US 11,834,608 B2
Silica nanoparticles for crude oil recovery using carbon dioxide, and crude oil recovery method
Takashi Hiraoka, Tokyo (JP); Hideharu Yonebayashi, Tokyo (JP); Yoshihiro Miyagawa, Tokyo (JP); Masanobu Sagisaka, Hirosaki (JP); and Masashi Abe, Sodegaura (JP)
Assigned to INPEX CORPORATION, Tokyo (JP); HIROSAKI UNIVERSITY, Hirosaki (JP); and NISSAN CHEMICAL CORPORATION, Tokyo (JP)
Appl. No. 17/780,419
Filed by INPEX CORPORATION, Tokyo (JP); HIROSAKI UNIVERSITY, Hirosaki (JP); and NISSAN CHEMICAL CORPORATION, Tokyo (JP)
PCT Filed Nov. 26, 2020, PCT No. PCT/JP2020/044098
§ 371(c)(1), (2) Date May 26, 2022,
PCT Pub. No. WO2021/107048, PCT Pub. Date Jun. 3, 2021.
Claims priority of application No. 2019-215612 (JP), filed on Nov. 28, 2019.
Prior Publication US 2023/0002669 A1, Jan. 5, 2023
Int. Cl. C09K 8/594 (2006.01)
CPC C09K 8/594 (2013.01) [C09K 2208/10 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A crude oil recovery method for recovering crude oil from a subsurface hydrocarbon-containing reservoir, the method comprising:
step (a): injecting an aqueous sol, water and carbon dioxide, each alternatingly or simultaneously, into a subsurface oil reservoir;
wherein the aqueous sol comprises silica particles having an average particle diameter of 1 to 100 nm as measured by dynamic light scattering and having surfaces at least partially coated with a silane compound having a hydrolyzable group, wherein the hydrolyzable group is selected from the group consisting of an alkoxy group, an acyloxy group, and a halogen group, the silica particles serving as a dispersoid and being dispersed in an aqueous solvent having a pH of 1.0 or more to 6.0 or less serving as a dispersion medium; and
step (b): following the injecting, recovering oil extracted by an oil production well drilled into the subsurface oil reservoir.