Abstract: A viscosified aqueous solution, optionally for use in a subterranean wellbore, is made by reacting in aqueous solution (i) an initial polymer with either carboxylic acid or amino groups on its polymer chain, (ii) a second compound with an amino group or carboxylic acid group, and (iii) a coupling agent, so that molecules of the second compound join to the polymer chain through amide groups, thereby forming an aqueous solution of a modified polymer which, without separation from the aqueous solution, participates in cross-linking thereby enhancing viscosity of the solution. The second compound may include hydrophobic groups so that the modified polymer contains hydrophobic groups and is able to cross-link with itself or a viscoelastic surfactant through association of hydrophobic groups (without covalent bond formation) in aqueous solution. Such cross-links can reform after the fluid has been subjected to shear.

Abstract: A viscosified aqueous solution, optionally for use in a subterranean wellbore, is made by reacting in aqueous solution (i) an initial polymer with either carboxylic acid or amino groups on its polymer chain, (ii) a second compound with an amino group or carboxylic acid group, and (iii) a coupling agent, so that molecules of the second compound join to the polymer chain through amide groups, thereby forming an aqueous solution of a modified polymer which, without separation from the aqueous solution, participates in cross-linking thereby enhancing viscosity of the solution. The second compound may include hydrophobic groups so that the modified polymer contains hydrophobic groups and is able to cross-link with itself or a viscoelastic surfactant through association of hydrophobic groups (without covalent bond formation) in aqueous solution. Such cross-links can reform after the fluid has been subjected to shear.

Abstract: A marine seismic streamer comprising a solid, hydrophobic core member that is encased in a hydrophobic streamer skin/casing. The hydrophobic streamer skin may be extruded onto and/or heat welded to the hydrophobic core member. The hydrophobic streamer skin/casing may comprise a thermoplastic polyurethane that includes fluorine and/or silicon moieties, silicon, polydimethylsiloxane or the like. The hydrophobic streamer skin/casing may reduce the drag of the streamer and may provide anti-biofouling properties to the streamer. A hydrophobic paint, coating or polymer may in some instances be disposed on top of the hydrophobic streamer skin/casing.

Abstract: A marine seismic streamer comprising a solid, hydrophobic core member that is encased in a hydrophobic streamer skin/casing. The hydrophobic streamer skin may be extruded onto and/or heat welded to the hydrophobic core member. The hydrophobic streamer skin/casing may comprise a thermoplastic polyurethane that includes fluorine and/or silicon moieties, silicon, polydimethylsiloxane or the like. The hydrophobic streamer skin/casing may reduce the drag of the streamer and may provide anti-biofouling properties to the streamer. A hydrophobic paint, coating or polymer may in some instances be disposed on top of the hydrophobic streamer skin/casing.

Abstract: An anti-biofouling casing for a seismic streamer is described, the anti-biofouling casing comprising a polymer system comprising a hydrophobically-modified base polymer, the hydrophobically-modified base polymer comprising a base polymer having a backbone and a hydrophobically derivatized chain extender coupled to said backbone of said base polymer, wherein the the hydrophobically derivatized chain extender comprises a hydrophobic moiety. The anti-fouling casing comprises a hydrophobic surface to which a layer—such as a coating or a paint—of a material having low surface energy may be coupled to provide an anti-biofouling layer on the seismic streamer.

Abstract: The current application discloses fluids and methods for treating a subterranean formation penetrated by a wellbore. In one aspect, there is provided a fluid comprising chitosan and titanate, where the fluid has an increased viscosity compared with a solution containing chitosan without titanate. In another aspect, there is provided a method of using such fluid to treat a subterranean formation penetrated by a wellbore. The method may comprise mixing chitosan and titanate in a carrying medium, forming a gel comprising chitosan and titanate, introducing the gel into a subterranean formation, and treating the subterranean formation with the gel.

