Use of methyl glycine diacetic acid (MGDA) as additive in processes for recovering crude oil and/or gas from subterranean formations, wherein the MGDA is a mixture of L- and D-enantiomers of MGDA or salts thereof, said mixture containing an excess of the respective L-isomer, and the enantiomeric excess (ee) of the L-isomer is in the range of from 10% to 75% Preferably, the process is a processes of acidizing subterranean formations.

For hydrocarbon recovery from a reservoir of bituminous sands, steam and a multi-function agent are injected into the reservoir for mobilizing bitumen in the reservoir to form a fluid comprising hydrocarbons, water and the multi-function agent. The fluid is produced from the reservoir. The multi-function agent may comprise an organic molecule that reduces viscosity of oil and the interfacial tension between oil and water or a gas or rock in the reservoir, and has a partition coefficient favoring solubility in oil over water and a partial pressure in the reservoir allowing the organic molecule to be transported with steam as a vapor. The multi-function agent may comprise a solvent for reducing viscosity of oil and a surfactant for reducing interfacial tension, where both the solvent and surfactant are transportable with steam as vapor.

A method of increasing recovery of liquid hydrocarbons from subsurface reservoirs, and particularly from those located in tight formations, is disclosed. One aspect includes calculating the in situ fractured formation wettability from real-time measurement of flowback volume and composition. Another aspect includes determining the composition of the fracturing fluid, the overflush or both, that will achieve higher liquid hydrocarbon recovery by increasing the water wettability of rock surfaces within the reservoir. Monitoring of rock-surface wettability through flowback volume and composition profiles allows the above mentioned injectates to be adjusted in the field to achieve maximal recovery. Other methods, apparatuses, and systems are disclosed.

A method of increasing recovery of liquid hydrocarbons from subsurface reservoirs, and particularly from those located in tight formations, is disclosed. One aspect includes calculating the in situ fractured formation wettability from real-time measurement of flowback volume and composition. Another aspect includes determining the composition of the fracturing fluid, the overflush or both, that will achieve higher liquid hydrocarbon recovery by increasing the water wettability of rock surfaces within the reservoir. Monitoring of rock-surface wettability through flowback volume and composition profiles allows the above mentioned injectates to be adjusted in the field to achieve maximal recovery. Other methods, apparatuses, and systems are disclosed.

A method is provided herein for using produced water (PW), for example, for use in a fracturing fluid. The method includes performing ultrafiltration on the PW to form filtered PW, filtering seawater (SW) to form filtered SW, and blending the filtered PW with the filtered SW to form an aqueous blend.

A process for recovering oil is provided. The process entails recovering an oil-water mixture from an oil-bearing formation. Next, the process entails separating oil from the oil-water mixture and producing produced water having hardness and other scale-forming compounds, suspended solids, free oil and emulsified oil. A pre-treatment process is undertaken to remove hardness and other scale-forming compounds. This entails precipitating hardness and other scale-forming compounds. After the precipitation of hardness and other scale-forming compounds, the produced water is directed to a membrane separation unit for filtering the produced water and producing a retentate having suspended solids, hardness and other scale-forming compounds, free oil and emulsified oil. The membrane separation unit also produces a permeate stream substantially free of hardness and other scale-forming compounds, suspended solids, free oil and emulsified oil. Thereafter, the permeate stream is chemically treated to enhance the recovery of oil in the oil-bearing formation. After treating the permeate stream from the membrane separation unit, the treated permeate is injected into the oil-bearing formation.

Nano-sized mixed metal oxide carriers capable of delivering a well treatment additive for a sustained or extended period of time in the environment of use, methods of making the nanoparticles, and uses thereof are described herein. The nanoparticles can have a formula of:

A/[M.sub.x.sup.1M.sub.y.sup.2M.sub.z.sup.3]O.sub.nH.sub.m

where x is 0.03 to 3, y is 0.01 to 0.4, z is 0.01 to 0.4 and n and m are determined by the oxidation states of the other elements, and M.sup.1 can be aluminum (Al), gallium (Ga), indium (In), or thallium (Tl). M.sup.2 and M.sup.3 are not the same and can be a Column 2 metal, Column 14 metal, or a transition metal. A is can be a treatment additive.

The invention relates to a composition comprising a fatty acid-methyl ester component and an alcohol component, the composition being liquid at normal pressure at 20° C. and being immiscible with water. The invention further relates to a mixture containing crude oil, oil sludge and/or oil residues and the aforementioned composition. The invention also relates to a method for reducing the viscosity of crude oil, oil sludge and/or oil residues. The invention finally relates to a method for cleaning a surface from crude oil, oil sludge and/or oil residues.

Provided is an injection fluid that may include a nanoemulsion having an oil phase dispersed in an aqueous phase, and non-superparamagnetic magnetic nanoparticles that are present in the dispersed oil phase. Further provided is a method for preparing an injection fluid that may include preparing a nanoemulsion from an aqueous phase and an oil phase having non-superparamagnetic magnetic nanoparticles therein, and may be used to form nanodroplets of the non-superparamagnetic magnetic nanoparticles. Further provided is a method for tracking movement of an injection fluid. The method may include introducing a tagged injection fluid into a hydrocarbon-containing reservoir, the tagged injection fluid may be a nanoemulsion that includes: an aqueous phase, an oil phase dispersed in the aqueous phase, and non-superparamagnetic nanoparticles that are present in the dispersed oil phase; and tracking the movement of the tagged injection fluid.

Provided is an injection fluid that may include a nanoemulsion having an oil phase dispersed in an aqueous phase, and non-superparamagnetic magnetic nanoparticles that are present in the dispersed oil phase. Further provided is a method for preparing an injection fluid that may include preparing a nanoemulsion from an aqueous phase and an oil phase having non-superparamagnetic magnetic nanoparticles therein, and may be used to form nanodroplets of the non-superparamagnetic magnetic nanoparticles. Further provided is a method for tracking movement of an injection fluid. The method may include introducing a tagged injection fluid into a hydrocarbon-containing reservoir, the tagged injection fluid may be a nanoemulsion that includes: an aqueous phase, an oil phase dispersed in the aqueous phase, and non-superparamagnetic nanoparticles that are present in the dispersed oil phase; and tracking the movement of the tagged injection fluid.