Patent ID: 9410077
Filing Date: 2016-08-09
CPC Classification: C09K

Claim Text:
1. A method for preparing an ultra-light-weight (ULW) proppant, comprising the steps of: dispersing a silica fume (SF) to an organic solvent for form a SF-organic solvent mixture; heating the SF-organic solvent mixture to a temperature of 75-95° C.; adding a silane coupling agent to the SF-organic solvent mixture to form a first reaction mixture, and allow a first reaction be performed for 1-3 hours (h); adding an organic acid to the first reaction mixture that is reacted for 1-3 h, to form a second reaction mixture, and allow a second reaction be performed for 1-3 h; centrifuging and drying the second reaction mixture that is reacted for 1-3 h, to obtain a modified SF; adding the modified SF, a cross-linking agent and an initiating agent to a monomer solution to form a SF-monomer mixture, the monomer solution comprising at least one monomer; dispersing at least one dispersant in distilled water to form a dispersant solution; adding the SF-monomer mixture to the dispersant solution to synthesize composite microspheres by in situ suspension polymerization; filtering, washing, drying, screening with 20-80 mesh, and pre-oxidizing the synthesized microspheres, to obtain the ULW proppant, wherein a density of the ULW proppant is in a range of 1.109 g/cm wherein after the step of filtering, washing, drying, screening with 20-80 mesh of the synthesized microsphere, the step of pre-oxidization comprises: placing the synthesized microsphere in an incubator having temperature control; increasing a temperature at a rate of 3° C./minutes to 150-240° C.; and incubating for 0.5-2 hours under air atmosphere.