An effective amount of amphiphilic star polymers and surfactants may be applied to downhole fluids containing oil-in-water and water-in-oil emulsions, such as drilling fluids, completion fluids, drill-in fluids, workover fluids, and remediation fluids, to stabilize the emulsions and improve rheological properties of these fluids for use in oil and gas production operations. The star polymers and surfactants may be applied to the downhole fluid separately or as a blend to generate emulsions within the fluid that have substantially uniform droplet size.

Apparatus and methods for determining the fluid conductivity of a fluid network. The method includes injecting a nanoemulsion into the formation, the nanoemulsion including a carrier liquid and nanodroplets. The nanodroplets are stabilized within the carrier liquid by polymer-coated iron oxide nanoparticles. After extracting fluid from the formation, a parameter of the extracted nanodroplets is determined. Based on the determined parameter, the fluid conductivity of the fluid network is determined.

A process for making a composition of matter that includes the steps of preparing an aqueous phase and an oil phase, and emulsifying the aqueous phase and the oil phase together to form a water-in-oil emulsification. The water-in-oil emulsification is then homogenized or otherwise processed to form an emulsification product, followed by the step of initiating a polymerization reaction of the emulsification product to form a polymerization reaction product. Lastly, the process includes inverting or otherwise processing the polymerization product to form the composition of matter having: 15-25% oil phase; 35-50% water; 20-35% polymer; 0-10% surfactant; and 0-3% other trace materials.

A method of reducing a density of a density of a stable emulsion drilling fluid may comprise providing a stable emulsion drilling fluid comprising: an aqueous liquid; a biopolymer; an emulsifier; solid particulates; and an oil; wherein the stable emulsion drilling fluid is capable of remaining in quiescent storage at approximately 70 F. and atmospheric pressure without phase separation for about 8 hours or longer; circulating the stable emulsion drilling fluid though a drill string and annulus; adding additional oil to the stable emulsion drilling fluid to decrease the density of the stable emulsion drilling fluid and produce a reduced density stable emulsion drilling fluid; and circulating the reduced density stable emulsion drilling fluid though the drill string and the annulus.

Emulsions, treatment fluids and methods for treating subterranean formations are provided, wherein the emulsions comprise water, a water-immiscible liquid, one or more polymers, one or more ethoxylated amine compounds and optionally, one or more organic or inorganic salts. The emulsions are particularly suitable for use in harsh brine conditions.

Emulsions, treatment fluids and methods for treating subterranean formations are provided, wherein the emulsions comprise water, a water-immiscible liquid, one or more polymers, one or more ethoxylated amine compounds and optionally, one or more organic or inorganic salts. The emulsions are particularly suitable for use in harsh brine conditions.

A drilling fluid containing a liquid phase, a weighting agent (e.g. barite, calcite, ilmenite), and perlite is described. The drilling fluid may further contain one or more additives including a defoamer, a fluid-loss control agent, a viscosifier, an antiscalant, a deflocculant, a lubricant, a clay stabilizer, a bridging agent, and a surfactant. A process of drilling a subterranean geological formation utilizing the drilling fluid is also specified. The introduction of perlite to the drilling fluid is effective in reducing the thickness and permeability of filter cakes formed during the drilling process.

Methods for treating an oil or gas well having a wellbore and selecting compositions for treating an oil or gas well having a wellbore.

Methods for treating an oil or gas well having a wellbore and selecting compositions for treating an oil or gas well having a wellbore.

Flowback aid mixtures and oil-in-water microemulsions produced by combining an aqueous brine with the flowback aid mixtures are disclosed. The flowback aid mixture comprises an oil, a fatty alcohol ethoxylate, and a quaternized fatty amine ethoxylate. The amount of oil is less than or equal to 12 wt. % based on the amount of flowback aid mixture. The microemulsions have a surface tension at 25 C. less than 30 mN/m and a Z-average particle size as determined by dynamic light scattering at 25 C. of less than or equal to 10 nm. Also disclosed are processes that utilize the flowback aid mixtures. In one process, the mixture is introduced into a subterranean formation and is combined prior to or during its introduction into the formation with a formation brine, process water, or both to give the microemulsion. In one hydraulic fracturing process for recovering gas, oil, or both, a fracturing fluid and the flowback aid are co-injected into a subterranean formation to give the microemulsion.