HIGH-PERFORMANCE SEAWATER-BASED FLUID COMPOSITION FOR DRILLING PETROLEUM WELLS WITH HIGHLY HYDRATABLE AND DISPERSIBLE FORMATIONS

摘要

The present invention relates to the petroleum industry in general and in particular relates to the means, systems and fluid compositions used in petroleum-well drilling, and more specifically to a high-performance seawater-based fluid composition for drilling petroleum wells with highly hydratable and dispersible formations, characterized in that it comprises at least one alkalinizing element, pH controllers and a magnesium precipitator, preferably caustic soda; at least one organic modifier with rheological properties that comprises a high-purity biopolymer, preferably xanthan gum; at least one calcium sequestrant, preferably sodium carbonate (soda ash); clay inhibitors; fluid-loss controllers; at least one mechanical hole stabilizer; at least one penetration-speed enhancer and lutite inhibitor; one thermal stability extender; a sealing and densifying agent; and at least one disinfectant, preferably barite.