Uplift keeps the oil rigs drilling
In a different setting, Trelleborg CRP’s expertise in weight reduction plays a vital role in facilitating access to the new oil and gas supplies needed to keep the world turning.
We are increasingly dependent on oil and gas produced at sea for supplies of this dominant energy source. To ensure supplies, exploration and production is pushing into ever-deeper waters. This creates a challenge for floating drilling oil rigs. The drill bit, and the drill string connecting it to the rig, are protected in the water column by a drill riser, a cylindrical metal casing deployed from the rig down to the wellhead on the seabed.
As the water depth increases, so does the weight of the drill riser and as the drill riser gets longer, problems arise in handling it and maintaining its integrity. In very deep waters, the weight can simply be too much for the rig.
These difficulties are overcome with the use of buoyancy modules placed around the riser to provide uplift and reduce the drill riser’s weight in water.
Trelleborg CRP is supplying buoyancy modules to the majority of the market, according to Billy Nitsche, Product Group Manager for drilling and syntactic products at Trelleborg CRP.
“To date, we have supplied some 175,000 modules to the market – more than any other company,” he says.
The typical requirement for weight reduction is a massive 95 percent or more. Nitsche presents some figures to illustrate what this means in practice. A typical 22-meter drill riser joint (the drill riser string is made up of multiple riser joints attached together) weighs more than 14 tons in air. With buoyancy modules attached, the combined weight could be 25 tons in air. However, when placed in water, the uplift provided by the buoyancy modules reduces the combined weight to just 250 kilograms.
Based in Houston, Texas, the world’s oil center, Trelleborg CRP is currently experiencing a boom for its product. High oil prices and concerns about future supplies have encouraged a wave of orders for new offshore drilling rigs, in turn, triggering orders for new sets of buoyancy modules.
“We are really busy now, working 24/7 and producing record levels of modules each week,” says Nitsche. “We are also in the midst of an expansion program that will substantially increase our capacity by April/May 2008.”
Why is the company so dominant in the drilling buoyancy market?
“We know how to design modules to provide the maximum uplift with the minimum amount of material,” says Nitsche. “The key components are syntactic foam and microballoons, both of which we developed ourselves. Consequently, we understand their behavioral characteristics when blended in this unique composite product.”
www.trelleborg.com/offshore
This article relates to the following industries:
- Energy and power
- Oil and gas