Abstract: The present invention provides aqueous viscoelastic compositions comprising a cleavable surfactant and possibly also an electrolyte. The cleavable surfactants useful in the present invention comprise at least one weak chemical bond, which is capable of being broken under appropriate conditions, to produce oil soluble and water soluble products typically having no interfacial properties and surface activity compared with the original surfactant molecule. Further, the rheological properties of the aqueous viscoelastic composition are usually altered upon cleavage of the cleavable surfactant generally resulting in the elimination of the viscosifying, viscoelastic and surfactant properties of the composition. Aqueous viscoelastic compositions in accordance with the present invention are suitable for use in oil-field applications, particularly for hydraulic fracturing of subterranean formations.

Abstract: A seismic streamer and associated method are provided. The seismic streamer may include a seismic streamer core having a cylindrical configuration. A melt-processable thermoplastic layer may be coupled with the seismic streamer core, the melt-processable thermoplastic layer being extruded to form a first tube. An elastomeric layer may be coupled with the melt-processable thermoplastic layer, the elastomeric layer being extruded to form a second tube.

Abstract: The present invention provides aqueous viscoelastic compositions comprising a cleavable anionic surfactant which is a sulphonate and possibly also an electrolyte. The cleavable surfactants useful in the present invention comprise a chemical bond, which is capable of being broken under appropriate conditions, to produce oil soluble and water soluble products typically having no interfacial properties and surface activity compared with the original surfactant molecule. Further, the rheological properties of the aqueous viscoelastic composition are usually altered upon cleavage of the cleavable surfactant generally resulting in the elimination of the viscosifying, viscoelastic and surfactant properties of the composition. Aqueous viscoelastic compositions in accordance with the present invention are suitable for use in oil-field applications, particularly for hydraulic fracturing of subterranean formations.

Abstract: An aqueous solution comprising a thickening polymer with diol groups distributed along it, such as guar or other polysaccharide, is cross linked with a cross-linker which contains a plurality of boroxole groups of the partial formula wherein R1 is hydrogen or a substituent group or an attachment to the remainder of the cross-linker molecule, R2 is hydrogen or a substituent group, R3 is hydrogen or an aliphatic or aromatic group and the carbon atoms joined by a double bond are part of an aromatic ring. The thickened fluid may be a wellbore fluid and may be a hydraulic fracturing fluid in which a particulate proppant is suspended.

Abstract: A composition flowing along an elongate conduit to a location accessed by that conduit contains a precursor substance which, arriving at the location, is converted electrochemically to chemically reactive intermediate. This intermediate reacts with another constituent of the composition, thereby bringing about a change in the composition. The reactive intermediate may be a cross-linking agent for a polymeric constituent of the composition so that the electrochemical reaction and subsequent cross-linking increases the viscosity of the composition as it arrives at the location where it is required.

Abstract: In an arrangement for monitoring of flow within a hydrocarbon well or reservoir by means of one or more tracers which are placed at subterranean locations such that they may be present in flow produced from the well, the analysis of the flow produced from the well is carried out using an electrochemical method, preferably voltammetry, to detect tracer chosen to undergo a detectable electrochemical reaction. The tracer may be provided as nanoparticles in the well fluid.

Abstract: Apparatus and methods to prevent the proliferation of undesired life forms in a subterranean formation, comprising forming a fluid comprising an inhibitor; and introducing the inhibitor to a surface in the formation. Apparatus and methods to prevent the proliferation of undesired life forms along a surface of tubular or equipment for use in the oil field services industry, comprising forming a coating comprising an inhibitor; and introducing the coating to a surface of the tubular or equipment. Apparatus and methods to prevent the proliferation of undesired life forms along a surface of tubular or equipment for use in the oil field services industry, comprising forming a material comprising an inhibitor; and embedding the material into a surface of the tubular or equipment.

