US 12,460,120 B1
Methods for curing lost circulation in subterranean formations
Don Lawrence, Houston, TX (US); Ahmed Al-Dughaither, Dhahran (SA); Abdullah Abahussain, Dhahran (SA); Abdulaziz Bahamdan, Dhahran (SA); and Aljazi Al-Ajmi, Dhahran (SA)
Assigned to SAUDI ARABIAN OIL COMPANY, Dhahran (SA)
Filed by SAUDI ARABIAN OIL COMPANY, Dhahran (SA)
Filed on Jul. 24, 2024, as Appl. No. 18/782,635.
Int. Cl. C09K 8/487 (2006.01); C04B 22/12 (2006.01); C04B 28/26 (2006.01); E21B 33/138 (2006.01); C04B 103/20 (2006.01); C04B 103/50 (2006.01)
CPC C09K 8/487 (2013.01) [C04B 22/124 (2013.01); C04B 28/26 (2013.01); E21B 33/138 (2013.01); C04B 2103/20 (2013.01); C04B 2103/50 (2013.01)] 13 Claims
 
1. A method comprising:
(a) introducing a first portion of a first fluid pill comprising a calcium salt into a subterranean formation containing a first lost circulation zone via a wellbore, wherein the first lost circulation zone comprises one or more lost circulation zones;
(b) introducing a first portion of a second fluid pill comprising a silicate into the subterranean formation via the wellbore;
(c) allowing the first portion of the first fluid pill to interact with the first portion of the second fluid pill to form a solid within the first lost circulation zone;
(d) introducing a first cement into the subterranean formation after introducing the first portions of the first fluid pill and the second fluid pill into the subterranean formation via the wellbore;
(e) allowing at least a portion of the first cement to solidify within the first lost circulation zone;
(f) consecutively introducing a second portion of the first fluid pill and a second portion of the second fluid pill into the subterranean formation via the wellbore after allowing at least the portion of the first cement to solidify within the first lost circulation zone;
(g) introducing a second cement having a higher thixotropy than the first cement into the subterranean formation via the wellbore after introducing the second portions of the first fluid pill and the second fluid pill into the subterranean formation;
(h) allowing at least a portion of the second cement to solidify within the first lost circulation zone;
(i) consecutively introducing a third portion of the first fluid pill and a third portion of the second fluid pill into the subterranean formation via the wellbore after allowing at least the portion of the second cement to solidify within the first lost circulation zone;
(j) introducing a third cement having a higher thixotropy than the second cement into the subterranean formation via the wellbore; and
(k) allowing at least a portion of the third cement to solidify within the first lost circulation zone;
wherein a flow of fluids from the wellbore into the subterranean formation is mitigated due to the solidification of at least the portions, respectively, of the first cement, the second cement, and the third cement in the first lost circulation zone.