A method for pumping a liquid-gas mixture into a subsurface well includes introducing gas into a liquid at a first pressure to generate a mixture. The mixture is pumped through a first positive displacement pump to a second pressure greater than the first pressure. The mixture at the second pressure is pumped through at least a second positive displacement pump to a third pressure greater than the second pressure. The mixture is moved into the subsurface well at at least the third pressure.

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.

The invention provides a method and an apparatus for determining an integrated exploitation approach for a shale and adjacent oil reservoirs. The method includes: determining a thickness of an effective shale, a top effective boundary and a bottom effective boundary of adjacent effective oil reservoirs; determining a maximum seepage radius of each of the adjacent effective oil reservoirs to the effective shale; determining a well pattern; determining a well completion approach; and determining a total number of perforation clusters of gas injection wells, a number of perforation clusters corresponding to each of the adjacent effective oil reservoirs, a gas injection amount per unit time of each of the perforation clusters, and a total gas injection amount per unit time of the gas injection wells. The effective shale is in communication with all the adjacent effective oil reservoirs by boring-through of a fluctuating horizontal well or a vertical well.

A method includes selecting a model for a simulation of hydrocarbon recovery from a reservoir having a plurality of fractures during injection of an injected gas into the plurality of fractures. Selecting the model includes determining a flux ratio of a convection rate to a diffusion rate for the reservoir, determining whether the flux ratio is less than a threshold, and in response to the flux ratio being less than the threshold, selecting the model that includes diffusion. Selecting the model includes performing the simulation of the hydrocarbon recovery from the reservoir based on the model.

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.

Systems, methods, and computer program products can be used for determining the amount of oil removed by a miscible gas flood. One of the methods includes identifying locations of oil within a volume representing a reservoir rock sample. The method includes identifying locations of gas within the volume. The method also includes determining the amount of oil removed based on locations within the volume where oil is either coincident with the gas or is connected to the gas by a continuous oil path.

A resource exploration and recovery system includes a first system and a second system extending into a wellbore. The second system includes a completion having a casing defining a wellbore internal diameter. A chemical injection tubing extends from the first system into the completion. The chemical injection tubing includes a terminal end portion. A chemical introduction system is arranged at the first system and is fluidically connected to the chemical injection tubing. The chemical introduction system is operable to deliver a chemical into the chemical injection tubing. A chemical injector assembly is mounted to the terminal end portion. The chemical injection system includes an anchor and a chemical injector valve.

An injection valve for introducing fluids into a subsurface environment includes a valve housing including a conduit having an inlet and an outlet. A valve seat member is arranged in the valve housing. The valve seat member includes an outlet portion and a valve seat. An anti-rotation dart is arranged in the valve housing. The anti-rotation dart includes a valve element that selectively extends into the outlet portion and is engageable with the valve seat. An anti-rotation feature is provided on at least one of the valve seat and the anti-rotation dart. The anti-rotation feature constrains rotation of the anti-rotation dart relative to the valve seat.

Herein are provided tools and processes for extracting oil from subterranean formation. The processes can include lightening the oil in the formation prior to extraction by the addition of a nanogas solution. The tools include injectors for the formation of the nanogas solution within the subterranean formation.

The invention relates to a composition which comprises within an aqueous medium: —at least one ethoxylated alkylamine; and—at least one amphoteric or zwitterionic surfactant. The invention further relates to the use of said compositions as foaming compositions, in particular for EOR (enhanced oil recovery).