Abstract: An aqueous, viscoelastic fluid gelled with a viscoelastic surfactant (VES) is inhibited against hydrate formation with an effective amount of an additive that could be one or more halide salts of alkali metals and alkali earth metals, formate salts, alcohols, glycols, glycol amines, sugars, sugar alcohols, amidoamine oxides, polymers such as polyamines, polyvinylpyrrolidones and derivatives thereof, polyvinyl alcohols and derivatives thereof, polycaprolactams and derivatives thereof, hydroxyethylcellulose, and mixtures thereof. These fluids are inhibited against hydrate formation and may have increased viscosity as well. The additives may increase viscosity to the point where less VES is required to maintain a given viscosity. These inhibited, aqueous, viscoelastic fluids may be used as treatment fluids for subterranean hydrocarbon formations, such as in stimulation treatments, e.g. hydraulic fracturing fluids.

Abstract: A system for preferable use in gravel packing is disclosed which includes a plurality of transport tubes which are mounted outside of gravel pack screens. The multiplicity of shunt tubes cover a particular zone so that the tubes have a varying length to deposit gravel at different portions of the zone. The tops of the tubes are preferably sealed until ready for use and activated by applied pressure. In the preferred embodiment, rupture discs are found at the tops of each of the tubes, set for different pressures so as to open up the transport tubes to the lower most portion of a particular zone and later in sequence to the higher-most portion. The transport tubes are affixed to each section of pipe and are made up when two sections of pipe are made up to alignment marks. When the marks are aligned, the transport tube segments from each pipe section are in an aligned and sealed relation while the tool joint is properly torqued.

Abstract: A completion assembly facilitates gravel-packing and fracturestimulation of closely spaced zones. The assembly includes a pair of spaced screens with a production packer in between. The production packer has a short bypass flowpath therethrough to allow fluids carrying the gravel to pass the production packer so that the upper and lower zones can be gravel-packed simultaneously, as well as fracture-stimulated simultaneously. Thereafter, the presence of the gravel in the bypass tube in the packer between the zones provides some limited isolation based on the permeability of the gravel found in the bypass passage and the pressure drop across that passage. Production then can follow from the lower zone, the upper zone, or both zones depending on the completion configuration.