US 12,065,615 B2
Coated proppants
Praveen Agarwal, Pearland, TX (US); and Juan Carlos Medina, Lake Jackson, TX (US)
Assigned to Dow Global Technologies LLC, Midland, MI (US)
Appl. No. 17/630,808
Filed by Dow Global Technologies LLC, Midland, MI (US)
PCT Filed Apr. 30, 2020, PCT No. PCT/US2020/030587
§ 371(c)(1), (2) Date Jan. 27, 2022,
PCT Pub. No. WO2021/021262, PCT Pub. Date Feb. 4, 2021.
Application 17/630,808 is a continuation in part of application No. PCT/US2020/014508, filed on Jan. 22, 2020.
Claims priority of provisional application 62/881,149, filed on Jul. 31, 2019.
Prior Publication US 2022/0275270 A1, Sep. 1, 2022
Int. Cl. C09K 8/80 (2006.01); C09K 8/62 (2006.01); E21B 43/267 (2006.01)
CPC C09K 8/805 (2013.01) [C09K 8/62 (2013.01); E21B 43/267 (2013.01)] 14 Claims
 
1. A method for forming a coated proppant, comprising applying at least one polyisocyanate and starch to the surface of solid substrate particles, wherein the solid substrate particles are thermally stable to a temperature of at least 150° C., and reacting at least a portion of the polyisocyanate with at least a portion of the starch at the surface of the substrate particles in the presence of a urethane catalyst at an elevated temperature of up to 150° C. and for a period of up to 10 minutes to produce a solid polymeric coating at the surface of the solid substrate particles.