Abstract: A method is disclosed for gravel packing a hole in a subterranean formation including the step of pumping into the hole a gravel pack composition comprising gravel and a carrier fluid comprising a brine-in-oil emulsion, said emulsion being stabilized by an emulsifier based on at least one sorbitan fatty acid ester presenting a shoulder peak before the peak depicted to be the monomer peak when analyzed by gel permeation chromatography. The emulsifiers that exhibit the shoulder exhibit good stability without causing formation damage.

Abstract: Well treatment is disclosed that includes injecting a well treatment fluid with insoluble polyol polymer such as polyvinyl alcohol (PVOH) dispersed therein, depositing the insoluble polymer in the wellbore or an adjacent formation, and thereafter dissolving the polymer by reducing salinity and/or increasing temperature conditions in the environment of the polymer deposit. The method is disclosed for filter cake formation, fluid loss control, drilling, hydraulic fracturing and fiber assisted transport, where removal of the polyol at the end of treatment or after treatment is desired. The method is also disclosed for providing dissolved polyol as a delayed breaker in crosslinked polymer viscosified systems and viscoelastic surfactant systems. Also disclosed are well treatment fluids containing insoluble amorphous or at least partially crystalline polyol, and a PVOH fiber composition wherein the fibers are stabilized from dissolution by salinity.

Abstract: The present invention relates to novel aqueous wellbore treatment fluids containing a gas component, a heteropolysaccharide, an electrolyte, and a surfactant, wherein the fluids may further include an organoamino compound. The fluids exhibit good theological properties at elevated temperatures. Methods of use of fluids comprising at least an aqueous medium, a gas component, a heteropolysaccharide and a surfactant for hydraulically fracturing, well cleanup and gravel packing operations, are also disclosed.

Abstract: Suspensions are provided of water-soluble materials in non-aqueous carrier fluids using suspension agents that include organophilic clays. Methods of forming such suspensions are provided. Methods are also provided for using such suspensions to prepare aqueous solutions, in particular thickened aqueous solutions, in particular for use in oilfield treatments.

Abstract: A method is described for treating a subterranean formation with a low viscosity fluid system that contains a surfactant or mixture of surfactants that does not divert fluid flow in the formation, but that develops the ability to divert flow as the fluid flows through the formation. The fluid optionally contains a formation-dissolving agent. The fluid is used in matrix acidizing, acid fracturing, and diversion.

Abstract: A composition for use in an oil chamber of a tool includes a hydraulic oil; and a surfactant, wherein the surfactant is present at an amount sufficient to form micelles in the hydraulic oil. The composition may further include an amphiphilic copolymer. A method includes providing a hydraulic fluid composition comprising a hydraulic oil and a surfactant capable of forming micelles in the hydraulic oil; and filling a hydraulic chamber in the tool with the hydraulic fluid composition. The hydraulic fluid composition may further include an amphiphilic copolymer.

Abstract: A method is given for treating a subterranean formation penetrated by a wellbore with a viscosified fluid. The fluid contains a solid hydrolysable polyacid that upon dissolution and hydrolysis releases an acid that is a breaker for the viscosifying system. Suitable solid hydrolysable polyacids include polylactic acid and polyglycolic acid. The fluid also contains a pH control agent, present in an amount sufficient to neutralize any acid present in the solid hydrolysable polyacid before the injection and to neutralize any acid generated by the solid hydrolysable polyacid during the injection, so that the acid breaker is not available to break the fluid during the injection. In one embodiment the viscosifier is a viscoelastic surfactant fluid system and the solid hydrolysable polyacid is of a size selected to be a fluid loss additive, for example in fracturing or gravel packing.

Abstract: A composition for use in an oil chamber of a tool includes a hydraulic oil; and a surfactant, wherein the surfactant is present at an amount sufficient to form micelles in the hydraulic oil. The composition may further include an amphiphilic copolymer. A method includes providing a hydraulic fluid composition comprising a hydraulic oil and a surfactant capable of forming micelles in the hydraulic oil; and filling a hydraulic chamber in the tool with the hydraulic fluid composition. The hydraulic fluid composition may further include an amphiphilic copolymer.

Abstract: Suspensions are provided of water-soluble materials in non-aqueous carrier fluids using suspension agents that include organophilic clays. Methods of forming such suspensions are provided. Methods are also provided for using such suspensions to prepare aqueous solutions, in particular thickened aqueous solutions, in particular for use in oilfield treatments.

Abstract: A formation consolidation process is described which comprises injecting into an unconsolidated or poorly consolidated subterranean formation penetrated by a wellbore an aqueous pumpable system comprising an insoluble silica source (e.g., colloidal silica, silica fume or fumed silica) and a source of calcium hydroxide (e.g., aqueous solutions of calcium chloride and sodium hydroxide). The aqueous system may contain a nucleation inhibitor. The components of the aqueous system react to produce a calcium silicate hydrate gel (C-S-H gel) having cementitious properties within the pores of the formation. After the C-S-H gel sets and hardens, the consolidated formation has a high compressive strength (e.g., 500 psi (about 3.5 MPa) or more). The technique can be performed as a remedial treatment or in new completions, but it is particularly useful in workover treatments for existing wells.

