Abstract: Methods and compositions (e.g., comprising an emulsion or a microemulsion) for use in various aspects of the life cycle of an oil and/or gas well are provided. In some embodiments, an emulsion or the microemulsion comprises water, a solvent, and a surfactant, and optionally, one or more additives, such as a co-surfactant or a linker. In some embodiments, a concentrate is provided which may be used to form an emulsion or microemulsion.

Abstract: Mesophase surfactant solutions and/or micellar solutions, pre-formed single phase microemulsions (SPMEs), and in situ-formed fluids may be used to clean up and remove hydrocarbons and synthetic oils such as oil-based mud filter cake and near wellbore damage in oil and gas wells. Removal occurs by solubilization of the hydrocarbons and synthetic oils into the micellar solutions, SPME, in situ-formed fluids, etc. when the fluid formulation contacts the hydrocarbons and synthetic oils. An in situ-formed fluid (e.g. microemulsion), may be formed when one or more surfactant, an optional linker, optional co-surfactant, optional acid, optional co-solvent and a polar high-density brine phase, and eventually some amount of organic phase, contacts the subterranean location and solubilizes the hydrocarbons and synthetic oils encountered, such as in the near wellbore of a subterranean formation. The micellar solutions, microemulsions, in situ-formed fluids, etc.

Abstract: A treatment composition may contact an oil-based mud (OBM) filter cake formed over at least part of a wellbore for cleaning the filter cake by incorporating more oil and/or filter cake particles into the treatment composition as compared to an otherwise identical filter cake absent the treatment composition. The treatment composition may include, but is not limited to, a surfactant, an aqueous-based fluid, an agent, an optional second acid, and combinations thereof. The agent may be or include long chain alcohols, phenol derivatives, fatty esters, a first acid, and combinations thereof. The first acid may be or include a diacid. The diacid may be a polycarboxylic diacid, such as but not limited to [N-(1,2-dicarboxyethylene)D,L asparagine acid] (IDS), polyaspartic acid (DS), ethylenediamine-disuccinic acid (EDDS), [N,N-bis(carboxylmethyl)L-glutamic acid] (GLDA), methylglycinediacetic acid (MGDA), salts thereof, derivatives thereof, and combinations thereof.

Abstract: Methods and compositions (e.g., comprising an emulsion or a microemulsion) for use in various aspects of the life cycle of an oil and/or gas well are provided. In some embodiments, an emulsion or the microemulsion comprises water, a solvent, and a surfactant, and optionally, one or more additives, such as a co-surfactant or a linker. In some embodiments, a concentrate is provided which may be used to form an emulsion or microemulsion.

Abstract: Incorporating at least oil-soluble organic peroxide into a mixture of an aqueous phase and at least one surfactant creates a breaker fluid that is a microemulsion or a nanoemulsion that can then perform as an internal breaker for reducing the viscosity of aqueous fluids gelled with a polymer, such as a crosslinked polysaccharide. One phase of the breaker fluid is water or water-based, e.g. brine, containing at least one oil-soluble organic peroxide as a non-aqueous internal phase that will, over time and optionally with heat, break the polymer-gelled portion of the gel. The overall breaking using the breaker fluid is slower as compared to introducing the organic peroxide breaker in a non-microemulsified or non-nanoemulsified form.

Abstract: Mesophase surfactant solutions and/or micellar solutions, pre-formed single phase microemulsions (SPMEs), and in situ-formed fluids may be used to clean up and remove hydrocarbons and synthetic oils such as oil-based mud filter cake and near wellbore damage in oil and gas wells. Removal occurs by solubilization of the hydrocarbons and synthetic oils into the micellar solutions, SPME, in situ-formed fluids, etc. when the fluid formulation contacts the hydrocarbons and synthetic oils. An in situ-formed fluid (e.g. microemulsion), may be formed when one or more surfactant, an optional linker, optional co-surfactant, optional acid, optional cosolvent and a polar high-density brine phase, and eventually some amount of organic phase, contacts the subterranean location and solubilizes the hydrocarbons and synthetic oils encountered, such as in the near wellbore of a subterranean formation. The micellar solutions, microemulsions, in situ-formed fluids, etc.

Abstract: A treatment composition may contact an oil-based mud (OBM) filter cake formed over at least part of a wellbore for incorporating more oil and/or filter cake particles into the treatment composition as compared to an otherwise identical filter cake absent the treatment composition. The treatment composition may include, but is not limited to, a surfactant, an aqueous-based fluid, an agent, an optional second acid, and combinations thereof. The agent may be or include long chain alcohols, phenol derivatives, fatty esters, a first acid, and combinations thereof. The first acid may be or include citric acid, oleic acid, tartaric acid, stearic acid, linoleic acid, linolenic acid, aromatic dicarboxylic acids, oxalic acid, malonic acid, succinic acid, glutaric acid, boric acid, adipic acid, a diacid, a triacid, a tetraacid, and combinations thereof.

Abstract: Incorporating at least oil-soluble organic peroxide into a mixture of an aqueous phase and at least one surfactant creates a breaker fluid that is a microemulsion or a nanoemulsion that can then perform as an internal breaker for reducing the viscosity of aqueous fluids gelled with a polymer, such as a crosslinked polysaccharide. One phase of the breaker fluid is water or water-based, e.g. brine, containing at least one oil-soluble organic peroxide as a non-aqueous internal phase that will, over time and optionally with heat, break the polymer-gelled portion of the gel. The overall breaking using the breaker fluid is slower as compared to introducing the organic peroxide breaker in a non-microemulsified or non-nanoemulsified form.