In 2006, Suedrohrbau Saudi Arabia Ltd (SRB), a subsidiary of Dutch international contractor Nacap bv, was granted a Euro 70-million contract by Saudi Aramco, the state-owned national oil company of Saudi Arabia, for the engineering, procurement and construction of the Khurais Sea Water Injection & Distribution Headers Project.

This involved, amongst others, the construction of 507 km of non-sour and sour sea water transfer lines and headers, size 8” to 36.”  For pipes 30” and above SRB applies automatic uphill welding for filling, relying on Magnatech’s Pipeliner II orbital welding system and ESAB’s PZ6113 all-position rutile cored wire. The project is scheduled for completion in October 2008.
The Khurais field is an existing field with an output of some 300,000 barrels per day (bpd). It is located in the area of Khurais, halfway on the motorway between Dammam and Riyadh in the middle of the “red dunes” desert. Water injection is envisaged to boost the production to 1.2 million bpd. The seawater is supplied from the Persian Gulf, and is then distributed throughout the Khurais field.

Welding in the desert
In principle, welding in the Saudi desert is not very different from cross-country pipeline construction anywhere else.
It follows the same pipeline laying principles; pipe stringing, bending, positioning, welding, NDT, and cleaning & coating – the front-end speed being the decisive factor.
One of the complicating factors to overcome, however, is often the remoteness and the associated problems of provision of logistical support to the workers’ compound and the front-end teams.
Another, very obvious problem is the tough working conditions. During summer, temperatures reach 40 degrees and up, requiring the utmost from the welding and supply teams in order to maintain the laying speed of a pipeline. In this respect, mechanised welding helps a lot, as it reduces the physical effort required to weld an often pre-heated pipeline.

Mechanised welding – an Aramco requirement
For various reasons, Saudi Aramco stipulates the use of mechanised welding equipment on its pipelines – the most important one being that they are in a great hurry to boost the oil and gas production, making them demand short time frames for their projects.
Mechanised welding makes the planning more predictable, and, since it is less strenuous for the welders, leads to a better weld quality. Also, manual pipeline welders, hired in from mainly Asian countries, are not as plentiful available as they used to be. Mechanised welding requires fewer welders and simplifies the associated logistical organisation.
A last reason is the increasing use of X70 quality pipeline steel and higher, requiring low-hydrogen welding consumables and therefore excluding the use of cellulosic downhill electrodes.

The Magnatech Pipeliner II
The Aramco requirement applies to the filling of the joint – the root pass may be done manually or through semi-automatic or mechanised means. The Magnatech solution for filling, used by Suedrohrbau, and brought on the Saudi Market by Pangulf Welding Solutions, is based on uphill welding with flux-cored wires (FCAW). At Suedrohrbau, it is used in combination with semi-automatic, controlled downhill short circuit welding with Lincoln Electric’s STT process for the root pass. It can be used equally well in combination with downhill or uphill MMA for the root pass.
There are a number of solutions available in the market for the filling of pipeline joints, along with their individual advantages and disadvantages. The characteristics listed for FCAW are valid for all-positional rutile cored wires, such as ESAB’s FILARC PZ6113 (AWS A5.20: E71T-1 H4/E71T-1M H8). It has a fast solidifying slag system that supports the fluid weld metal well and allows the placement of thicker beads, so less passes, but at a high deposition rate. The wire always operates in the spray arc mode, making it a tolerant process with a low weld defect rate.
Magnatech Pipeliner II is an easy-to-learn and use light weight equipment that is easily mounted and dismounted. The head is removed from the guide ring in seconds with a push button switch. The patented guide ring is not to be seen as a consumable, because it does not wear out, and is tolerant for weld spatter and grinding debris. The Positive Drive System guarantees a uniform rotation speed. The 300 A water-cooled torch can be programmed in three independent ways: travel speed, weaving width and endpoint dwell. A remote control allows cross weld steering and vertical adjustment, as well as the possibility to overrule the programmed weaving width.
The Pipeliner I can be applied on pipes as from 6” diameter up to 36” and higher, simply by changing the guide ring, which is an advantage relative to downhill mechanised equipment which starts at approximately 30.” Another advantage is that its use becomes economical as from significantly shorter pipeline lengths. Moreover, pipeline contractors will own the equipment and do not have to rent it.
The Pipeliner II forms the heart of a complete welding system with a digital power source with synergic lines for FCAW, a floor standing wire feeder for 16 kg spools, a programming unit with memory positions for four individual beads, a gas mixing unit and a power generator. All can be mounted on a truck for transport along the pipeline, together with the welding heads, while the guide ring is the only component remaining on the pipe. It is easily slided from joint to joint, by hand.

