Abstract: A brine-based viscosified pill including (1) a viscosified brine, (2) a surfactant-solvent blend containing about 5 wt. % to about 40 wt. % of at least one nonionic surfactant; about 5 wt. % to about 20 wt. % of at least one polyglycerol ester, about 20 wt. % to about 60 wt. % of at least one co-solvent; about 20 wt. % to about 25 wt. % water; and optionally about 1 wt. % to about 15 wt. % of at least one hydrophobic solvent, and (3) no solid weighting agent, may be introduced to a wellbore in an effective amount to clean the wellbore or displace fluid in the wellbore at a wide range of temperatures.

Abstract: A brine-based viscosified pill including (1) a viscosified brine, (2) a surfactant-solvent blend containing about 5 wt. % to about 40 wt. % of at least one nonionic surfactant; about 5 wt. % to about 20 wt. % of at least one polyglycerol ester, about 20 wt. % to about 60 wt. % of at least one co-solvent; about 20 wt. % to about 25 wt. % water; and optionally about 1 wt. % to about 15 wt. % of at least one hydrophobic solvent, and (3) no solid weighting agent, may be introduced to a wellbore in an effective amount to clean the wellbore or displace fluid in the wellbore at a wide range of temperatures.

Abstract: Methods and formulations useful for controlling and optimizing the rheological properties of invert emulsion (water-in-oil) drilling fluids at low and high temperatures, wherein an additive is incorporated into an invert emulsion drilling fluid, the additive being made up of at least one organophilic clay, at least one weighting agent, at least one emulsifier, at least one filtration control agent, at least one polyamide resin, and at least one ethoxylated alcohol-based or an ether carboxylic acid-based rheology modifier.

Abstract: Carbon black particles and/or optional additional particle(s) may be introduced into fluids, such as drilling fluids, completion fluids, production fluids, stimulation fluids, and combinations thereof. The carbon black particles and/or optional additional particle(s) may increase the electrical and/or thermal conductivity, enhance the stability of an emulsion, improve wellbore strength, improve drag reduction properties, decrease corrosion, and the like. In a non-limiting embodiment, the base fluid may include a brine having at least one multivalent cation.