Methods and compositions for performing a sealing operation in a wellbore. An example method introduces a sealant composition into the wellbore while the sealant composition is under shear. The sealant composition comprises a thixotropic material, a conformance gel system, and an aqueous base fluid. The sealant composition is placed into a target location, and applied shear is reduced to the sealant composition when in the target location thereby allowing the sealant composition to thicken in the target location. Fluid flow across the target location is reduced by a fluid seal formed by the thickened sealant composition.

A fluid for stabilising solids formed from particulate material, the fluid comprising glass and a carrier. A method for preparing the fluid comprising melting and fritting a glass, milling the glass to form a powder and adding the milled glass to a carrier. A method of stabilising a solid formed from particulate material, the method comprising the steps of mixing the fluid with a particulate material and setting, and the use of the fluid, in geoengineering, building preservation, construction, tunnelling, landscape restoration, land remediation, and/or flood protection/remediation.

A preparation method of a fully adaptive modified nanographene plugging type anti-collapse drilling fluid is disclosed. A modified nanographene slurry anti-collapse agent and a water-based drilling fluid containing the modified nanographene slurry anti-collapse agent are disclosed. The preparation method includes subjecting a nanographene and a mixed acid to a first contact to obtain a mixed liquid, dropwise adding potassium chlorate into the mixed liquid under the condition of ice-bath pan to carry out a modification treatment, so as to obtain a modified nanographene, and subjecting the modified nanographene to a second contact with water to prepare a modified nanographene slurry.

Release of hydrochloric acid, hydrofluoric acid and fluoroboric acid into a well may be controlled by introducing into the well an aqueous fluid containing ammonium chloride, ammonium bifluoride, ammonium fluoroborate, ammonium tetrafluoroborate or a mixture thereof and a breaker. After being introduced into the well, the ammonium salt reacts with the breaker and the acid is released into the well.

A method for strengthening a subterranean formation is disclosed herein. A method of strengthening a subterranean formation includes: introducing a first fluid into the subterranean formation, wherein the first fluid includes polyvalent cations; and introducing a second fluid into the subterranean formation, wherein the second fluid includes a dissolved silicate in an aqueous-base fluid; wherein the dissolved silicate reacts with the polyvalent cations in the subterranean formation to form a reaction product including precipitated silicate in the subterranean formation.

Methods for treating a formation may include introducing components of a treatment solution into a wellbore such that the treatment solution contacts the formation to be treated, where the treatment solution may include urea, urease, a calcium ion source, one or more polysaccharides, a casein protein, a protease, an ionic compound, and a sugar, where the formation may have an amount of sand production before treatment and may be in fluid contact with the wellbore, and where an amount of sand production after treatment may be less than the amount of sand production before treatment. Consolidated sand structure compositions may include previously unconsolidated sand interlinked by inter-particle cementitious bonds comprising deposited calcium carbonate crystals, where the consolidated sand has a structural strength and the consolidated sand structure is porous to permit fluid flow through the composition.

A method of mitigating lost circulation in a subterranean wellbore for oil and gas includes introducing basaltic particles and a carbonated mixture to the lost circulation zone of the subterranean wellbore, contacting the basaltic particles with the carbonated mixture, dissolving at least a part of the basaltic particles with the carbonated mixture, reacting divalent cations with the carbonate anions in the carbonated mixture to produce carbonate minerals, providing stimulus to the basaltic particles and the carbonated mixture, depositing at least a part of the carbonate minerals to fractures of the lost circulation zone, monitoring the reacting and depositing; and optionally repeating one or more of the aforementioned steps. A drilling system for oil and gas extraction includes basaltic particles, a carbonated mixture, at least one stimulus generator, and a mitigation device.

A method for zonal isolation in a subterranean formation includes identifying a zone of interest within the subterranean formation, determining a static temperature of the zone of interest, determining a time duration for gelation of a treatment fluid, determining a concentration of an accelerator in the treatment fluid, determining a volume of the treatment fluid to be delivered to the zone of interest, determining a correlation between cooling of a wellbore near the zone of interest and a delivery rate of the treatment fluid, determining a target wellbore temperature, delivering a cooling stage until the target wellbore temperature is reached, and delivering a treatment stage. Delivering the cooling stage and the treatment stage results in forming, within the zone of interest, a gel that is impermeable to fluid flow.

A downhole system includes a packer sealing an annular space around a downhole tubing and an insulating packer fluid positioned within the annular space and adjacent to the packer. The insulating packer fluid includes a sodium bicarbonate activator and an acidic nanosilica dispersion having silica nanoparticles and a stabilizer, wherein the pH of the acidic nanosilica dispersion ranges from 2 to 5, and the silica nanoparticles form at least 20 percent by weight of the acidic nanosilica dispersion.

A method of servicing a wellbore in a subterranean formation comprising: placing components of a wellbore servicing fluid in the wellbore and/or subterranean formation, wherein the components comprise a hydrophobically modified relative permeability modifier, a metal carbonate surface modifier, and a (e.g., aqueous) base fluid; and allowing the wellbore servicing fluid to modify the permeability of at least a portion of the wellbore and/or subterranean formation.