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 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.

Included are methods and systems for enhancing recovery of a hydrocarbon fluid. An example method includes selecting a liquefied natural gas capable of being processed into a modified liquefied natural gas having a desired composition and adjusting the composition of the liquefied natural gas to provide the modified liquefied natural gas with the desired composition. The method further includes preparing a treatment fluid from the modified liquefied natural gas, introducing the treatment fluid into a wellbore, and contacting the hydrocarbon fluid with the treatment fluid in the wellbore.

A thermal fluid generator utilizes a plasma energy heat source to generate steam, and combine the steam with nitrogen gas. Combined flow streams of steam and heated nitrogen are injected downhole into subterranean reservoir to thermally stimulate the flow of hydrocarbons (such as, for example, residual oil) from a reservoir, while also increasing fluid pressure in the reservoir. The thermal fluid generator can be located at the earth's surface, or positioned downhole within a wellbore.

The invention discloses an integrated method for nitrogen-assisted carbon dioxide fracturing and development of shale oil reservoirs, comprising the following steps: fracture the target shale reservoir with nitrogen-assisted carbon dioxide; after fracturing, firstly inject carbon dioxide gas into the target shale oil reservoir, and then inject nitrogen gas to push the carbon dioxide gas into the further location of the oil reservoir; shut in the well in the target shale oil reservoir; after shut-in, open the well to implement depletion production; after the first cycle of production, the slug volume of the injected gas and the shut-in time are 1.5 times of those in the previous cycle in the subsequent production, and Steps 5 to 7 are repeated for each cycle. The present invention maximizes the recovery efficiency of shale oil reservoirs; in this way, carbon dioxide gas can be used most efficiently, making the development of shale reservoir more economical and efficient; the integrated fracturing and development design enables the field operation to be streamlined and standardized, and thus different departments to cooperate each other closer.

The invention relates to a composition C which comprises, in an aqueous medium M: surfactants suitable for creating a foam in the presence of a gas; and polymers P based on acrylamide or acrylamido units, having a molecular mass of 1,000,000 to 20,000,000 g/mol;
or: composition C has a viscosity of less than 6 mPa.Math.s; and the content of polymer P is greater than the concentration limit beyond which the apparent viscosity of a foam obtained from composition C is greater by at least 10% than the apparent viscosity of a foam obtained from the same composition but deprived of polymers.

The invention further relates to the use of these compositions as foaming compositions for EOR.

A downhole treatment system, apparatus, and methods are disclosed. In some embodiments a treatment apparatus includes a first conduit configured to transport a first fluid from a first fluid source through a first enclosed channel to a first outlet. A second conduit is configured to transport a second fluid from a second fluid source through a second enclosed channel to a second outlet. The treatment apparatus further comprises a mixing applicator that includes the first outlet positioned to provide a discharge path for the first fluid that at least partially intersects a flow path of the second fluid within a confluence region within or external to the second conduit.

A cylinder porous cylinder, a gas flow control valve, and a mounting method for the gas flow control valve. The porous cylinder (1) includes a plurality of pipe bundles filled inside the pipe. A single flow passage is formed in each of the pipe bundles, such that a seepage passage is formed inside the pipe. The inner diameter, length and permeability of the pipe bundle are determined in advance based on a Reynolds number smaller than 2300. The porous cylinder (1) is capable of implementing a stable gas flow in a gas injection channel. The valve body (21) of the gas flow control valve (2) is provided therein with a plurality of tubular passages arranged in sequence along the horizontal direction of the valve body. The tubular passages include a pipe flow passage (24) and a plurality of seepage passages (25). The porous cylinder (1) is mounted in each of the seepage passages (25). A plurality of connection channels (221) are provided in the valve cap. One end of each of the connection channels (221) communicates with the interior of each of the tubular passages, and the other end of each of the connection channels (221) is provided respectively with a valve stem. The opening and closing of the plurality of tubular passages are controlled by the valve stem, thus regulating the output ratio of the injected gas. In addition, a mounting method for the gas flow control valve is further provided.

Disclosed is a method for performing integral plugging control on water invasion and steam channeling of an edge-bottom water heavy oil reservoir. The method for performing integral plugging control on water invasion and steam channeling of an edge-bottom water heavy oil reservoir comprises the following steps: (1) selecting an oil reservoir; (2) arranging a huff-puff well; (3) performing steam huff-puff development; and (4) performing integral plugging control. An integral plugging control technology is used for the method, a high-strength nitrogen foam system is injected by means of well rows at different positions in the oil reservoir, and effective plugging walls are formed at different positions from the edge-bottom water to reduce water invasion and steam channeling.

A foam for hydrocarbon recovery includes a gas phase and a liquid phase. The liquid phase includes a foaming mixture, and the foaming mixture includes an aqueous solution, one or more surfactants, and an oil mixture. At least 2 wt. % of the liquid phase includes the oil mixture. Also described are methods of recovering hydrocarbons from a deposit reservoir using such a foam, as well as a hydrocarbon well including such a foam.