US 12,448,307 B2
Removal of sulfate from seawater
Qiwei Wang, Dhahran (SA); Tao Chen, Dhahran (SA); Yasser A. Al-Jeshi, Al Qatif (SA); and Nada Alghamdi, Dhahran (SA)
Assigned to Saudi Arabian Oil Company, Dhahran (SA)
Filed by Saudi Arabian Oil Company, Dhahran (SA)
Filed on Apr. 13, 2022, as Appl. No. 17/659,076.
Prior Publication US 2023/0331598 A1, Oct. 19, 2023
Int. Cl. E21B 43/20 (2006.01); C02F 1/52 (2023.01); C02F 101/10 (2006.01); C02F 103/08 (2006.01)
CPC C02F 1/5236 (2013.01) [C02F 1/5209 (2013.01); E21B 43/20 (2013.01); C02F 2101/101 (2013.01); C02F 2103/08 (2013.01); C02F 2209/19 (2013.01); C02F 2303/22 (2013.01); C02F 2305/00 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A method of providing seawater into a subterranean formation, comprising:
adding chloride salt to the seawater to give a mixture, wherein the seawater comprises sulfate, wherein adding the chloride salt comprises:
adding a first chloride salt comprising a first metal cation during a first batch time;
adding a second chloride salt comprising a second metal cation during a second batch time that is distinct from and after the first batch time;
wherein the second metal cation is different than the first metal cation;
precipitating sulfate salt in the mixture in a batch process having a total batch time that includes the first batch time and the second batch time, the sulfate salt comprising the first metal cation, the second metal cation, and sulfate, and wherein the sulfate salt is precipitated during the first batch time and the second batch time of the batch process before removing the sulfate salt as precipitated from the mixture;
removing the sulfate salt as precipitated from the mixture to give treated seawater comprising less sulfate than the seawater; and
injecting the treated seawater into the subterranean formation.