Case story: Oil company increases manifold reliability and service life

Using deep sea manifolds produced by Sandvik's HIP technology a large oil and gas company could increase manifold reliability and service life.

The challenge

An international oil and gas company was looking for ways to improve the reliability of manifolds used on the ocean floor. Traditional manufacture of complex shaped manifolds needs over-dimensioned material thickness, complicated machining and a large number of welds that require high integrity inspection. Manifold failure must be avoided, since it leads to well shut downs for product replacement and such failures can involve lost production costing millions of dollars.

The Sandvik solution

The powder technology used by Sandvik addresses many of the problems involved with traditional manifold manufacture. Using hot isostatic pressing (HIP), Sandvik offers increased design flexibility and the manufacture of complex products with many fewer welds. Near net shape also means less machining.

Additional material benefits include very high impact toughness compared with alternatives and retained strength when exposed to low temperatures.

Manifolds manufactured in duplex stainless steels are in high demand for oil and gas production because of their high yield strength and excellent corrosion resistance. Traditionally manufactured duplex products can, however, be subject to hydrogen-induced stress cracking (HISC), a problem that can cause critical failures in some subsea installations, as has been experienced, for example, in the North Sea. HIP results in a homogenous and isotropic material with a much smaller grain size, which is easier to inspect by ultrasonic techniques and minimizes the risk of HISC.

The result

The decision to use HIP manifolds from Sandvik has provided the customer with maintenance-free and safe manifolds that will last the lifetime of the well.

Today, Sandvik HIP products such as manifolds, valve bodies, swivel components, flanges, fittings and wye-pieces are found in a great number of offshore subsea and topside installations worldwide.

To an industry continuously looking for increased reliability, Sandvik's powder technology capability greatly reduces the risk of costly failures.

The production process

Sandvik's hot isostatic pressing (HIP) is based on powder metallurgy (PM).

Offshore applications

Sandvik's HIP products excellent resistance to hydrogen-induced stress cracking (HISC) make them a perfect choice for various offshore applications.

HIP advantages

Using HIP products instead of, for example, castings and forgings mean several advantages, such as less machining and welding.