US 11,912,927 B2
Super-hydrophobic, thermally insulating, thermal-shocks resistant well cement composites for completion of geothermal wells at hydrothermal temperatures of up to 300° C
Tatiana Pyatina, Stony Brook, NY (US); and Toshifumi Sugama, Wading River, NY (US)
Assigned to Brookhaven Science Associates, LLC, Upton, NY (US)
Filed by Brookhaven Science Associates, LLC, Upton, NY (US)
Filed on Oct. 5, 2021, as Appl. No. 17/494,477.
Claims priority of provisional application 63/087,489, filed on Oct. 5, 2020.
Prior Publication US 2022/0106516 A1, Apr. 7, 2022
Int. Cl. C04B 20/10 (2006.01); C04B 24/42 (2006.01); C04B 28/26 (2006.01); C04B 40/00 (2006.01); C09K 8/467 (2006.01); C04B 28/06 (2006.01); C04B 18/08 (2006.01); C04B 111/20 (2006.01); C04B 111/27 (2006.01)
CPC C09K 8/467 (2013.01) [C04B 18/082 (2013.01); C04B 20/1037 (2013.01); C04B 20/1051 (2013.01); C04B 24/42 (2013.01); C04B 28/06 (2013.01); C04B 28/26 (2013.01); C04B 40/0042 (2013.01); C04B 2111/2084 (2013.01); C04B 2111/27 (2013.01); C04B 2201/20 (2013.01); C04B 2201/32 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A well cement composite comprising:
a mixture of calcium aluminate cement (CAC) and fly ash cenospheres (CS) in a weight ratio of from 30:70 to 80:20 CAC to CS;
sodium metasilicate (SMS) in an amount of from 1 to 10% of the total weight of the mixture of CAC and CS;
polymethylhydrosiloxane (PMHS) in an amount of from 0.5 to 6.0% of the total weight of the mixture of CAC and CS; and
water in a weight ratio of from 0.5:1.0 to 1.2:1.0 of water to CAC and CS.
 
10. A well cement composite comprising:
a mixture of calcium aluminate cement (CAC) and fly ash cenospheres (CS) in a weight ratio of from 30:70 to 80:20 CAC to CS;
sodium metasilicate (SMS) in an amount of from 1 to 10% of the total weight of the mixture of CAC and CS;
a siloxane with at least one hydrophobic functional group in an amount of from 0.5 to 6.0% of the total weight of the mixture of CAC and CS; and
water in a weight ratio of from 0.5:1.0 to 1.2:1.0 of water to CAC and CS.
 
11. A method of making a well cement composite comprising:
mixing polymethylhydrosiloxane (PMHS) with an aqueous solution of sodium metasilicate (SMS) to form an emulsion;
mixing fly ash cenospheres (CS) into the emulsion to release hydrogen gas and form a paste;
adding calcium aluminate cement (CAC) and water to the paste and mixing to form the well cement composite,
wherein the well cement composite comprises calcium aluminate cement (CAC) and fly ash cenospheres (CS) in a weight ratio of from 30:70 to 80:20 CAC to CS, sodium metasilicate (SMS) in an amount of from 1 to 10% of the total weight of CAC and CS, polymethylhydrosiloxane (PMHS) in an amount of from 0.5 to 6.0% of the total weight of CAC and CS, and water in a weight ratio of from 0.5:1.0 to 1.2:1.0 of water to CAC and CS.