Fiber technology is used for lost circulation and can enhance the mechanical properties of cement. For instance, fibers can add cohesiveness, increase ductility, and add resiliency to set cement, thus helping provide long-term durability while helping control cracking and rubblizing during drilling and perforating.
Historically, the most commonly used fibers have been glass, steel, graphite, polyesters, polyamides, polypropylenes, and polyolefins. Polypropylene fiber has been preferred in oilwell cementing because of its availability, resistance to corrosion and degradation, and because it is inert to alkaline media. However, most polypropylene fibers are hydrophobic, and may tend to clump together, preventing homogenous dispersion of the fiber into the slurry.
Halliburton has overcome this with Tuf Fiber® 594 Lost Circulation Additive. It is a hydrophilic polypropylene fiber readily dispersible in dry blend, slurry, or mixing water without matting. It is compatible with water-based, oil-based, and synthetic-based fluids, and has been tested and found to satisfy requirements of the U.S. Environmental Protection Agency for offshore drilling applications.
When blended into cement slurry systems, Tuf Fiber™ 594 cement additive helps overcome lost circulation while improving wellbore strength by adding cohesiveness and increased ductility to the set cement sheath.