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FUTUR Active Set-Cement Technology
New cement technology reacts to hydrocarbon leaks in the cement sheath and responds immediately to seal them permanently
Many of the world's oil and gas wells develop leaks. Produced natural gas or oil often finds its way up the casing annulus to the surface through cracks in the cement sheath—cracks that are created by geologic stress, temperature and pressure changes, and other factors incurred over time. The hydrocarbon leaks produced can cause what's known as "sustained casing pressure" at the wellhead, resulting in a host of environmental and safety concerns.
"This is a serious issue for our customers," says Schlumberger Well Services product champion Mario Bellabarba. "Until now, there was no way to permanently fix these problems without a potentially expensive workover."
To address this, the engineering team at the Schlumberger Riboud Product Center (SRPC) has developed FUTUR active set-cement technology, an innovative cement system that heals cracks automatically as they occur. With the FUTUR cement system, a new level of security is added to maintain the cement sheath. This protection is available as soon as the cement sets, continues throughout and after the productive life of the well, and is repeatable. Active self-repairing features remain dormant in the set cement until they come in contact with hydrocarbons flowing through leaks in the cement sheath. FUTUR technology can be used throughout the wellbore or applied only to trouble zones that have historically developed leaks or caused sustained casing pressures.
"FUTUR active set-cement technology is the first cement system that can react to preserve well integrity after the cement has set," explains Bellabarba. "Earlier efforts focused on cement slurry design and placement to ensure zonal isolation."
Pumping FUTUR cement technology requires no additional equipment, personnel, or training. "The cement system is sent to the location and mixed and pumped just as we do with any primary cement job," adds Bellabarba.
In the five years since the SRPC team began working on the concept of self-healing cement, extensive testing has been performed to find the most suitable system to achieve this unique step change in cementing technology. New procedures and protocols were developed to confirm and quantify the effectiveness of these innovative self-healing materials. In addition to extensive laboratory tests, the technology has been field tested on numerous new wells around the world.
"When you think of the added benefit to an operator in terms of avoiding lost production and well repair or abandonment, the FUTUR active set-cement system can be deployed on at least one casing string of every well, anywhere in the world," says Bellabarba.
FUTUR active set-cement technology became commercially available in December 2007.
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