The present disclosure relates to spacer fluids for use in subterranean operations and, more particularly, in certain embodiments, to spacer fluids that include a spacer additive comprising a solid scouring material and a biopolymer gum while being essential free of clay. An example method may comprise spacer fluid comprise water and a spacer additive. The spacer additive may comprise a solid scouring material and a biopolymer gum, wherein the solid scouring material comprises crystalline silica in an amount of about 5 wt. % or less, and wherein the spacer fluid is essentially free of clay. The example method may further comprise and introducing the spacer fluid into a wellbore to displace at least a portion of a first fluid in the wellbore.

The present disclosure relates to spacer fluids for use in subterranean operations and, more particularly, in certain embodiments, to spacer fluids that include a spacer additive comprising a solid scouring material and a biopolymer gum while being essential free of clay. An example method may comprise spacer fluid comprise water and a spacer additive. The spacer additive may comprise a solid scouring material and a biopolymer gum, wherein the solid scouring material comprises crystalline silica in an amount of about 5 wt. % or less, and wherein the spacer fluid is essentially free of clay. The example method may further comprise and introducing the spacer fluid into a wellbore to displace at least a portion of a first fluid in the wellbore.

An omniphobic emulsion comprising an aqueous continuous phase having dispersed therein a plurality of non-aqueous discontinuous phase droplets; wherein the non-aqueous discontinuous phase droplets are characterized by a droplet size of less than about 100 micrometers (μm); wherein each of the plurality of non-aqueous discontinuous phase droplets comprises a plurality of surfactant molecules and an omniphobic agent, wherein each surfactant molecule has a hydrophilic head portion and a hydrophobic tail portion; wherein each of the plurality of non-aqueous discontinuous phase droplets comprises the plurality surfactant molecules having the hydrophilic head portions disposed into a droplet outer layer with the hydrophobic tail portions extending inward from the droplet outer layer toward the omniphobic agent; and wherein the droplet outer layer encloses the omniphobic agent.

A method for acid treatment of a wellbore in a carbonate formation is provided. The method includes dropping spacer solids into the well to fill the wellbore to perforations in a casing, dropping acidic solids into the wellbore on the top of the spacer solids, allowing the acidic solids to dissolve on top of the spacer solids forming an acidic solution, and injecting water into the wellbore to force the acidic solution into the carbonate formation.

A method for acid treatment of a wellbore in a carbonate formation is provided. The method includes dropping spacer solids into the well to fill the wellbore to perforations in a casing, dropping acidic solids into the wellbore on the top of the spacer solids, allowing the acidic solids to dissolve on top of the spacer solids forming an acidic solution, and injecting water into the wellbore to force the acidic solution into the carbonate formation.

Well treatment compositions comprise water, a lipophilic anionic surfactant, a hydrophilic non-ionic surfactant, a second non-ionic surfactant, a water-solubilizing solvent, a water-immiscible solvent and a lipophilic non-ionic surfactant. Optionally, a second solvent may be incorporated. When added to spacer fluids, chemical washes or both, the compositions promote the removal of non-aqueous drilling fluids from casing surfaces. Additionally, the treated casing surfaces are water wet, thereby promoting optimal bonding to cement.

Well treatment compositions comprise water, a lipophilic anionic surfactant, a hydrophilic non-ionic surfactant, a second non-ionic surfactant, a water-solubilizing solvent, a water-immiscible solvent and a lipophilic non-ionic surfactant. Optionally, a second solvent may be incorporated. When added to spacer fluids, chemical washes or both, the compositions promote the removal of non-aqueous drilling fluids from casing surfaces. Additionally, the treated casing surfaces are water wet, thereby promoting optimal bonding to cement.

A method of treating a well comprising introducing a well treatment fluid into the well, and a well treatment fluid, are provided. The well treatment fluid comprises an aqueous base fluid, sepiolite clay, and a polymer component selected from the group of an acryloylmorpholine polymer, a polyvinylpyrrolidone polymer, and mixtures thereof. In one embodiment, for example, the method is a method of drilling a well. In this embodiment, the well treatment fluid is a drilling fluid.

A method of treating a well comprising introducing a well treatment fluid into the well, and a well treatment fluid, are provided. The well treatment fluid comprises an aqueous base fluid, sepiolite clay, and a polymer component selected from the group of an acryloylmorpholine polymer, a polyvinylpyrrolidone polymer, and mixtures thereof. In one embodiment, for example, the method is a method of drilling a well. In this embodiment, the well treatment fluid is a drilling fluid.

Methods and compositions comprising an emulsion or a microemulsion for use treating an oil and/or gas well are provided. In some embodiments, the emulsion or the microemulsion comprises an aqueous phase, a solvent, a surfactant comprising alkyl polyglycoside, an alcohol, and, optionally, one or more additives.