An aqueous sol used in CO.sub.2 foam flooding, one of EOR flooding methods for recovering crude oil by injection into the oil reservoir of an onshore or offshore oil field, the aqueous sol increasing foam stability even over a substantial period of time, at high temperatures and pressures, and in salt water, thus improving crude oil recovery rate. The aqueous sol for increasing stability of froth or emulsion in a mixture containing carbon dioxide, water, and oil in CO.sub.2 foam flooding of EOR, the sol including silica particles having an average particle diameter of 1 to 100 nm as measured by dynamic light scattering and having surfaces at least partially coated with a silane compound having a hydrolyzable group, the silica particles serving as a dispersoid and dispersed in an aqueous solvent having a pH of 1.0 to 6.0 serving as a dispersion medium.

An aqueous sol used in CO.sub.2 foam flooding, one of EOR flooding methods for recovering crude oil by injection into the oil reservoir of an onshore or offshore oil field, the aqueous sol increasing foam stability even over a substantial period of time, at high temperatures and pressures, and in salt water, thus improving crude oil recovery rate. The aqueous sol for increasing stability of froth or emulsion in a mixture containing carbon dioxide, water, and oil in CO.sub.2 foam flooding of EOR, the sol including silica particles having an average particle diameter of 1 to 100 nm as measured by dynamic light scattering and having surfaces at least partially coated with a silane compound having a hydrolyzable group, the silica particles serving as a dispersoid and dispersed in an aqueous solvent having a pH of 1.0 to 6.0 serving as a dispersion medium.

The present invention discloses a novel process for the mineralization of CO.sub.2 in mafic and ultramafic rocks or storage of CO.sub.2 in geological formations through the generation and use of nano-sized CO.sub.2 bubbles injected into a fluid-mixture.

The present invention discloses a novel process for the mineralization of CO.sub.2 in mafic and ultramafic rocks or storage of CO.sub.2 in geological formations through the generation and use of nano-sized CO.sub.2 bubbles injected into a fluid-mixture.

Systems and methods for enhanced or improved oil recovery includes injecting a Y-Grade NGL enhanced oil recovery fluid through an injection well into a hydrocarbon bearing reservoir to mobilize and displace hydrocarbons. The Y-Grade NGL enhanced oil recovery fluid comprises an unfractionated hydrocarbon mixture. Simultaneously and/or subsequently, a mobility control fluid is injected into the hydrocarbon bearing formation. Hydrocarbons from the hydrocarbon bearing reservoir are produced through a production well or the same injection well.

Systems and methods for enhanced or improved oil recovery includes injecting a Y-Grade NGL enhanced oil recovery fluid through an injection well into a hydrocarbon bearing reservoir to mobilize and displace hydrocarbons. The Y-Grade NGL enhanced oil recovery fluid comprises an unfractionated hydrocarbon mixture. Simultaneously and/or subsequently, a mobility control fluid is injected into the hydrocarbon bearing formation. Hydrocarbons from the hydrocarbon bearing reservoir are produced through a production well or the same injection well.

Injecting into an oil reservoir a gaseous mixture of carbon monoxide (CO) together with gaseous hydrocarbons comprising a mixture of one or more of methane (C1), ethane (C2), propane (C3), butane (C4), pentane (C5), and natural gasoline, also referred to as NGL, for the purpose of achieving additional oil recovery from any of conventional, heavy, and unconventional oil reservoirs, including shale oil reservoirs. The gaseous hydrocarbons and the CO may range from 0.1% gaseous hydrocarbons and 99.5% CO and associated minor gases including any of CO2, H2, N2 to 98.5% gaseous hydrocarbons and 1.5% CO and associated minor gases.

Injecting into an oil reservoir a gaseous mixture of carbon monoxide (CO) together with gaseous hydrocarbons comprising a mixture of one or more of methane (C1), ethane (C2), propane (C3), butane (C4), pentane (C5), and natural gasoline, also referred to as NGL, for the purpose of achieving additional oil recovery from any of conventional, heavy, and unconventional oil reservoirs, including shale oil reservoirs. The gaseous hydrocarbons and the CO may range from 0.1% gaseous hydrocarbons and 99.5% CO and associated minor gases including any of CO2, H2, N2 to 98.5% gaseous hydrocarbons and 1.5% CO and associated minor gases.

Provided are methods of recovering oil from a reservoir using carbon dioxide foam flooding in which a carbon dioxide foam of increased strength is used.

Provided are methods of recovering oil from a reservoir using carbon dioxide foam flooding in which a carbon dioxide foam of increased strength is used.