164 results about "Viscoelastic fluid" patented technology

Disclosed are implantable devices that are configured for implantation through tissue or membrane and into an implantation site comprising viscoelastic fluid or non-osseous tissue. In embodiments of the invention, the implantable devices comprise: (a) a nonlinear body member having a direction of extension, a longitudinal axis along the direction of extension, and a proximal portion and a distal portion, wherein at least a portion of the body member deviates from the direction of extension, (b) a retention element at the proximal portion of the body member, the retention element configured to retain the implantable device at the implantation site, the retention element presenting an external profile of no greater than 0.5 mm when the device is implanted in a patient; and (c) a bioactive agent delivery system at the distal portion of the body member, the bioactive agent delivery system comprising one or more bioactive agents. Also disclosed are methods of delivering a bioactive agent to a patient using the devices.

An aqueous, viscoelastic fluid gelled with a viscoelastic surfactant (VES) is stabilized and improved with an effective amount of an alkali earth metal oxide and/or alkali earth metal hydroxide. These fluids are more stable and have reduced or no tendency to precipitate, particularly at elevated temperatures. The additives may also increase viscosity to the point where less VES is required to maintain a given viscosity. These stabilized, enhanced, aqueous viscoelastic fluids may be used as treatment fluids for subterranean hydrocarbon formations, such as in hydraulic fracturing.

A viscoelastic fluid is prepared by shearing a gelled emulsion. The emulsion is an oil-in-water emulsion comprising 2% 12% (w/w) of a heat-treated protein that can form a heat-set gel and 5% 40% fat. The proteins used include whey protein and soy protein. The viscoelastic fluid may be used as a spread. It may also be used for the preparation of a plurality of different ultimate products formed from the original gel.

It has been discovered that fluids viscosified with viscoelastic surfactants (VESs) may have their viscosities reduced (gels broken) by the direct or indirect action of a biochemical agent, such as bacteria, fungi, and/or enzymes. The biochemical agent may directly attack the VES itself, or some other component in the fluid that produces a by-product that then causes viscosity reduction. The biochemical agent may disaggregate or otherwise attack the micellar structure of the VES-gelled fluid. The biochemical agent may produce an enzyme that reduces viscosity by one of these mechanisms. A single biochemical agent may operate simultaneously by two different mechanisms, such as by degrading the VES directly, as well as another component, such as a glycol, the latter mechanism in turn producing a by-product (e.g. an alcohol) that causes viscosity reduction. Alternatively, two or more different biochemical agents may be used simultaneously. In a specific, non-limiting instance, a brine fluid gelled with an amine oxide surfactant can have its viscosity broken with bacteria such as Enterobacter cloacae, Pseudomonas fluorescens, Pseudomonas aeruginosa, and the like.

The present invention relates to viscoelastic fluids that contain nanotube structures that may be used advantageously as oilfield stimulation fluids in many different applications, most particularly as a fracturing fluid. Viscoelastic fluid compositions of the present invention include an aqueous medium, a viscoelastic surfactant, an organic or inorganic acids, or salt thereof, organic acid salts, inorganic salts, and a nanotube component. The invention is also called to a methods of treating a subterranean well bores in which the viscoelastic fluid is injected into the wellbore to perform operations such as fracturing, drilling, acid fracturing, gravel placement, removing scale, matrix acidizing, and removing mud cake. Further, a method of preparing a nanotube viscoelastic fluid comprising the steps of effectively mixing a carbon nanotube component into a viscoelastic fluid, and sonicating the mixture in order to incorporate the carbon nanotube component is claimed.

The invention provides medium-temperature and high-temperature clean fracturing fluid used under high formation temperature and a preparation method thereof. The clean fracturing fluid contains Gemini cation surfactant, amphoteric surfactant, electrolyte salt, counter-ion salt, cosolvent and water. The clean fracturing fluid of the invention is used for oil and gas field fracturing and mainly comprises 2-5 percent of surfactant, 1-4 percent of amphoteric surfactant, 1-4 percent of electrolyte, 0.05-0.15 percent of counter ion and 0.1-1.5 percent of cosolvent by weight percent. Viscoelastic fluid is formed under agitation. The invention has the advantages that the viscoelasticity of the system is high, the friction resistance is low and good sand suspending performance is kept within 90-130 DEG C.

Disclosed are highly resilient and cohesive gels formed by the cross-linking of hyaluronan or hylan, their salts or derivatives thereof, using divinyl sulfone (DVS) as the cross-linking agent. Also disclosed are viscoelastic fluids containing alkylsulfone groups covalently attached to the backbone of the polymer, formed by the mono-functionalization of the cross-linking monomer DVS with hyaluronan and/or hylan. Mechanical properties such as values of hardness and cohesiveness are specified by the rheological properties of the gels. Also disclosed are methods for the preparation of such products. They have use in many applications as injectable and/or implantable devices and as drug delivery systems.

