Abstract: Viscoelastic surfactant (VES) gelled aqueous fluids containing water, a VES in an amount effective to increase the viscosity of the water, and an internal breaker may be useful in removing a residual polymer from a hydraulic fracture. Optionally, a pseudo-crosslinker may be present to further improve the properties related to treatment fluid placement and polymer clean-up. A plurality of aliquots of VES gelled fluid may be injected into a subterranean formation. A stop-start interval may exist between the injection of each aliquot. The VES gelled fluid may contact at least some of the residual polymer in the hydraulic fracture, and a broken fluid is formed once the viscosity of the VES gelled fluid is reduced with the internal breaker. At least a portion of the residual polymer and a majority of the broken fluid may be removed.

Abstract: Nanoparticle-treated substrates, such as screens, sand beds or proppant beds, may effectively filter and purify fluids such as waste water or fluids produced from a formation, as well as other liquids. When tiny contaminant particles in a fluid such as waste water flow contact the nanoparticle-treated substrate, the nanoparticles will capture and hold the tiny contaminant particles on the substrate due to the nanoparticles' surface forces, including, but not necessarily limited to van der Waals and electrostatic forces or other associative forces. Coating agents such as alcohols, glycols, polyols, vegetable oil, and mineral oils may help apply the nanoparticles to the surfaces of structures in the filter beds or packs.

Abstract: A flow control device includes, a body defining at least a portion of a flow passageway, at least one movable member in operable communication with the body, movable between at least a first position that provides a first restriction to flow through the flow passageway and a second position that provides a second restriction to flow through the flow passageway, and a circuit in operable communication with the at least one movable member that is configured to sense conductivity of fluid flowing through the flow passageway and to promote movement of the at least one movable member to move from the first position to the second position in response to a change in conductivity of fluid flowing through the flow passageway.

Abstract: Devices, systems and related methods control a flow of a fluid between a wellbore tubular and a formation using a flow control device having a flow space formed therein; and a flow control element positioned in flow space. The flow control element may be configured to flex between a first radial position and a second radial position to in response to a pressure differential along the flow space.

Abstract: Emulsified acids have been used to increase production rates of oil and gas in carbonate reservoirs through acid fracturing and matrix acidizing operations. An emulsifier is used to emulsify the aqueous acid with an oil, usually diesel. Very small particles, such as colloidal clay particles and/or nanoparticles increase the stability of the emulsified acids over an elevated temperature range.

Abstract: Compositions including relatively low reactivity acids and having a pH of from about 2 to about 5, mixed with viscoelastic surfactants (VESs) and internal breakers may serve as fluids, in a non-limiting embodiment as drilling fluids, to open underground hydrocarbon reservoirs with carbonate contents of 10 wt % or above. The fluids initially have low viscosities. After the fluid flows out of the drill bit, the acids react with carbonates in the formation thereby increasing the pH of the fluids causing the VES to gel the fluid at the bottom of the hole and within the formation rock. Even when the subterranean formation contains naturally-occurring fractures, the viscosified fluid will reduce fluid loss into the formation. After drilling through the targeted formation, internal breakers in the viscosified fluids will break down the fluids to permit their removal, and production of the well with very little or no near well bore damage.

Abstract: A disposable downhole tool is disclosed. The tool is suitable for use as a frac tool. The tool includes a housing having an inner wall surface defining a bore. The tool also includes a valve structure disposed within the bore, the valve structure comprising a disposable plug seat, the disposable plug seat comprising a first natural rock material. The disposable tool may also include a disposable plug in fluid sealing engagement with the seat, the plug comprising a second natural rock material, the plug and the plug seat comprising a plug valve. The first and second natural rock materials may include sedimentary rock, such as various forms of limestone, including Carrara marble or Indiana limestone.

Abstract: The components of surfactant-laden fluids, such as those used in hydrocarbon recovery operations such as for stimulation, e.g. hydraulic fracturing, may be re-used and re-cycled into components for subsequent use in a wide range of similar or different operational fluids. In particular, aqueous fluids gelled with viscoelastic surfactants and having components therein to pseudo-crosslink the elongated VES micelles and for internal breaking may be separated into its component parts by relatively inexpensive methods such as filtration. One filtration method includes contacting the surfactant-containing fluid with a particle pack having particulate additives therein which filter out or extract fine solids from the fluid. In an alternate embodiment the surfactant-laden fluid is a nano- and/or micro-emulsion wellbore cleanup fluid.

