A process for altering a wettability characteristic of a carbonate formation to stimulate oil production includes selecting an oil bearing carbonate formation, injecting a silicide dispersion into the carbonate formation, and reacting the injected silicide dispersion with water. The reaction alters the wettability characteristic of the carbonate formation toward water wettability. The silicide dispersion can include an alkali metal silicide, such as sodium silicide. The reaction generates hydrogen, silicate, and heat that pressurizes the carbonate formation with the generated hydrogen, heats the carbonate formation with the generated heat, and reduces the viscosity of the hydrocarbons in the carbonate formation with the generated silicate. The reaction re-mineralizes the surfaces in the carbonate formation and alters the wettability characteristics of the carbonate formation as a calcium-silicon phase is formed. The hydrocarbons are recovered from the carbonate formation with a production well.

Fracturing fluids in the form of a hydrocarbon foam, an emulsion based foam, an emulsion, and a gelled fracturing fluid, each comprising Y-Grade NGL, which is an unfractionated hydrocarbon mixture that comprises ethane, propane, butane, isobutane, and pentane plus, wherein the unfractionated hydrocarbon mixture is a byproduct of a condensed and demethanized hydrocarbon stream.

Systems and methods of optimizing stimulation fluids in the form of a hydrocarbon foam, an emulsion based foam, an emulsion, and a gelled stimulation fluid, each comprising Y-Grade NGL, which is an unfractionated hydrocarbon mixture that comprises ethane, propane, butane, isobutane, and pentane plus, wherein the unfractionated hydrocarbon mixture is a byproduct of a condensed and demethanized hydrocarbon stream.

A method, system and apparatus for producing hydrocarbons from a low permeability reservoir formation. A wellbore with a plurality of fractures designated as one of a first or a second set of fractures is provided. A first fluid conduit is formed by an annulus between an outer casing of a tubular and an inner tubular member, and is arranged to transport produced hydrocarbons. An interior of the inner tubular member forms a second fluid conduit which is arranged to transport an injection fluid. A set of first openings is provided in fluid connection with the first fluid conduit, each first opening being located to substantially align with one of a first set of fractures. A set of second openings is provided in fluid connection with the second fluid conduit, each second opening being located to substantially align with one of a second set of fractures. A high pressure fluid is injected into the second set of fractures, which pushes hydrocarbons located in the low permeability reservoir towards the first set of fractures, thereby increasing the recovery rate of hydrocarbons in the low permeability reservoir.

An apparatus includes a first flow line, a second flow line and a seabed-disposed pump station. The first and second flow lines extend to a sea surface platform. The pump station to, in response to a shut down of a production flow in the first flow line, operate a pump of the station to transfer liquid from the first flow line to the second flow line to reduce a liquid column in the first flow line and push liquid in the second flow line to the sea surface platform for removal; and open a bypass valve for the pump to allow a liquid column in the second flow line to decrease to reduce a pressure in the second flow line during a period in which the pump station is shut down. The pump station may also be operated to communicate a pig through flow lines, and during a time interval in which the production is shut down, the pump station may be operated in a bypass mode to prevent hydrate formation in a subsea flow line.

A formation treatment fluid may include a wettability alteration agent, a solvent, an injection gas, and an optional foaming agent. The wettability alteration agent may include a fluorinated surfactant, a silicon-based surfactant, charged nanoparticles partially modified with fluorine containing groups, or combinations thereof. Methods for altering a hydrocarbon-bearing reservoir surface wettability may include providing the formation treatment fluid, injecting the formation treatment fluid into the hydrocarbon-bearing reservoir, and recovering fluids produced from the hydrocarbon-bearing reservoir.

Self-suspending proppants including proppant particles coated with a CO.sub.2-philic coating are provided. The CO.sub.2-philic coating may be lightly crosslinked and may have a physical structure that constrains CO.sub.2 molecules. Methods of making self-suspending proppants may include coating a proppant particle with a polymerizable precursor material of a CO.sub.2-philic material and polymerizing the polymerizable precursor material to form a self-suspending proppant are also provided. Additionally, hydraulic fracturing fluids that may include a CO.sub.2-based fluid and the self-suspending proppants and methods of treating subterranean formations by contacting a subterranean formation with hydraulic fracturing fluid and propagating at least one subterranean fracture are provided.

Self-suspending proppants including proppant particles coated with a CO.sub.2-philic coating are provided. The CO.sub.2-philic coating may be lightly crosslinked and may have a physical structure that constrains CO.sub.2 molecules. Methods of making self-suspending proppants may include coating a proppant particle with a polymerizable precursor material of a CO.sub.2-philic material and polymerizing the polymerizable precursor material to form a self-suspending proppant are also provided. Additionally, hydraulic fracturing fluids that may include a CO.sub.2-based fluid and the self-suspending proppants and methods of treating subterranean formations by contacting a subterranean formation with hydraulic fracturing fluid and propagating at least one subterranean fracture are provided.

Self-suspending proppants including proppant particles coated with a CO.sub.2-philic coating are provided. The CO.sub.2-philic coating may be lightly crosslinked and may have a physical structure that constrains CO.sub.2 molecules. Methods of making self-suspending proppants may include coating a proppant particle with a polymerizable precursor material of a CO.sub.2-philic material and polymerizing the polymerizable precursor material to form a self-suspending proppant are also provided. Additionally, hydraulic fracturing fluids that may include a CO.sub.2-based fluid and the self-suspending proppants and methods of treating subterranean formations by contacting a subterranean formation with hydraulic fracturing fluid and propagating at least one subterranean fracture are provided.

Viscosifying proppants including proppant particles coated with a CO.sub.2-philic coating in which the CO.sub.2-philic coating has a solvable portion that viscosifies a CO.sub.2-based fluid when the viscosifying proppant is added to the CO.sub.2-based fluid are provided. Methods of making viscosifying proppants are also provided that include coating proppant particles with a precursor material of a CO.sub.2-philic material, and polymerizing the precursor material to form a viscosifying proppant. Viscous hydraulic fracturing fluids include a CO.sub.2-based fluid and the viscosifying proppants and methods of treating subterranean formations that include contacting a subterranean formation with a viscous hydraulic fracturing fluid and propagating at least one subterranean fracture are also provided.