Back to the desert
The picture on page 32 shows the STT root pass welding of a 36” diameter 28 mm WT pipeline for the Khurais Sea Water Injection & Distribution Headers Project. It is welded by two welders simultaneously, from 12 to 6 o’ clock – clockwise and counter clockwise. They are true artists, able to continue welding with a weaving motion, while changing from standing, to squatting, to sitting, until they lie under the pipeline.
When hands meet, one of the welders grinds away his end crater while the other finishes the weld. These are the guys that determine the front-end laying speed of the pipeline. No time to be lost. When ready, they immediately move to the next weld. The internal clamp is removed directly after the hot pass. They make about 30 root passes a day, in a 12-hour shift.
From here, mechanised uphill FCAW with the Pipeliner II takes over, accounting for almost the full weld volume. There are two operators depositing only the hot pass and filler pass with two Pipeliners walking the guide ring, from 6 to 12 o’clock. The total hot pass and first fill team comprises not only two welders, but also a number of helpers and the truck driver. The hot pass is deposited at a high travel speed (19.5””/min) to avoid burning through the root pass, and the first filler pass at 10”/min.

Welding of a hot pass
The welder supervises the process and, when needed, fine-tunes the parameters with the remote control. For the first filler pass, the Pipeliner is transported back to 12 o‘clock and the second set of preprogrammed parameters is choosen.
Six additional teams are individually responsible for filling the joints left behind by the hot pass and filling team to a total of 10 layers. Split beads (two) starts after four layers and weaving is applied as from the hot pass. All passes are performed at the same current of about 250A at a wire feed speed of 8”/min. The cored wire diameter is 1.2 mm and the shielding gas is Ar/20 per cent CO2.
At Suedrohrbau it pays to work your way up and become a mechanised welder. They hold a high status and earn significantly more than the company’s MMA welders. The upshot is that everyone wants to become one and harasses the management to let them enter a training programme. Only the best are allowed, though.
Mechanised welders, at SRB, receive a very decent base salary for eight hours’ work, in which they are expected to complete three welds on the 36” diameter/28 mm WT pipe. On top of this, they get overtime payment for the four extra hours they can make to the maximum 12 hours shift. They will land a final bonus, when they complete a total of four welds per filling team. This encouragement system works well because practically always the maximum of 6 x 4 welds per day is achieved. These welders, the majority coming from countries such as India, Pakistan and the Philippines, understandingly display a great loyalty to SRB, because they are well-treated and paid well.

Nacap
Nacap - a global player Nacap bv with head quarters in Eelde, The Netherlands, is a global managing contractor, asset manager and preferred supplier specialised in underground infrastructures, providing multidisciplinary solutions for transporting oil, gas, water, electricity and data. In the Middle East, Nacap operates as Suedrohrbau, in the CIS as Fernleitungs- und Anlagenbau GmbH and in other parts of the world as Nacap. Nacap has offices and operating bases in all of these areas, giving strong representation at regional and local levels. Since the early 1960s Nacap circled the globe with the construction of more than 45,000 km of pipelines in a variety of diameters up to DN 1500 (60”).

Pangulf Welding Solutions and Magnatech
Pangulf Welding Solutions is part of the Pangulf Group, the principal steel products supplier to the Saudi Arabian market and listed in the top 100 Saudi companies. It is a “one-stop” welding solutions supplier with competent and experienced personnel. It stocks an extensive product range of consumables and equipment of world-class brands such as ESAB and Magnatech. Pangulf’s services to the industry include consultation and training.
Magnatech Europe BV is the sales and service organisation for Magnatech Limited Partnership, East Granby, USA, for the continent of Europe, the Middle East and Africa. Magnatech Ltd. is the manufacturer of specialised equipment for orbital pipe and tube welding using the GTAW, FCAW and GMAW welding process. Magnatech Europe is located in Dronten, The Netherlands. It supplies innovative systems to both manufacturers and contractors, who require precision welding tools for tasks from simple fusion welding to multipass applications requiring wire feed, torch oscillation and arc voltage control.