A method of protecting a first well from stimulation fluid of a second well includes shutting in the first well; starting injection of natural gas into the first well to increase a pressure of the first well; treating the second well using a stimulation fluid after starting natural gas injection; and stopping injection of natural gas.

The present invention is a method of monitoring recovery site hydrocarbons (HC) using an unconventional method which permits quantifying the HC present in zones above the exploration and development zone. The method according to the invention is based on the adjustment of a model describing the gas concentration as a function of time, using in-situ geochemical analyzes of rare gases and, when appropriate, of injected gas used for fracturing, contained in fluid phases of subsoil samples. By use of rare gas analysis, the method according to the invention allows anticipation of hydrocarbon leakage above the exploration/development site.

A method for extracting geothermal energy from a geothermal reservoir formation. A production well is used to extract brine from the reservoir formation. At least one of nitrogen (N.sub.2) and carbon dioxide (CO.sub.2) may be used to form a supplemental working fluid which may be injected into a supplemental working fluid injection well. The supplemental working fluid may be used to augment a pressure of the reservoir formation, to thus drive a flow of the brine out from the reservoir formation.

A method includes collecting a first set of borehole gravity data at a first time step along a length of a first wellbore and collecting a second set of borehole gravity data at the first time step along a length of a second wellbore. The method also includes interpolating a third set of borehole gravity data at the first time step in an area between the first wellbore and the second wellbore using the first and the second sets of borehole gravity data. Further, the method includes determining a first fluid saturation and a fluid saturation change over time in a reservoir containing the first wellbore and the second wellbore using the first set, the second set, and the third set. Moreover, the method includes controlling wellbore production operations or wellbore injection operations at the first wellbore based on the fluid saturation change.

Methods for producing hydrocarbons from subterranean reservoirs are disclosed herein. The methods utilize a production well that comprises a plurality of fluid-inlet components that are spaced apart to define a plurality of production-well fluid-inlet zones. The methods comprise injecting an injection fluid comprising a non-condensable gas (NCG) into the reservoir, such that a drainage fluid comprising at least a portion of the NCG occupies the production-well fluid-inlet zones. The method further comprises modulating the gas phase:liquid phase ratio of a production fluid by orchestrating variations in pump speed and the flow states of the plurality of fluid-inlet components to prioritize hydraulic communication with a subset of the plurality of production-well fluid-inlet zones that are not plagued by high NCG content.

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.

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.

Disclosed herein are methods for producing hydrocarbons from a subterranean reservoir that is penetrated by an injection well and a production well. The methods comprise operating the injection well under a set of injection parameters and operating the production well under a set of production parameters to produce a production fluid that has an API gravity that changes over time (ΔAPI) as the method is advanced towards an ultimate recovery factor (RF.sub.o,u) for the reservoir. The methods further comprises modulating the injection parameters, the production parameters, or a combination thereof to decrease or increase the API gravity of the production fluid depending on whether ΔAPI and RF.sub.o,u satisfy a set of requirements as disclosed herein.

The embodiments of the present disclosure disclose an ultrasonic microbubble generation method, apparatus and system. The apparatus comprises a horn-shaped conductor including an upper horn-shaped body and a lower cylindrical body; the horn-shaped body is provided with a cavity having an upper opening, an upper end of the cavity is fixedly connected with a micropore vibration thin sheet, a micropore array of the micropore vibration thin sheet is corresponding to the upper opening of the cavity, and a side wall of the cavity is provided with a through hole for external gas to enter the cavity; the cylindrical body is provided with a transducing ring and an electrode sheet, an outer side of the cylindrical body is insulated and sealed, and a connection wire of the electrode sheet is led out by a steel pipe and connected with an external ultrasonic oscillation controller.