Abstract: A wellbore fluid may include a non-oleaginous internal phase, an oleaginous external phase, and an emulsifier having a molecular weight of at least 700 daltons, whereby the emulsifier may include at least one tertiary amine. A method of completing a wellbore operation may include injecting a wellbore fluid downhole, the wellbore fluid including a non-oleaginous internal phase, an oleaginous external phase, and an emulsifier having a molecular weight of at least 700 daltons. The emulsifier may include at least one tertiary amine. The method may further include injecting a wash fluid comprising a protonating agent downhole.

Abstract: A wellbore fluid may include a non-oleaginous internal phase, an oleaginous external phase, and an emulsifier having a molecular weight of at least 700 daltons, whereby the emulsifier may include at least one tertiary amine. A method of completing a wellbore operation may include injecting a wellbore fluid downhole, the wellbore fluid including a non-oleaginous internal phase, an oleaginous external phase, and an emulsifier having a molecular weight of at least 700 daltons. The emulsifier may include at least one tertiary amine. The method may further include injecting a wash fluid comprising a protonating agent downhole.

Abstract: Emulsion-preventing compositions may contain one or more sorbitan esters; and one or more non-ionic surfactants; where the ratio of the one or more sorbitan esters to the one or more non-ionic surfactants is in the range of 1:1 to 1:5. Methods may include contacting an emulsion with a treatment fluid, the treatment fluid containing one or more sorbitan esters and one or more non-ionic surfactants, where the ratio of the one or more sorbitan esters to the one or more non-ionic surfactants is in the range of 1:1 to 1:5; and separating the emulsion into an aqueous phase and an oleaginous phase.

Abstract: Non-emulsifying compositions may contain one or more sorbitan esters; one or more non-ionic surfactants; and one or more amphoteric surfactants, wherein the ratio of the one or more sorbitan esters to the one or more non-ionic surfactants to the one or more amphoteric surfactants is in the range of 1:1:1 to 1:5:3. Methods may include contacting an emulsion with a treatment fluid, the treatment fluid containing one or more sorbitan esters, one or more non-ionic surfactants, and one or more amphoteric surfactants, wherein the ratio of the one or more sorbitan esters to the one or more non-ionic surfactants to the one or more amphoteric surfactants is in the range of 1:1:1 to 1:5:3; and separating the emulsion into an aqueous phase and an oleaginous phase.

Abstract: A method comprising degrading a filtercake with a breaker comprising a urea-based polymer is provided. Also, a breaker composition is provided which includes a urea-based polymer that can hydrolyze in the presence of water and heat to release water-soluble byproducts and intermediates.

Abstract: Emulsion-preventing compositions may contain one or more sorbitan esters; and one or more non-ionic surfactants; where the ratio of the one or more sorbitan esters to the one or more non-ionic surfactants is in the range of 1:1 to 1:5. Methods may include contacting an emulsion with a treatment fluid, the treatment fluid containing one or more sorbitan esters and one or more non-ionic surfactants, where the ratio of the one or more sorbitan esters to the one or more non-ionic surfactants is in the range of 1:1 to 1:5; and separating the emulsion into an aqueous phase and an oleaginous phase.

Abstract: Non-emulsifying compositions may contain one or more sorbitan esters; one or more non-ionic surfactants; and one or more amphoteric surfactants, wherein the ratio of the one or more sorbitan esters to the one or more non-ionic surfactants to the one or more amphoteric surfactants is in the range of 1:1:1 to 1:5:3. Methods may include contacting an emulsion with a treatment fluid, the treatment fluid containing one or more sorbitan esters, one or more non-ionic surfactants, and one or more amphoteric surfactants, wherein the ratio of the one or more sorbitan esters to the one or more non-ionic surfactants to the one or more amphoteric surfactants is in the range of 1:1:1 to 1:5:3; and separating the emulsion into an aqueous phase and an oleaginous phase.

Abstract: Methods may include circulating a first wellbore fluid into a wellbore, wherein the first wellbore fluid contains: a non-aqueous continuous phase, and a polyester internal breaker; wherein the first wellbore fluid generates a filter cake in at least a section of the wellbore; circulating a second wellbore fluid into the wellbore, wherein the second wellbore fluid contains an acid source and a surfactant; and allowing the second wellbore fluid to degrade at least a portion of the filter cake. Other methods may include circulating a wellbore fluid into a wellbore drilled with an oil-based mud containing a polyester fluid loss additive, wherein the wellbore fluid comprises one or more surfactants and an acid source.

Abstract: A drilling fluid, comprising an aqueous continuous phase, a polymeric fluid loss control agent formed from at least an acrylamide monomer, and a sulfonated anionic monomer, and a gelling material comprising at least one of clay or a cross-linked polyvinylpyrrolidone.