The invention discloses an integrated chip system for high-throughput sorting and counting detection of biological particles, and an application. The chip system comprises a main microfluidic chip, a micropipe, a sample liquid micropump, an exchange liquid micropump, a first waste liquid collecting device, a second waste liquid collecting device, a third waste liquid collecting device, laser emitters, photoelectric conversion devices, optical fibers and a computer, wherein the main microfluidic chip comprises an asymmetric curved flow path, a first branch channel, a second branch channel, a third branch channel, a main flow path, a branch flow path, aligning marks, etc. The system utilizes the asymmetric curved flow path to realize pre-focusing and sorting for the particles, utilizes a liquid changing flow channel to realize change of a carrier liquid of to-be-tested particles and particle cleaning, and utilizes a viscoelastic effect and an inertial effect of a viscoelastic fluid to realize focus of single equilibrium position of section centers of the particles. The system does not need a sheath liquid, complex pre-cleaning of the particles, and optical alignment, has advantages of high speed, high precision, integration, miniaturization, automation, low cost, simple production process, easy batch production, etc.

A personal care absorbent article such as a disposable diaper, sanitary pad or tampon, wound dressing or bandage which includes a nonwoven web material made from a plurality of polymeric fibers having at least one treatment chemistry suitable for modifying at least one characteristic of a high viscoelasticity fluid upon contact with the high viscoelasticity fluid. In accordance with one particularly preferred embodiment, the treatment chemistry is suitable for immobilizing the high viscoelasticity fluid within the nonwoven web material.

Composition and method for shortening the shear recovery time of cationic, zwitterionic, and amphoteric viscoelastic surfactant fluid systems by adding an effective amount of a co-gelling agent selected from triblock oligomeric compounds having hydrophilic (for example polyether) and hydrophobic (for example alkyl) portions. The co-gelling agent also increases fluid viscosity and very low co-gelling agent concentration is needed. Preferred surfactants are betaines and quaternary amines. The fluids are useful in oilfield treatments, for example fracturing and gravel packing.

A process for enhancing the productivity of a formation consists of introducing into the formation a viscoelastic fluid which contains at least one surfactant, at least one quaternary amine polyelectrolyte, water, and a non-aqueous solvent. The surfactant forms aggregation structures or vesicles. The fluid, which significantly enhances fluid viscosity and thermal stability, is particularly effective as a diverting fluid to divert an acid treatment package from a high permeability or damaged portion of a formation to a low permeability or undamaged portion of a formation as well as a fracturing fluid. In addition, the fluid is useful for sand control completion.

A method for producing visco-elastic fluidic material flows by drawing a visco-elastic fluidic material with corresponding separate second fluid flows associated therewith to form a visco-elastic fiber vacillating in a repeating, generally omega-shaped pattern having a bowed portion with first and second side portions that first converge toward each other and then diverge outwardly in generally opposing directions. In one operation, the visco-elastic fiber vacillating in the repeating, generally omega-shaped pattern is an adhesive material deposited onto woven and non-woven fabric substrates and stretched elongated elastic strands in the manufacture of a variety of bodily fluid absorbing hygienic articles.

The present invention generally relates to a viscoelastic fluids, thickened acid compositions and the like and to methods of using said gelled compositions. The thickened compositions of the present invention can usefully be employed in methods of stimulating and/or modifying the permeability of underground formations, in drilling fluids, completion fluids, workover fluids, acidizing fluids, fracturing, gravel packing and the like.

In accordance with the present invention, the rheology of an aqueous fluid is modified by a method which comprises adding to said aqueous fluid an amount of a viscoelastic composition sufficient to form a viscoelastic fluid. The viscoelastic composition of the invention comprises a combination of i) at least one alkyl amido quaternary amine, and ii) at least one coadditive that comprises a C_8-24 linear alkyl and/or alpha-olefin sulfate and/or sulphonate.

An aqueous, viscoelastic treating fluid gelled with a crosslinked guar or guar derivative is stabilized and improved with an effective amount of a glycol, such as ethylene glycol. These fluids are more stable in that viscosity is maintained, particularly at elevated temperatures. The additives may also increase viscosity to the point where less of a crosslinked guar or guar derivative gelling agent is required to maintain a given viscosity. These stabilized, enhanced, aqueous, viscoelastic fluids may be used as treatment fluids for subterranean hydrocarbon formations, such as in hydraulic fracturing.

The invention relates to the viscoelastic surfactant based fluids and methods for utilizing same in oilfield applications including, but not limited to gravel packing, cleanup, drilling, acidizing, fracturing and the like in a subterranean formation. The viscoelastic fluid of the invention comprises at least one amphoteric surfactant and at least one synergistic cosurfactant that increases the gel strength and extends the brine tolerance of said viscoelastic-based fluid.

The invention discloses a magneto-rheological viscoelastic fluid and a preparation method thereof. The fluid raw materials comprise the following components in percentage by weight: 15-70% of hydroxy iron powder, 25-80% of methylsiloxane, 3-4% of phenyl siloxane, 0.1-0.2% of basic catalyst, 0.1-0.3% of neutralizer, 0.1-0.3% of blocking agent, 0.1-0.3% of thixotropic agent and 0.2-0.5% of lubricant. The magneto-rheological viscoelastic fluid has compressibility, can improve the wear resistance of the magneto-rheological plaster, so as to prolong the service life; zero magnetic field viscosity of the carrier fluid is higher, no occurrence of sedimentation or agglomeration happens to the suspended phase for a long time, thereby having a favorable static stability; the carrier medium and the additive have a wide range of temperature adaptation, the magneto-rheological viscoelastic fluid material has a favorable stability in a temperature range of minus 90 to 250 DEG C; at a shear rate of 300 1/second, the magnetic induction intensity of the magneto-rheological viscoelastic fluid is 0-0.6T, the variation range of shear stress is 75-105KPa, and the viscosity of the zero magnetic field is 4.5-6Pa.S.