Controlling fluid flow in a subterranean formation with a reinforced clay gel
US6720292B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 2000 |
| Grant date | Apr 13, 2004 |
| Priority date | — |
| Expiry date | Jun 12, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K8/5045
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method is provided for blocking high permeability regions in subterranean geological formations, using a reinforced swelling clay gel. A reinforced clay slurry is prepared by mixing swelling clay, such as bentonite, an aqueous solution containing the salt of certain cations, which inhibit clay swelling, and a reinforcing agent. The cations K+, Ca2+, Mg2+, Cs2+, Fe2+, Al3+ and NR4+, where each R can independently be H, CH3, C6H5, or CH2CH3, and combinations thereof, among others, are clay swelling inhibitors. The reinforcing agent is non-swelling particles, including, without limitation, particles of produced sand, silica sand, sandy or silty soil, crushed rock, minerals, mine tailings, and combinations thereof. The reinforced clay slurry is introduced into a geological formation, where it preferentially enters high permeability regions. There the slurry is contacted by NaCl brine solution present in natural or injected drive fluids, and the inhibitive cations bound to the clay particles are replaced by Na+ ions, which attract water molecules and promote clay swelling. The reinforced Na+-clay swells, causing the slurry to acquire a gel-like consistency. The reinforced clay gel so …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.