Abstract: An electrochemical sensor measuring concentration of an analyte in a test fluid at 50° C. or above by voltammetry uses electrodes in contact with an electrolyte containing the analyte and a redox-active species electrochemically convertible between reduced and oxidised forms. At least one form of the redox active species is present within surfactant micelles. The surfactant micelles enhance thermal stability of the redox active species and may also solubilise a species with poor water solubility, such as t-butylferrocene. A downhole tool incorporating such a sensor comprises a barrier, permeable to the analyte, to separate the electrolyte from subterranean reservoir fluid, so that the sensor directly measures analyte which has passed through the barrier and thereby indirectly measures analyte in the test fluid.

Abstract: Some embodiments of the disclosed invention include a method for acquiring marine seismic data using solid streamers in a curved pattern. Streamers can be towed in a curved pattern within a body of water. While being towed in the curved patter the source may be fired and response data can be collected by the streamers as they are towed through the water in the curved/circular pattern. These streamers can be solid streamers and can be filled with a gel like substance. Moreover, the streamers can be placed at various known depths within the body of water.

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: A water-based wellbore treatment fluid contains: one or more viscoelastic-gelling carboxylic acids and/or alkali metal salts thereof; and one or more solubilizing alkylolamines. The carboxylic acids and/or alkali metal salts and the alkylolamines are present in the fluid in respective amounts such that, at 25° C., the alkylolamines solubilize a sufficient portion of the carboxylic acids and/or alkali metal salts to render the fluid viscoelastic. A remaining portion of the carboxylic acids and/or alkali metal salts forms a suspension of solid particulates in the fluid.

Abstract: Disclosed herein is a gel or a gel concentrate comprising, polyacrylamide crosslinked with a non-metallic crosslinker comprising a polylactam. A well treatment fluid comprising the gel or the gel concentrate, a method of making the gel or the gel concentrate, and a method of using the gel or the gel concentrate are also disclosed.

Abstract: Disclosed herein is a gel comprising, polyacrylamide crosslinked with a non-metallic crosslinker, the non-metallic crosslinker comprising a polyamine. A method of making the gel and a method of using the gel are also disclosed.

Abstract: A reservoir sampling apparatus comprising at least one probe adapted to provide a fluid flow path between a formation and the inner of the apparatus with a heating projector adapted to project heat into the formation surrounding the probe and a controller to maintain the temperature in the formation below a threshold value.

Abstract: The invention relates to the use of one or more water-soluble reactive liquid component capable of subsequent polymerization or cross-linking to form a solid to improve the zonal isolation and alleviate the impacts of cracks and fissures in the cement sheath around a completed subterranean well. It includes the steps of injecting a wellbore fluid carrying the reactive component or additive into the wellbore, injecting a cementitious composition as slurry into the wellbore and letting said reactive liquid component pass through at least one of the interfaces between cement and formation, cement and filter cake, and filter cake and formation before forming a solid of said reactive liquid component that traverses said at least one of the interfaces.

Abstract: A reservoir sampling apparatus (20) is described having at least one probe (26) adapted to provide a fluid flow path between a formation and the inner of the apparatus with the flow path being sealed from direct flow of fluids from the borehole annulus with a heating projector (251) adapted to project heat into the formation surrounding the probe and a controller (253) to maintain the temperature in the formation below a threshold value.

Abstract: This invention relates to compositions and methods for treating subterranean formations, in particular, oilfield stimulation compositions and methods using water-in-water polymer emulsions to uniformly dissolve a rheologically active polymer, such as a thickener or friction reducer, in the treatment fluid. The emulsions have a low viscosity and are easily pumped for mixing into a treatment fluid, where upon dilution with an aqueous medium, the polymer is easily hydrated without forming fish-eyes. The partitioning agent in the water-in-water emulsion does not generally affect the rheology of the treatment fluid. The invention also relates to further processing of the emulsion by wet grinding, high shear mixing and/or heating to enhance the hydration rate in the preparation of the well treatment fluid.

