A method of sealing in a bore, such as plugging a well for abandonment. The method includes applying a swellable in particulate form to the bore. The swellable includes a polymer. The particulate swellable is positioned in place within the bore at a desired location. The method includes swelling the swellable so as to form a seal at the desired location. The technology may also include a well comprising a bore with a seal applied by injecting the swellable in particulate form as a flowable into the bore.

A method of sealing in a bore, such as plugging a well for abandonment. The method includes applying a swellable in particulate form to the bore. The swellable includes a polymer. The particulate swellable is positioned in place within the bore at a desired location. The method includes swelling the swellable so as to form a seal at the desired location. The technology may also include a well comprising a bore with a seal applied by injecting the swellable in particulate form as a flowable into the bore.

A method may include: providing a spacer fluid comprising water and an agglomerated zeolite catalyst; and displacing a drilling fluid in a wellbore using the spacer fluid. The agglomerated zeolite catalyst may be a spent agglomerated zeolite catalyst and may include a matrix, a filler, a binder, and zeolite crystals. The zeolite crystals may be selected from the group consisting of type x, type y, ultra-stable type y, ZSM-5, SAPO-11, silicalite-1, mordenite, ferrierite, beta, and combinations thereof.

An example method includes pumping fluid into a wellbore to fill, at least partly, a region in a lost circulation zone, with the fluid having a first density; and after pumping the fluid, pumping cement slurry into the wellbore. The cement slurry has a second density. The first density is greater than, or equal to, the second density, which causes the fluid to prevent, at least partly, the cement slurry from mixing with other fluid in the lost circulation zone for at least a period of time.

An example method includes pumping fluid into a wellbore to fill, at least partly, a region in a lost circulation zone, with the fluid having a first density; and after pumping the fluid, pumping cement slurry into the wellbore. The cement slurry has a second density. The first density is greater than, or equal to, the second density, which causes the fluid to prevent, at least partly, the cement slurry from mixing with other fluid in the lost circulation zone for at least a period of time.

A lost circulation material (LCM) composition for sealing lost circulation zones in wellbores may include 50 weight percent to 97 weight percent epoxy resin, 2 weight percent to 30 weight percent curing agent, 0.1 weight percent to 40 weight percent weighting material, and 0.1 weight percent to 20 weight percent amide accelerator. The LCM composition may have a density of greater than or equal to 1121 kilograms per cubic meter and may be capable of being injected through a drill bit of a drill string into the lost circulation zone. The amide accelerator may enable the viscosity of the LCM composition to be reduced while providing a reduced cure time. Methods of treating a lost circulation of a wellbore with the LCM compositions are also disclosed.

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.

Nano-sized mixed metal oxide carriers capable of delivering a well treatment additive for a sustained or extended period of time in the environment of use, methods of making the nanoparticles, and uses thereof are described herein. The nanoparticles can have a formula of:
A/[M.sub.x.sup.1M.sub.y.sup.2M.sub.z.sup.3]O.sub.nH.sub.m
where x is 0.03 to 3, y is 0.01 to 0.4, z is 0.01 to 0.4 and n and m are determined by the oxidation states of the other elements, and M.sup.1 can be aluminum (Al), gallium (Ga), indium (In), or thallium (Tl). M.sup.2 and M.sup.3 are not the same and can be a Column 2 metal, Column 14 metal, or a transition metal. A is can be a treatment additive.

Nano-sized mixed metal oxide carriers capable of delivering a well treatment additive for a sustained or extended period of time in the environment of use, methods of making the nanoparticles, and uses thereof are described herein. The nanoparticles can have a formula of:
A/[M.sub.x.sup.1M.sub.y.sup.2M.sub.z.sup.3]O.sub.nH.sub.m
where x is 0.03 to 3, y is 0.01 to 0.4, z is 0.01 to 0.4 and n and m are determined by the oxidation states of the other elements, and M.sup.1 can be aluminum (Al), gallium (Ga), indium (In), or thallium (Tl). M.sup.2 and M.sup.3 are not the same and can be a Column 2 metal, Column 14 metal, or a transition metal. A is can be a treatment additive.

A degradable plug for use in a wellbore, wherein the degradable plug involves an inducibly degradable composition containing solid polyacetal. After placing the degradable plug in a wellbore, it can be degraded by allowing a portion of the polyacetal present in the inducibly degradable composition to react with an inducer.