Multiple charged cationic compounds, which are derived from polyamines through an aza-Michael addition with an α, β-unsaturated carbonyl compound, in a clay treatment composition to reduces clay swelling, clay migration, and sludge formation in a subterranean formation in oil and gas operations are provided. The disclosed methods or compositions are found to be more effective than those methods or compositions commonly used for reducing clay swelling, clay migration, and sludge formation.

Multiple charged cationic compounds, which are derived from polyamines through an aza-Michael addition with an α, β-unsaturated carbonyl compound, in a clay treatment composition to reduces clay swelling, clay migration, and sludge formation in a subterranean formation in oil and gas operations are provided. The disclosed methods or compositions are found to be more effective than those methods or compositions commonly used for reducing clay swelling, clay migration, and sludge formation.

A tight oil reservoir CO.sub.2 flooding multi-scale channeling control system and a preparation method, including nanoscale CO.sub.2 responsive worm-like micellar systems and micron-scale CO.sub.2 responsive dispersion gel, are provided. The nanoscale CO.sub.2 responsive worm-like micelle system is prepared by CO.sub.2 reactive monomers and organic anti-ion monomers stirred in water. The micron-scale CO.sub.2 responsive dispersion gel is made of acrylamide, a responsive monomer, a silane coupling agent modified hydroxylated multi-walled carbon nanotubes as raw materials, cross-linked in water. The tight oil reservoir CO.sub.2 multi-scale channel control system, has strong flow control ability during CO.sub.2 displacement, and high-strength carbon nanotubes are introduced into the micro-scale CO.sub.2 responsive dispersion gel, which effectively improves the strength and long-term stability of the dispersion gel, significantly enhances the sealing effect on cracks, and after displacement of the CO.sub.2 of the system, the worm-like micelles revert to spherical micelles with good responsive reversibility.

A tight oil reservoir CO.sub.2 flooding multi-scale channeling control system and a preparation method, including nanoscale CO.sub.2 responsive worm-like micellar systems and micron-scale CO.sub.2 responsive dispersion gel, are provided. The nanoscale CO.sub.2 responsive worm-like micelle system is prepared by CO.sub.2 reactive monomers and organic anti-ion monomers stirred in water. The micron-scale CO.sub.2 responsive dispersion gel is made of acrylamide, a responsive monomer, a silane coupling agent modified hydroxylated multi-walled carbon nanotubes as raw materials, cross-linked in water. The tight oil reservoir CO.sub.2 multi-scale channel control system, has strong flow control ability during CO.sub.2 displacement, and high-strength carbon nanotubes are introduced into the micro-scale CO.sub.2 responsive dispersion gel, which effectively improves the strength and long-term stability of the dispersion gel, significantly enhances the sealing effect on cracks, and after displacement of the CO.sub.2 of the system, the worm-like micelles revert to spherical micelles with good responsive reversibility.

A system and method for water shutoff, including providing a treatment fluid including a polymer and a nitrogen-generating compound through a wellbore into a water zone in a subterranean formation, generating nitrogen gas in the water zone by a reaction of the nitrogen-generating compound, generating foam from the nitrogen gas and the treatment fluid in the water zone to give foamed polymer in the water zone, and sealing the water zone with the foamed polymer.

A method for enhanced oil recovery may comprise inputting into a computer system data related to properties of a hydrocarbon reservoir and depletion of the hydrocarbon reservoir; calculating, with the computer system, a current oil saturation and a current gas saturation of the hydrocarbon reservoir based on the data; determining, with the computer system, that the current reservoir pressure is less than a bubble point pressure based on the data; calculating, with the computer system, a time to repressure the hydrocarbon reservoir by waterflooding based on the data; comparing, with the computer system, the data related to properties of the hydrocarbon reservoir to oil recovery screening criteria; selecting a flooding technique from a plurality of flooding techniques, with the computer system, based on satisfying the oil recovery screening criteria with the data related to properties of the hydrocarbon reservoir.

A method for enhanced oil recovery may comprise inputting into a computer system data related to properties of a hydrocarbon reservoir and depletion of the hydrocarbon reservoir; calculating, with the computer system, a current oil saturation and a current gas saturation of the hydrocarbon reservoir based on the data; determining, with the computer system, that the current reservoir pressure is less than a bubble point pressure based on the data; calculating, with the computer system, a time to repressure the hydrocarbon reservoir by waterflooding based on the data; comparing, with the computer system, the data related to properties of the hydrocarbon reservoir to oil recovery screening criteria; selecting a flooding technique from a plurality of flooding techniques, with the computer system, based on satisfying the oil recovery screening criteria with the data related to properties of the hydrocarbon reservoir.

Surfactants for use in formulations and processes suitable for hydrocarbon recovery. These formulations, include formulations suitable for fracking, enhancing oil and or gas recovery, and the recovery and or production of bio-based oils.

Surfactants for use in formulations and processes suitable for hydrocarbon recovery. These formulations, include formulations suitable for fracking, enhancing oil and or gas recovery, and the recovery and or production of bio-based oils.

A method for recovering hydrocarbons from a hydrocarbon bearing formation includes introducing a first solution having a first salt into the hydrocarbon bearing formation. A second solution is also introduced into the hydrocarbon bearing formation, wherein the second solution has a second salt and a foaming agent. The first salt and the second salt produces a nitrogen gas, and the nitrogen gas and the foaming agent produces a foam formed in-situ within the formation. The foam forms a foam barrier, and carbon dioxide is introduced into the formation to form a gas cap, wherein the carbon dioxide gas cap has a gas front that is separated from the hydrocarbons by the foam barrier.