Abstract: A method of processing an aqueous fluid produced from a wellbore in order to collect or remove a minor constituent therefrom, comprises adding one or more solutes to the aqueous fluid so as to form an aqueous mixture which separates into two aqueous phases in contact with each other, with a first solute present at a greater concentration in the larger, first aqueous phase than in the second aqueous phase and a second solute present at a greater concentration in the smaller, second aqueous phase than in the first aqueous phase; while the compositions of the two phases are such that the said minor constituent preferentially partitions into the smaller, second aqueous phase so that the concentration of that constituent in the smaller second phase exceeds its concentration in the larger first aqueous phase. The second aqueous phase with the said constituent concentrated therein is then separated from the first aqueous phase.

Abstract: This invention relates to compositions and methods for treating subterranean formations, in particular, oilfield stimulation compositions and methods using water-in-water polymer emulsions to uniformly dissolve a rheologically active polymer, such as a thickener or friction reducer, in the treatment fluid. The emulsions have a low viscosity and are easily pumped for mixing into a treatment fluid, where upon dilution with an aqueous medium, the polymer is easily hydrated without forming fish-eyes. The partitioning agent in the water-in-water emulsion does not generally affect the rheology of the treatment fluid. The invention also relates to further processing of the emulsion by wet grinding, high shear mixing and/or heating to enhance the hydration rate in the preparation of the well treatment fluid.

Abstract: This invention relates to compositions and methods of treating a subterranean formation penetrated by a well bore including providing a treatment composition comprising a rheological polymer, a partitioning agent, a charged polyelectrolyte, and a first liquid medium, forming a stabilized heterogeneous mixture comprising a dispersed rheological polymer-rich phase and a partitioning agent-rich phase, and injecting the treatment fluid into the well bore. The invention relates to methods and compositions for preparing a well treatment fluid, including mixing polyethylene glycol partitioning agent, a charged polyelectrolyte, a first aqueous medium, and one or more rheological polymers selected from the group consisting of guar, modified guar, cellulose, modified cellulose, heteropolysaccharide, heteropolysaccharide derivative, or polyacrylamide, to hydrate the one or more polymers and form a water-in-water emulsion, and mixing the water-in-water emulsion with a second aqueous medium to form a well treatment fluid.

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: A fluid loss control method uses a fluid loss control pill in a well in advance of a completion operation. An embodiment of the fluid loss control pill comprises polyester solids that are hydrolysable and can exhibit plastic deformation at formation conditions. An embodiment of the method comprises spotting the fluid loss control pill in the well adjacent to a formation to form a filtercake to inhibit fluid entry from the well into the formation, performing a completion operation comprising contacting the filtercake with overbalanced wellbore fluid, and degrading the filtercake wherein the polyester particles are hydrolyzed to remove formation damage.

Abstract: A subterranean location accessed via a wellbore is treated with an oilfield fluid containing a viscosifying agent which is a polymer and a cross-linking agent which can undergo the Diels-Alder reaction to form a gel. Conditions at the subterranean location alter fluid viscosity by bringing about the Diels-Alder reaction to increase viscosity or the retro Diels-Alder reaction to decrease the viscosity of the gel.

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. The procedure may start by forming a dispersible powder composition, which is done 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, any soluble constituents of the powder dissolve and the insoluble substance becomes a dispersion of nanoparticles of the substance. Then, the fluid containing the dispersed substance is pumped to the subterranean location. The dispersion of nanoparticles has surprising stability, facilitating transport to the subterranean location.

Abstract: Methods and apparatus for forming a fluid for use within in a subterranean formation including combining a partitioning agent and viscosifying polymer into a fluid, introducing the fluid into the subterranean formation, and recovering at least a portion of the fluid at a uppermost surface of the subterranean formation. Methods and apparatus of forming a fluid for use within in a subterranean formation including combining a partitioning agent and viscosifying polymer into a fluid, introducing the fluid into the subterranean formation at a temperature of about 45° C. or higher, and recovering at least a portion of the fluid at a uppermost surface of the subterranean formation at a temperature of about 45° C. or lower.