An invert emulsion fluid may include a oleaginous external phase, a nonoleaginous internal phase, wherein a ratio of the oleaginous external phase to nonoleaginous internal phase is less than 55:45, a emulsifier, a particulate weighting agent dispersed in the non-oleaginous internal phase, and a viscosifier stabilizing the dispersion of the particulate weighting agent in the non-oleaginous internal phase.

An invert emulsion fluid may include a oleaginous external phase, a nonoleaginous internal phase, wherein a ratio of the oleaginous external phase to nonoleaginous internal phase is less than 55:45, a emulsifier, a particulate weighting agent dispersed in the non-oleaginous internal phase, and a viscosifier stabilizing the dispersion of the particulate weighting agent in the non-oleaginous internal phase.

Precipitated particles may be formed under conditions that provide a particle morphology suitable for conveying a desired set of properties to a wellbore circulation fluid. Methods for using precipitated particles in a wellbore may comprise: selecting precipitation conditions for producing precipitated particles that are substantially non-spherical in shape, are about 1 micron or under in size, or any combination thereof; forming the precipitated particles from a reaction mixture under the precipitation conditions without using a polymeric dispersant; and introducing a wellbore circulation fluid comprising a plurality of the precipitated particles into a wellbore penetrating a subterranean formation. The precipitation conditions may include one or more of modulating various reaction conditions, applying an electric field to the reaction mixture, or including a carbohydrate-based material in the reaction mixture.

Precipitated particles may be formed under conditions that provide a particle morphology suitable for conveying a desired set of properties to a wellbore circulation fluid. Methods for using precipitated particles in a wellbore may comprise: selecting precipitation conditions for producing precipitated particles that are substantially non-spherical in shape, are about 1 micron or under in size, or any combination thereof; forming the precipitated particles from a reaction mixture under the precipitation conditions without using a polymeric dispersant; and introducing a wellbore circulation fluid comprising a plurality of the precipitated particles into a wellbore penetrating a subterranean formation. The precipitation conditions may include one or more of modulating various reaction conditions, applying an electric field to the reaction mixture, or including a carbohydrate-based material in the reaction mixture.

A well treatment composition for use in a hydrocarbon-bearing reservoir comprising a reversible aminal gel composition. The reversible aminal gel composition includes a liquid precursor composition. The liquid precursor composition is operable to remain in a liquid state at about room temperature. The liquid precursor composition comprises an organic amine composition; an aldehyde composition; and a polar aprotic organic solvent. The liquid precursor composition transitions from the liquid state to a gel state responsive to an increase in temperature in the hydrocarbon-bearing reservoir. The gel state is stable in the hydrocarbon-bearing reservoir at a temperature similar to a temperature of the hydrocarbon-bearing reservoir, and the gel state is operable to return to the liquid state responsive to a change in the hydrocarbon-bearing reservoir selected from the group consisting of: a decrease in pH in the hydrocarbon-bearing reservoir and an addition of excess metal salt composition in the hydrocarbon-bearing reservoir.

A well treatment composition for use in a hydrocarbon-bearing reservoir comprising a reversible aminal gel composition. The reversible aminal gel composition includes a liquid precursor composition. The liquid precursor composition is operable to remain in a liquid state at about room temperature. The liquid precursor composition comprises an organic amine composition; an aldehyde composition; and a polar aprotic organic solvent. The liquid precursor composition transitions from the liquid state to a gel state responsive to an increase in temperature in the hydrocarbon-bearing reservoir. The gel state is stable in the hydrocarbon-bearing reservoir at a temperature similar to a temperature of the hydrocarbon-bearing reservoir, and the gel state is operable to return to the liquid state responsive to a change in the hydrocarbon-bearing reservoir selected from the group consisting of: a decrease in pH in the hydrocarbon-bearing reservoir and an addition of excess metal salt composition in the hydrocarbon-bearing reservoir.

Acrylamide-derived hydrogels and methods of fabrication thereof from an acrylic monomer, a crosslinking agent comprising an organosilicon compound, a polymerization initiator, a solvent and a polymerization accelerator, as well as their use in controlling circulation losses. The obtained hydrogels interact with the walls of the reservoir and exhibits an increase in viscosity, either at delayed times or in response to a given stimulus, such as changes in temperature, pressure, pH, salinity, using a simple and easily scalable methodology.

Methods for treating a formation may include introducing components of a treatment solution into a wellbore such that the treatment solution contacts the formation to be treated, where the treatment solution may include urea, urease, a calcium ion source, one or more polysaccharides, a casein protein, a protease, an ionic compound, and a sugar, where the formation may have an amount of sand production before treatment and may be in fluid contact with the wellbore, and where an amount of sand production after treatment may be less than the amount of sand production before treatment. Consolidated sand structure compositions may include previously unconsolidated sand interlinked by inter-particle cementitious bonds comprising deposited calcium carbonate crystals, where the consolidated sand has a structural strength and the consolidated sand structure is porous to permit fluid flow through the composition.

Methods may include introducing a polymerizable composition containing a polycyclic monomer and a catalyst into a subterranean formation; and polymerizing the polymerizable composition in the presence of the catalyst in situ to form a polymer. Methods may also include lowering a wellbore tool into the subterranean formation, wherein the tool contains a first partition containing a polymerizable composition, and a second partition containing a catalyst; releasing the polymerizable composition from the first partition; releasing the catalyst from the second partition; contacting the polymerizable composition and the catalyst in a mixing region; and reacting the polymerizable composition and the catalyst in situ to form a polymer.

A method of sealing a formation that includes drilling a wellbore through the formation while pumping a non-aqueous based wellbore fluid comprising a first sealing component into the wellbore, wherein the non-aqueous based wellbore fluid filters into the formation as a filtrate and substantially thickens is disclosed. The substantially thickening may result from adding a second sealing component to the wellbore fluid, whereby the first sealing component initiates a reaction of the second sealing component.