US 12,473,483 B1
Low-molecular-weight composite contamination-resistant additive for well cementing
Sheng Huang, Chengdu (CN); Yuan Gao, Chengdu (CN); Zaoyuan Li, Chengdu (CN); Donghua Su, Chengdu (CN); Baowen Zhang, Chengdu (CN); and Can Zhou, Chengdu (CN)
Assigned to Southwest Petroleum University, Chengdu (CN)
Filed by Southwest Petroleum University, Chengdu (CN)
Filed on Jun. 26, 2025, as Appl. No. 19/251,652.
Claims priority of application No. 202510363693.9 (CN), filed on Mar. 26, 2025.
Int. Cl. C08F 230/02 (2006.01); C04B 24/24 (2006.01); C04B 28/26 (2006.01); C08F 220/58 (2006.01); C08F 226/10 (2006.01); C08K 3/34 (2006.01); C08L 33/24 (2006.01); C08L 43/02 (2006.01); C09K 8/467 (2006.01)
CPC C09K 8/467 (2013.01) [C04B 24/243 (2013.01); C04B 28/26 (2013.01); C08F 220/585 (2020.02); C08F 226/10 (2013.01); C08F 230/02 (2013.01); C08K 3/34 (2013.01); C08L 33/24 (2013.01); C08L 43/02 (2013.01); C08F 220/58 (2013.01); C08F 2800/20 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A composite additive for well cementing, comprising:
60-85 parts by mass of phosphonic acid polymer solution,
15-40 parts by mass of silicate solution;
wherein a preparation method of the composite additive for well cementing comprises: stirring the phosphonic acid polymer solution and the silicate solution at a temperature of not higher than 40° C. at a speed of 200-400 r/min;
a preparation method of phosphonic acid polymer in the phosphonic acid polymer solution comprises the following steps:
Step S1: mixing and dissolving a phosphonic acid group-containing monomer, a rigid group-containing monomer and a carboxylic acid group-containing monomer in a molar ratio of 4-7:2-4:1-3 in deionized water to obtain a monomer solution with a mass fraction of 20%-50%;
Step S2: adding a chain transfer agent accounting for 3%-20% of a total mass of the monomers into the monomer solution, stirring and dissolving at a speed of 200-300 r/min, and heating to 45° C. under the protection of inert gas in the stirring process;
Step S3: dripping a solution of an initiator in deionized water in a concentration of 10%-20% into the monomer solution with stirring, and reacting for 3-8 h at 50-70° C. after dripping within 30-50 min, wherein the initiator in the solution of the initiator in deionized water accounts for 0.05%-1.5% of a total mass of the monomers;
Step S4: distilling a reactant under reduced pressure at 30-80° C., cooling the reactant to room temperature, freezing, drying, and grinding into powder;
the phosphonic acid group-containing monomer is at least one of vinylphosphonic acid, dimethyl-vinyl phosphonate, diethyl-vinyl phosphonate, and 2-acrylamide-2-methylpropane phosphonic acid;
the rigid group-containing monomer is N-vinyl pyrrolidone or 4-acryloylmorpholine; and
the carboxylic acid group-containing monomer is one of acrylic acid, maleic acid, methacrylic acid, and itaconic acid.