Abstract: The present invention relates to novel aqueous wellbore treatment fluids containing a gas component, a heteropolysaccharide, an electrolyte, and a surfactant, wherein the fluids may further include an organoamino compound. The fluids exhibit good rheological properties at elevated temperatures. Methods of using fluids containing at least an aqueous medium, a gas component, a heteropolysaccharide and a surfactant for hydraulically fracturing, well cleanup and gravel packing operations, are also disclosed.

Abstract: Disclosed are methods of treating subterranean formations with rapidly hydratable treatment fluids based upon heteropolysaccharides. In particular, the invention relates to treatment methods with fluids containing a heteropolysaccharide, aqueous medium, and an electrolyte, wherein the fluids may further include a gas component, a surfactant and/or an organoamino compound. The fluids exhibit good rheological properties at elevated temperatures, and unusually rapid hydration rates which allows utilizing such fluids without the need of hydration tanks.

Abstract: The present invention relates to novel aqueous wellbore treatment fluids containing a gas component, a heteropolysaccharide, an electrolyte, and a surfactant, wherein the fluids may further include an organoamino compound. The fluids exhibit good rheological properties at elevated temperatures. Methods of use of fluids comprising at least an aqueous medium, a gas component, a heteropolysaccharide and a surfactant for hydraulically fracturing, well cleanup and gravel packing operations, are also disclosed.

Abstract: Well treatment is disclosed that includes injecting a well treatment fluid with insoluble polyol polymer such as polyvinyl alcohol (PVOH) dispersed therein, depositing the insoluble polymer in the wellbore or an adjacent formation, and thereafter dissolving the polymer by reducing salinity and/or increasing temperature conditions in the environment of the polymer deposit. The method is disclosed for filter cake formation, fluid loss control, drilling, hydraulic fracturing and fiber assisted transport, where removal of the polyol at the end of treatment or after treatment is desired. The method is also disclosed for providing dissolved polyol as a delayed breaker in crosslinked polymer viscosified systems and viscoelastic surfactant systems. Also disclosed are well treatment fluids containing insoluble amorphous or at least partially crystalline polyol, and a PVOH fiber composition wherein the fibers are stabilized from dissolution by salinity.

Abstract: A method is described for treating a subterranean formation with a low viscosity fluid system that contains a surfactant or mixture of surfactants that does not divert fluid flow in the formation, but that develops the ability to divert flow as the fluid flows through the formation. The fluid optionally contains a formation-dissolving agent. The fluid is used in matrix acidizing, acid fracturing, and diversion.

Abstract: It is proposed a method for completing an unconsolidated interval, including particulates, in a subterranean formation, including a consolidation steps. The consolidation step is performed by injection of an aqueous solution of colloidal particles with a pH modifier and/or an ionic-strength modifier. A hard gel is formed that holds the particulates together. The consolidation is followed by hydraulic fracturing. Diversion towards area of less permeability may be enhanced by the use of micrometric particles.

Abstract: A formation consolidation process is described which comprises injecting into an unconsolidated or poorly consolidated subterranean formation penetrated by a wellbore an aqueous pumpable system comprising an insoluble silica source (e.g., colloidal silica, silica fume or fumed silica) and a source of calcium hydroxide (e.g., aqueous solutions of calcium chloride and sodium hydroxide). The aqueous system may contain a nucleation inhibitor. The components of the aqueous system react to produce a calcium silicate hydrate gel (C-S-H gel) having cementitious properties within the pores of the formation. After the C-S-H gel sets and hardens, the consolidated formation has a high compressive strength (e.g., 500 psi (about 3.5 MPa) or more). The technique can be performed as a remedial treatment or in new completions, but it is particularly useful in workover treatments for existing wells.

Abstract: A composition for use in an oil chamber of a tool includes a hydraulic oil; and a surfactant, wherein the surfactant is present at an amount sufficient to form micelles in the hydraulic oil. The composition may further include an amphiphilic copolymer. A method includes providing a hydraulic fluid composition comprising a hydraulic oil and a surfactant capable of forming micelles in the hydraulic oil; and filling a hydraulic chamber in the tool with the hydraulic fluid composition. The hydraulic fluid composition may further include an amphiphilic copolymer.

Abstract: A method is given for treating a subterranean formation penetrated by a wellbore with a viscosified fluid. The fluid contains a solid hydrolysable polyacid that upon dissolution and hydrolysis releases an acid that is a breaker for the viscosifying system. Suitable solid hydrolysable polyacids include polylactic acid and polyglycolic acid. The fluid also contains a pH control agent, present in an amount sufficient to neutralize any acid present in the solid hydrolysable polyacid before the injection and to neutralize any acid generated by the solid hydrolysable polyacid during the injection, so that the acid breaker is not available to break the fluid during the injection. In one embodiment the viscosifier is a viscoelastic surfactant fluid system and the solid hydrolysable polyacid is of a size selected to be a fluid loss additive, for example in fracturing or gravel packing.

Abstract: The present invention is a method for treating a subterranean wellbore. More specifically, the invention is a method for removing wellbore solids. A first, polymer containing fluid is placed in the solids bed. A second, viscosifying fluid is then placed into the solids bed thereby agitating the solids in the bed and causing the formation of a gel capsules when mixed with the biopolymer fluid. These gel capsules are capable of trapping or entraining the agitated solids. The gel capsules typically have a relatively high volume and a relatively low density, thereby making their removal from the wellbore easier.