Saudi Arabian Oil Company

Yun Chang

Mazen Kanj

Howard Khan Schmidt

Sunil Kokal

Fawaz M Al-Otaibi

Xianmin Zhou

Curt Thies

This invention generally relates to the field of oil recovery from reservoirs. More specifically, it relates to the recovery of oil from sandstone and carbonate reservoirs using a process for preparing a dispersion of capsules for use downhole including the steps of providing capsules containing a dense liquid, each capsule having a capsule wall defining an inner area, the capsule wall having an outer side. The capsules are functionalized by adding a carbon dioxide-philic compound to the outer side of the capsule wall. A dispersion is then prepared by adding the functionalized capsules to supercritical carbon dioxide such that a stable dispersion of capsules in supercritical carbon dioxide is achieved.

Densifying carbon dioxide with a dispersion of carbon dioxide-philic water capsules

A sparingly soluble sulfonate-metal salt particle includes the metal ion salt of an alkyl aryl sulfonate, the metal ion salt of a petroleum sulfonate and a hydrophobically modified hydrophilic polymer, and has an average particle size diameter in a range of from about 50 nm to about 450 nm and is sparingly soluble in water at room temperature. A method of producing a sparingly soluble sulfonate-metal salt particle includes the steps of introducing an aqueous solution containing a metal ion salt into a reactor, introducing an aqueous solution containing a sulfonate surfactant and a polymer into the reactor, and operating the reactor such that the sparingly soluble sulfonate-metal salt particle forms from the interaction of the metal ion from the salt, the sulfonate surfactant and the polymer.

Controlled release of surfactants for enhanced oil recovery

A method for increasing production in a liquid hydrocarbon reservoir formation comprising the steps of introducing a nanoencapsulated composition solution capable of reducing the surface tension of a liquid hydrocarbon fraction, where the nanoencapsulated composition solution comprises a nanocapsule and a carrier fluid, such that the nanocapsule is dispersed in the carrier fluid; allowing the nanoencapsulated composition solution to interact with the liquid hydrocarbon fraction such that the surface tension of the liquid hydrocarbon fraction is reduced such that at least a portion of the liquid hydrocarbon fraction is capable of being displaced; introducing a water fraction into the wellbore under conditions such that at least a portion of the liquid hydrocarbon fraction is displaced from the liquid hydrocarbon reservoir formation; and recovering the at least a portion of the liquid hydrocarbon fraction and at least a portion of the nanoencapsulated composition solution using the wellbore.

Encapsulated nanocompositions for increasing hydrocarbon recovery

The present technology relates to compositions and related methods for stabilizing surfactants capable of increasing liquid hydrocarbon production from subterranean reservoirs. In some embodiments, the technology relates to the stabilization of sulfonate based surfactants for enhanced oil recovery ('EOR') operations. In certain embodiments, the sulfonate based surfactants are characterized by increased thermal and chemical stability under crude oil recovery conditions.

Stabilization of petroleum surfactants for enhancing oil recovery

The present application provides for an acid precursor capsule that includes an acid precursor that is a non-aqueous ester and a polymerized shell that encapsulates the acid precursor. In some embodiments, the acid precursor converts into an associated acid during a hydrolysis period while in contact with water at an elevated temperature. In further embodiments, the associated acid is soluble in water and forms an aqueous acid solution with water. In certain embodiments, the polymerized shell contains the acid precursor and prevents interaction between the acid precursor and water at the elevated temperature until the polymerized shell dissolves in the water during a dissolution period. An acid precursor capsule suspension can include the acid precursor capsule and a suspension fluid. In some embodiments, a method of treatment using acid precursor capsules is provided that includes the step of introducing an acid precursor capsule suspension into a well bore such that the acid precursor capsules contact water at an elevated temperature.

Encapsulation of an acid precursor for oil field applications

A controlled release composition comprising an aqueous sulfonate solution; an anionic surfactant; and a salt selected from aluminum nitrate nanohydrate, calcium chloride dehydrate, magnesium chloride hexahydrate, cobalt chloride hexahydrate, and other metal salts. Methods of delivering a controlled release of surfactants composition, the method comprising the steps of: delivering a solution into a reservoir, the solution comprising an aqueous sulfonate solution; an anionic surfactant; and a salt selected from aluminum nitrate nanohydrate, calcium chloride dehydrate, magnesium chloride hexahydrate, cobalt chloride hexahydrate, and other metal salts; and delivering water to the reservoir.

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Dhahran, Saudi Arabia

Yun Chang