US 11,939,520 B2
Methods and cement compositions for reducing corrosion of wellbore casings
Sara A. Alkhalaf, Alkhobar (SA); Abdullah S. Al-Yami, Dhahran (SA); Vikrant Wagle, Abqaiq (SA); and Mohammed Murif Al-Rubaii, Dammam (SA)
Assigned to SAUDI ARABIAN OIL COMPANY, Dhahran (SA)
Filed by Saudi Arabian Oil Company, Dhahran (SA)
Filed on Aug. 12, 2020, as Appl. No. 16/991,299.
Prior Publication US 2022/0049150 A1, Feb. 17, 2022
Int. Cl. C09K 8/54 (2006.01); C09K 8/42 (2006.01)
CPC C09K 8/54 (2013.01) [C09K 8/42 (2013.01)] 8 Claims
 
1. A corrosion inhibiting cement composition for reducing corrosion of wellbore casings, the corrosion inhibiting cement composition comprising:
30 wt.% cement precursor based on the total weight of the corrosion inhibiting cement composition, where the cement precursor is API Class G cement;
40 percent by weight of cement (BWOC) silica flour;
150 percent BWOC of the weighting agent;
3 percent BWOC expansion additive;
0.2 percent BWOC defoamer;
9 percent BWOC latex;
1.4 percent BWOC latex stabilizer;
2.6 percent BWOC cement retarder; and
0.9 percent BWOC amine corrosion inhibitor, where the amine corrosion inhibitor comprises a polyethylene polyamine, where the polyethylene polyamine comprises hexaethyleneheptamine (HEHA), one or more polyethylene polyamines having molecular weights greater than a molecular weight of hexaethyleneheptamine, or both; and
the balance water, where the corrosion inhibiting cement composition comprises from 5 weight percent to 70 weight percent water based on the total weight of the cement composition;
where the corrosion inhibiting cement composition has a thickening time of from 0.5 hours to 6 hours.