft/lbs and required break-out torque values of up to 300,000 ft/lbs. The typical tong gripping size of these riser connections is up to 21-in. Due to the required torque-turn curve, a rotational device was preferred compared to a wrenching device, which technically would have been an easier solution. An integrated backup-tong to counteract for the reactive torque was required to be included in the design concept. The gripping area of a typical production riser connection is clearly defined and the distance between the tong and the backup is another important design factor.

DEVELOPMENT AND CONCEPT

Several concepts were discussed in order to find the optimum design. Conventional power tongs often use a cam curve system to engage the gripping elements. The advantage is that the gripping force directly depends on the torque value applied, which is especially important for thin-wall casing and tubing connections. The required maximum torque value of 300,000 ft/lbs, however, requires a much higher radial gripping force than a cam curve system can deliver.

The solution was to utilize a hydraulically activated gripping system that had already been used for smaller tongs. A hydraulically activated gripping system is capable of applying the necessary clamping force of 800 k N (180,000 ft/lbs). To prevent riser damage, a three-jaw gripping system with a six-point gripping arrangement is used.

The gripping system is activated hydraulically with adjustable gripping force by a separate hydraulic clamping circuit driven by a motor/pump unit. Three

spring-loaded hydraulic clamping cylinders within the rotor force the jaws against the riser connection OD. During make-up or break-out operations, the riser to be rotated is first enclosed in the tong and backup and the tong and backup doors are closed and latched. Then a motor/pump unit (at the tong and backup) consisting of a hydraulically driven motor mounted to the tong housing and a piston pump mounted on the tong rotor produces hydraulic pressure for the clamping cylinders. The piston pump is equipped with six pistons. Two pump pistons supply the pressure for each clamping cylinder. This ensures that each clamping cylinder gets exactly the same amount of oil to provide symmetrical and centric clamping forces for the jaw grip. The rotor then rotates the riser. Finally, the jaws release and back off from the pipe. Changeover between make-up and break-out operation can be accomplished at every rotor position. The size range of jaws is designed to accommodate all variations in riser and casing diameters within their nominal size range from 9-in. through maximum 21-in. diameter.

MOTOR ARRANGEMENT

With its two different gear shifting systems, a shift able planetary gear reducer for the two operation modes (riser and casing mode) and a hydraulic gear, shifting covers a total rotating speed range from 0.2-16 rpm. Three parallel-driven hydraulic motors located on the tong casing to rotate the riser and to distribute the forces symmetrically from three sides drive the system. A large rotary gear accomplishes closure and rotation of the riser-gripping jaws. Mechanical power is transmitted from the hydraulic motors to turn the rotary gear in either direction. The rotary gear is a large-diameter gear that has been segmented into three sections with pivotal hinges and latching mechanism. The smaller rotary gear segments pivot open to encircle the riser being worked and then close and latch while working the riser. The internal diameter of the gear has an insert surface for the clamping unit, which is driven by a separate motor/pump unit on top of the tong case to secure hydraulic pressure during rotation. The gear train consists of the three hydraulic motors mounted on a

planetary gearbox in a separate housing on the tong rotary. Each hydraulic motor drives directly a pinion, which in turn drives the rotary gear.

FREE-FLOATING BACK UP

The free-floating backup underneath the tong restrains it from moving around the pipe when torque is applied. No backup line is required that would cause a possible safety hazard at the high torque values the tong can deliver. It also contains three hydraulic clamping cylinders to provide sure string grip with maximum gripping forces. The free-floating type of reaction system eliminates any shear and bending loads across the tool joint, thereby subjecting the joint only to torsion loads and minimizing the risk of damaging thread flanks or shoulders by galling. The separable free-floating backup is mechanically and hydraulically (via hoses) linked to the tong and is self-compensating for connection thread travel in both make-up and break-out directions. A load cell (torque cylinder) is fitted between tong and backup and, by selection, can be used to record make-up or break-out torques. Three jaws provide the gripping means. A gripping system in the same manner as in the tong (also with separate hydraulic circuit) ensures a centric clamping action of the hydraulic clamping cylinder. The backup clamping range is designed to accommodate all variations in collar diameters within their nominal size range from 9 -in. through maximum 24-in. diameter.

