Abstract: An organic acid system with high temperature resistance, including: 80-90% by weight of a solid organic acid anhydride, 3-10% by weight of a hydrolysis catalyst, and 5-10% by weight of a stabilizer. A preparation method and an application of the organic acid system are also provided herein.

Abstract: A spherical organic nano boron crosslinker with a PAMAM core and a preparation method thereof, and a gel fracturing fluid.

Abstract: A spherical organic nano boron crosslinker with a PAMAM core and a preparation method thereof, and a gel fracturing fluid.

Abstract: An emulsifier with high temperature resistance, low viscosity and low corrosiveness, and an emulsified acid system comprising the same. The emulsifier includes a viscoelastic surfactant, which is prepared by a quaterization of fatty acid acyl propyl dimethylamine and a halogenated compound; by a quaterization of a long-chain halogenated hydrocarbon and a tertiary amine compound; or by a reaction of the fatty acid acyl propyl dimethylamine with a linking group synthesized by epichlorohydrin and an alkylamine compound.

Abstract: An organic acid system with high temperature resistance, including: 80-90% by weight of a solid organic acid anhydride, 3-10% by weight of a hydrolysis catalyst, and 5-10% by weight of a stabilizer. A preparation method and an application of the organic acid system are also provided herein.

Abstract: An emulsifier with high temperature resistance, low viscosity and low corrosiveness, and an emulsified acid system comprising the same. The emulsifier includes a viscoelastic surfactant, which is prepared by a quaterization of fatty acid acyl propyl dimethylamine and a halogenated compound; by a quaterization of a long-chain halogenated hydrocarbon and a tertiary amine compound; or by a reaction of the fatty acid acyl propyl dimethylamine with a linking group synthesized by epichlorohydrin and an alkylamine compound.

Abstract: Disclosed are a recyclable clean fracturing fluid thickener, a preparation method and a recovery method thereof, and a high-temperature resistant clean fracturing fluid, which relate to the stimulation treatment of oil and gas fields. Diethanolamine and thionyl chloride are used as raw materials and reacted to obtain an intermediate, which is then reacted with an unsaturated fatty acid amidopropyl dimethylamine to produce the recyclable clean fracturing fluid thickener. The clean fracturing fluid can be used in the fracturing stimulation treatment of low and medium permeability reservoirs.

Abstract: A three-poly cationic viscoelastic and a clean fracturing fluid containing the three-poly cationic viscoelastic surfactant are provided. N, N?-dimethyl-1,3-propanediamine and epichlorohydrin are used to prepare an intermediate A, and then the intermediate A and a fatty acid amidopropyl dimethylamine is used to prepare the three-poly cationic viscoelastic surfactant. The preparation process is simple. The clean fracturing fluid including the three-poly cationic viscoelastic surfactant has excellent temperature and shear resistance, strong suspended sand performance, simple on-site preparation, automatic gel breaking, small damage to formation, low cost and simple preparation process. The clean fracturing fluid including the surfactant also has strong temperature resistance, and the viscosity of the product can be maintained at 42 mPa·s after 80 minutes at 180° C. and 170 s?1, which is higher than the viscosity requirement (>25 mPa·s) of the clean fracturing fluid in on-site construction.

Abstract: Disclosed are a recyclable clean fracturing fluid thickener, a preparation method and a recovery method thereof, and a high-temperature resistant clean fracturing fluid, which relate to the stimulation treatment of oil and gas fields. Diethanolamine and thionyl chloride are used as raw materials and reacted to obtain an intermediate, which is then reacted with an unsaturated fatty acid amidopropyl dimethylamine to produce the recyclable clean fracturing fluid thickener. The clean fracturing fluid can be used in the fracturing stimulation treatment of low and medium permeability reservoirs.

Abstract: The present invention discloses a tri-cationic viscoelastic surfactant, a preparation method and an application thereof, and clean fracturing fluid. According to the present invention, N,N?-dimethyl-1,3-propanediamine and epichlorohydrin are used to prepare an intermediate A, and then the intermediate A and a fatty acid amidopropyl dimethylamine is used to prepare the tri-cationic viscoelastic surfactant. The preparation process is simple. And the clean fracturing fluid including the surfactant have excellent temperature and shear resistance, good suspended sand performance, simple on-site preparation, automatic gel breaking, low damage to formation, low cost and simple preparation process. The clean fracturing fluid including the surfactant also has strong temperature resistance, and the viscosity of the product can be maintained at 42 mPa·s after 80 minutes at 180° C. and 170 s?1, which is higher than the viscosity requirement (>25 mPa·s) of the clean fracturing fluid in on-site construction.

Abstract: An ultra-high temperature fracturing fluid, including the following components in mass percentages: 0.4 wt %-0.8 wt % of a polymer thickener, 0.015 wt %-0.02 wt % of a non-metallic crosslinking agent, 0.04 wt %-0.06 wt % of a gel breaker and the rest is water. The polymer thickener is obtained by a polymerization of acrylamide, acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, rigid monomer and cationic hydrophobic monomer in a weight ratio of 55-70:15-20:15-20:0.5-3:0.1-1.0, the polymerization temperature is 30-40° C. and the polymerization time is 8-10 hours. The fracturing fluid of the present invention can effectively solve the technical problems that traditional fracturing fluids are easily decomposed at high temperatures and affect performance.

Abstract: An ultra-high temperature fracturing fluid, including the following components in mass percentages: 0.4 wt %-0.8 wt % of a polymer thickener, 0.015 wt %-0.02 wt % of a non-metallic crosslinking agent, 0.04 wt %-0.06 wt % of a gel breaker and the rest is water. The polymer thickener is obtained by a polymerization of acrylamide, acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, rigid monomer and cationic hydrophobic monomer in a weight ratio of 55-70:15-20:15-20:0.5-3:0.1-1.0, the polymerization temperature is 30-40° C. and the polymerization time is 8-10 hours. The fracturing fluid of the present invention can effectively solve the technical problems that traditional fracturing fluids are easily decomposed at high temperatures and affect performance.

Abstract: A computer-aided system identifies aneurysm suspects in 3D image datasets. The system takes the raw image dataset as input and assigns one or more points of interest (POIs) in the image data. The system determines one or more features for each POI and identifies one or more aneurysm suspects from among the assigned POIs based on the determined features.

Abstract: A computer-aided system identifies aneurysm suspects in 3D image datasets. The system takes the raw image dataset as input and assigns one or more points of interest (POIs) in the image data. The system determines one or more features for each POI and identifies one or more aneurysm suspects from among the assigned POIs based on the determined features.