Provided is a loss circulation material that may consist essentially of an acidic nanosilica dispersion and an activator. The acidic nanosilica dispersion may consist of acidic silica nanoparticles, stabilizer, and water, and may have a pH in a range of 3 to 6. The activator may be one or more from the group consisting of sodium bicarbonate, sodium chloride, or an amine salt. A method is provided for controlling lost circulation in a lost circulation zone in a wellbore comprising introducing the loss circulation material and forming a gelled solid from the loss circulation material in the lost circulation zone.

A method of treating a subterranean formation penetrated by a well comprises combining an aqueous base fluid, a viscoelastic surfactant gelling agent, two or more types of the following nanoparticles: an alkaline earth metal oxide; an alkaline earth metal hydroxide; a transition metal oxide; or a transition metal hydroxide to form a treatment fluid, and pumping the treatment fluid into the well, wherein the weight ratio of the two or more types of the nanoparticles is selected such that the treatment fluid has an improved fluid efficiency as compared to an otherwise identical reference fluid except for comprising only one type of the nanoparticles selected from an alkaline earth metal oxide; an alkaline earth metal hydroxide; a transition metal oxide; and a transition metal hydroxide.

A method of treating a subterranean formation penetrated by a well comprises combining an aqueous base fluid, a viscoelastic surfactant gelling agent, two or more types of the following nanoparticles: an alkaline earth metal oxide; an alkaline earth metal hydroxide; a transition metal oxide; or a transition metal hydroxide to form a treatment fluid, and pumping the treatment fluid into the well, wherein the weight ratio of the two or more types of the nanoparticles is selected such that the treatment fluid has an improved fluid efficiency as compared to an otherwise identical reference fluid except for comprising only one type of the nanoparticles selected from an alkaline earth metal oxide; an alkaline earth metal hydroxide; a transition metal oxide; and a transition metal hydroxide.

The present invention relates to a method for sealing and/or consolidating a subterranean formation, wherein a gelling aqueous solution comprising an alkaline solution of potassium silicate, acetic acid and an aluminate is prepared and injected into the subterranean formation.

Methods for separating fluids with a barrier pill within a downhole environment are provided. The method includes introducing a barrier pill fluid into the wellbore containing a first fluid to form the barrier pill on top of the first fluid in the wellbore and introducing a second fluid into the wellbore. The barrier pill separates the first fluid and the second fluid. The barrier pill includes a viscoelastic surfactant and an aqueous fluid, such as a brine containing water and about 5 wt % to about 50 wt % of a salt.

Methods for separating fluids with a barrier pill within a downhole environment are provided. The method includes introducing a barrier pill fluid into the wellbore containing a first fluid to form the barrier pill on top of the first fluid in the wellbore and introducing a second fluid into the wellbore. The barrier pill separates the first fluid and the second fluid. The barrier pill includes a viscoelastic surfactant and an aqueous fluid, such as a brine containing water and about 5 wt % to about 50 wt % of a salt.

A silicon oxide Janus nanosheets relatively permeability modifier (RPM) for carbonate and sandstone formations. The silicon oxide Janus nanosheets RPM may be used to treat a water and hydrocarbon producing carbonate or sandstone formation to reduce water permeability in the formation and increase the production of hydrocarbons. The silicon oxide Janus nanosheets RPM for carbonate formations includes a first side having negatively charged functional groups and a second side having alkyl groups. The silicon oxide Janus nanosheets RPM for sandstone formations includes a first side having positively charged functional groups and a second side having alkyl groups. The negatively charged functional groups may include a negatively charged oxygen group groups and hydroxyl groups. The positively charged functional groups may include amino groups and an amine. Methods of reducing water permeability using the silicon oxide Janus nanosheets RPM and methods of manufacturing the silicon oxide Janus nanosheets RPM are also provided.

A silicon oxide Janus nanosheets relatively permeability modifier (RPM) for carbonate and sandstone formations. The silicon oxide Janus nanosheets RPM may be used to treat a water and hydrocarbon producing carbonate or sandstone formation to reduce water permeability in the formation and increase the production of hydrocarbons. The silicon oxide Janus nanosheets RPM for carbonate formations includes a first side having negatively charged functional groups and a second side having alkyl groups. The silicon oxide Janus nanosheets RPM for sandstone formations includes a first side having positively charged functional groups and a second side having alkyl groups. The negatively charged functional groups may include a negatively charged oxygen group groups and hydroxyl groups. The positively charged functional groups may include amino groups and an amine. Methods of reducing water permeability using the silicon oxide Janus nanosheets RPM and methods of manufacturing the silicon oxide Janus nanosheets RPM are also provided.

A ternary water control and gas recovery method suitable for an unconsolidated siltstone gas reservoir is provided. It includes the following steps: first, running a silt control screen pipe manufactured by an interface hydrophobic modification into a wellbore to realize wellbore water control and silt control; second, filling a surface hydrophobic modified gravel in an annular space between the silt control screen pipe and the wellbore to form a hydrophobic gravel packing layer for water control and silt control; third, injecting a wetting agent aqueous solution into a stratum, and performing a hydrophobic modification on a gas reservoir seepage channel surface to realize in-situ waterblocking and silt migration of the unconsolidated siltstone gas reservoir, and then closing a well for a preset time before exploitation.

A ternary water control and gas recovery method suitable for an unconsolidated siltstone gas reservoir is provided. It includes the following steps: first, running a silt control screen pipe manufactured by an interface hydrophobic modification into a wellbore to realize wellbore water control and silt control; second, filling a surface hydrophobic modified gravel in an annular space between the silt control screen pipe and the wellbore to form a hydrophobic gravel packing layer for water control and silt control; third, injecting a wetting agent aqueous solution into a stratum, and performing a hydrophobic modification on a gas reservoir seepage channel surface to realize in-situ waterblocking and silt migration of the unconsolidated siltstone gas reservoir, and then closing a well for a preset time before exploitation.