TORQUE MEASUREMENT

Bending and shearing forces are eliminated by the free-floating backup system as these forces are symmetrically distributed into the torque posts, allowing measurement of applied torque to be made very accurately. A torque measuring system combined with a power tong with free floating back-up eliminates oscillations and additional interfering forces. Consequently, make-up and breakout torque can be measured with the same accuracy. Torque load is measured with an active compression-type load cell. The force is directly measured within the torque reaction system of the free-floating backup. If desired, a make-up or a break-out with the Riser Tong 21-300 can

be controlled using a torque/turn system that records the torque over turn graph while making-up (or breaking-out) the connection. That halts the make-up process when the pre-selected optimum torque value is reached. Many of the production riser connectors used today are externally shouldered and require “pre-loading” of those shoulders to ensure they will withstand the bending stresses caused by the environment while not backing out. This is achieved by applying “delta torque” to the connections after the connection has shouldered. Manufacturers require that this delta torque is applied and controlled within very tight tolerances. New proprietary software was designed to analyze the connection torque/turn data in real time, then applying a predetermined amount of delta torque or delta turns to the connection for final makeup.

TONG MANEUVERING

The Riser Tong 21-300 was designed with various types of rigs in mind. The tong can either be suspended from a lift cylinder and manipulated to and from well center with the Weatherford Power- Scope, or the other option is to integrate the Riser Tong 21-300 into the Weatherford rail-mounted Power Frame and Servo Frame system. Depending upon the application, all functions of the tong can be controlled either directly from the hydraulic control panel at the side of the tong or via a remote control panel. Remote control can be accomplished through an air-over hydraulic control or electronically with the tong being an integral part of an electronic control system. In this case, the tong and the tong carrier device can be connected to the rig’s zone management system to prevent collisions between different devices such as Power Frame, top drive, or pipe handling systems.

CASE HISTORIES

Two 21-300 tongs were delivered for the West Seno Tension Leg Platform (TLP) operated by Unocal in the Makassar Strait in Indonesia. The challenge presented to Weatherford was to run approximately 3,000 ft of 13 3/8-in. steel casing (below mud line), titanium tapered stress joint (crossover joint), and

approximately 3,000 ft of production risers (above mud line) as one string in a severely deviated open hole. The production risers consisted of joints with weld on connectors in the high stress areas that required more than 100,000 ft/lbs of make-up/breakout torque, and specialized threaded and coupled connectors for the remainder of the string above the mud line. Due to fatigue concerns, the requirements for handling the production risers were minimal marking to the OD of the risers. As a result, Micro Grip slips were developed for the project and used in a 500 ton spider with a remotely operated retractable base plate. The slips did not penetrate into the pipe body and the spider was remotely and safely retracted from well center to accommodate all large OD riser string components. Two tongs were rigged up simultaneously opposite each other on the rig floor to handle the non-marking requirements of the threaded and coupled risers and the high torque requirements of the weld-on riser connections. Due to open hole conditions, it was imperative to reduce time on slips for the pipe string to avoid stuck pipe. A semi-mechanized 24-80 tong with a pneumatic/hydraulic gripping device and aluminum inserts was used to make up the threaded and coupled risers, leaving no penetration into the pipe body wall. This tong was positioned on and off the pipe remotely with the hydraulic Push Master, and the tong doors were actuated remotely open/close.

The semi-mechanized 21-300 tong was used to make up all weld-on specialty connections and was positioned on and off the pipe with the Power Scope. The tong doors were also actuated remotely open/close. All production risers and casing was installed with no human stabber in the derrick. The derrick mounted Stab Master was used to vertically align all joints during makeup. All equipment was manufactured by Weatherford; lab tested and delivered to Indonesia within 12 months from the design kick-off meeting to final acceptance test, and successfully performed the first batch set of production risers. When Weatherford was awarded the work, simultaneous design, manufacturing, training, and preparation occurred, including:

As a result of the success of the 21-300 in Indonesia, two follow-up projects were awarded in 2004 to install production riser in the Gulf of Mexico. These projects required four additional 21-300 tongs to be built. The Front Runner development project for Murphy Exploration also required a tong that could produce well over 200,000 ft/lbs. As with the Unocal West Seno project, this project also had a mixed string of production risers with weld-on and threaded and coupled connections. With this project, only one tong was required to run all 13 3/8-in. outer risers and the 9 7/8-in. inner risers with no penetration into the pipe body wall. The 21- 300 was used successfully for all applications. The mechanized tongs and Power Scope were run remotely from a pneumatic/hydraulic control panel. The following additional equipment was used.