Before Schlumberger introduced its FUTUR active-set cement technology, mechanical properties of cement were designed to maintain hydraulic isolation during regular operations in well construction and production. Once cement has set, though, any damage to the sheath can allow hydrocarbons to leak. FUTUR, which is automatically activated upon contact with hydrocarbons, guards against leaks and sustained casing pressure at the wellhead during drilling, perforation and stimulation, and production. The technology guards against such damage after the cement has set.

“The self-healing characteristics of FUTUR when it comes in contact with hydrocarbons equips us to be prepared for unplanned operations,” Dominique Guillot, cement domain manager of well integrity technology for Schlumberger, said. The technology won the remediation category of Hart Energy’s 2008 Meritorious Awards for Engineering Innovation.

Whenever the cement sheath is damaged during a well’s long-term productive life, the technology reacts with any hydrocarbons flowing through cracks or microannuli and seals the pathways within hours. “One issue we sought to address with the FUTUR active-set cement technology was the uncertainty about the potential for mechanical failure of cementing materials behind a casing or liner or as a wellbore plugging material,” Guillot said.

The technology’s self-healing response can be repeated should annular integrity be compromised again later in the life of a well. “FUTUR is more flexible than many other cement systems at the same density and is therefore more resistant to most stresses associated with operations inducing a change in pressure or a change in temperature downhole,” Guillot said.

Since its introduction, the technology has been used in more than 15 countries around the world and for more than 20 companies. In the United Arab Emirates the active-set cement technology was used in a well located in the Khuff formation, one of the Middle East’s most challenging gas fields, according to International Petroleum Technology Conference (IPTC) Paper 14279. The active-set cement technology helped the operator solve casing problems around the well’s 9 5/ 8 -in. liner as well as in the 9/ 8 -in. tieback section, providing a secondary barrier.

While it does not replace good cementing practices, the technology can be used to increase the chance of success in wells with a perceived long-term risk of hydrocarbon leakage. The technology focuses on addressing the long-term durability of the cement sheath in wells, making needed repairs without the need for well intervention. In Pakistan, for example, the technology helped guard against hydrocarbon flow in a well subjected to surface pressures as high as 10,000 psi caused by fracturing operations, according to IPTC Paper 13049. Faced with the challenge of preserving long-term integrity in an HP/HT well, the operator used FUTUR to cement the production string and achieve long-term zonal isolation.

The technology continues to be used by the industry as a proactive solution. Since 2008, the company has increased the range of applications of the technology by extending the density range from 12 lb/gal to 10 lb/gal. “We also have extended the self-healing capabilities to perform when in contact with pure methane, which was a significant technical challenge,” Guillot said.