Abstract: Breaker nanoparticles may be added to gelled aqueous fluids where the gelled aqueous fluid may include an aqueous base fluid, e.g. a drilling fluid, gelled with at least one viscoelastic surfactant (VES) in an amount to increase the viscosity of the aqueous base fluid. The addition of the breaker nanoparticles may reduce the viscosity, or break the gel, of the gelled aqueous fluid by the direct or indirect action of the breaker nanoparticles. The breaker nanoparticles may be or include, but are not limited to inorganic semiconductor particles, organic semiconductor particles, and combinations thereof.

Abstract: Emulsified acids have been used to increase production rates of oil and gas in carbonate reservoirs through acid fracturing and matrix acidizing operations. An emulsifier is used to emulsify the aqueous acid with an oil, usually diesel. Very small particles, such as colloidal clay particles and/or nanoparticles increase the stability of the emulsified acids over an elevated temperature range.

Abstract: A fracturing fluid, gravel pack fluid and/or frac pack fluid containing particles such as proppants, gravel and/.or sand, may contain an effective amount of a nano-sized particulate additive to fixate or reduce fines migration, where the particulate additive is an alkaline earth metal oxide, alkaline earth metal hydroxide, alkali metal oxides, alkali metal hydroxides transition metal oxides, transition metal hydroxides, post-transition metal oxides, post-transition metal hydroxides piezoelectric crystals and pyroelectric crystals. The nano-sized particulate additive is optionally bound to the particles with a coating agent such as an oil, alcohol, glycol, glycol ethers, ketones, terpenes, etc. The particle size of the magnesium oxide or other agent may be nanometer scale but may be a larger scale than nanometer but still relatively small, which scale may provide unique particle charges that help fixate the formation fines.

Abstract: Incorporating water-based polymer breakers, such as oxidizers, enzymes and/or acids, into a mixture of an oil and oil-soluble surfactants creates an emulsion that can then perform as a dual-functional breaker for reducing the viscosity of hybrid fluids gelled with both a viscoelastic surfactant (VES) and a polymer. The outer phase of the dual-functional breaker emulsion is oil, e.g. a mineral oil, containing an oil-soluble surfactant that will, over time and with heat, break the VES portion of the gel. As it does so, the polymer breaker in the internal aqueous phase will be released to then break the polymer portion of the gel. The polymer breaker will not start to break the polymer gel before the oil-soluble surfactant starts to break the VES gel. The overall breaking using the emulsion is slower as compared to introducing the polymer breaker and the oil-soluble surfactant in a non-emulsified form.

Abstract: Alkaline earth metal compounds may be fluid loss control (FLC) agents for viscoelastic surfactant (VES) fluids used for fluid loss control pills, lost circulation material pills and kill pills in hydrocarbon recovery operations. The FLC agents may include, but not be limited to oxides and hydroxides of alkaline earth metal, and in one case magnesium oxide where the particle size of the magnesium oxide is between 1 nanometer to 0.4 millimeter. The FLC agent may alternatively be transition metal oxides and/or transition metal hydroxides. The FLC agent appears to associate with the VES micelles and together form a novel pseudo-filter cake quasi-crosslinked viscous fluid layer that limits further VES fluid flow into the porous media. The FLC agent solid particles may be added along with VES fluids. The pills may also contain internal breakers to reduce the viscosity thereof so that the components of the pill may be recovered.

Abstract: In hydrocarbon recovery applications, viscoelastic surfactant (VES) gelled fluids may be preheated to a temperature that will increase viscosity of the VES gelled fluid. The preheated VES gelled fluid retains at least a portion of its preheated viscosity when cooled such as by introduction into a low temperature condition. In an embodiment, the VES gelled fluid may be a drilling fluid, completion fluid, or fracturing fluid, and the low temperature condition may be an offshore operation, an operation in a locality having a cold climate, and/or a shallow oil, gas, or both land-based operation where the formation temperature is 120° F. or less. The surfactant in the VES gelled fluid may be one or more of an amine, amine salt, quaternary ammonium salt, betaine, amidoamine oxide, amine oxide, and combinations thereof.

