US 12,203,030 B2
Method for reducing pressure and increasing injection by continuous operation system of biological acid acidification and nano coating
Fan Zhang, Wuhan (CN); Yuehui She, Wuhan (CN); Qing Feng, Wuhan (CN); Xiaonan Li, Wuhan (CN); and Shengsheng Li, Wuhan (CN)
Assigned to CHINA UNIVERSITY OF GEOSCIENCES, BEIJING, Beijing (CN); and YANGTZE UNIVERSITY, Wuhan (CN)
Filed by CHINA UNIVERSITY OF GEOSCIENCES, BEIJING, Beijing (CN); and YANGTZE UNIVERSITY, Wuhan (CN)
Filed on Sep. 2, 2022, as Appl. No. 17/901,913.
Prior Publication US 2024/0076538 A1, Mar. 7, 2024
Int. Cl. C09K 8/582 (2006.01); C09K 8/72 (2006.01); C12N 1/20 (2006.01); C12R 1/125 (2006.01)
CPC C09K 8/582 (2013.01) [C09K 8/72 (2013.01); C12N 1/20 (2013.01); C12R 2001/125 (2021.05)] 1 Claim
OG exemplary drawing
 
1. A method for reducing pressure and increasing injection by a continuous operation system of biological acid acidification and a nano film coating, wherein the continuous operation system comprises the following steps:
step i):
determining a 1 PV injected in accordance with the following formula:
1PV=πR2HØ
wherein R=treatment radius (m), H=thickness of water absorbing layer, and Ø=average porosity of stratum; and
step ii):
carrying out a continuous operation procedure of the biological acid acidification and acidified nano film coating by stopping injection of water into a water injection well;
injecting 1.5-3 PV of a 2% KCl solution into a wellhead of the water injection well at a rate of 5-20 m3/h;
injecting 1.8-5 PV of 33% of a biological acidizing agent into the wellhead of the water injection well;
injecting in sequence 0.5-1.5 PV of the 2% KCl solution and 10-20 m3 of water;
shutting down the water injection well for 6-18 hours;
injecting in sequence 1-2.5 PV of a 10% nano coating agent and 20-30 m3 of water; and
resuming water injection in the water injection well after 48-72 hours of a shut-in well.