A method for providing a mixture downhole at or about a location in an open or cased wellbore. The method includes extending a retrievable delivery sub-system downhole through the wellbore, delivering two or more chemical components downhole through the retrievable delivery sub-system, and mixing the two or more chemical components to provide the mixture at or about the location. The delivery sub-system has a tubing assembly having at least two fluidly separated delivery channels, and each delivery channel is for delivering at least one of the two or more chemical components.

A method for enhancing wellbore integrity and/or for sealing a wellbore by sealing formation or micro-annulus fractures in a wellbore. Such sealing can be at least partially accomplished by the use of timed expansion of an expandable sealant material that is placed a wellbore. The expansion of the expandable sealant material causes the cement surface or formation surface to be compressed, thereby creating a tight seal and/or eliminating annulus cracking, fracture, and/or gas channels in the wellbore. A degradable polymer can be used when restoration of the wellbore formation is desired.

A solids-control fluid for controlling flow of solids in a subterranean formation is disclosed herein. The solids-control fluid can include a diluent and a curable resin. The diluent can include a mutual solvent and an ethylene glycol. The curable resin can be dispersed within the diluent for controlling flow of solids in the subterranean formation.

Methods of the present disclosure relate to designing lost circulation material (LCM) based on permeability of filter cake. A method comprises determining if a lost circulation material (LCM) has the potential to bridge a fracture, the fracture extending from a wellbore; determining a permeability of filter cake formed due to the LCM, wherein the permeability is determined if the LCM has the potential to bridge the fracture; and formulating a composition that includes the LCM, to control losses from the wellbore.

Methods of the present disclosure relate to designing lost circulation material (LCM) based on permeability of filter cake. A method comprises determining if a lost circulation material (LCM) has the potential to bridge a fracture, the fracture extending from a wellbore; determining a permeability of filter cake formed due to the LCM, wherein the permeability is determined if the LCM has the potential to bridge the fracture; and formulating a composition that includes the LCM, to control losses from the wellbore.

The current method comprises producing a loss control blend by selecting blend ingredients that contribute to thixotropy of the blend, density of the blend, and compressive strength of the set blend, wherein at least one of the blend ingredients contributes positively to all three of these attributes.

The current method comprises producing a loss control blend by selecting blend ingredients that contribute to thixotropy of the blend, density of the blend, and compressive strength of the set blend, wherein at least one of the blend ingredients contributes positively to all three of these attributes.

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 reversible gel composition including nanosilica and polyethylene oxide, the nanosilica and polyethylene oxide present at concentrations operable to allow for the reversible gel composition to be a flowable liquid at pH greater than about 8 and operable to allow for the reversible gel composition to be a substantially solid gel at pH less than about 8.

The disclosure is directed to methods and compositions delaying the gelation of polymers in water flooding by sequentially or co-injecting a carboxylate-containing polymer solution, a gel-delaying polymer, and gelation agent into a hydrocarbon reservoir. Delays of weeks are observed.