31results about How to "Reduce insoluble content" patented technology

The invention discloses a temperature-resistant salt-resistant quick-dissolving thickening agent used for a seawater-based fracturing fluid and a preparation method thereof. The temperature-resistant salt-resistant quick-dissolving thickening agent comprises the following components in percentages by mass: 6% to 8% of acrylic acid, 5% to 6% of sodium hydroxide, 18% to 23% of acrylamide, 1% to 2% of an isolation monomer, 3% to 4% of a functional anion monomer, 3% to 5% of a functional cationic monomer, 4% to 6% of an association intermediate, and 0.4% to 0.8% of an ammonium persulfate-sodium bisulfite redox system or 0.6% to 1.0% of azobisisobutyronitrile which is used as an initiator, with the balance being deionized water. The preparation method for the temperature-resistant salt-resistant quick-dissolving thickening agent comprises the following steps: 1, synthesis of the association intermediate; 2, synthesis of a thickener colloid; and 3, colloid postprocessing. The thickening agent provided by the invention has the following advantages: salt resistance is excellent; the degree of mineralization of a solution has little influence on the rate of swelling; the viscosity-increasing capacity in seawater is strong; antibacterial stability of the solution is strong; the solution has excellent temperature resistance and shearing resistance; and the content of an insoluble substance is extremely small and can not be measured with a conventional method, so the damage of residues on reservoir strata is almost eliminated.

The invention relates to a Gleditsia sinensis polysaccharide gum and a preparation method thereof. The preparation method of the Gleditsia sinensis polysaccharide gum comprises the following steps: preprocessing the Gleditsia sinensis seed with sulfuric acid, then shelling, drying, chipping, selecting, screening, hydrating, and grinding. The method prepares the polysaccharide gum by steps of preprocessing the Gleditsia sinensis with sulfuric acid, and separating by washing with water, chipping, and so on, the ratio of galactose to mannose in product is changed while the content of water insoluble matter in product is lowered, so that the polysaccharide gum has better gel property after being blended with xanthan gum.

The invention discloses a method for preparing sodium fluoride from defluorination residue generated in production of phosphoric acid by a wet process. The method comprises the following steps of respectively recycling mother liquid, sodium carbonate and defluorination residue slurry, reacting and crystallizing the defluorination residue slurry and a sodium carbonate solution and simultaneously returning fine sodium fluoride particles to the system for secondary growth. By larger sinking speed difference between sodium fluoride and silicon dioxide, the separation of sodium fluoride from silicon dioxide is achieved, and the technical problem of difficulty in separation of sodium fluoride from SiO2 is effectively solved. The sodium fluoride product obtained by the method is coarse, more than 85% of the sodium fluoride product has particle diameter greater than 0.35mm and the yield of fluorine in the sodium fluoride product is above 85%. By the method, the circulation of the mother liquid is achieved, the water consumption as well as the production cost are decreased, and the method has good social and economic values and is suitable for being popularized and applied.

The invention discloses a high-temperature-resistant full-suspension low-injury fracturing fluid, which comprises the following components in weight percent: 0.3-0.5% of a low-injury thickener, 0.1-0.4% of a multi-functional stabilizer, and 0.1-0.3% of a regulator , suspension synergist 0.4-0.8%, the rest is clear water or salt water; the preparation method of fracturing fluid is: Step 1, add low-damage thickener, multi-functional stabilizer and regulator into clear water or salt water under stirring conditions, Stir evenly and swell for 2 to 4 hours to obtain the fracturing fluid base fluid; step 2, fully mix the fracturing fluid base fluid and the suspension synergist, and form sand-carrying performance and Full-suspension fracturing fluid with excellent thermal performance. The fracturing fluid of the present invention is a super-strength structural fluid formed by physical cross-linking and chemical cross-linking of acrylamide polymers and suspension synergists, with a temperature resistance of up to 150°C; excellent sand-carrying performance, The spatial structure can fully suspend the proppant and is less affected by temperature.