The invention relates to a method including a system of additives which increase fluidity and/or flow capacity and minimize pressure drops from the steps of lifting in production wells, collection lines, dehydration systems and ducts for transporting heavy and extra-heavy hydrocarbons. In addition, the injected system of chemical additives increases the dilution capacity of the solvents that need to be applied to improve the quality of the crude oil (reduce viscosity and density, and increase API gravity), thereby facilitating the dehydration and transport.

Disclosed are surface-modified nanoparticles and surfactants used in compositions and methods for enhancing hydro-carbon recovery from subterranean formations.

A chelating agent can be used to enhance secondary hydrocarbon-fluid recovery during waterflooding operations. A composition can include a fluid and a chelating agent. The chelating agent can increase the viscosity of the fluid, which can enhance the efficacy of the waterflooding operations. The chelating agent can also form complexes with divalent cations in precipitates and solids formed by the divalent cations. The complexes can keep the cations in a soluble form until the composition exits the production well, which can prevent precipitates from forming in the production well and blocking pore throats in the production well.

A chelating agent can be used to enhance secondary hydrocarbon-fluid recovery during waterflooding operations. A composition can include a fluid and a chelating agent. The chelating agent can increase the viscosity of the fluid, which can enhance the efficacy of the waterflooding operations. The chelating agent can also form complexes with divalent cations in precipitates and solids formed by the divalent cations. The complexes can keep the cations in a soluble form until the composition exits the production well, which can prevent precipitates from forming in the production well and blocking pore throats in the production well.

Synthesizing Janus material including forming a lamellar phase having water layers and organic layers, incorporating nanosheets and a functional agent into the lamellar phase, and attaching the functional agent to the nanosheets in the lamellar phase to form Janus nanosheets.

A method for oil recovery by calculating, with a computer system, a current oil saturation of a reservoir, comparing, with the computer system, reservoir properties to screening criteria, determining, with the computer system, a minimum miscibility pressure based on correlations between the reservoir properties and the screening criteria; determining, with the computer system, if the minimum miscibility pressure is greater than a bubble point pressure of the reservoir and is less than or equal to an initial reservoir pressure, determining, with the computer system, a time to repressure the reservoir with water injection, performing a reservoir simulation with the computer system, and flooding the reservoir.

Synthesizing Janus material including forming a lamellar phase having water layers and organic layers, incorporating nanosheets and a functional agent into the lamellar phase, and attaching the functional agent to the nanosheets in the lamellar phase to form Janus nanosheets.

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.

A method for modifying surface wettability of a surface of a solid substrate may include contacting the surface of the solid substrate with a brine solution containing carbon nanodots. The carbon nanodots may have carbon, oxygen, nitrogen, and hydrogen as constituent elements and may include one or more functional groups disposed at outer surfaces of the carbon nanodots. The brine solution has a salinity of greater than 30,000 TDS. A concentration of carbon nanodots in the brine solution is less than or equal to 500 ppmw. Contacting the solid substrate with the brine solution comprising the carbon nanodots is characterized by a contact duration, a contact volume, or both, that is sufficient to reduce the oil wettability of the surface of the solid substrate by at least 15%, as defined by a contact angle of a crude oil droplet contacted with the surface of the solid substrate.