A composition and method for using seawater as a treatment fluid is provided. The treatment fluid comprises N-(phosphonomethyl)iminodiacetic acid and seawater. The provided treatment fluid is stable and viscous, even at high temperatures and a high pH.

The present invention relates to a foam containing water, between 5 and 30 wt % on total weight of the foam of a chelating agent selected from the group of glutamic aid N,N-diacetic acid or a salt thereof (GLDA), aspartic acid N,N-diacetic acid or a salt thereof (ASDA), methylglycine N,N-diacetic acid or a salt thereof (MGDA), N-hydroxyethyl ethylenediamine-N,N′,N′-triacetic acid or a salt thereof (HEDTA), a foaming agent, and at least 25 vol % on total volume of the foam of a gas, and having a pH of between 2 and 5, to a viscosified composition containing water, between 5 and 30 wt % on total volume of the composition of a chelating agent selected from the group of glutamic aid N,N-diacetic acid or a salt thereof (GLDA), aspartic acid N,N-diacetic acid or a salt thereof (ASDA), methylglycine N,N-diacetic acid or a salt thereof (MGDA), N-hydroxyethyl ethylenediamine-N,N′,N′-triacetic acid or a salt thereof (HEDTA), and at least 0.01 wt % on total weight of the composition of a viscosifying agent, and having a pH of between 2 and 5, and to a process for treating a subterranean formation comprising introducing the above foam or viscosified composition into the formation.

The present invention relates to a foam containing water, between 5 and 30 wt % on total weight of the foam of a chelating agent selected from the group of glutamic aid N,N-diacetic acid or a salt thereof (GLDA), aspartic acid N,N-diacetic acid or a salt thereof (ASDA), methylglycine N,N-diacetic acid or a salt thereof (MGDA), N-hydroxyethyl ethylenediamine-N,N′,N′-triacetic acid or a salt thereof (HEDTA), a foaming agent, and at least 25 vol % on total volume of the foam of a gas, and having a pH of between 2 and 5, to a viscosified composition containing water, between 5 and 30 wt % on total volume of the composition of a chelating agent selected from the group of glutamic aid N,N-diacetic acid or a salt thereof (GLDA), aspartic acid N,N-diacetic acid or a salt thereof (ASDA), methylglycine N,N-diacetic acid or a salt thereof (MGDA), N-hydroxyethyl ethylenediamine-N,N′,N′-triacetic acid or a salt thereof (HEDTA), and at least 0.01 wt % on total weight of the composition of a viscosifying agent, and having a pH of between 2 and 5, and to a process for treating a subterranean formation comprising introducing the above foam or viscosified composition into the formation.

Nano-sized clay minerals enhance the viscosity of aqueous fluids that have increased viscosity due to the presence of viscoelastic surfactants (VESs). In one non-limiting theory, the nano-sized phyllosilicate mineral viscosity enhancers associate, link, connect, or relate the VES elongated micelles into associations thereby increasing the viscosity of the fluid, possibly by mechanisms involving chemisorption or surface charge attractions. The nano-sized phyllosilicate mineral particles, also called clay mineral nanoparticles, may have irregular surface charges. The higher fluid viscosity is beneficial to crack the formation rock during a fracturing operation, to reduce fluid leakoff, and to carry high loading proppants to maintain the high conductivity of fractures.

Nano-sized clay minerals enhance the viscosity of aqueous fluids that have increased viscosity due to the presence of viscoelastic surfactants (VESs). In one non-limiting theory, the nano-sized phyllosilicate mineral viscosity enhancers associate, link, connect, or relate the VES elongated micelles into associations thereby increasing the viscosity of the fluid, possibly by mechanisms involving chemisorption or surface charge attractions. The nano-sized phyllosilicate mineral particles, also called clay mineral nanoparticles, may have irregular surface charges. The higher fluid viscosity is beneficial to crack the formation rock during a fracturing operation, to reduce fluid leakoff, and to carry high loading proppants to maintain the high conductivity of fractures.

A well fracturing fluid is shown which includes an aqueous base fluid, a hydratable polymer, such as a guar gum, and a suitable crosslinking agent for crosslinking the hydratable polymer to form a polymer gel. The hydratable polymer has a higher molecular weight which is achieved by improvements in the processing of the guar split. The higher molecular weight polymer provides improved performance in well fracturing operations.

A method for treating a subterranean formation that includes preparing a treatment fluid comprising a base fluid, a relative permeability modifier (RPM) and a particulate and performing a treatment operation by injecting the treatment fluid into a portion of the subterranean formation.

A method for treating a subterranean formation that includes preparing a treatment fluid comprising a base fluid, a relative permeability modifier (RPM) and a particulate and performing a treatment operation by injecting the treatment fluid into a portion of the subterranean formation.

Degradable material for treatment fluids for use in fluid loss control, diversion, and plugging operations, methods of preparing the degradable material, and methods of using the degradable material in treatment fluids are disclosed. The degradable materials are polymer-based solid acid precursor particles that have been partially or fully coated with an anti-caking agent to prevent agglomeration of the polymer-based solid acid precursor particles during storage and transport. These coated polymer-based solid acid precursor particles can then be added to a variety of treatment fluids to temporarily create a physical barrier to fluid flow before degrading and generating acids that can be used in other treatment operations. This degradable coated polymer-based solid acid precursor additive can be combined with other traditional downhole additives such surfactants, viscosifiers, and biocides, allowing for a wide variety of applications in hydrocarbon reservoirs.

Degradable material for treatment fluids for use in fluid loss control, diversion, and plugging operations, methods of preparing the degradable material, and methods of using the degradable material in treatment fluids are disclosed. The degradable materials are polymer-based solid acid precursor particles that have been partially or fully coated with an anti-caking agent to prevent agglomeration of the polymer-based solid acid precursor particles during storage and transport. These coated polymer-based solid acid precursor particles can then be added to a variety of treatment fluids to temporarily create a physical barrier to fluid flow before degrading and generating acids that can be used in other treatment operations. This degradable coated polymer-based solid acid precursor additive can be combined with other traditional downhole additives such surfactants, viscosifiers, and biocides, allowing for a wide variety of applications in hydrocarbon reservoirs.