Abstract: Aqueous treating fluids may include a viscoelastic surfactant (VES) and an aqueous base fluid, e.g. a drilling fluid, whereby the VES may increase and/or maintain the viscosity of the aqueous treating fluid. Metal ions may be present within the aqueous treating fluid that break, reduce, and/or digest the VES within the aqueous treating fluid. An effective amount of complexation particles may be added to the aqueous treating fluid for complexing at least a portion of these metal ions and thereby disallowing the metal ions from breaking, reducing, and/or altering the VES within the aqueous treating fluid.

Abstract: Emulsified acids have been used to increase production rates of oil and gas in carbonate reservoirs through acid fracturing and matrix acidizing operations. An emulsifier is used to emulsify the aqueous acid with an oil, usually diesel. Very small particles, such as colloidal clay particles and/or nanoparticles increase the stability of the emulsified acids over an elevated temperature range.

Abstract: A fracturing fluid, gravel pack fluid and/or frac pack fluid containing particles such as proppants, gravel and/.or sand, may contain an effective amount of a nano-sized particulate additive to fixate or reduce fines migration, where the particulate additive is an alkaline earth metal oxide, alkaline earth metal hydroxide, alkali metal oxides, alkali metal hydroxides transition metal oxides, transition metal hydroxides, post-transition metal oxides, post-transition metal hydroxides piezoelectric crystals and pyroelectric crystals. The nano-sized particulate additive is optionally bound to the particles with a coating agent such as an oil, alcohol, glycol, glycol ethers, ketones, terpenes, etc. The particle size of the magnesium oxide or other agent may be nanometer scale but may be a larger scale than nanometer but still relatively small, which scale may provide unique particle charges that help fixate the formation fines.

Abstract: Incorporating water-based polymer breakers, such as oxidizers, enzymes and/or acids, into a mixture of an oil and oil-soluble surfactants creates an emulsion that can then perform as a dual-functional breaker for reducing the viscosity of hybrid fluids gelled with both a viscoelastic surfactant (VES) and a polymer. The outer phase of the dual-functional breaker emulsion is oil, e.g. a mineral oil, containing an oil-soluble surfactant that will, over time and with heat, break the VES portion of the gel. As it does so, the polymer breaker in the internal aqueous phase will be released to then break the polymer portion of the gel. The polymer breaker will not start to break the polymer gel before the oil-soluble surfactant starts to break the VES gel. The overall breaking using the emulsion is slower as compared to introducing the polymer breaker and the oil-soluble surfactant in a non-emulsified form.

Abstract: Fluids viscosified with viscoelastic surfactants (VESs) may have their fluid loss properties improved with the presence of at least one mineral oil slurried together in combination with at least one particulate fluid loss control agent that may be an alkaline earth metal oxides, alkaline earth metal hydroxides, transition metal oxides, transition metal hydroxides, and mixtures thereof. The mineral oil having the particulate fluid loss control agents slurried within it may initially be dispersed oil droplets in an internal, discontinuous phase of the fluid. In one non-limiting embodiment, the slurry is added to the fluid after it has been substantially gelled. The mineral oil/particulate slurry may enhance the ability of a particulate fluid loss control agent to reduce fluid loss. The presence of the mineral oil may also eventually reduce the viscosity of the VES-gelled aqueous fluid.

Abstract: An aqueous, viscoelastic fluid gelled with a viscoelastic surfactant (VES) is stabilized and improved with an effective amount of an alkaline earth metal oxide alkaline earth metal hydroxide, alkali metal oxides, alkali metal hydroxides transition metal oxides, transition metal hydroxides, post-transition metal oxides, and post-transition metal hydroxides. These fluids are more stable and have a reduced or no tendency to precipitate, particularly at elevated temperatures. The additives may reduce the amount of VES required to maintain a given viscosity. These stabilized, enhanced, aqueous viscoelastic fluids may be used as treatment fluids for subterranean hydrocarbon formations, such as in hydraulic fracturing. The particle size of the magnesium oxide or other agent may be nanometer scale, which scale may provide unique particle charges that use chemisorption, crosslinking and/or other chemistries to associate and stabilize the VES fluids.