The present invention provides a device, system, and method that eliminates the short-circuiting and improves energy sweep in geothermal reservoirs.

A system and method for water shutoff, including providing a treatment fluid including a polymer and a nitrogen-generating compound through a wellbore into a water zone in a subterranean formation, generating nitrogen gas in the water zone by a reaction of the nitrogen-generating compound, generating foam from the nitrogen gas and the treatment fluid in the water zone to give foamed polymer in the water zone, and sealing the water zone with the foamed polymer.

Disclosed are a high-temperature-resistant tertiary amine-grafted silica nano-plugging agent and water-based drilling fluids, relating to oil-gas field drilling. The nano-plugging agent is prepared from a hydrazine compound, a diallyl compound, an enamine compound, silica particle, and an amino-containing silane coupling agent by stepwise reaction. The nano-plugging agent has a grain size of 58-280 nm.

The present disclosure a leak-proof lost-circulation control water-based drilling fluid composition and preparation method and use thereof.

In accordance with one or more embodiments of the present disclosure, a drilling fluid may include a base fluid and one or more formaldehyde-based resins. The drilling fluid may further comprise one or more water-soluble acid catalyst precursors or the reaction products of such water-soluble acid catalyst precursors. The base fluid may include an aqueous or non-aqueous solution. The present disclosure also describes sealed subterranean petroleum formations that include such drilling fluids and methods for sealing subterranean wellbores by utilizing such drilling fluids.

In accordance with one or more embodiments of the present disclosure, a drilling fluid may include a base fluid, one or more formaldehyde-based resins, and one or more water-soluble acid catalysts. The base fluid may include an aqueous or non-aqueous solution. The one or more water-soluble acid catalysts may be present in an amount sufficient to reduce the pH of the drilling fluid to less than or equal to 6. The present disclosure also describes sealed subterranean petroleum formations that include such drilling fluids and methods for sealing subterranean wellbores by utilizing such drilling fluids.

Methods and compositions for the use of thermally responsive lost circulation materials in subterranean formations are provided. In one embodiment, the methods include introducing a treatment fluid including a base fluid and a thermally responsive lost circulation material including a thermally responsive hydrogel that includes at least one thermoresponsive polymer into a wellbore penetrating at least a portion of a subterranean formation including a loss zone; allowing the thermally responsive lost circulation material to reach a thickening transition temperature; and allowing the treatment fluid to at least partially set in the subterranean formation.

Disclosed are a high-temperature-resistant tertiary amine-grafted silica nano-plugging agent and water-based drilling fluids, relating to oil-gas field drilling. The nano-plugging agent is prepared from a hydrazine compound, a diallyl compound, an enamine compound, silica particle, and an amino-containing silane coupling agent by stepwise reaction. The nano-plugging agent has a grain size of 58-280 nm.

A method, wellbore, and pill for treating a region of a subterranean formation adjacent a wellbore zone of the wellbore, including injecting a gellable treatment composition (e.g., as the pill) through the wellbore zone into the region of the subterranean formation adjacent the wellbore zone, allowing the gellable treatment composition to form nanoparticles in-situ in the region and gel in the region via heat provided by the region to prevent or reduce flow of an unwanted fluid from the region into the wellbore zone. The gellable treatment composition may include a zwitterionic gemini surfactant (ZGS).

Described are methods and compositions for treating a subterranean formation. The method comprising introducing into the subterranean formation via a well-bore a diverter composition, the diverter composition comprising a combination of at least one deformable particle and at least one non-deformable particle; and allowing the diverter composition to block the flow of at least a portion of a treatment fluid from a first location within the well-bore to a second location.