A method of forming a barrier to overcome lost circulation in a subterranean formation. The method includes injecting a polymer-sand nanocomposite into one or more lost circulation zones in the subterranean formation where the polymer-sand nanocomposite is formed from sand mixed with a polymer hydrogel. Further, the polymer hydrogel includes a hydrogel polymer, an organic cross-linker, and a salt. The sand additionally comprises a surface modification. The associated method of preparing a polymer-sand nanocomposite lost circulation material for utilisation in forming the barrier is provided.

A method of forming a barrier to overcome lost circulation in a subterranean formation. The method includes injecting a polymer-sand nanocomposite into one or more lost circulation zones in the subterranean formation where the polymer-sand nanocomposite is formed from sand mixed with a polymer hydrogel. Further, the polymer hydrogel includes a hydrogel polymer, an organic cross-linker, and a salt. The sand additionally comprises a surface modification. The associated method of preparing a polymer-sand nanocomposite lost circulation material for utilisation in forming the barrier is provided.

The present disclosure relates to delivery and release systems, such as core-shell particles. An exemplary composition according to the disclosure can include a degradable polymeric shell surrounding a core that includes a crosslinker, which can encompass a metal, such as chromium. The core-shell particles can be provided with a gel-forming polymer, such as a polyacrylamide, into a subterranean reservoir having conditions such that the shell of the core-shell polymer degrades, and the so-released metal is effective to at least partially crosslink the gel-forming polymer to form a gel. The so-formed gel can be effective to control water flow through the subterranean reservoir, such as in relation to a waterflood of the reservoir.

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 including providing a treatment fluid comprising a hardenable acid curable resin and a hydrolysable dimer acid ester. The treatment fluid is combined with a carrier fluid and is introduced into a subterranean formation. Upon the hydrolyzing of the ester in the formation and the contacting of unconsolidated proppants, the treatment method produces consolidated proppants.

Pumpable process-fluid compositions comprise polyacrylamide, a non-metallic crosslinker and a pH-adjustment material. Such compositions have utility in the context of controlling lost circulation in subterranean wells. Upon entering at least one lost circulation zone, the compositions crosslink, thereby forming a barrier that minimizes or stops fluid flow from the wellbore into the lost circulation zone.

Pumpable process-fluid compositions comprise polyacrylamide, a non-metallic crosslinker and a pH-adjustment material. Such compositions have utility in the context of controlling lost circulation in subterranean wells. Upon entering at least one lost circulation zone, the compositions crosslink, thereby forming a barrier that minimizes or stops fluid flow from the wellbore into the lost circulation zone.

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 a cross-linker 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 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 a cross-linker 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.

Modified Drilling fluid compositions, lost circulation material compositions and methods for using drilling fluid compositions are provided with enhanced loss control properties where the modified drilling fluid may include a carrier fluid, one or more drilling fluid additives, and a lost circulation shape-adaptable material. The loss lost circulation shape-adaptable material may include a plurality of oval shaped composite particles, wherein the plurality of oval shaped composite particles comprise a first component, a second component, and a high temperature, high pressure (HTHP) binding adhesive. Methods to control lost circulation in a lost circulation zone in a wellbore may include introducing a modified drilling fluid into the wellbore such that the modified drilling fluid contacts the lost circulation zone.