TPi January 2017

Injection pipes allow chemicals to be used in the extraction process in targeted fashion to liquefy the oil

TIG orbital weld from inside: in order to supply lengths of 15,000m and more, individual pipes are orbitally welded together

Careful testing of control and injection pipes

that the orbital weld is airtight and free of any pores. Before delivery to customers, Schoeller Werk also subjects the control and injection pipes to a hydraulic test. This involves filling the finished coils with hydraulic fluid and subjecting them to pressures of up to 2,500 bars to simulate the extreme conditions sometimes experienced in offshore work. Service offering supplements manufacturing skill Apart from pure manufacture of pipes, Schoeller Werk offers its customers from the offshore industry a comprehensive service package that includes, for example, encapsulation of pipes with plastic sheathing in so-called flat packs. This means that bundles of pipes can be attached to the extraction tubes and protected from buckling and squashing. Other services include flushing and filling of pipes. Here, the insides of the pipes are flushed with hydraulic fluid until the fluid reaches the specified ISO or SAE purity classification. The fluid filtered in this way can remain in the pipes if the customer requires, meaning that users obtain a product that is ready to use. It is also possible to equip the pipe bundles with electrical wiring or stainless steel support cables. Thanks to the smooth internal surface, plug-drawn pipes are also suitable for use as ducting for optical fibre cables transmitting signals using light. Offshore – a global market In its work with the offshore industry, Schoeller Werk has joined an international market. Apart from Norway and Great Britain around the North Sea in Europe, Russia, Saudi Arabia, UAE, Africa, Asia, Australia and South America all count among the key target regions for use of the Schoeller control- line and chemical-injection pipes. Photo credit: Schoeller Werk

The offshore industry uses such pipes as hydraulic control lines for safety valves as well as for pumping chemicals into an oil reservoir. In this way, they support the entire extraction process. The injection pipes make it possible for rig operators to use chemicals in targeted fashion to liquefy the oil and thus improve its flow properties. During the complex manufacturing process, the pipes undergo various tests in order to ensure the special quality of the products before they are installed. Strips of metal are welded with a longitudinal seam using the tungsten inert gas (TIG) welding process and rolled into tubes. Apart from the obligatory eddy current testing, the tubes subsequently undergo an air under water (AUW or ‘bubble’) test. The tubes are submerged in water and filled with air to a pressure of up to 210 bars. A visual inspection is made along the entire length of the tubes to check that they are airtight. So that Schoeller Werk can supply its customers with the required lengths of 15,000m and more, individual pipes are orbitally welded together and an X-ray is made to check

Schoeller Werk’s service package includes ‘flat packs’, in which pipes are sheathed in plastic

Schoeller Werk GmbH & Co KG – Germany info@schoellerwerk.de www.schoellerwerk.de

58

TUBE PRODUCTS INTERNATIONAL January 2017

www.read-tpi.com