Schlumberger Extends Temperature Range of Durable Cement Technology

Schlumberger announced the availability of FlexSTONE HT* flexible cement, which is an extension of the FlexSTONE* advanced cement system for permanent zonal isolation of hydrocarbon reservoirs.

Both the temperature and flexibility range of the set cement system have been increased with the FlexSTONE HT formulation, which provides excellent mechanical properties at temperatures ranging from 40°F to 482°F, or 4°C to 250°C. Deeper, hotter, more complex wells can be reliably sealed for life to achieve maximum production from the reservoir.

"The FlexSTONE HT advanced cement system is designed in synergy with downhole rock properties and to endure dynamic downhole conditions, such as variable pressures and temperatures, some of which can be caused by downhole testing and treatments or formation loading," said Sandra Aldana, cementing business development manager, Schlumberger.

An operator in the North Sea recently used the FlexSTONE HT system to create a seal above a high-pressure formation that potentially could cause annular pressure problems later in the production cycle of the well.

The unique capabilities of the CemCRETE* family of cements were adapted to create the FlexSTONE HT system, which uses flexible and expansive materials. CemCRETE technology increases the solids content of a slurry using optimized particle-size distribution. With up to two percent cement expansion, it is possible to prestress FlexSTONE HT cement, enabling the sheath to close a microannulus several hundred microns in size, potentially sealing fluid leak paths.

Coupling the FlexSTONE HT system with advanced job design, including the ability to model downhole properties and conditions expected during well operation, ensures its long-term performance in the field. By imparting the ability to engineer the cement system's mechanical properties to match dynamic downhole HPHT conditions, FlexSTONE HT technology provides solutions for long-term zonal isolation of well fluids during the drilling, production and abandonment stages of a well's life cycle.