Web Exclusive — High-pressure accumulators make deep sea drilling safer

Deep-sea drilling rigs are going deeper than ever before.

For the past three months, the world has been bombarded with stories and images from the Gulf Coast oil spill. The news has put a close spotlight on hydraulics, which is used extensively in offshore drilling, because of its high-pressure capabilities and safety features. One such component is the piston accumulator, which can help control blowout prevention systems (BOPs), well-head control panels, “Christmas” trees and other emerging drilling systems.

Parker Hannifin Corp.’s Global Accumulator Div., Rockford, Ill., offers piston accumulators for the oil and gas market with working pressure ratings up to 30,000 psi and capacities of 160+ gallons. Such high-pressures are required as offshore drilling rigs go deeper and deeper in their search for oil and gas. With most of the controls on deck, it is necessary to have high-pressure components that can move fluid 10,000 ft or more below the surface

The extreme depths and power needs of offshore drilling are met with high-pressure components such as piston accumulators.

In addition, the harsh environments of these mostly saltwater areas require special materials, often stainless steel, to prevent rust and corrosion. As a result, piston accumulators need special pressure vessel certifications, including:

• ABS – American Bureau of Shipping
• DNV – Det Norske Veritas (E-101 regulations)
• PED – European Pressure Equipment Directive “CE” Marking
• ASME – American Society of Mechanical Engineers
• CRN – Canadian Registration Number
• AS1210 – Australian Certification
• Multiple certifications on a single vessel

While certification means different things in different markets, its ultimate goal is to guarantee safety. For instance, when used on a BOP, accumulators can be used to shut down the oil well, and prevent oil leakage. They are often used when the primary power source fails. At the deck level, they provide an emergency source of energy.

Parker Hannifin’s piston accumulators for the oil and gas market with working pressure ratings up to 30,000 psi and capacities of 160+ gallons.

Offshore is leading the way, but all industries are moving towards higher pressure requirements, including mobile equipment. One benefit: systems generate more force from smaller accumulators and smaller cylinders. Accumulators are also key components in increasing safety on mobile equipment. For example, they can used to steer or stop a large mining truck in case of loss of hydraulic control.

In addition to high pressure-rated units for subsea applications, Parker offers piston accumulators rated to below -40°F. This extreme temperature range lets users operate their equipment in virtually any environment.

Parker’s piston accumulator line includes 1.5- to 25-in. bore sizes with capacities up to 200 gal. All are custom designed to fit a specific application.

The information in this article was provided by Jeff Sage (JSage@parker.com), Bryan E McGehee (BEMcGehee@parker.com), and Mike Schubert (MSchubert@parker.com). For more information, visit www.parker.com/accumulator or call (815) 636-4100.