Spacer fluid compositions, methods, and systems for aqueous based drilling mud removal

Abstract

Spacer fluids include an emulsion, a surfactant package, and at least one additive that modifies the rheology of the spacer fluid, the density of the spacer fluid, or both. The emulsion may include an aqueous external phase and a hydrocarbon-based internal phase. The surfactant package may include one or more surfactants. The surfactant package may also include a surfactant having the general structure R—(OCH2CH2)9—OH, where R is a hydrocarbyl having 12 carbon atoms, 13 carbon atoms, or 14 carbon atoms. The spacer fluid may contain at least 4.25 pounds of R—(OCH2CH2)9—OH per barrel of the spacer fluid.

Dependencies are inferred from the claim text.