Drilling fluid compositions may include a weighting agent, a nitrite-containing compound, and an ammonium-containing compound, where the nitrite-containing compound and the ammonium-containing compound may be encapsulated together in copolymer micro-particles forming encapsulated thermochemical compounds, and where at least one property selected from the group consisting of the density, the plastic viscosity, the yield point, the gel strength, and the pH, of the drilling fluid composition may be substantially similar to the at least one property of a comparable drilling fluid composition devoid of the encapsulated thermochemical compounds. Methods for reducing a filter cake from a wellbore surface in a subterranean formation are also provided. The methods may include introducing into the wellbore the drilling fluid compositions, allowing the drilling fluid composition to reach a temperature in the wellbore sufficient for the encapsulated thermochemical compounds to react, where the reaction of the encapsulated thermochemical compounds generates heat and nitrogen gas.

Drilling fluid compositions may include a weighting agent, a nitrite-containing compound, and an ammonium-containing compound, where the nitrite-containing compound and the ammonium-containing compound may be encapsulated together in copolymer micro-particles forming encapsulated thermochemical compounds, and where at least one property selected from the group consisting of the density, the plastic viscosity, the yield point, the gel strength, and the pH, of the drilling fluid composition may be substantially similar to the at least one property of a comparable drilling fluid composition devoid of the encapsulated thermochemical compounds. Methods for reducing a filter cake from a wellbore surface in a subterranean formation are also provided. The methods may include introducing into the wellbore the drilling fluid compositions, allowing the drilling fluid composition to reach a temperature in the wellbore sufficient for the encapsulated thermochemical compounds to react, where the reaction of the encapsulated thermochemical compounds generates heat and nitrogen gas.

A scale removal agent may effectively be introduced into a well having a formation temperature of 300° F. The scale removal agent is a component of a gelled fluid containing an amine oxide viscoelastic surfactant.

A scale removal agent may effectively be introduced into a well having a formation temperature of 300° F. The scale removal agent is a component of a gelled fluid containing an amine oxide viscoelastic surfactant.

Compositions containing a first reactant; an emulsion comprising a surfactant and silicon dioxide (SiO.sub.2) nanoparticles; and a carrier fluid containing a second reactant and methods of making. When the first and second reactants react, they generate heat. At a first time, the emulsion surrounds the first reactant, and the carrier fluid with the second reactant surrounds the emulsion. At a second time, the emulsion surrounds a first portion of the first reactant; and a second portion of the first reactant surrounds the emulsion.

Compositions containing a first reactant; an emulsion comprising a surfactant and silicon dioxide (SiO.sub.2) nanoparticles; and a carrier fluid containing a second reactant and methods of making. When the first and second reactants react, they generate heat. At a first time, the emulsion surrounds the first reactant, and the carrier fluid with the second reactant surrounds the emulsion. At a second time, the emulsion surrounds a first portion of the first reactant; and a second portion of the first reactant surrounds the emulsion.

A process for coating a product by ion exchange including: a) providing a product that contains a surface segregating species (SSS) having a low surface energy component and an ionic component wherein the SSS has segregated to an outer surface of the product to form an activated surface; and b) treating the activated surface of the product with a liquid containing a surface modifying agent comprising one or more polyionic species, wherein the polyionic species is attracted to and deposits on the activated surface through a process of ion exchange.

Amidoamine-based gemini surfactants having dual chains connected via an alkyl linker. Each chain contains a quaternary ammonium head group and an ethoxylated alkyl tail. Properties of the surfactant including thermal stability, critical micelle concentration, and foam stability are specified. A method of recovering oil from a reservoir using an aqueous composition that contains the surfactant and a polymer (e.g. AM-AMPS) is also provided. This method is particularly effective for oil recovery in reservoirs of high temperature and/or high salinity.

Disclosed are a variety of amphoteric compounds containing a quaternary nitrogen group, a covalently bound counterion, and an ester or amide group. These amphoteric compounds can be advantageously prepared via a chemoenzymatic green process, and exhibit good surfactant properties.

A stable dispersion of exfoliated layer substances is prepared through interlayer exfoliation of a layered compound. A dispersion including quaternary ammonium ions (A) each having a total carbon atom number of 15 to 45 and one or two C.sub.10-20 alkyl groups, and an anionic surfactant (B) having an ammonium ion, wherein plate-like particles (C) having an average thickness of 0.7 to 40 nm, an average major-axis length of 100 to 600 nm, an average minor-axis length of 50 to 300 nm, and a ratio of average major-axis length to average minor-axis length of 1.0 to 10.0 are dispersed in a liquid medium, and the plate-like particles (C) in the dispersion have an average particle diameter of 10 to 600 nm as measured by dynamic light scattering, and a transparent substrate using the dispersion.