A method of cementing a wellbore includes injecting into the wellbore a non-aqueous fluid; injecting into the wellbore a cement slurry and a non-ionic surfactant composition after injecting the non-aqueous fluid; and allowing the cement slurry to set, wherein the non-ionic surfactant composition comprises an alkyl end-capped ethoxylated fatty alcohol, a chain extended non-ionic surfactant, or a combination comprising at least one of the foregoing.

Methods of determining the integrity of a well are provided. The methods include mixing conductive materials into a fluid, introducing the fluid into the well, and allowing the conductive materials to coat a surface of a subsurface formation, thereby forming an electrically conductive data conduit coating. The methods further include transmitting data through the electrically conductive data conduit coating to determine the integrity of the well.

A cement spacer fluid and a method for making and a method for using the cement spacer fluid are provided. The cement spacer fluid includes a polyethyleneimine hydrochloride (PEI HCl) salt, an aqueous solvent, a viscosifier, and a weighting agent.

According to one or more embodiments of the present disclosure, a spacer fluid includes an aqueous fluid, a weighting agent, and a clay stabilizer consisting of one or more polyethylene polyamines having a first structure H.sub.2NCH.sub.2CH.sub.2(NHCH.sub.2CH.sub.2).sub.xNH.sub.2, where x is an integer greater than or equal to 3. The amount of the clay stabilizer may be from 0.1 wt. % to 10 wt. % relative to the total weight of the spacer fluid. The average molecular weight of the polyethylene polyamines in the spacer fluid having the first structure may be from 200 g/mol to 400 g/mol. All of the polyethylene polyamines in the spacer fluid having the first structure may be encompassed in the clay stabilizer. Methods for cementing a casing in a wellbore using the spacer fluid are also disclosed.

Fluid flows, such as slurries, conditioning fluids, spacer fluids, or the like, may be modified to carry materials having high magnetic permeability characteristics that can be detected by a magnetic permeability sensing apparatus positioned along the fluid flow path in wellbores or downhole tools. Sensed presence of the high magnetic permeability material by the sensing apparatus positioned in the fluid flow path may result in initiation of an operational event. The operational event may include, but not limited to closing or opening a valve, moving a component, conveying a signal, activating or deactivating a device, or the like.

An elasticator and a preparation method thereof and a casing expansion loss prevention elastic spacer fluid for cementing are provided. The preparation method of the elasticator includes the following steps of: (1) taking polycaprolactone and an inorganic porous material for fully mixing under a heating condition to obtain a mixture; and (2) mixing the mixture with a high-elastic modulus rubber powder to obtain an elasticator.

Spacer fluids or chemical washes are prepared that comprise water, a hydraulic cement and particles of an oil-absorbent material. The particles are present in an amount sufficient to alter a property of a non-aqueous drilling fluid. The spacer fluid or chemical wash is placed in a subterranean well, whereupon the spacer fluid or chemical wash contacts residual drilling fluid on casing and formation surfaces. The oil-absorbent material in the spacer fluid or chemical wash may reduce the mobility of the drilling fluid, thereby improving zonal isolation.

A method of servicing a wellbore penetrating a subterranean formation, comprising placing a wellbore servicing fluid (WSF) into the wellbore proximate a permeable zone having an average fracture width of about W microns, wherein the WSF comprises a particulate blend and water, and wherein the particulate blend comprises (a) a type A particulate material characterized by a weight average particle size of equal to or greater than about W/3 microns, and (b) a type B particulate material characterized by a weight average particle size of less than about W/3 microns, wherein a weight ratio of the type A particulate material to the type B particulate material is from about 0.05 to about 5.

Methods may include introducing a polymerizable composition containing a polycyclic monomer and a catalyst into a subterranean formation; and polymerizing the polymerizable composition in the presence of the catalyst in situ to form a polymer. Methods may also include lowering a wellbore tool into the subterranean formation, wherein the tool contains a first partition containing a polymerizable composition, and a second partition containing a catalyst; releasing the polymerizable composition from the first partition; releasing the catalyst from the second partition; contacting the polymerizable composition and the catalyst in a mixing region; and reacting the polymerizable composition and the catalyst in situ to form a polymer.

Fluid flows, such as slurries, conditioning fluids, spacer fluids, or the like, may be modified to carry materials having high magnetic permeability characteristics that can be detected by a magnetic permeability sensing apparatus positioned along the fluid flow path in wellbores or downhole tools. Sensed presence of the high magnetic permeability material by the sensing apparatus positioned in the fluid flow path may result in initiation of an operational event. The operational event may include, but not limited to closing or opening a valve, moving a component, conveying a signal, activating or deactivating a device, or the like.