Abstract: An anti-biofouling casing for a seismic streamer is described, the anti-biofouling casing comprising a polymer system comprising a hydrophobically-modified base polymer, the hydrophobically-modified base polymer comprising a base polymer having a backbone and a hydrophobically derivatized chain extender coupled to said backbone of said base polymer, wherein the the hydrophobically derivatized chain extender comprises a hydrophobic moiety. The anti-fouling casing comprises a hydrophobic surface the serves to prevent biofouling of the surface.

Abstract: An anti-biofouling casing for a seismic streamer is provided, the casing comprising an outer-skin, the outer skin comprising a mix of a base material and a molecular additive, wherein the molecular additive is localized throughout the base material and the molecular additive is configured to impart a high contact angle and/or a low surface energy to an outer surface of the anti-biofouling casing to prevent adhesion of living organism thereto. The outer-skin may comprise a casing/skin for a seismic streamer such that the streamer skin comprises a base material with a hydrophobic molecular additive distributed throughout the streamer skin.

Abstract: An anti-biofouling casing for a seismic streamer is described, the anti-biofouling casing including a polymer system having a hydrophobically-modified base polymer, the hydrophobically-modified base polymer including a base polymer having a backbone and a hydrophobically derivatized chain extender coupled to the backbone of the base polymer. The polymer system including between about 0.1% and 10% of the hydrophobically derivatized chain extender by weight. The anti-fouling casing including a hydrophobic surface that serves to prevent biofouling of the surface.

Abstract: Delivery of a substance to a subterranean location is achieved by suspending the substance as nanoparticles in a carrier fluid in which the substance is insoluble. First a dispersible powder composition, is formed by dissolving the substance in a solvent, emulsifying the resulting solution as the dispersed phase of an emulsion, and freeze-drying the emulsion to a powder. On mixing the powder with a fluid in which the substance is insoluble, the insoluble substance becomes a dispersion of nanoparticles which is pumped to the subterranean location. At the subterranean location a tracer dispersed as nanoparticles may migrate from injected water into hydrocarbon in a hydrocarbon reservoir. Another possibility is that the carrier fluid contains polymer and the dispersed nanoparticles comprise an agent which participates in cross-linking and consequent viscosification of the polymer at the subterranean location.

Abstract: An anti-biofouling material for use on marine equipment is described, the anti-biofouling material comprising a polymer system comprising a hydrophobically-modified base polymer, the hydrophobically-modified base polymer comprising a base polymer having a backbone and a hydrophobically derivatized chain extender coupled to said backbone of said base polymer, wherein the hydrophobically derivatized chain extender comprises a hydrophobic moiety. The anti-fouling casing comprises a hydrophobic surface that serves to prevent biofouling of the surface.

Abstract: The current application discloses fluids and methods for treating a subterranean formation penetrated by a wellbore. In one aspect, there is provided a fluid comprising chitosan and titanate, where the fluid has an increased viscosity compared with a solution containing chitosan without titanate. In another aspect, there is provided a method of using such fluid to treat a subterranean formation penetrated by a wellbore. The method may comprise mixing chitosan and titanate in a carrying medium, forming a gel comprising chitosan and titanate, introducing the gel into a subterranean formation, and treating the subterranean formation with the gel.

Abstract: The current application discloses fluids and methods for treating a subterranean formation penetrated by a wellbore, such as hydraulic fracturing. In one aspect, there is provided an oilfield fluid comprising chitosan at an amount sufficient to inhibit the growth of bacterial in the oilfield fluid. In another aspect, there is provided a method of preserving an oilfield fluid containing adding chitosan at a concentration that is sufficient to inhibit the growth of bacteria in the oilfield fluid. In a further aspect, there is provided a method of treating a subterranean formation penetrated by a wellbore, comprising preparing a treatment fluid, adding chitosan at a concentration sufficient to inhibit the growth of bacteria in the treatment fluid, introducing the mixture to the subterranean formation, and treating the subterranean formation with the mixture.