	US 12,104,117 B2
	Amphiphilic block copolymer surfactant for attenuating acid reactivity during acid stimulation of carbonate rich reservoirs
Sivaprakash Shanmugam, Houston, TX (US); Amy J. Cairns, Houston, TX (US); and Mohammed Sayed, Katy, TX (US)
Assigned to SAUDI ARABIAN OIL COMPANY, Dhahran (SA)
Filed by ARAMCO SERVICES COMPANY, Houston, TX (US)
Filed on Jul. 31, 2023, as Appl. No. 18/362,741.
Application 18/362,741 is a division of application No. 17/452,913, filed on Oct. 29, 2021, granted, now 11,781,057.
Prior Publication US 2024/0018411 A1, Jan. 18, 2024
Int. Cl. C09K 8/54 (2006.01); C08F 293/00 (2006.01); C09K 8/60 (2006.01); C09K 8/74 (2006.01); E21B 43/27 (2006.01)

CPC C09K 8/54 (2013.01) [C08F 293/005 (2013.01); C09K 8/604 (2013.01); C09K 8/74 (2013.01); E21B 43/27 (2020.05); C08F 2438/03 (2013.01); C09K 2208/32 (2013.01)]

9 Claims

1. A method for controlling reactivity of a formation treatment composition with a formation, the method comprising:

introducing a formation treatment composition into a wellbore such that that the formation treatment composition contacts a surface of the formation, wherein

the formation treatment composition comprises a surfactant including an amphiphilic block copolymer and an acid, and

the amphiphilic block copolymer, having a first block and a second block, is synthesized by reversible addition-fragmentation chain transfer polymerization (RAFT) in a two-step reaction using a first monomer, a second monomer, a chain transfer agent (CTA), and a radical initiator;

providing an adsorption of the surfactant onto a surface of the formation such that a temporary barrier is formed; and

attenuating a reaction rate between the acid and the formation.